Istraživanja i projektovanja za privredu - Applied Engineering Science 9(2011)3 by JAES

CONTENTS

Mr Jasna Glišoviü, Dr Miroslav Demiü, Mr Danijela Miloradoviü REVIEW OF VIRTUAL REALITY APPLICATIONS FOR REDUCING TIME AND 361 - 372 COST OF VEHICLE DEVELOPMENT CYCLE Dr Zoran Nikoliü, Dr Zlatomir Živanoviü DEVELOPMENT, CHARACTERISTICS AND 373 - 382 PROSPECTS OF THE ELECTRIC VEHICLES Dr Ĉorÿe Vukeliü, Dr Igor Budak, Dr Branko Tadiü, Dr Ognjan Lužanin, Dr Miodrag Hadžisteviü, Dr Peter Krizan 383 - 392 AUTOMATED GENERATION OF WORKPIECE LOCATING SCHEME IN FIXTURE DESIGN Mr Miroslav Kuburiü, Mr Mladen Lero 393 - 400 SURVEYING WORKS IN ROAD DESIGNING AND CONSTRUCTION MSc Dragan Sekuliü, Dr Vlastimir Dedoviü INTERCITY BUS USERS VIBRATION COMFORT ANALYSIS THROUGH AN 401 - 410 OSCILLATORY MODEL WITH SEVEN DOF USING ADAMS/VIEW SOFTWARE MSc Nenad Paviü, Dr Vladimir Popoviü, Miloš Vasiü DRIVERS AGE AS THE DOMINANT DEMOGRAPHIC 411 - 416 FACTOR IN TRAFFIC ACCIDENT Dr Deda Ĉeloviü, Mr Dijana Medenica Mitroviü SOME BASIS FOR DEFINING CORRELATIONS BETWEEN CHAGES IN 417 - 423 SEA PORT ORGANIZATION AND CHANGES OF PRODUCTIVITY EVENTS REVIEW

424

ANNOUNCEMENT OF EVENTS 425 - 426 BOOK RECOMMENDATION

427 - 428

EDITORIAL AND ABSTRACTS IN SERBIAN LANGUAGE 429

Journal of Applied Engineering Science 9(2011)3

IMPRESSUM Nauþno-struþni þasopis ISTRAŽIVANJA I PROJEKTOVANJA ZA PRIVREDU Journal of APPLIED ENGINEERING SCIENCE The journal publishes original and review articles covering the concept of technical science, energy and environment, industrial engineering, quality management and other realted sciencies. The Journal follows new trends and progress proven practice in listed ﬁelds, thus creating a unique forum for interdisciplinary or multidisciplinary dialogue. All published articles are indexed by international abstract base Elsevier Bibliographic Databases through service SCOPUS since 2006 and through service SCImago Journal Rank since 2011. Serbian Ministry of Education and Science admitted the Journal of Applied Engineering Science in a list of reference journals. Same Ministry ﬁnancially supports journal’s publication.

Publisher

International Editorial Board

Institute for Research and Design in Commerce and Industry www.iipp.rs For publisher: Prof. dr Branko Vasiü

Prof. dr Robert Bjekoviü, Germany; Prof. dr Jozef Aronov, Russia; Dr Jezdimir Kneževiü, England; Dr Nebojša Kovaþeviü, England; Adam Zielinski, Poland; Doc. dr Miloš Kneževiü, Montenegro; Dr Vladimir Buljak, Italy; MSc Siniša Vidoviü, USA.

Copublisher Faculty of Transport and Trafﬁc Engineering – Belgrade University www.sf.bg.ac.rs For copublisher: Prof. dr Slobodan Gvozdenoviü

Publishing Council Editor in Chief Prof. dr Jovan Todoroviü Faculty of Mechanical Engineering, Belgrade; Assistant Editor Dr Predrag Uskokoviü Belgrade Waterworks and Sewerage, Belgrade;

Editorial Board Prof. dr Gradimir Danon, Faculty of Forestry, Belgrade; Doc. dr Dušan Milutinoviü, Institute for Transport and Trafﬁc CIP, Belgrade; Mr Ĉorÿe Milosavljeviü, CPI - Process Engineering Center, Belgrade; Prof. dr Miodrag Zec, Faculty of Philosophy, Belgrade; Prof. dr Nenad Ĉajiü, Mining and Geology Faculty, Belgrade; Prof. dr Vlastimir Dedoviü, Faculty of Transport and Trafﬁc Engeneering, Belgrade; Dr Dejan Curoviü, Faculty of Mechanical Engineering, Belgrade; Doc. dr Vladimir Popoviü, Faculty of Mechanical Engineering, Belgrade. ISSN 1451-4117 UDC 33 Papers are indexed by SCOPUS Journal of Applied Engineeering Science (Istraživanja i projektovanja za privredu) is also available on www.engineeringscience.rs

Nebojša Divljan, Delta Generali, Belgrade; Prof. dr Miloš Nedeljkoviü, Faculty of Mechanical Engineering, Belgrade; Milutin Ignjatoviü, Institute for Transport and Trafﬁc CIP, Belgrade; Dragan Beliü, Transport Company “Lasta”, Belgrade; Dr Miljko Kokiü, Zastava, Kragujevac; Dr Zdravko Milovanoviü, Faculty of Mechanical Engineering, Banja Luka; Dr Drago Šeroviü, Adriatic Shipyard, Bijela; Vladimir Taušanoviü, Belgrade Waterworks and Sewerage, Belgrade; Nenad Jankov, Power Plant Kostolac B, Kostolac; Ljubiša Vuletiü, National Bank of Serbia, Belgrade; Dušan Ĉuraševiü, Euro Sumar, Belgrade.

Editorial Office Nada Stanojeviü, Darko Stanojeviü, Miloš Vasiü, Miloš Dimitrijeviü, Mirjana Solunac Institute IIPP, Belgrade; Bojan Manþiü, Ivana Spasojeviü Faculty of Mechanical Engineering, Belgrade. Printed by: Beograﬁka, Beograd Design and prepress: IIPP Journal of Applied Engineering Science 9(2011)3

EDITORIAL

Serbia is now on course to join the European Union, while the energy sector, with the signing of the Energy Community for South East Europe agreement several years ago, has already made a signiﬁcant step in that direction. This was contributed with earlier adoption of the Law on Energy in 2004 (which was changed this year and approved with signiﬁcant changes) and Strategy of long-term energy development of the Republic of Serbia until 2015 in 2005 (new Strategy is in preparation), documents who have determine the European path of energy. Prof. dr Nenad Ĉajiü

The new Law on Energy of the Republic of Serbia aligns us with the requirements of the European Union in the ﬁeld of energy and provides:

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Safety and quality of supply;

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Market competition;

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Creating attractive and stable conditions for development of energy sector;

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Energy efﬁciency improvement;

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Creation of conditions for stimulated use of renewable energy sources and cogeneration;

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Environmental protection Improvement;

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Deﬁnition of privileged energy producers, etc.

The current “Strategy of long-term development of the Serbian Energy till 2015” was made in 2005, in order to adopt the basic objectives of the new energy policy, to determine priority directions of development in the energy sector and to approve the program of creating appropriate instruments, which enables the implementation of key priorities in the work, operations and development of whole energy system of Serbia (in the sectors of energy production and consumption), according to the previous Law on Energy. The basic premise in choosing objectives, setting priorities and appropriate instruments, is based on the country’s political commitment to the rational development of the whole energy sector aligned with business and economic development of the country and its inclusion in European integration. But now it must be noted that many plan determinations deﬁned in the “Strategy for long-term Energy Development of Serbia till 2015” was based on large number of assumptions that could not been achieved today, due to objective reasons: •

There was no envisaged economic, especially industrial, development of Serbia;

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Intensive exploration of energy resources is not carried out;

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Import dependence is not being reduced;

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No major positive developments within aggregate energy efﬁciency;

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Consumption of energy, especially electricity, is still very irrational;

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Economic status of the energy industry is not significantly improved, and economic criteria as the basis of control of the energy sector are insufficiently represented, particularly in the field of price policy;

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Energy prices are not economical and does not increase even to the level that provides a simple reproduction;

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Pricing policy of energy products is heavily inﬂuenced by social problems and control of inﬂationary trends;

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Activities on the restructuring and transformation of energy companies have not been completed, and so on.

Journal of Applied Engineering Science 9(2011)3

EDITORIAL Also, during the privatization and development of new energy facilities, contracts signed with foreign companies achieved over the years (RWE, SECI Energia SpA, Gazprom, Gaspromneft, Comico, etc...) were not foreseen. Consequently, the predictions made in the Strategy could not be achieved. Therefore, every other year a Strategy Implementation Programme is made, in order to realistically perceive energy development opportunities in the short term. Last year ended with the production of second Strategy Implementation Programme which is explained in detail the content and schedule of implementation of Priority programs for development of the energy sector by 2012. Programme is adjusted according to actual needs for energy and energy products, enabling change and actualization of the Strategy of long-term energy development of the Republic of Serbia. However due to these ongoing changes occurring in the energy sector of our country (and world) it is necessary to create a new long-term Energy Development Strategy, which should be implemented as soon as possible. In my opinion, the new Strategy should be adopted for the period until 2030 with a vision to 2050. Since the energy facilities are built in a long time (4 to 7 years or longer) and since itâ&#x20AC;&#x2122;s optimal exploitation life is from 25 to 30 years and with the revitalization even up to 40 years, since the introduction of new technologies and renewable resources requires a longer period, since all the deposits of fossil fuels during the next 20 to 30 years will be occupied, since we do not have large reserves of oil and natural gas, it is useful to consider the need for the development in a longer period of time. In this way we could comply with the Energy Development Strategies performed by international energy agencies, developed countries and the EU for their own development, which are all made mostly by 2030, although there were some up to half of this century. The vision by 2050 is needed to be done, because based on the analysis made for the spatial plans of mining Kolubara and Kostolac, can be assessed that their reserves will be largely exhausted by then, and this represents the largest part of our energy resources (excluding potential in Kosovo and Metohija who are presently not available). Through this vision we must be prepared for the period when our reserves of fossil fuels will be virtually exhausted and when only sources of renewable energy will remain at our disposal.

Prof. dr Nenad Ä&#x2C6;ajiĂź

Journal of Applied Engineering Science 9(2011)3

Paper number: 9(2011)3, 201, 361 - 372

REVIEW OF VIRTUAL REALITY APPLICATIONS FOR REDUCING TIME AND COST OF VEHICLE DEVELOPMENT CYCLE Mr Jasna Glišoviü * University of Kragujevac, Faculty of Mechanical Engineering, Kragujevac, Serbia Dr Miroslav Demiü University of Kragujevac, Faculty of Mechanical Engineering, Kragujevac, Serbia Mr Danijela Miloradoviü University of Kragujevac, Faculty of Mechanical Engineering, Kragujevac, Serbia

The vehicle development process has been defined by increasing requirements for quicker and less costly development cycles, combined with reduced vehicle fuel consumption. The complete requirements for new vehicle development include the need for rapid prototyping and durability evaluation to achieve an accelerated vehicle development process. There is now a convergence of market and technical changes that directly affect this development process. A clear trend in the automotive industry is that the manufacturers outsource more development work to subcontractors. Consequently, the overall quality of the finished product will depend on how well the automotive companies and the subcontractors work together in the development processes. Lack of harmonization between the subcontractors and the automotive company – but also between different development departments at the manufacturer – causes expensive errors. Although research in virtual reality has been done for over 20 years, only a few years ago the non-academic world started to evaluate its use to solve real-world problems. Among others, the automotive industry is evaluating its potential in design, development, and manufacturing processes. In fact, the automotive industry has been among the first, but others, such as suppliers, have begun to evaluate VR, too. The resulting benefits of using Virtual Technologies (the reduction of development time, the reduction of development costs-better design through virtual pre-checks, less modifications and increasing quality) are presented in this paper. Key words: virtual reality, vehicle, development cycle INTRODUCTION Automotive manufacturers are pressured to deliver complex products with increased quality in shorter development cycles. Engineering the performance of mechanical designs with traditional test-based development processes is no longer an option. The only valid alternative is evaluating functional performance attributes on a virtual prototype. Modern software enables engineers to effectively analyze and optimize reallife performance of mechanical systems, long before physical testing. The most challenging task for engineers is to guarantee that the dynamic performance of their mechanical systems will match specifications. They need to make sure that the numerous com-

ponents interact and move as planned under the inﬂuence of real-life conditions, such as gravity and frictional forces. Virtual prototyping has to deliver the right answers, with the required accuracy, and on time to positively impact the development process. The best solutions are those that can be easily re-scaled to support the various stages of the entire development process. Equally important is that these solutions assess the dynamic motion performance in light of all system requirements, including durability, noise and vibration. The entire vehicle development process requires a combination of many separate performances, how the Figure 1 shows [06]. These activities are frequently performed in separate departments with little internal communication. Automotive

* Faculty of Mechanical Engineering, Sestre Janjiü 6, 34000 Kragujevac, Serbia; jaca@kg.ac.rs

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companies are now redesigning their internal processes to coordinate these diverse tasks and provide some logical structure for communication. In addition, a more formal design process is being implemented to ensure that separate design groups can work on different parts of the development activity in parallel and also ensure that the ﬁnal combined activity produces a design that meets the performance targets initially set. The typical sessions of design review are, today, performed in virtual reality rooms, where both geometric and functional features of new products are investigated. The main scope is to supply a virtual validation of the product, reducing the needs of prototyping physical mock-ups (PMUs) building. Starting from the conceptual stage of a new product, a conceptual Digital Mock-Up (DMU) of the product is built and it represents the reference model for all the following phases of Virtual Development Product (VDP), down to the market launch and its use. CAE (Computer Aided Engineering) engineers use DMU data to create their simulation models in order to analyze and monitor the performances of the new product. Another important technology is Virtual Reality (VR) that today seems to be very integrated in

Figure 1. Vehicle Development Plan [06]

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the VDP. In fact VR is used in the fields of Styling, DMU and Physical Mock Up (PMU), Design, Ergonomics, Simulation, Digital Plant, Marketing and Sales. The VR Centre is becoming the place where the designer chooses the car style model, where the car development team executes DMU design reviews, analyses alternative solutions and deliberates product and process validation. VR represents a user interface technology that enables the interaction of the engineer with the virtual models of the car, thanks also to the immersion feature. VR allows, in fact, intuitive analysis and simple presentation of complex three-dimensional systems. Furthermore with immersive virtual environment, ergonomist can study the “man-car-environment” interaction and evaluate the comfort of a new car. Starting from the early stages of product development a DMU is implemented to provide all geometrical constraints for designer that have to define the style of the new car. The vehicle DMU evolves along the VDP until it is delivered to the market and it represents the reference model for product a production engineers and for decisionmaker teams. The core of DMU is the creation of a database containing the CAD/CAE models of car with the related structural and functional properties. The objective of the DMU is to simulate the entire development process by the use of methods and software and to integrate the DMU with style definition process, tolerance analysis, digital manikin, virtual simulation and digital factory.

Figure 2. Progress of Virtual Knowledge Journal of Applied Engineering Science 9(2011)3 , 201

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Figure 3. Digital Product Lifecycle

Previous research has shown that a virtual environment can offer a wide variety of analytical post-processing tools. For example, the Virtual Windtunnel project described by Bryson [02,01] is one of the first applications based on virtual reality techniques that clearly shows the advantages of this approach compared to traditional finite element analysis post-processing methods. Ye [13] and Yeh [14] also use a virtual environment for the visualization of finite element models which further illustrates the usefulness of this technique. The study of realistically simulated scenarios in structural and fluid mechanics involves very large, transient data sets. In the past it was far beyond the available hardware capabilities to display those data sets in realtime. However, due to advances in hardware technologies and due to the efforts of a number of researchers in the area of data reduction techniques [11], the visualization of these data sets became possible.

COMPUTER AIDED DESIGN (CAD) Computer aided design has evolved from the simple replacement of traditional drafting equipment to a very sophisticated, highly visual design tool. The earlier CAD programs used the computer to generate lines for 2D drawings. As the software and hardware advanced, these 2D drawings could be converted into 3D objects. Modern software used for solid modeling often functions in the reverse order; the three-dimensional object is drawn and then two-dimensional, orthographic drawings are generated from that model. Advantages of wireframe 3D modeling over exclusively 2D methods include but are not limited to: •

Flexibility, ability to change angles or animate images with quicker rendering of the changes;

Figure 4. Comparisons between Traditional and Virtual Prototyping [15] Journal of Applied Engineering Science 9(2011)3, 201

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Ease of rendering, automatic calculation and rendering photorealistic effects rather than mentally visualizing or estimating; Accurate photorealism, less chance of human error in misplacing, overdoing, or forgetting to include a visual effect.

In the product development process, prototyping is an essential step. Prototypes represent important features of a product, which are to be investigated, evaluated, and improved. They are used to prove design alternatives, to do engineering analysis, manufacturing planning, support management decisions, and to get feedback on a new product from prospective customers. Markets are becoming more and more dynamic and quick-paced. In order to stay competitive, companies must deliver new products with higher quality and/or less cost in a shorter time. Additionally, they must provide customers with a broader variety of versions at minimum costs. Therefore, rapid prototyping and virtual prototyping (VP) are quickly becoming interesting tools for product development.

There seem to be two different understandings of exactly what VP is: the “computer graphics” and the “mechanical engineering” point of view. The computer graphics deﬁnition of virtual prototyping (VPCG) is the application of virtual reality for prototyping physical mock-ups (PMUs). The VR system simulates and renders all characteristics relevant to the particular context as precise and realistic as possible in an immersive environment. In the mechanical engineering deﬁnition of virtual prototyping (VPME), the idea is to replace physical mock-ups by software prototypes. This also includes all kinds of geometrical and functional simulations, whether or not involving humans. For instance, simulations of assembly lines, FEM crash tests, etc., are VPME activities, too.

While some automotive companies have already begun to routinely use VR as a tool in styling and design reviews in the concept phase, it has not been clear that VR can be an efficient tool in assembly/disassembly simulations maintenance verifications. Assembly simulations are much more difficult in that they involve a lot of interaction and real-time simulation. However, it is revealed that the assembly process often drives the majority of the cost of a product. Up to 70% of the total life cycle costs of a product are committed by decisions made in the early stages of design.

Figure 6. Assembly simulation

Figure 5. The goal of virtual prototyping is to reduce signiﬁcantly the amount of hardware prototypes during conception, design, and evaluation of new products. The effect will be a reduction in time-tomarket [15]

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Digital mock-up (DMU) is a realistic computer representation of a product with the capability of performing all required functionalities from design/- engineering, manufacturing, product service, up to maintenance and product recycling. In a sense, DMU can be viewed as the medium through which stylists, designers, testers, manufacturers, marketing people, customer supportJournal of Applied Engineering Science 9(2011)3, 201

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ers, etc., exchange information about a new product. So, immersive virtual prototyping is but one technique for implementing the DMU strategy [15]. STRUCTURAL ANALYSIS Modern software provides all the necessary tools for advanced designers and specialists involved in structural analysis. The processes covered include stress, frequency, thermo-mechanical, buckling and contact analysis with multiple load, restraint and mass complex conﬁgurations. Analysis can be performed on single parts as well as on hybrid models mixing solid, shell and beam elements. This allows for a wider number of mechanical behavior and sizing assessments of parts and assemblies earlier in the product development process.

Figure 7. Stress analysis of a rotating brake disk and diaphragm clutch spring

KINEMATICS SIMULATION A simulation is an imitation of the real thing. It refers to a broad collection of methods and applications to mimic the behavior of real systems, usually on the computer with appropriate software. Kinematics simulation is the process of modeling kinematic systems and then simulating it in the suitable environment under the appropriate constraints. Figure 8. Simulation of single cylinder motor’s kinematics [05] Journal of Applied Engineering Science 9(2011)3, 201

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Discussed below are features of the DMU Kinematics Simulator available with the software CATIA (Computer Aided Three-dimensional Interactive Application) as advertised on its website (IBM Software: CATIA). 3D mechanisms: 3D mechanisms based on different types of joints are available: Revolute, Prismatic, Cylindrical/Actuator, Planar, Rigid, Spherical, Universal, Point-Surface, PointCurve, Roll-Curve, Slide-Curve, Screw, Gear, Rack, Cable and Constant Velocity joints. It is possible to define and verify joint limits (travel limits or joint stops) and thus guiding the design of the assembly. Automatically generates mechanism: Constraints defined in CATIA Assembly Design product can be automatically interpreted as joints. Simulates mechanism motion: Users can easily simulate motion using the mouse and guide possible actions thanks to a co-pilot which pops up icons under the mouse. Users can also create a wide range of kinematics laws allowing timebased simulation. The laws can be graphically visualized. Analyzes mechanism motion dynamically: During mock-up design review, the designer can not only view simulated kinematics motion but also analyze the mechanism’s consistency with the functional specifications. Records motion analysis’ results: Users can replay a motion simulation, or save it as a video file. Generates useful information: DMU Kinematics Simulator provides the ability to define a point in a moving part and generate its trace in order to design cams. During a simulation with laws, it is possible to plot sensors according to time but this functionality also offers the possibility to plot a sensor according to another sensor. Users can run, for instance the simulation of an engine, and plot the position of an inlet valve according to the rotation of the crankshaft. Allows automation of mechanism creation and simulation through Visual Basic macro programming: Multiple combined simulations are possible for advanced digital product synthesis when using this product in conjunction with other DMU products. For example, users can simulate and synchronize un-mounting procedures with a kinematics motion when both the DMU Kinematics Simulator and DMU Fitting Simulator products are installed.

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Simulates mechanisms: The data used to create the full digital mock-up may come from any number of supported data formats, including: CATIA, STL, IGES, OBJ (from Wave front) or other multi-CAD environments. The kinematics simulation and associated kinematics analysis functions are identical whatever data format is used. If made an integral part of the design process, it can be used effectively in the testing and evaluation stages. It has the ability to replace physical prototypes and make the design process not only cheaper but also faster and more ﬂexible [08]. ERGONOMICS IN THE AUTOMOTIVE INDUSTRY In the last years the human factor is assuming more and more importance in the design, engineering, production and maintenance of new industrial products. In the car design a primary requirement is to assure the comfort of driver and passengers, taking into account problems related to: •

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positioning of the main and secondary controls, that have to be reachable and operable through simple and natural movements; driver visibility that depends on general design of the interiors (i.e. seats, glass surfaces, mirrors, etc.); habitability and design of a driver’s seat that have to minimize driver fatigue; accessibility (space area for driver and passengers); visual appeal (material, color, texture, surfaces) [09].

The car interior design process should be: identify the human factors that influence comfort judgment; • identify the main design parameters; • define and to realize a specific test to measure biological and physiological human characteristics and to get the subjective evaluations related to the different values of the project parameters; • define final values and parameters project. The exposed objectives are very difficult to achieve with traditional design methods (i.e. two dimensional representation, static models). The modern tendency is to use 3D human modeling •

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software and mechanical or electronic vehicle simulator. Parametric vehicle simulators are used to reproduce the driver seat position of a new car considering the main components associated to the digital car model.

formed in less time. However, simply increasing the volume of the testing can be prohibitively costly, implying that the testing and veriﬁcation processes must be made more efﬁcient, reducing the need for more prototypes.

A simulation system allows to quickly identify

While some automotive manufacturers still use clay models to prototype new cars, most of the industry’s R&D centers now have the technology to create virtual environments in which to view and manipulate their designs. The use of virtual models to collaboratively review and modify designs on a desktop computer is, for the most part, a basic capability of any automotive manufacturer today, but there is one aspect of the design process-the use of interactive, 1:1 ratio immersive displays-that sets apart the cutting-edge designers from the rest of the ﬁeld.

Figure 9. Human builder

One of the main benefits of the concept is that different disciplines involved in the product development process can use the system to enhance the concurrency between them. Control systems and mechanical engineers can view ongoing tests in real time and change designs, re-simulate and influence ongoing tests in a distributed and efficient way. Through advanced visualization of simulation results and measurement data, the engineers can get a clearer view on how the system or product behaves, improving the quality of the validation process. The concept for distributed real-time simulation

Figure 10. Driver and passenger simulation

critical aspects of the vehicle design comparing alternative solutions in a very short time and achieving a quickly convergence towards the optimum one [09]. VIRTUAL TEST ENVIRONMENT Due to the increasing complexity of embedded systems and software in vehicles, the automotive industry faces an increasing need for testing and veriﬁcation of components and subsystems under realistic conditions. At the same time, development cycles must be shortened in order for vehicle manufacturers to be competitive on the global market. Consequently, an increased amount of testing and veriﬁcation must be perJournal of Applied Engineering Science 9(2011)3, 201

Figure 11. Virtual Suspension Test Rig

and visualization will gather more information in the early stages of product development. Furthermore, it will speed up the product development process due to its real-time nature. The fact that engineers can stay at their home ofﬁce and only follow the test when it is needed will enhance their efﬁciency. Today’s automotive companies must be able to

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cope with distributed product development, due to the many suppliers involved in the development of vehicles. It is estimate that there are around 5000 suppliers to the automotive industry today. Since suppliers and subcontractors from all over the world frequently need to be involved in the testing and veriﬁcation of the vehicles, it is necessary to develop sophisticated methods and tools for distributed validation and simulation, and to incorporate these tools and methods into the overall framework for distributed product development.

the development site of the manufacturer, for analysis and visualization, in real-time if desired. Having the possibility to share and view data in real-time from the test track will reduce costs and lead-times signiﬁcantly for vehicle manufacturers. By integration of this framework with the system presented here, live measurement data can be used as input for hardware-in-the-loop simulation and real-time visualization, giving the opportunity to study effects not directly measurable, such as the normal forces on the tires of a moving car.

The idea with the distributed real-time simulation and visualization (DRTSV) concept is to extend the testing and veriﬁcation processes, from the test tracks to the manufacturer’s and subcontractors’ development ofﬁces. This will result in more effective test expeditions and shorter development time. Furthermore, connecting mechanical and/or control system modules to the DRTSV concept in a black box fashion, will give the manufacturer and subcontractors a good development tool for the PD process.

If the expert can speak to the test driver through an audio link, he can influence the ongoing test to better suit his needs. There is also a possibility for the remote expert to download new software to the vehicle directly through the wireless communication link. Working in this manner will reduce the overall test time which gives room for even more tests. All of the engineers from the home office no longer have to travel to the test expedition; they can follow the expedition from their office workplace and let local entrepreneurs perform the tests for them. This will save the automotive manufacturers and suppliers a lot of time and money.

Using a wireless local area network (WLAN) at the test tracks, live measurement data can be sent from the vehicles at the test track back to

Table 1. The different characteristics of input and output devices imply different types of VR

type ﬁsh-tank VR

head-coupled VR

advantages disadvantages best resolution and least distortion; low immersion; familiar and easy-to-use; stereoscopic violation because of fairly inexpensive. clipping; best immersion because of large ﬁeld-of-view, allsurrounding view, and almost no stereoscopic violation; fairly large range of user’s movements;

affordable. projection-based VR high resolution, large ﬁeld-of-view; high degree of presence, because user can see himself; easier to share; easy-to-use.

small range of user’s movements. either heavy or low resolution; large distortion because of wideangle optics; not easy-to-use (intruding interface).

needs more graphics pipes for more walls; possible stereoscopic violation, because user’s limbs always occlude virtual objects; requires a lot of space; not so easy to maintain.

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By using a dynamic simulation system to simulate the behavior of the vehicle, it will be possible to access data that is hard or even impossible to measure, for instance force between tire and road and forces in joints, etc. The visualization module can be set up to present data that is interesting to many disciplines at the same time, e.g. climate, fatigue, control systems, vibration analysis, etc. National Advanced Driving Simulator (NADS) configuration is illustrated in Fig. 12. The cab controls and displays are identical to those of production vehicles and, through computer control, vehicle dynamics is used to supply control feel feedback associated with driver control actions or vehicle motion. Vehicle dynamics computers enable drivers to experience vehicle motion in a total of nine degrees of freedom to provide accurate haptic driving cues. This motion is complemented by correlated 360-degree visual and audio cues, also under computer control. The photorealistic visual scenes provided by a high-end Evans and Sutherland image generator include moving vehicles and pedestrians to complete the driver’s perception of being immersed in urban and rural traffic situations. The audio system provides appropriate sounds internal and external to the cab, including Doppler and side-to-side directional effects. The design of NADS allows for a wide range of potential applications, including new cockpit intelligent vehicle systems (ITS) technology, control and instrument layout, vehicle control systems, driving while impaired, and problems with novice and elderly drivers. NADS virtual driving experience is intended to be a complete sensory environment that allows drivers to be immersed in realistic tasks under real-world motivations. The simulation environment permit roadway hazards and traffic conflict situations to be presented that are impractical to control on test tracks or public roads but can be experienced in the NADS without safety consequences in the event of accidents. In the case of crash simulation, geometry together with physical properties is displayed (Fig. 13). With the cost of vehicles steadily increasing as a result of heightened safety standards and growing customer demand for bells and whistles, a major overhaul of the automotive design process is taking place. Sensor technology used in interJournal of Applied Engineering Science 9(2011)3, 201

Figure 12. National Advanced Driving Simulator

Figure 13. Car crash in the VR environment [12]

active immersive displays is at the heart of this change, helping automakers identify, design, and assess vehicle improvements. In tandem with 3D software and other visualization technologies, motion-tracking sensors enable interactive testing and design via computer models in a fraction of the typical design time. Interactive immersive displays are a collection of complementary technologies that, when used together, can save auto manufacturers time

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and money. Motion-tracking technology and advanced visualization techniques, coupled with collaborative design processes, have enabled auto manufacturers to reduce the average design time from three years to 18 months. The shorter design cycle provides manufacturers with faster time to market, enabling the designer to keep up with changing consumer requirements and offers the company a quicker return on its investment in new models and features [04].

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The user must be able to interact intuitively with the virtual factory depicted in the virtual environment. He has to be able to obtain additional information by interacting with the visualized components, e.g., by selecting a station and requesting a detailed use statistics.

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The user shall be able to interactively inﬂuence the simulation run from the virtual environment by changing routings, processing times, worker allocations, etc. This provides the capability for the user to experiment with the model in an immersive environment as if he is standing in a real factory.

•

The user must be able to interactively modify the simulation model. This case is partially similar to the previous alternative with the difference that the users actions indeed change the simulation model of the simulator permanently.

Figure 14. Immersive visualization using seating buck

VIRTUAL PRODUCTION The overall objective of the solutions described here is to provide a virtual-interactive environment which supports the entire life cycle of a factory. The term “virtual-interactive” denotes the capability of the environment to display and navigate through a virtual 3D-model and to allow a wide range of user interactions with this model. Towards this objective the environment must support tasks like factory design, production program planning, process optimization, and worker qualiﬁcation. The applicability must not be limited to the design and planning phases of a factory, but also has to include the operation phase. Therefore the environment has to offer advanced planning, simulation and visualization capabilities under a uniﬁed user interface. Furthermore, an important requirement for such a virtual environment is its interactivity which has to be supported in different ways: 370

Figure 15. Interactive, 1:1 immersive displays [04]

Journal of Applied Engineering Science 9(2011)3, 201

Mr Jasna Glisoviü and etc. - Review of virtual reality applications for reducing time and cost of vehicle development cycle

•

The user can be inserted into the simulation, e.g., take over tasks of workers which are normally part of the simulation. This can be done for training purposes, e.g., to show workers which effect certain actions will have [10,07].

“Digital human modeling is becoming increasingly important to today’s manufacturers,” says Delmia CEO Phillippe Charlès. “Determining the performance of people in the context of a workplace or a product before it exists ensures conformance to health and safety standards, accelerates time-to-market, increases productivity, and reduces design timeframe and associated costs”. VR solutions enable worker activities to be created, simulated, and analyzed through a wide range of advanced ergonomics analysis tools that evaluate all elements of human interaction with a workcell. Using the V5 DPM planning and simulation infrastructure, digital manikins (workers representing populations around the world) perform all movements and activities associated with working within a workcell, such as walking, picking up and operating tools, tracking an assembly line, and performing installation/assembly tasks. With the objective of training assembly workers in virtual environment different levels of training depending on the interactivity, guidance and realism required, can be distinguished. 1) Assembly Visualization 2) Assembly Procedure Training Integrated Virtual Assembler Training. CONCLUSIONS The needs of reducing development time and costs and improving the car design have pushed the automotive companies to innovate theirs methods and to adopt new technologies. In this context VR is taking an increasing place because it is a technology that improves the interaction between users and virtual models, largely used in the VDP. Through a novel combination of software tools for distributed collaborative engineering, real-time simulation, visualization, and black box simulation, a system is realized that makes it possible for vehicle manufacturers and their subcontractors to work more concurrently and efﬁciently with testing and validation. Journal of Applied Engineering Science 9(2011)3, 201

Figure 16. Ergonomic optimization of a body welding work cell [03]

REFERENCES 1) Bryson, S. and Lewit, C., (1992). The Virtual Windtunnel. IEEE Computer Graphics and Applications, 12(4): pp.25-34. 2) Bryson, S. and Feiner, S., (1995). Virtual Environments in Scientific Visualization. In VirtualReality for Visualization, Course Notes of Tutorial 5 at Visualization 95. 3) Caputo, F., Di Gironimo, G., Marzano A., (2006). Ergonomic Optimization of a Manufacturing System Work Cell in a Virtual Environment, Acta Polytechnica Vol. 46 No. 5/2006, pp.21-27. 4) Donfrancesco, M., Wormell, D., (2007). Cutting-Edge Automotive Design, Sensors Automotive. 5) Glisovic, J., (2008). Virtual reality for efficient vehicle lifecycle management, Congress MVM, Kragujevac 6) Grote, P., Sharp, M., (2001). Defining the Vehicle Development Process, Keynote Paper, Symp. on Int. Automotive Technology, SAE. 7) Kokic, M., (2004). Platforma kao osnova virtuelnog inženjeringa razvoja automobila, Istraživanja i projektovanja za privredu, 3/2004, pp.57-61 8) Koshti, S., (2008). Designing a Passenger Lift and Transfer Device Using 3D Modeling and Kinematic Simulation Techniques, MSc Thesis, Oregon State University.

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9) Monacelli, G. (2003). VR Applications for reducing time and cost of Vehicle Development Process, Proceedings of 8th International Conference ATA on Vehicle Architectures: Products, Processes and Future Developments, Italy, Florence. 10) Schenk, M., Straßburger, S., Kissner, H. (2005). Combining Virtual Reality and Assembly Simulation for Production Planning and Worker Qualiﬁcation, Proc. of the International Conference on Changeable, Agile, ReconFig.urable and Virtual Production (CARV 2005), München, pp. 411-414. 11) Schroeder, W. J., Zarge, J. A. and Lorensen, W. E. (1997). Decimation of Triangle Meshes, Computer Graphics (Proc. of ACM SIGGRAPH 92), pp. 65-69. 12) Schulz, M., Reuding, T., Ertl, T. (1998). Analyzing Engineering Simulations in a Virtual Environment, Computer Graphics and Applications, Vol.18, Issue 6, pp.46-52.

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13) Ye, W. and Vance, J.M. (1997). Visualization of Structural Impact Problems in a Virtual Environment. In Proc. SCS Simulation MultiConference, Atlanta, GA., pp. 325-330. 14) Yeh, T.P. and Vance, J.M. (1997). Combining Sensitivity Methods, Finite Element Analysis and Free-Form Deformation to Facilitate Structural Shape Design in a Virtual Environment. In Proc. 23rd ASME Design Automation Conference, Sacramento, CA. 15) Zachmann, G. (2000). Virtual Reality in Assembly Simulation-Collision Detection, Simulation Algorithms, and Interaction Techniques, Dissertation, Technischen Universitat Darmstadt.

Paper sent to revision: 10.06.2011. Paper ready for publication: 15.08.2011.

Journal of Applied Engineering Science 9(2011)3, 201

Paper number: 9(2011)3, 202, 373 - 382

DEVELOPMENT, CHARACTERISTICS AND PROSPECTS OF THE ELECTRIC VEHICLES Dr Zoran Nikoliü * Institute Goša, Belgrade, Serbia Dr Zlatomir Živanoviü Institute Vinþa, Belgrade, Serbia Development, advantages and disadvantages of EV are presented in this paper. Future of the electric vehicles largely depends on the price of oil in the world market, environmental and technical characteristics of the EV drive system. As a result of the first oil crisis, in the seventies of the last century, there are some first thoughts on electric vehicles in our country. The first electric vehicle had been made in the former Yugoslavia, under the leadership of Academician A. Despiü. Today, they are mostly, all electrical component needed to drive high quality and have a degree of efficiency, at a high level, so that the overall efficiency of passenger electric propulsion system (battery-wheels), is around 75%. The biggest problem remains a “reservoir of energy.” Even the best batteries today have a mass energy density to 200 Wh/kg, the electric vehicles can not, in terms of performance, compete with the vehicles with conventional drive. Promising battery system with 1700 Wh/kg will be able to provide a comparative performance and to, thereby, make the transition to completely clean vehicles. As far as researches do not invent such battery, now used HEV will be solution for reducing emission which vehicles produces and fuel consumption, in order to reduce gradually dependence on oil imports. Key words: electric vehicles, hybrid vehicles, electric drive, batteries, Li-air, TAM 2001-E INTRODUCTION The electric vehicle (EV), in the context of this paper, is a motor vehicle powered by an electric motor and feed from an electrochemical power sources. Often, such an electric vehicle called the vehicle a zero-emission (ZEV), because particulates are not emitted into the atmosphere. In the older literature, the electric car used the terms electromobil (EM) or an autonomous electric vehicle (AEV) [15], while in the recent literature, these vehicles are called battery electric vehicles (BEV). In addition to battery-powered, which are the subject of this work, in vehicles with electric drive include: hybrid electric vehicles (HEV), plug in hybrid electric vehicles (PHEV) and electric vehicles with fuel cells (FCV). The EV,s have been designed, since the beginning of the present on the same principles (Figure 01). Driving electromotor, in past for DC, and asynchronous today for AC, through mechanical transmission power, drives the wheels. Electric motor speed controller, in past chopper and inverter today, regulates the speed of vehicles, in

both directions and recuperative braking also. Driving electric energy is stored in battery that the vehicle carries [18]. Recharging the battery pack is done through the charger which EV also carries with it. If the vehicle has a small engine with internal combustion engine (IC) equipped with a generator, this vehicle is called HEV.

Figure 1. The basic components of the electric drive. Rechargeable battery pack (3), through speed regulator (4) supply an electric motor (5) which, through mechanical transmission (6) turn on wheels (7). If the vehicle has the IC engine (1) equipped with a generator (2), such a vehicle is called a HEV

* Institut Goša, Milana Rakiüa 35, Belgrade, Serbia; zor.nikolic@yahoo.com

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The beginning of electric drives used in motor vehicles had begun along before the vehicles with IC engines, and had marked the entire nineteenth century. Nevertheless, they could not stand the competition vehicles with engines that were faster, stronger and more robust. The main reason for leaving the electric drive, at the early twentieth century, lies in the fact that rechargeable battery can accumulate about 35 Wh energy and liquid fuels about 12,000 Wh. This means, that the reservoir of the classic vehicle with IC engine, which weighs about 40 kg, can store about 480 kWh energy, but in leaded of, about 300 kg about 10.5 kWh electric energy. Modern lithium-ion batteries have the option of storing about 40 kWh electric energy in the battery of the same weight. Till today, this stay the main reason, why there has been no massive production and use of EV.

the engine up to several kilowatts, which were allowed at the maximum speed of about 20 km/h, and cross a distance over a hundred kilometers on a single charge of batteries. Series DC electric motors were used, usually. Batteries have a high capacity, as far as 400 Ah, and voltages up to 100 V. Proportion of battery weight, compared to a fully loaded vehicle with passengers, was over half, which allowed so many autonomous movement radius.

DEVELOPMENT OF THE ELECTRIC VEHICLES IN THE WORLD AND IN OUR COUNTRY Although the first electric motor drive had been made in 1838. on the river Neva, where professor Moric Jacobi [04], for a short time, powered a boat with 14 people, the beginning of creation and use of electric vehicles on the land, can be taken 1839. when Robert Davidson [14], from Scotland, had made the first vehicle powered by electric energy, in order to replace the steam locomotives, rated as heavy, noisy and dirty, due to smoke and coal. This EV on the rails, that is moved on the railway Edinburgh - Glasgow, about 130 km with one coach and incorporating more primitive electric motor, had used, as a source of electrical energy, primary battery. The achieved speed was about 6,5 km/h, and the vehicle had a modest payload carrying capabilities. A suitable battery pack had been found in 1860. year, what was enabling the commercialization of EV,s. The first production of small batch EV had began in 1892., in Chicago. These vehicles had been very cumbersome but even so had a very good pass by customers also. They had look like of carriages (Figure 02), with large wheels, no roof, with eaves that protected passengers from rain and sun. They were used for trips, in order to perform some business, and even as a taxi to transport more passengers. Passenger’s EV had

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Figure 2. First EV was possible to cross up to 100 km, moving with speed below 20 km/h

Disadvantage of EV had been relatively short range between battery charging. In the late of 19. century, the energy density in storage batteries had been around the 10 Wh/kg. In the early 20 century, this value had improved to a level of 18 Wh/kg, and only a decade later, 25 Wh/kg. In addition, the rechargeable stations were not widely spread, although the situation began to improve in the early 20 century. EV had been cumbrous with large mass of batteries, at contributed their small speed. But, they had met the modest needs of owners until the stronger vehicles emerged. Discovering oil resources had led to the low price of gasoline and the advancement of technology in production of IC engines had created the conditions for rapid progress in production and use of cars with this engines. Those vehicles were allowed a greater speed and virtually unlimited radius of movement. The highways were made and people began to live “on wheels”. Therefore, the development of EV remained by sidelines. Formed habits of drivers were affected by that but even with signiﬁcantly improved storage batteries, couldn’t completely replace existing vehicles. Journal of Applied Engineering Science 9(2011)3 , 202

Dr Zoran Nikoliü and etc. - Developments, characteristics and prospects of the electric vehicles

Early production of EV had been made manually. The mass production of vehicles with IC engines on the moving assembly line [03] had begun in 1908. Infrastructure for EV did not exist outside of urban areas so that their drive was limited to urban areas. Another factor that contributed to the decline of EV was the invention of electric starting IC engines in 1913. year, so that were eliminated all the difﬁculties and dangers in putting these vehicles into service. This had resulted that, at the end of World War I, production of EV stopped and they become only a technical vehicles - serving as taxis, small trucks, vans and trolleys to transport cargo. In the late sixties and early seventies, the results were fueled by the rebirth of EV due to air pollution and oil embargo by OPEC. Recognizing that EV still can not apply for its performance to vehicles with IC, the big automakers had turned to the development of HEV. This reduced fuel consumption in city driving and emissions of exhausted gases. Cars with IC engines were, the main means of mass transportation, marked the twentieth century. However, the consequence of this form of mass transport was a large amount an exhaust of harmful substances that pollute the environment. Search for an alternative energy source that would drive vehicles could solve out this problem. The renaissance of EV began in the seventies of last century. A constant race in prices of oil, which had less and less, and problems related to its production and transport, were leading to repetition interest in EV. It had appeared that at that time, the coal and oil reserves quickly wearied out, predicted already. In the end of second millennium, it began to think about “energy conservation”. In addition, a constant technical progress had given the quality and effective solutions to handle the speed of electric motors, lighter batteries and lighter materials for the vehicles body. In our country, the beginning of the EV development was related to commercial “TAM 2001-E” and Bureau of autonomous electric vehicles of the Institute of Technical Sciences SASA, in the mid-seventies. The ﬁrst EV, in the former Yugoslavia, and the Balkans, called “Commercial autonomous electric vehicle” was built in 1976. under the leadership by Academician Aleksandar Despiü. EV for bread transport,“TAM 2001-E” (Figure 03), had a DC drive rated power 27kW, Journal of Applied Engineering Science 9(2011)3, 202

thyristor chopper and lead battery voltage 108 V and capacity of 350 Ah The vehicle had a top speed of 42 km/h and autonomous movement radius 48 km [21]. This vehicle had initiated several attempts of making delivery EV. So, the Institute of chemical power sources (IHIS) had reconstructed, in the 1979th, the delivery vehicle “Zastava 435” which was registered and driven.

Figure 3. The ﬁrst EV in the country had DC series motor 27 kW and could reach speed of 42 km/h, battery voltage 108 V, a capacity of 350 Ah which allowed radius of the 48 km

The first passenger car with an electric drive that appeared in the streets of Belgrade, was made in 1980, by professor Zoran Stojiljkovic. During the oil crisis, this vehicle “Trabant” had been used about 4 years, everyday. Original design of the drive transistor and power regulator, proved as a reliable and qualitative, and allowing the vehicle to move about 20,000 km. With the electric motor, rated power of 4 kW, a transistor chopper and storage batteries voltage 54 V and capacity of 240 Ah, the vehicle could reach a speed up to 60 km/h. After that, there were several attempts to make a passenger car by enthusiasts or professionals, but it has never been realized to a series production. Interest in EV,s in our country had been rapidly increased during the oil crisis and during the sanctions. At that time, interest had increased especially in various EV,s for special purposes. In addition, there was interest in the floating EV,s, so, the firm “Melbat” made a several environmental and tourist boats, on the river Sava powered electrical rated power in range 1,5 - 7,5 kW. The first commercial electric car made the same company, too. It was the reconstruction of “Lada Niva”, at the end of 1994, and it was for

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every day use, in municipal purposes. This vehicle with the mass of 1.820 kg, with the electric motor 5 kW, the battery voltage 72 V, and capacity 350 Ah could reach the top speed of 32 km/h. At the end of 1996, the vehicle “Lada” was reconstructed with a more powerful motor power of 12 kW and could develop the speed of 65 km/h. Within the Institute of Technical Sciences of SASA, in July 1996, were reconstructed and registered two EV type Yugo-E. The vehicles were able to develop a maximum speed of 75 km/h and a radius of autonomous movement of the 45 km, with the electric motor of 6.3 kW, 72 V of storage batteries voltage and capacity of 143 Ah, EV were thoroughly tested and provided data on energy efficiency in the amount of 5 km/ kWh on the open road, and the specific energy consumed was 0,2 kWh/km. In city driving, the results were about 10% weaker. At the end of the 20. century, has begun the construction of EV with the alternative electric motors. The company “Raskovnik” made some very interesting and light EV in range of electric power 2 – 4 kW. Independently, in cooperation with the institutes “Crvena Zastava” and Electrical Engineering Faculty, under the leadership of Professor Slobodan Vukosaviü, vehicle Yugo-Electra is reconstructed with a driving motor rated power 7.5 kW. In our country, development of EV had been gradual, according to “step by step” system. Although there were a number of smaller and larger trials, virtually the only program that found commercial application was so-called “Black Lada”. Big support to development of EV had given the United States, where was formed an anti air pollution program in 1989. with the aim of preventing air pollution. In Los Angeles, had passed a law that until 1998 the 2 % of vehicles have to be to “zero emissions” of harmful substances ZEV. In some countries, for example in Switzerland, local regulations on air pollution were also given support to the implementation of EV. The Law about Prevention of air pollution and economic opportunities the United States, urged the automobile manufacturers to engage in making EV, so the company General Motors made the first real EV named EV-1 [06], which, was producing in a series later satisfied most of the drivers habits. The vehicle has an asynchronous motor and inductive charger with no possibility of

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electric shock. In addition, it was made the first station for recharging batteries in California.The modified vehicle type EV1 had reached in 1994. the largest measured speed of EV from 295km/h. Understanding that EV couldn’t quickly replace existing vehicles, U.S. president made a new plan. One of the objectives of the plan, which Mr. Obama described as “historical”, is to replace the present complicated system of federal and state laws and regulations on exhaust emissions and fuel economy. Announcing the plan [05], Mr. Obama said that “the status quo is not acceptable anymore” as it creates dependence on foreign oil and contributes to climate changes. Effects of new measures will be as if the roads in the United States removed 177 million vehicles and state saving in oil as much as when was imported from Saudi Arabia, Venezuela, Libya and Nigeria in 2008. The work on the application of HEV has been accelerated. PROBLEMS WITH CONVENTIONAL MOTOR VEHICLES Modern transport with conventional motor vehicles contributed to overall economic progress but also caused the problems of environmental pollution and energy supply difficulties – especially, in times of energy crisis. Air pollution from IC engines that use oil products is not limited to the immediate surroundings, but there are also regional and global significance. Air pollution by burning fuel in motor vehicles becomes a major problem of urban areas, worldwide. Emissions of pollutants, originated from motor vehicles, caused by the level of traffic, road negotiability and weather conditions. Pollutants from exhaust systems of motor vehicles due to the atmosphere depend on the composition, combusting and volatility of fuel. In terms of impact on global atmospheric pollution and associated problems, the most important consequence is increase of global mean temperature. From the standpoint of global warming, the greatest danger is carbon dioxide, an unavoidable ingredient of combustion of petroleum products [26]. In order to reduce air pollution from vehicles and to build more economical cars, to combat global warming and reduce U.S. dependence on oil, new standards are preparing in the U.S., to reJournal of Applied Engineering Science 9(2011)3, 202

Dr Zoran Nikoliü and etc. - Developments, characteristics and prospects of the electric vehicles

duce emissions of cars and fossil fuel consumption. The intention of the administration is that these measures, by 2016. decreased for 30% the emissions from vehicles. It is expecting that the new proposals increase as the price of new cars, in an average of about U.S. $ 1,300, by 2016. year. Energy consumption in transport has a steady growth, so that today it represents nearly half of oil consumption. To reduce consumption of oil and oil products is the economic and environmental necessity but it can create a technological problem. In this situation, the development of environmental facilities and EV are becoming one of the possible solutions. As world population are increasing, so and need for all types of energy. Today, more than half, 56 % of the world energy consumption is in the U.S., Japan and the European Union. As these countries are relatively poor in energy sources, they represent the largest energy importers. In addition to high economic dependence on oil and its derivatives, there are constantly in present the problem of protecting environment, reduce emissions and greenhouse gases. Estimates indicate that due to increasing consumer demands particularly because of increasing demands for transport of goods and people, demand for energy is constantly increasing by about 1.5 to 2% per year. It is expected that in the period from 2007. to 2035. the energy needs will increase by about 47% [26]. Although the share of oil, in total primary energy percentage is decreasing, the production and consumption of oil is generally increasing. In ﬁnding a new sources have been investing great efforts but inevitable facts are indicating that this form of energy has been slowly reducing and scientists expect that, for some time, will dry up sources of this energy. Forecast growth in consumption of liquid fuels, by end users, according to the U.S. Energy Information Administration (EIA) [11], shows that the consumption of liquid fuels, in this period will increase from about 13,7 million tons per day in 2007. to 17,6 million tons per day in 2035, or 28,5%. The price of oil had reached the maximum value of 147 dollars for a barrel (159l) in 2008, and although, there are forecasts that will not exceed the value of 133 $ to 2035 years, less optimistic forecasts are indicating that it may reach a value over $ 200. Earlier made analysis, suggests that oil price of over Journal of Applied Engineering Science 9(2011)3, 202

$ 100 per barrel, and is creating real conditions for broader use of EV. Oil becomes the cause of wars and on the other side, directly affects increasing in its price in world market. As production so and consumption of electricity will have, from 2007 to 2035, the highest increase of all other forms of energy, for about 87%. ADVANTAGES OF ELECTRIC VEHICLE AND BATTERY CHARACTERISTICS EV, electricity needed for power derives from batteries, which carry with itself, and it has many advantages over cars that have power with IC engines [20, 19, 1]: • • • • • • • • • • • • • •

There is no need for petroleum derivatives It is, the environmentally absolutely accepted It does not produce exhaust gases It has a quiet operation Vibrations in operation are at the minimum It is easy to manage There are no problems with starting, in the winter time It is immediately ready for operation at full power Operational characteristic of the electric motor is very good There are possibilities of overloading, especially by accelerating Recuperation of electric energy by breaking regime It has a high efﬁciency It requires a little maintenance and Operation costs are low.

It is normal that electric drive has a certain disadvantages, compared to existing vehicles: reducing speed, reducing the autonomy of operation without recharging, possibly increasing the mass of the drive device, and vehicle and batteries recharging problems. The main problems in the application are rechargeable batteries. It is expecting, that signiﬁcantly greater improvement. Key criteria’s for broader use of the battery are performance, such as energy density, volumetric energy, the price of investment, duration (measured by years and kilometers road EV), and safety.

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The energy density of gasoline is 13,000 Wh/ kg, which is shown as “a theoretical energy density” (Figure 04). The average utilization rate of passenger cars with IC engine, from the fuel tank to the wheels, is about 13% in US, so that “useful energy density” of gasoline for vehicles use is around 1.700 Wh/kg. It is shown as “practical” energy density of gasoline. The efﬁciencies of autonomous electric propulsion system (batterywheels) is about 85%.

Figure 4. Image Energy density of different types of batteries and gasoline [07]

Significantly improvement of current Li-ion energy density of batteries is about 10 times, which today is between 100 and 200 Wh/kg (at the cellular level), could make that electric propulsion system be equated with a gasoline powered, at least, to specific useful energy. However, there is no expectation that the existing batteries, as Liion, have ever come close to the target of 1,700 Wh/kg. Oxidation of 1 kg of lithium metal, releases about 11,680 Wh/kg, which is slightly lower than gasoline. This is shown as a theoretical energy density of lithium-air batteries. However, it is expected that the real energy density of Li-ion batteries will be much smaller. The existing metal-air batteries, such as Zn-air, usually have a practical energy density of about 40-50% of its theoretical energy density. However, it is safe to assume, that even fully developed Li-air cells will not achieve such a great relationship, because lithium is very lightweight, and therefore, the mass of the battery casing and electrolytes will have a much bigger impact. Fortunately, the energy density of 1700 Wh/kg for a fully charged battery pack, fits only 14.5%

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of the theoretical energy content of lithium metal. It is realistic to expect, achieve mint of such energy density, at the cellular level, considering the intense and long team’s development [07]. Energy density of complete batteries is only a half of density, realized at the cellular level. It is interesting to mention, that the significant results in development this type of battery are achieved in the laboratories of the Institute of Electrochemistry ICTM and the Institute of Technical Sciences SASA, where they were working on development of aluminum-air battery with the aluminium anode alloyed with small amounts of alloying components and the neutral aqueous solution NaCl, as the electrolyte [02]. The prototype of such batteries, had achieved a power density of 34/39 W/kg, and energy density of 170-190 Wh/kg, by optimal current density between 50 and 100 mA/cm2. Volumetric energy (in Wh/l) in the storage batteries is an important feature of the design considerations also. This requirement is the best expressed by condition that there is a maximum capacity of 300 dm3 (family car) for battery pack and auxiliary systems. A driving range of 500 miles (800 km) requires that the reservoir of energy, store energy of 125 kWh (with power consumption of 250 Wh/km), so that the volume of 300 dm3 is limiting specific gravity of the battery pack, including space for air circulation, must not be less than 0,5 kg/dm3. Power density: While Li-air systems imply an extremely high energy density, their power density (measured in W/kg of batteries weight) is relatively low. The prototype of Li-air cells achieves current density, in average 1mA/cm2, which is insufficient and is expecting significantly increase of the current density for at least 10 times. One way to achieve the required power density is the creation of a hybrid electric drive system, where a small, high power battery, for example, on the basis of Li-ion technology, would provide the power in short periods of high demand, such as it is acceleration. Supercapacitors could be used instead of these batteries. Duration: The current Li-air cells show a possibility of full charge cycles, only about 50, with less capacity loss. Future research efforts must be directed towards improving the accumulated capacity in multiple discharges. In addition, the total number of charge cycles and discharge do Journal of Applied Engineering Science 9(2011)3, 202

Dr Zoran Nikoliü and etc. - Developments, characteristics and prospects of the electric vehicles

not mean to be very large, due to the high energy capacity of Li-ion cells. For example, a battery, designed for duration of 250,000 km, and projected to cross the EV radius of movement of 800 km, should be charged only 300 times (Full cycle equivalent) [22]. It is necessary to keep in mind that a lot of air will go through the battery during operation, and even a short-term accumulation of moisture, can be harmful to duration. Safety: EV batteries will be, especially in the beginning of the application, complying with extremely high safety standards, even more strictly than at gasoline car. Price: Design requirements of high-capacity battery for the drive EV are quite strict, but they are quite well deﬁned. They will serve as guidelines for the scientiﬁc research, conducted on the Liair battery system. Batteries for EV power have been just carrying out the transition from nickel metal hydride to Li-ion batteries, after years of researching and developing. Transition to the Li-ion batteries should be viewed in terms of a similar development cycle. It is known that, the price of each product, decreases with increasing mass production. It is expecting that the EV pric-

es will decline, because of falling down prices of Li-air batteries, including the price of EV. However, support to introduction of new vehicles in traffic would be systematically addressed. Accommodation of batteries as a power source, for vehicles with electric drive, is a big problem also depending on technological solution of batteries. As it can be seen, in table 1, [09] lead-acid batteries have a low energy, per unit mass and volume and a relatively small number of charge cycles. In contrast, modern Li-ion batteries and NaNiCl, have significant energy capacity, with a larger number of charges and are of a stable voltage. However, the latter ones are sensitive to warming and may have an energy loss up to 7.2%. Battery duration should be, always, taken into account, when their price is consideration. The duration depends on several factors, such as how often the vehicle is in use and how many times the batteries have been filled up. In Table 1, there are data on duration expectancy of certain batteries types and price per unit of energy.

Table 1. Characteristics of different types of batteries

Battery types

Energy density Wh/kg/ Wh/litar

Spec. power W/kg

Number of Energ. rechar. efﬁciency cycles

Energ. Self density, % discharge based on for 24 hours PbO

Duration years

Price US$/ kWh

PbO

40/60-75

180

500

82%

100%

2,5-4

100-150

NiCd

50/50-150

150

1.350

72,5%

150%

NiMH

70/140-300 250-1000

1.350

70,0%

175%

5-7

300-500

Li-ion

125/270

1800

1.000

90,0%

313%

5-10

>>1000

Li-ion polymer

200/300

>3000

500%

125/300

1.000

92,5%

313%

NaNiCl (Zebra)

Journal of Applied Engineering Science 9(2011)3, 202

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PROSPECTS OF ELECTRIC DRIVE OF EV Car driver’s habits and their way of living and work cause the appropriate technical features and characteristics of the car. EV does not have yet enough energy to compete the existing vehicles, with IC engines. It means that EV does not have enough energy for consumers such as air conditioners, for example (Figure 05). Reservoir of energy in EV can’t be quickly recharged and there are no distribution stations to supplement electricity. Testings of EV, made in our country, show that reconstructed EV with 300 kg batteries with a specific electric energy of 35 Wh/kg, can reach 50 km and to developing maximum speed 75 km/h [10, 18]. EV can achieve range over 150 km and to develop maximum speed of 130 km/h with more quality Li-ion batteries [10, 08]. Conditions for rapid transition to vehicles which would be fully able to replace existing vehicles, when battery of much higher specific power, will develop. It will take some time, until then. As an interim solution, have been producing a HV with a larger or smaller batteries, so they are called “pure HV” or “plug-in HV”. Sometimes the electric drive is used only to improve acceleration and braking energy stored in electrical energy, but in any case, gets more efficient use of fuel and reduced emissions of particulates (Figure 06). Towards the new standards for passenger vehicles, the fuel economy must be reduced to a level of 15 km/l fuel, which represents the consumption of (6.6l/100km) [05].

Figure 5. Typically EV, as the producer MiEV Mitsubishi Motors [08], is shown at the Belgrade automotive Fair in 2011., has exterior dimensions less than 3.5 x 1.5 m and 35 kW AC electric motor, developing a maximum speed of 130 km/h and Li-ion accumulators that allow a maximum range to 150km

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The world’s leading car manufacturers participate in the race, trying to develop EV successfully. The U.S. government has recommended to manufacturers, as reducing emission which vehicles produces so and fuel consumption, in order to reduce gradually dependence on oil imports. In Detroit, are preparing for the production of EV,s all three major car manufacturers General Motors (GM), Ford and Chrysler. In the U.S. automotive industry, widely accepted solution is a highly sophisticated one the electric drive with IC motor, which increases the radius of movement. It is believed, that the share of vehicles with alternative drives in selling new vehicles in the world, will grow up, but it is, also, considered that in the near future, will be dominance of vehicles by IC engines.

Figure 6. The most famous HV, Toyota Prius, which is registered for 5 passengers, has a IC engine power 73 kW, electric motor power 60 kW, so that the urban driving consumption is 4,6l/100km, on highway 4,9l/100km, and combined 4,7l/100km.

CONCLUSION It is believed that future, so and past belongs to EV [23]. Even there have been constantly ﬁnding new sources of liquid fuels, their exploitation are becoming more and more expensive and there existence less and less, in the world. It is necessary, to preserve oil as a resource for other industries, where there is no alternatives. On the other hand, electricity has been usually enough. If it will start soon, running more efﬁcient renewable energy, it may open a possibility of its cheaper production. It means that environmental and economical conditions will extend use of EV,s. Almost, all the problems related to production EV technology are resolved well enough, except energy storage. New electrochemical sources Journal of Applied Engineering Science 9(2011)3, 202

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upon Li-air base, made enough a cheap and compact, would allow, in the near future, transition from vehicles that use liquid fuel to EV [07]. EV batteries price seems more expensive than buying a suitable vehicle with the classic drive. Accordingly, the price of EV,s, by kilometer, comparing with IC vehicles powered, would be the same. Fuel for EV is cheap, maintenance is minimal, and the duration of electric motors is signiﬁcantly longer than the IC engine. Taking into consideration the price of air pollution, gas emissions that contribute the “greenhouse gases” effect and other market conditions, factors, that society have to pay, it is believed that the time of EV is certainly coming.

Europe (10 to 15%) if the necessary conditions are fulﬁlled (i.e. infrastructure, public incentives). Hybrid one will be an interim solution bridging the way to pure electric cars. As regards hydrogen vehicles, the Alliance Considers this technology as a medium to long term development.

Probably, it will not be a rapid transition from IC vehicles to EV vehicles [25]. The latter ones are still inferior and can not satisfy potential customers, in all circumstances. Batteries development has been made great progress, but still, not enough. The introduction of EV into service, no doubt, pure the environment, where vehicles are used. However, in case of EV that are supplemented with electricity, emissions of carbon dioxide only transferred it to the combustion of fossil fuels, in power plants. The introduction of renewable energy sources, such as the use of solar, wind and hydro resources, will be providing a real transport of people, with zero emissions. In the world, currently are making a great efforts, to move in that direction.

This work has been ﬁnancially supported by projects MNIT TR 35042 and TR 34028.

As a transient solution, to clear EV, there are developing HV,s today. This vehicles are operating like EV in urban areas, and outside the city, it is used IC power engine or recharging batteries. In this way, HEV contribute, greatly to the ecology, affecting the economy of operation [24], and at the same time, intensively developing new types of batteries as a promising reservoir of energy for application in EV. The most recent technology developments and the clear interest of many European countries have strongly accelerated the mass market introduction of EV. Probably, the most effective measures for the implementation of the environmentally friendly vehicles are economic measures[13]. Taxes and fees are economic measures in the transport sector that can reduce pollution and preserve the clean environment [12]. The Renault-Nissan Alliance estimates that around 10% of the world automotive market will be full electric by 2020 [16], and even more in Journal of Applied Engineering Science 9(2011)3, 202

On informal Competitiveness Council in San Sebastian, at 2010, ACEA president, Dieter Zetsche [27] was clear: The question is no longer if diesel and petrol will be replaced by electricity and hydrogen as the dominant means to fuel a car. It’s just a question of when. ACKNOWLEDGEMENTS

ABBREVIATIONS AC Alternating current AEV Autonomous electric vehicle BEV Battery electric vehicle DC Direct current EM Electromobil EV Electric vehicle FCV Fuel cell vehicle GM General Motors Company HEV Hybrid electric vehicle IC Internal combustion engine Li-air Lithium air Li-ion Lithium ion NiMH Nickel-metal hydride OPEC Organization of the Petroleum Exporting Countries PHEV Plug-in hybrid electric vehicle ZEV Zero emission vehicle REFERENCES 1) Curcic, M., Nikolic, Z., (1997), “Fast Lada” to ride around the city, sources of electricity, Belgrade, 1, 155-164. 2) Despic, A. R., Milanoviü, P. D., (1979), Aluminium-air battery for Electric vehicles, Recueil des travaux de l, Institut des Sciences Techniques de L Academie des Sciences et Anglais arts, Vol 12 No, 1, pages 1-18. 3) Eckstein, L., Faßbender, S., Lesemann, M., Ickert, L., Hartmann, B., Bröckerhoff, M.,

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(2010) “A car for everyone“- the winning concept of the international Ford model T challenge, Journal of Applied Engineering Science, 8(4), 17–22. 4) Fredzon, I.R., (1958). Sudovbie elektromehanizmbi, Gosudarsvenoe soioznoe izdetelbstvo sudostroitelbnoi promibišlennosti, Leningrad, p. 5. 5) Garden, R., (2009), Remarks by the President of the national fuel efficiency standards, http://www.whitehouse.gov/the_press_office/Remarks-by-the-President-on-nationalfuel-efficiency-standards/, May 19th, 2009. 6) [General Motors (1996) Zeroing in on the EV1, Electric & Hybrid vehicle technology 96, 20 – 25 7) Girishkumar, L.G.G., McCloskey, B., Luntz, A. C., Swanson, S., and Wilcke, W., (2010), Lithium-Air Battery: Promise and Challenges, J. Phys. Chem. Lett. 2010, 1, 2193-2203, doi: 10.1021/jz1005384 8) http://www.mitsubishi-motors.com/special/ ev/whatis/index.html 9) http://www.seai.ie/News_Events/Press_ Releases/Costs_and_benefits.pdf 10) http://xdconcept.com/, XD Concept Leaflet. 11) International Energy Outlook 2010, DOE/ EIA-0484 (2010), ww.eia.gov / oiaf / EMI / index.htm 12) Kaplanovic, S., Ivkovic, I., Petrovic, J., (2010) Tax on motor fuels in transportation sector – instrument for environment protection, Journal of Applied Engineering Science, no. 16, 39 – 46. 13) Kaplanovic, S., Petrovic, J., Ivkovic, I., (2009). Economic instruments in function of sustainable development of road transportation, Journal of Applied Engineering Science, no. 25, 17–22. 14) Kordesch, K., (1978). The electric cars, Union Carbide Corporation Battery Product Division, Ohio 15) More authors, (1973). Problems and prospects of development the electric vehicles and their introducing in traffic, Belgrade, Institute of Technical Sciences of SASA. 16) More authors, (2010), A European Strategy on Clean and energy-efficient Vehicles, Renault-Nissan Comments.

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17) Nikolic, Z., Marjanovic, S., Jankovic, Z., Rancic, M., (1997), YUGO with electric drive, electric energy sources, Belgrade, 1,141-153. 18) Nikolic, Z., Curcic, M., Porter, Z., Ranisavljevic, R., (1997), Development of commercial autonomous electric vehicles, Proceedings of the IX Symposium Power Electronics 97, Novi Sad, 102–107 19) Nikolic, Z., Dakic, P., Marjanovic, S., Pavlovic, S., (1997), Some properties of the reconstructed electric vehicles Yugo-E for Electric Power, Power, 25, Belgrade, 3, 266-280. 20) Nikolic, Z., (1981), Some experience with electric vehicle, Proceedings of the Conference “Science and Motor Vehicles 81”, Kragujevac, A01-1 to A01-14. 21) Nikolic, Z., (2010), Electric vehicles in the world and in our country, Belgrade, Gosa Institute. 22) Ogasawara, T., Debart, A., Holzapfel, M., Nov_ak, P., Bruce, P. G., (2006) Electrode for Rechargeable Li2O2 Lithium Batteries. J. Am. Chem. Soc. 128 (4), 1390-1393. 23) Slavnich, D., (2010), Electric Avenue, Electric & Hybrid Vehicle Technology July 2010, 52-56. 24) Slavnich, D., (2011), Jet Power, Electric & Hybrid Vehicle Technology January 2011, 06-09. 25) Slavnich, D., (2011), Shimmering star, Electric & Hybrid Vehicle Technology January 2011, 88-94. 26) Solomon, S. S., Qin, D., Manning, M., Marquis, M., Averyt, K., Tignor, M., LeRoy H., Chen, Z., (2007)Climate Change 2007 The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment of the IPCC (ISBN 978 0521 8800 9-1 Hardback; 978 0521 7059 6-7 Paperback) 27) Zetsche, D., (2010), The Future of Electric Cars - The Automotive Industry Perspective, San Sebastian, 9 February 2010, http://www. acea.be/images/uploads/files/20100211_ Speech_Dieter_Zetsche.pdf

Paper sent to revision: 21.06.2011. Paper ready for publication: 22.08.2011.

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Paper number: 9(2011)3, 203, 383 - 392

AUTOMATED GENERATION OF WORKPIECE LOCATING SCHEME IN FIXTURE DESIGN Dr Ĉorÿe Vukeliü * University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia Dr Igor Budak University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia Dr Branko Tadiü University of Kragujevac, Faculty of Mechanical Engineering, Kragujevac, Serbia Dr Ognjan Lužanin University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia Dr Miodrag Hadžisteviü University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia Dr Peter Krizan Slovak University of Technology, Faculty of Mechanical Engineering, Bratislava, Slovakia This paper proposes a methodology which aims to fill the gap in the area of automated fixture design. The approach is based on detailed consideration, analysis, and synthesis of all operating requirements related to automated definition of possible workpiece locating schemes for machining processes. Reviewed in the paper are the system concept, functions, and a case study. Key words: fixture, locating, locating error. INTRODUCTION Fixtures is widely used in manufacturing, e.g. machining (Figure 1.a), inspection (Figure 1.b), assembly (Figure 1.c), and welding (Figure 1.d). Fixture is one of essential components in manufacturing. It is used for efficient and reliable locating of workpiece, as well as for supporting, and clamping, in a way which provides machining within predefined tollerances [12]. Although the primary function of fixture is precise locating and clamping of workpiece, there are many additional criteria regarding ergonomics which should be met. Finally, one of the most important requirements of every fixture is cost-efficiency, which means that it should not increase costs of manufacture due to e.g., protracted fixture assembly, costly materials, costs of fixture manufacture, etc. Costs related to fixture design and manufacture can contribute up to 20% to total manufacturing costs. This contribution does not only pertain to material costs, and costs of fixture manufacture and assembly, but also to the costs of fixture design. Lower costs of fixture design contribute to significant financial effects. Another important aspect related to fixture design is

that it embodies many conflicting requirements, bearing in mind that fixture solution must meet a number of mutually exclusive requirements. For example, heavy fixture might be desireable considering workpiece stability. However, the increased fixture weight contributes to additional costs, due to higher material costs, and more difficult fixture handling. All this contributes to complexity of fixture design. In addition, fixtures directly influence the quality of machining, productivity, and product cost [17]. There exist two approaches to solving this problem. One is based on the development of flexible fixtures, while the other leans on simplification of design process. Simplification of the design process is primarily centered on design automation, i.e., the development of CAFD (Computer Aided Fixture Design) systems [18]. Asante [01] presented a model that combines contact elasticity with finite element methods to predict the contact load and pressure distribution at the contact region in a workpiece-fixture system. Dai et al. [02] described a modular element database creation method, which can be used effectively for integrating with a Computer-Aided

* Faculty of tehnical science, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia; vukelic@uns.ac.rs

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Figure 1. Fixtures a) Machining fixtures [24], b) Inspection fixtures [24], c) Assembly fixtures [25, 26, 27], d) Welding fixtures [25].

Design system and for modelling fixture subassemblies. Deng and Melkote [03] presented a model-based framework for determining the minimum required clamping forces that ensure the dynamic stability of a fixture-workpiece system. DeMeter [04] presented an approach to determine support location that minimises the maximum displacement. Finite element analysis was used to find displacements. Gologlu [05] developed a knowledge-based methodology for setup planning and datum selection incorporating machining and fixturing constraints. Hazarika et al. [06] developed a setup planning system for machining prismatic parts considering fixturing aspect. The proposed setup planning system provides inputs to fixture designer in terms of recommended depth of cut and feed, fuzzy clamping forces, approximate optimal locator and clamp layout, and sizes of the locators and clamps. Kaya [07] used a genetic algorithm-based continuous fixture layout optimization method, but the dynamic effects of the workpiece were not considered. King and Hutter /8/ proposed a approach for generating optimal fixturing locations to secure workpieces ideally 384

with respect to maximum stiffness, resistance to slip and stability. Kulankara et al. 09] applied the genetic algorithm for fixture layout and clamping force optimization to a compliant workpiece. In their model, an iterative algorithm that minimizes the workpiece’s elastic deformation by alternatively varying the fixture layout and clamping force is proposed. Li and Melkote [10] presented a fixture layout and clamping force optimal synthesis approach that accounts for workpiece dynamics during machining. They used the contact elasticity modeling method that accounts for the influence of workpiece rigid body dynamics during machining. Menassa and DeVries [11] used finite element analysis for calculating deflections using the minimisation of the workpiece deflection at selected points as the design criterion. The design problem was to determine the position of supports. Sanchez et al. [13] calculated the contact load at the fixture-workpiece interface using a simple and direct mathematical tool along with the finite element analysis, which simplifies the deformation minimisation problem. They also ascertained the interpolating functions which relate the clamping position Journal of Applied Engineering Science 9(2011)3 , 203

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with respect to the load contact in order to define valid clamping regions. Tan et al. [14] described the modeling, analysis, and verification of optimal fixturing configurations by the methods of force closure, optimization and finite element modeling. Tao et al. [15] presented a geometrical reasoning methodology for determining the optimal clamping points and clamping sequence for arbitrarily shaped workpieces. Vallapuzha et al. [16] presented a genetic algorithm-based optimization method that uses spatial coordinates to represent the locations of fixture elements. They optimized the locator’s position and ignored the clamp’s position. Vukelic et al. [19] used a combination of feature-based, knowledge-based and geometry-based methodology for development complex system for fixture selection, modification, and design. Wang et al. [20] developed an intelligent fixturing system to adjust the clamping forces adaptively to achieve minimum deformation of the workpiece according to cutting forces. Linear static finite element analysis was used to find the workpiece deformation. Wardak et al. [21] used a finite element analysis and optimisation algorithms to design optimal fixturing layouts for the drilling processes. Xie et al. [22] introduced another experimental investigation to evaluate the coefficients of the static friction of workpiece-fixture element pairs. Yeh and Liou [23] used the finite element analysis to establish an analytical model to describe the clamping conditions between the workpiece and fixture elements in a modular fixturing system and to estimate the contact stiffness. •

•

The discussed investigations suffer from two major disadvantages:They are based on 3-2-1 locating method and complete restriction of workpiece degrees of freedom using locating elements. Thereby, they disregard the fact that this significantly increases fixture costs by shear increase of constituent fixture elements. In addition, there is an increased possibility of machining errors. The influence of locating error is completely disregarded. The fact that locating error greatly impacts the total machining error. On the other side, in contrast to all other errors which occur prior to or after the machining, locating error is unique in that it can be exactly determined at all times. Therefore, its numerical value and impact on the total machining error are known.

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As can be seen, there is still a need for reliable methods which help designers to plan fixtures on conceptual level, where the key task is to identify most adequate fixture structure, i.e. locating workpiece surfaces which satisfy particular criteria. WORKPIECE LOCATING The purpose of workpiece locating is to bring it into correct and definite position prior to clamping, i.e., to restrict some but not all workpiece degrees of freedom, thus allowing proper machining. The number of degrees of freedom to be restricted depends on the shape of workpiece and the measure to be achieved by machining (Figure 2 and Figure 3). Locating variants and primary locating surface are determined depending on workpiece shape and geometric specifications. Hereby, conditions of stability,

Figure 2. Locating of a prismatic workpiece a) restriction of 3 degrees of freedom, b) restriction of 5 degrees of freedom, c) restriction of 6 degrees of freedom

Figure 3. Locating of a cylindrical workpiece a) restriction of 4 degrees of freedom, b) restriction of 5 degrees of freedom, c) restriction of 6 degrees of freedom

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machining precision, and the ability to machine larger number of surfaces in one locating, are to be observed.

are considered as a cummulative error: (3)

LOCATING ERRORS Most accurate machining is performed in cases when it is possible to use a single primary locating surface. However, in most cases it is not possible to machine workpiece on a machine tool using just one primary locating surface. Primary locating surfaces should be chosen in a way which allows rapid and easy workpiece locating. The selection of primary locating surfaces should allow construction and technological base to match. This allows more accurate machining due to avoidance of locating errors. During workpiece machining there are deviations from the required geometry and nominal measures deﬁned by the engineering drawing. Machining errors are common to every machining process which involves transformation of geometry, dimensions, or material structure. The basic criterion of machining accuracy requires that the total machining error (ǻ) must be less than the allowed machining tollerance (T), i.e.: ǻ<T

j= (GME, ME, CE, TSE, EDE, TDE, MAE, WE, ISE, CSDE). Including equation (3) into equation (1) yields: ǻLE + ǻCUM < T

Cummulative error is approximated as the mean economic accuracy of a particular machining process. The economic accuracy of machining can be expressed as the machining tolerance grade which is possible to achieve through particular machining processes. Presented in Table 1 are international tolerance grades (IT) for economic accuracy, i.e., the cummulative error for particular machining types. Locating errors occur either due to adoption of auxiliary seat, or due to a clearance between the locating surfaces on the workpiece, and the corresponding ﬁxture elements (locating elements which are interfacing locating surfaces). Table 1. Cummulative error for particular types of machining

(1)

The errors which occur prior to and during machining process depend on a large number of factors. These errors are numerous and they involve: geometric machining erros (¨GME), methodical errors (¨ME), locating errors (¨LE), clamping errors (¨CE), tool setup errors (¨TSE), elastic deformation errors (¨EDE), thermal deformation errors (¨TDE), machining allowance errors (¨MAE), wear errors (¨WE), internal stress errors (¨ISE), and errors of cutting system dynamics (¨CSDE). Calculations should take into account that all these errors are random variables, which means that the possibility of the total machining error equals:

Type of machining rough Turning

i= (GME, ME, LE, CE, TSE, EDE, TDE, MAE, WE, ISE, CSDE). As mentioned before, with the exception of locating errors (ǻLE), the rest of these errors are not always possible to calculate. For that reason these errors are not dealt with individually, but

386

12÷14 9÷11

ﬁnish

6÷8

Drilling

11÷13

Countersinking Reaming Milling

Cummulative error

semi-ﬁnish

rough semi-ﬁnish ﬁnish

(2)

(4)

9÷10 6÷8 12÷14 10÷11 8÷9

Workpiece can be located so that its locating error equals zero (¨LE=0), or is different from zero (¨LE 0). From the machining accuracy point of view, zero locating error is preffered. It is possible under certain conditions to have locating error which is different from zero - its sum with the Cummulative error (¨CUM) lower than the machining tolerance (T), i.e., ¨LE+¨CUM<T. Journal of Applied Engineering Science 9(2011)3 , 203

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However, such ﬁxture could have lower price, or signiﬁcantly higher productivity, thus representing a better solution compared to the previous one which features ¨L=0. Locating surfaces should be always chosen so that they do not impact the total machining error. SYSTEM STRUCTURE The structure of system for automated generation of workpiece locating schemes (locating surfaces) is shown in Figure 4. The system takes following input information: • • • •

• •

•

machining process to be performed on a workpiece, required number of degrees of freedom to be restricted on a workpiece, workpiece locating method, basic locating characteristic (locating from external surface, locating from internal surface, locating from internal and external surfaces), possible characteristic workpiece locating schemes, characteristic dimensions of workpiece surfaces from which it is possible to locate workpiece, geometric speciﬁcation of workpiece (tolerances) for the chosen characteristic workpiece surfaces.

Based on workpiece orientation during machining process on a particular machine tool, workpiece surfaces, given machining measures and their geometric specifications, possible locating surfaces are generated, while taking into consideration the required number of degrees of freedom to be restricted on the workpiece. Once possible locating schemes have been defined, the resulting locating error is checked for all generated solutions, and all the solutions, if any, which satisfy requirement of zero or sufficiently small locating error, are selected. Based on the calculated workpiece locating errors, the system outputs one or several possible locating schemes. CASE STUDY On the workpiece shown in Figure 5 drilling process is performed which consists of eight holes 10 H10 on the 118±0.3 mm diameter.

Figure 5. Workpieces used in case study Figure 4. System structure Journal of Applied Engineering Science 9(2011)3 ,203

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Figure 6. Possible workpiece locating strategies

Figure 7. Machining accuracy checked according to locating strategy no. 1

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In Figure 6 three possible workpiece locating strategies are shown. In all the three cases locating elements are used to restrict five degrees of freedom. In the example from Figure 6, there is a locating error in all three cases due to the fact that constructive and technological bases are not identical. In these three examples, surface A is the primary locating surface (restricting 3 degrees of freedom), while surface B is the secondary locating surface (restricting 2 degrees of freedom). Locating errors for all three conceptual variants are different and are always ¨L 0. During system operation, the user firstly defines the machining surfaces by entering or selecting parameters. These surfaces are defined by entering characteristic dimensions and geometric

specifications, as well as the number of possible locating strategies. Following this, the number of possible locating schemes is defined for each locating strategy, as well as the number of degrees of freedom which need to be restricted, and the locating method. Selection of basic locating characteristics and characteristic locating scheme is performed for all the possible locating strategies. After this follows the defining of characteristic dimensions and allowed deviations of the characteristic workpiece surfaces from which the locating is performed. Once the required parameters have been selected or entered, the system presents a form from which the designer is informed whether the workpiece can be located so that the requested machining process can meet the tolerances.

Figure 8. Machining accuracy checked according to locating strategy no. 2

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Figure 9. Machining accuracy checked according to locating strategy no. 3

Figure 10. Comparative review of the possible locating variants

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Shown in Fig. 7-9 are characteristic input forms which allow definition of possible locating schemes. In these forms locating error is checked for workpiece location based on: strategy no. 1 (Figure 7), strategy no. 2 (Figure 8), and strategy no. 3 (Figure 9). Beside allowing machining accuracy checks for each selected locating strategy, the system also provides a unified presentation of results for all chosen locating strategies, thus allowing the designer to opt for the best solution (Figure 10). In this particular example, the best solution from the machining accuracy point of view is locating strategy no. 1. CONCLUSION Manual calculation of locating errors is time consuming and susceptible to human error. At the same time, this process is suitable for automation, since it is multi-variant, formalized, and requires voluminous processing. The proposed system was designed in order to reduce processing time and eliminate possible human error. Automated computation demands exact, analytic relations. Automated computation of locating error not only increases the quality, accuracy, productivity, but also reduces the total time, and in this way steps up the cost effectiveness of manufacturing process in general. ACKNOWLEDGMENT This research was supported by by the Ministry of Science and Technological Development of the Republic of Serbia (Project No. TR 035020). REFERENCES 1) Asante, J. N., (2008). A combined contact elasticity and finite element-based model for contact load and pressure distribution calculation in a frictional workpiece-fixture system. The International Journal of Advanced Manufacturing Technology. 39(5-6), pp. 578-588. 2) Dai, J., Nee, A. Y. C., Fuh, J. Y. H., (1997). An approach to automating modular fixture design and assembly. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 211(7), pp. 509-521.

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3) Deng, H., Melkote, S. N., (2006). Determination of minimum clamping forces for dynamically stable fixturing. International Journal of Machine Tools and Manufacture, 46(7–8), pp. 847-857. 4) DeMeter, E. C., (1998). Fast support layout optimisation. International Journal of Machine Tools and Manufacture, 38(10-11), pp. 1221-1239. 5) Gologlu, C., (2004). Machine capability and fixturing constraints-imposed automatic machining set-ups generation. Journal of Materials Processing Technology, 148(1), pp. 83-92. 6) Hazarika, M., Dixit, U. S., Deb, S., (2010). A setupplanning methodology for prismatic parts considering fixturing aspects. The International Journal of Advanced Manufacturing Technology, 51(9-12), pp. 1099-1109. 7) Kaya, N., (2006). Machining fixture locating and clamping position optimization using genetic algorithms. Computers in Industry, 57(2), pp. 112-120. 8) King, L. S., Hutter, I., (1993). Theoretical approach for generating optimal fixturing locations for prismatic workparts in automated assembly. Journal of Manufacturing Systems, 12(5), pp. 409-416. 9) Kulankara, K., Satyanarayana, S., Melkote, S. N., (2002). Iterative fixture layout and clamping force optimization using the genetic algorithm. Journal of Manufacturing Science and Engineering, 124(1), pp. 119-125. 10) Li, B., Melkote, S.N., (2001). Optimal fixture design accounting for the effect of workpiece dynamics, The International Journal of Advanced Manufacturing Technology, 18(10), pp. 701-707. 11) Menassa, R. J., DeVries, W. R., (1991). Optimisation methods applied to selecting support positions in fixture design, Journal of Engineering for Industry, 113, pp. 412-418. 12) Ostojic, G., Stankovski, S., Vukeliü, D. ,(2009). Automatizacija rukovanje priborima i elementima pribora u fleksibilnim tehnološkim strukturama, Journal of Applied Engineering Science, 7(4), pp. 7-12.

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13) Sanchez, H. T., Estrems, M., Faura, F. ,(2006). Fixturing analysis methods for calculating the contact load distribution and the valid clamping regions in machining processes. The International Journal of Advanced Manufacturing Technology, 29(5), pp. 426-435. 14) Ian, E. Y. T., Kumar, A. S., Fuh, J. Y. H., Nee, A. Y. C., (2004). Modeling, analysis and verification of optimal fixturing design. IEEE Transactions on Automation Science and Engineering, 1(2), pp. 121-132. 15) Tao, Z. J., Kumar, A. S., Nee, A. Y. C., (1999). A computational geometry approach to optimum clamping synthesis of machining fixtures, International Journal of Production Research, 37(15), pp. 3495-3517. 16) Vallapuzha, S., De Meter, E. C., Choudhuri, S., Khetan, R. P., (2002). An investigation into the use of spatial coordinates for the genetic algorithm based solution of the fixture layout optimization problem. International Journal of Machine Tools and Manufacture, 42(2), pp. 265–275. 17) Vukelic, D., Hodolic, J., (2008). Razvoj sistema za projektovanje pribora za mašinsku obradu upotrebom zakljuþivanja na osnovu sluþaja, Journal of Applied Engineering Science, 6(22), pp. 39-48. 18) Vukelic, D., Tadic, B., Hodolic, J., (2009). Stanje i tendencije razvoja raþunarom podržanog projektovanja pribora u mašinskoj obradi rezanjem. Tehnika-Mašinstvo, 58(2), pp. 1-11. 19) Vukelic, D., Zuperl, U., Hodolic, J., (2009). Complex system for fixture selection, modification, and design. International Journal of Advanced Manufacturing Technology, 45(7-8), pp. 731-748.

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20) Wang, Y. F., Wong, Y. S., Fuh, J. Y. H., (1999). Off-line modelling and planning of optimal clamping forces for an intelligent fixturing system. International Journal of Machine Tools and Manufacture, 39(2), pp. 253-271. 21) Wardak, K. R., Tasch, U., Charalambides, P. G. (2001). Optimal fixture design for drilling through deformable plate workpieces. Part I: Model formulation, Journal of Manufacturing Systems, 20(1), pp. 23-32. 22) Xie, W., De Meter, E. C. Trethewey, M. W.,(2000). An experimental evaluation of coefficients of static friction of common workpiece – fixture element pairs. International Journal of Machine Tools and Manufacture, 40(4), pp. 467488. 23) Yeh, J.H., Liou, F.W., (1999). Contact condition modeling for machining fixture setup processes. International Journal of Machine Tools and Manufacture, 39(5), pp. 787-803. AeroCad 24) http://www.aerocaddesign.com, Design, Inc., 4012 W. Kitty Hawk, Chandler, AZ 85226. 25) http://www.waynesborodesign.com, Waynesboro Design Services, Inc., 11662 Orchard Road, Waynesboro, PA 17268. Saul 26) http://www.saulparkerdesign.co.uk, Parker Design Consultants Ltd., Perseverance Mill, Grange Lane, Accrington, Lancashire, BB5 1HX. 27) http://www.mastertoolinc.com, Master Tool & Die, Inc., 1950 Shawnee Road, Eagan, MN 55122.

Paper sent to revision: 28.06.2011. Paper ready for publication: 01.09.2011.

Journal of Applied Engineering Science 9(2011)3 , 203

Paper number: 9(2011)3, 204, 393 - 400

SURVEYING WORKS IN ROAD DESIGNING AND CONSTRUCTION Mr Miroslav Kuburiü * Geoput d.o.o, Belgrade, Serbia Mr Mladen Lero Geoput d.o.o, Belgrade, Serbia The paper presents an outline of geodetic works related to the development of technical documentation during construction of roads (highways, trunk roads, etc.). Special emphasis is placed on the needs, goals and significance of geodetic works, as well as on the extent or level of detail of necessary technical documentation. Key words: design of geodetic marking, geodetic maps, design of geodetic observations, land acquisition design INTRODUCTION (1) The up-to-date practice has proved that the geodetic profession and its practitioners failed to affirm their role in a multidisciplinary team, that is to say, that their participation and significant responsibility during developing of technical design documentation for the needs of construction of various roads, participation in construction and the procedure itself of technical acceptance and subsequent use of built structures is usually underestimated by other professions. Reasons for such a status of geodetic profession may be sought in insufficient understanding of the structure and importance of the activities of this profession by representatives of other engineering fields. However, the blame should be first of all looked for within the profession itself. Namely, geodetic professionals should primarily make sure that their staff receive quality professional development (both in terms of theory and practice) as well as that adequate IT infrastructure (equipment and software) is ensured, which should help create pre-conditions for responsible and reliable participation in the process of preparation, designing and implementation of surveying tasks, more specifically: •

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from the moment of identiﬁcation of the concerned land parcels on which construction is planned, collection of numerical and graphical data from cadastral and other public records,

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establishing geodetic network of the concerned object and its connection to state geodetic base, geodetic surveying and developing updated geodetic base for all stages of design documentation, in required accuracy, in the state coordinate system, in digital form, and correct printing in appropriate-required scale, integrating topographical map with cadastral plan, forming geodetic survey, participation in all stages of development of design documentation, development of necessary surveying designs, translation of the designed structure on the ground from all design stages of the concerned structure, forming the construction lot for the needs of construction of the concerned structure, participation in the building of the structure from the moment of onset of works by the Contractor, permanent detailed marking and monitoring the construction process, until the moment of providing proofs that the structure was built in accordance with and based on design documentation and building permit, in spatial form development of as-built design and geodetic surveying and gathering all necessary data on newly-built structure and development of necessary surveying analy-

* Geoput d.o.o, Tome Rosandiüa 2, 11 000 Belgrade, Serbia, e-mail: geodelta@geoput.com

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sis and its submission to the competent service for real estate cadastre, for its review and veriﬁcation and for registration in real estate records, and further monitoring and observation of the ground and structures during use, independent geodetic supervision of conducting all surveying works as they are performed and during measurement and development of design analysis and building of the concerned structures; technical control and veriﬁcation of acceptance of design technical documentation.

PROBLEMS RELATED TO DEVELOPMENT OF DESIGN DOCUMENTATION (2) Geodetic works, that is to say, development of concerned technical documentation, although clearly defined by relevant legislation, [01], [02] and by-laws, most frequently do not have a prescribed form. Habits inherited from the past period when this field was not clearly defined in terms of legislation, inconsistencies in observance of law, investors’ incompetence during the stage of development of Design Task, inertia of supervision bodies, indolence or lack of competence of persons in charge of technical check, are only some of the reasons for such a situation. On the other hand, one of the peculiarities of geodetic profession is the fact that during the implementation of multi-disciplinary projects, such as infrastructure projects in civil engineering, the segments of designing and carrying out of surveying work overlap within the surveying stage itself. Namely, the basic task of geodetic professionals as far as those designs are concerned, includes development of a geodetic map, with the digital model of the ground, as a basis for designing, as well as development of the design of geodetic marking and observation of structures during construction and exploitation, and the land acquisition (expropriation) design (if a completely new structure is involved). That is to say, the main task implies designing, immediately followed by carrying out of surveying works, i.e. gathering data and performing works on the ground. Only after completion of the construction design of the structure, can the designs of geodetic marking, observation of ground and structures during

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building and use of the structure, and the land acquisition design be made, which is then followed by submission of the design documentation to technical control by an authorized independent institution. Taking into account all the above-mentioned, it is not difﬁcult to conclude that the process itself of developing design documentation, although it is done in accordance with the law, contains some logical inconsistencies. It is certainly not logical or useful that the technical control of the design of geodetic works (which includes the design of geodetic base – the main traverse) is done after completion of geodetic works and making geodetic map. On the other hand it is not adequate or technically correct to present the results of such works within the design of geodetic works, that is to say, that the elements of the analysis of performed geodetic works be a part of design documentation. All the mentioned peculiarities and problems indubitably point out at the need of a clearer and more systematic regulation of this issue, both from the normative and the good engineering practice points of view. FUNCTIONAL AND TECHNICAL CHARACTERISTIC (3) Surveying works and interpretation of geo-spatial data should, both by their size and contents, respond to real multidisciplinary needs of all stages and all segments of the construction design of the concerned structure, and conform, by both their volume and contents, to the level of detail of the design itself. DESIGNING BASES (4) Subject to the level of the design itself, basis for the development of design documentation of a geodetic design, may comprise the following: • Previous plan and design (project) documentation; • Report by the competent review committee (expert control), of previously existing technical documentation, along with the proposal of measures that the investors are required to apply during development of technical documentation; • Geodetic base information relating to the area of the concerned location, obtained from the Journal of Applied Engineering Science 9(2011)3, 204

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competent service for real estate cadastre; Information related to the cadastral status of lots within the perimeters of the location of the concerned structure.

SIZE AND CONTENTS OF DESIGN DOCUMENTATION (5) Design documentation of surveying works for the concerned structure should be developed on the basis of the Design Task and in accordance with speciﬁc requirements for responsible designers of a certain stage pertaining to a part of design documentation, and pursuant to legal regulations. Design documentation of surveying works is comprised of the following [03], [04], [05], [06]: • Geodetic network of the structure (main traverse) • Analysis of surveying and making geodetic map for designing • Main design of geodetic marking • As-built design • Design of geodetic observation of the ground and the structures during building and exploitation • Land acquisition design 5.1 GEODETIC NETWORK OF A STRUCTURE (MAIN TRAVERSE) Points of geodetic network of a structure, i.e. of main traverse represent a spatial basis for developing geodetic bases and for carrying out surveying works. Trigonometry points (as well as reference points) of state network, on which the points of the geodetic network of a structure will rely in order to be incorporated in the state coordinate system, comprise the positional basis for determining the coordinates of points of geodetic network of that structure. Practical application of positioning in 3-D space was made possible by use of development of Information Technologies, Geodetic Information systems, computer systems, global positioning system, total stations, digital levels as well as other digital technologies. Design documentation of the geodetic network of a structure, i.e. main traverse comprises the following: Journal of Applied Engineering Science 9(2011)3, 204

5.1.1. General documentation 5.1.1.1. Excerpt from the registration of economic subject (Contractor for the Concerned Works) 5.1.1.2. Decision on fulfillment of conditions for issuing the license to the Contractor 5.1.1.3. Decision of the Republic Geodetic Institute on Contractor’s fulfillment of conditions 5.1.1.4. Certificate of Compliance with Quality System 5.1.1.5. List of participants taking part in developing technical documentation 5.1.1.6. Decision on appointment of responsible designers 5.1.1.7. Responsible designer’s license 5.1.1.8. Certificate on validity period of the responsible designer’s license 5.1.1.9. Certificate confirming that responsible designers fulfill the conditions referred to in the Law on Planning and Construction 5.1.1.10. Decision on Appointment of the Person in charge of internal control 5.1.1.11. License of the person in charge of internal control 5.1.1.12. Certificate on validity period of the persons in charge of internal control 5.1.1.13. Statement by responsible designers on conformity of technical documentation 5.1.1.14. Statement by responsible designers on application of the Laws, regulations and standards 5.1.1.15. statement by a person in charge of internal control 5.1.1.16. Statement by the responsible designer that all the copies of technical documentation are identical 5.1.2. Design task 5.1.3. Textual documentation 5.1.3.1. Technical report 5.1.3.2 Introduction 5.1.3.3. Basic data on designed structure 5.1.3.4. Subject of geodetic works 5.1.3.5. Inclusion of the geodetic network of the structure in the state coordinate system 5.1.3.6. Designing and reconnaissance of geodetic network points for a structure 5.1.3.7. Stabilizing the points of geodetic network of the structure 5.1.3.8. Geodetic measurements aimed at

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determining coordinates of points of geodetic network of a structure 5.1.3.9. Data processing related to measurement of geodetic network of a structure 5.1.3.10. Determining rectangular coordinates of points of geodetic network of a structure 5.1.3.11. Determining the heights of points of geodetic network of a structure 5.1.3.12. Forming technical documentation of geodetic network of a structure 5.1.3.13.Conclusion 5.1.4. Numerical documentation 5.1.4.1. List of coordinate points and newly-determined geodetic networks (TO 25a) 5.1.4.2. Minutes of ground measurements and numerical processing 5.1.5. Graphical documentation 5.1.5.1. General map of a concerned site 5.1.5.2. Geodetic network sketch 5.1.5.3. Description of position of points (ɌɈ 27) 5.1.6. Appendixes 5.1.6.1. Applying for works at the Service for Real Estate Cadastre 5.1.6.2. Certiﬁcate of correctness of measuring devices 5.1.6.3. Data on geodetic base obtained from the Republic Geodetic Institute 5.1.6.4. Contract on development of concerned documentation 5.2. ANALYSIS (STUDY) OF GEODETIC SURVEYING AND OF MAKING GEODETIC BASE FOR DESIGNING In order to provide a spatial basis for designing, it is necessary to perform geodetic surveying of the existing situation on the ground, both horizontally and vertically, in accordance with the required precision. The width of the surveying area should be such to ensure the required spatial basis for designing all the contents of the concerned structure. The basis for developing design technical documentation (all stages of construction design) implies the data from the ground, collected through standard geodetic methods, and on topographical maps, made on the basis of such data, along with digital models of the ground, adjusted for printing at a required scale 1:1000, 1:1500, etc.

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The contents of design documentation of the analysis of geodetic surveying and making the geodetic base for designing includes the following: 5.2.1. General documentation The contents of general documentation is the same as in 5.1.1. of this paper. 5.2.2. Design task 5.2.3. Textual documentation 5.2.3.1. Technical report 5.2.3.1.1. General information about design 5.2.3.1.2. Basic data on designed structure 5.2.3.1.3. Subject of geodetic works 5.2.3.1.4. Plan of geodetic surveying 5.2.3.1.5. Geodetic base 5.2.3.1.6. Geodetic surveying method 5.2.3.1.7. Instruments and tools for geodetic surveying 5.2.3.1.8. Geodetic surveying and collecting data for making geodetic base 5.2.3.1.9. Geodetic surveying data processing 5.2.3.1.10. Making geodetic map 5.2.3.1.11. Geodetic analysis development for making design documentation 5.2.3.1.12. Conclusion 5.2.4. Numerical documentation 5.2.4.1. List of coordinate points of geodetic network 5.2.4.2. List of coordinates and levels of detailed points 5.2.5. Graphical documentation 5.2.5.1. General map – layout at scale 1:25000 5.2.5.2. Geodetic network sketch 5.2.5.3. Topographical plan at scale 1:1000 (1:500) 5.2.5.4. Digital form of topographical plan (designing base) 5.2.6. Appendixes 5.2.6.1. Applying for works with the Service for Real Estate Cadastre 5.2.6.2. Certiﬁcate of correctness of measuring instruments 5.2.6.3. Data on Geodetic base collected from the Republic Geodetic Institute

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5.3. MAIN DESIGN OF GEODETIC MARKING

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Design task

5.3.3.2.16. Mathematical model of equalization and evaluation of accuracy of measuring results 5.3.3.2.17. Model of testing compatibility of marked vs. designed geometry of structure 5.3.3.2.18. Model of testing of belonging of controlled points to appropriate geometrical element of the structure 5.3.3.2.19. Method of ﬁxing (materialization) of characteristic points of the structure 5.3.3.2.20. Concept and organization of surveying works during the implementation of the design of making geometry of the structure 5.3.3.2.21. Safety at work measures 5.3.3.2.22. Contents of the analysis of the implementation of the design of marking the geometry of structure 5.3.3.2.23. Priced bill of quantity 5.3.3.2.24. Technical requirements for performing works

5.3.3.

Textual documentation

5.3.4. Numerical documentation

The main purpose of this design is to ensure exact translation of the design of the concerned structure in real space, in conformity with pre-determined accuracy and marking methods. Marking methods should be brought in line with the current possibilities of surveying instruments and contemporary computer technology, bearing in mind the fact that the design of surveying works will not only serve the purpose of successful building of a structure but also of making of as-built design. The content of design documentation of the Main Design of Geodetic Surveying is comprised of: 5.3.1. General documentation The contents of general documentation is the same as in 5.1.1 of this paper.

5.3.3.1. Technical report 5.3.3.2. Design solution 5.3.3.2.1. General data on the design 5.3.3.2.2. Basic data on designed structure 5.3.3.2.3. Esting the points of the existing networks 5.3.3.2.4. Assessment of stabilization status of the existing geodetic networks 5.3.3.2.5. Form (geometry) of geodetic network of the structure 5.3.3.2.6. Connecting the structure with the geodetic network of the structure 5.3.3.2.7. Analytical elaboration on the geometry of designed structure (calculating coordinates of characteristic points of the structure) 5.3.3.2.8. Subject of geodetic marking 5.3.3.2.9. Selection of the method of marking of the geometry of the structure 5.3.3.2.10. Calculation of accuracy (accuracy optimization) of marking the geometry of the structure 5.3.3.2.11. Calculating the elements for marking characteristic points of geometry of structures 5.3.3.2.12. Selection of the measuring method and of the instruments for marking and control measuring 5.3.3.2.13. Analysis of the measuring method 5.3.3.2.14. Measuring plan for the needs of the control geometry of marked structure 5.3.3.2.15. Model of testing the results of control measurings according to the requirements in the design of marking the geometry of structure Journal of Applied Engineering Science 9(2011)3, 204

5.3.4.1. The list of coordinates of geodetic network points (basis for marking the geometry of structure) 5.3.4.2. List of coordinates of characteristic points of the structure (main and detailed points according to the design task and the subject of marking) 5.3.4.3. Elements for marking characteristic points of structures for the proposed method of marking and measuring instruments. 5.3.5. Graphical documentation 5.3.5.1. General map of geodetic network 5.3.5.2. Positional description of points of main traverse ɌɈ 27 5.3.5.3. Drawing of the base of construction design with characteristic points of the structure for marking along with necessary details 5.3.5.4. Marking plan 5.3.6. Appendixes 5.3.6.1. Transformational parameters of the concerned site 5.3.6.2. Minutes of performed control measuring of geodetic marking

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5.4. AS-BUILT DESIGN Technical documentation for technical acceptance of newly-built structure should be prepared, to the end of putting the newly-built structure to the intended function (issuing of exploitation permit) and its further maintenance during its exploitation-utilization, in accordance with legal regulations. The said technical documentation includes, but is not limited to: •

As-built design of the concerned structure (including proofs that the structure was built in all details according to the Main Design, i.e. according to possible changes that are in conformity with the Building Permit) • Excerpt from the real estate cadastre (numerical and spatial data about the cadastral lot on which the structure was built, and ownership rights on that lot along with other rights and their extent) • A proof that geodetic survey of newly-built structure has been performed (i.e. collecting all ﬁeld data related to geodetic survey and making full analysis of bill of quantity of concerned real estate, in accordance with legal regulations) and that the analysis of geodetic survey-bill of quantity has been received, acknowledged and veriﬁed by a competent service for real estate cadastre, to the end of registering changes during maintenance of real estate cadastre. The contents of technical documentation contained in the analysis of geodetic survey of newly-built structure, as the main and the most important proof as to how the concerned structure was built and positioned in appropriate space, and whether it was built in accordance with the technical documentation from the Main As-Built Design, which is therefore an important part of As-Built Design (while the other parts are related to the documentation of construction design, and of other related stages of design documentation of the new structure) includes the following: 5.4.1. General documentation The contents of general documentation is the same as in 5.1.1. of this paper. 5.4.2. Design task 5.4.3. Textual documentation 5.4.3.1. Technical report

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5.4.3.1.1. General data on design 5.4.3.1.2. Main data on designed structure 5.4.3.1.3. Subject of surveying works 5.4.3.1.4. Plan of geodetic survey 5.4.3.1.5. Geodetic base 5.4.3.1.6. Geodetic survey methods 5.4.3.1.7. Instruments and tools for geodetic survey 5.4.3.1.8. Geodetic survey and gathering data for making the analysis of bill of quantity 5.4.3.1.9. Processing geodetic survey data 5.4.3.1.10. Developing geodetic analysis of bill of quantity of newly-built structure 5.4.3.1.11. Forming geodetic analysis for making design documentation 5.4.3.1.12. Conclusion 5.4.4. Numerical documentation 5.4.4.1. List of coordinates of points of geodetic network 5.4.4.2. List of coordinates and levels of detailed points 5.4.5. Graphical documentation 5.4.5.1. General map-layout of scale 1:25000 5.4.5.2. Geodetic network sketch 5.4.5.3.Topographic plan of scale 1:1000 (1:500) 5.4.5.4. Geodetic survey (bill of quantity) sketches - manuals 5.4.6. Appendixes 5.4.6.1. Application of papers at the Service for Real Estate Cadastre 5.4.6.2. Certiﬁcate of Validity of Measuring Devices 5.4.6.3. Data on geodetic base collected from the Republic Geodetic Institute 5.4.6.4. Excerpt from the real estate cadastre (numerical and spatial data on cadastral plot on which the concerned structure was built, and ownership rights on that lot along with other types of rights and their extent) 5.5. DESIGN OF GEODETIC OBSERVATION OF THE GROUND AND THE STRUCTURES DURING CONSTRUCTION AND USE The purpose of this design is to deﬁne the subject, accuracy, method of work, instruments, dynamics and (priced) bill of quantities necessary for successful implementation of geodetic observation of ground and the structure during construction and use. The contents of the Design Journal of Applied Engineering Science 9(2011)3, 204

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of geodetic observation is required to have the following contents: 5.5.1. General documentation The contents of general documentation is the same as in 5.1.1. of this paper. 5.5.2.

Design task

5.5.3.

Textual documentation

5.5.3.1. Technical report 5.5.3.2. Design solution 5.5.3.2.1. General data on the design 5.5.3.2.2. Goal and task of observation 5.5.3.2.3. Design of geodetic observation works 5.5.3.2.4. Measuring places, measuring instruments, plan and program of measuring 5.5.3.2.5. Series of observations and time schedule of observations 5.5.3.2.6. Visual observation of construction elements 5.5.3.2.7. Measuring processing method, presentation of results and forming documentation on observation 5.5.3.2.8. Criteria for comparing the results of measuring against the permitted values 5.5.3.2.9. Requirements for maintenance of measuring places and instruments during the period of observation 5.5.3.2.10. Method of monitoring and interpretation of the results of object observation 5.5.3.2.11. Technical conditions for the implementation of the main design of observation 5.5.3.2.12. Subjects and way of informing about the obtained observation results 5.5.3.2.13. Measures to be taken in case that the results of observation reach or exceed the prescribed or allowed parameters 5.5.3.2.14. Conclusion 5.5.4. Priced bill of quantities 5.5.5. Graphical documentation 5.5.5.1. Plan of network of observation from stable points 5.5.5.2. Position of benchmarks (permanent points being observed) 5.5.5.3. Details of permanent points being observed 5.5.5.4. Other documentation Journal of Applied Engineering Science 9(2011)3, 204

5.5.6. Appendixes 5.5.6.1. Summary table of monitoring observation (Form) 5.6. LAND ACQUISITION DESIGN The main goal of making the land acquisition design is to deﬁne optimum area (forming of the construction parcel) of the future structure as well as of all the accompanying structures that should be both in the function of construction and maintenance of future facility. In land acquisition design the data are transferred necessary to translate the land acquisition area from design to the ground, mark it on the ground, with all the characteristic points that fully deﬁne the land acquisition area for the designed structure, that is to say for it be positioned in space, within the borders of determined or prescribed tolerances. The contents of the land acquisition design comprises the following: 5.6.1. General documentation The contents of general documentation is the same as in 5.1.1. of this paper. 5.6.2. Design task 5.6.3. Textual documentation 5.6.3.1. Technical report 5.6.3.2. Design solution 5.6.3.2.1. General data on the design 5.6.3.2.2. Basic data on designed structure 5.6.3.2.3. Form (geometry) of geodetic network of the structure 5.6.3.2.4. Analytic elaboration on the geometry of designed land acquisition area (calculating coordinates of characteristic points) 5.6.3.2.5. Subject of geodetic marking 5.6.3.2.6. Selection of marking method of land acquisition area 5.6.3.2.7. Calculation of accuracy (accuracy optimization) for marking geometry of the concerned area 5.6.3.2.8. Calculating elements for marking characteristic points of geometry of the concerned area 5.6.3.2.9. Selection of measuring methods and instruments for marking and for control measuring

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5.6.3.2.10. Analysis of measuring method 5.6.3.2.11. Plan of measuring for the needs of the control of geometry of marked land acquisition area 5.6.3.2.12. Method of ﬁxing (materialization) of characteristic point of the land acquisition area 5.6.3.2.13. Concept and organization of geodetic works during realization of the design 5.6.3.2.14. Safety at work measures 5.6.3.2.15. Contents of the analysis of design realization 5.6.3.2.16. Priced bill of quantities 5.6.3.2.17. Technical requirements for performing works 5.6.4. Numerical documentation 5.6.4.1. List of coordinate points of geodetic network (basis for marking the land acquisition area) 5.6.4.2. List of coordinates of characteristic points deﬁning the land acquisition area (taken from the construction part of the design) 5.6.4.3. Elements for marking characteristic points of land acquisition for the proposed method of marking and measuring instruments 5.6.4.4. List of lots or parts of lots with their sizes that make part of the land acquisition area. 5.6.5. Graphical documentation 5.6.5.1. General map of geodetic network 5.6.5.2. Drawing of the base of construction design with characteristic points for marking the land acquisition area and with necessary details 5.6.5.3.Plan of marking (integrated with cadastral status of concerned lots) 5.6.6. Appendixes 5.6.6.1. Possession and title deeds (real estate deeds) for lots or parts of lots that make part of the land acquisition area.

CONCLUSION (6) Surveying works and interpretation of geo-spatial data, by their size and contents, should respond to real multidisciplinary needs of all stages and all segments of the construction design of the concerned structure, while conforming by their volume and contents to the level of detail of the design itself. It is a task of geodetic experts, in cooperation with other professions and in a multidisciplinary activity, to make constant efforts on improvement and modernization, through the activities on improving the legal regulation and other standards, by establishing a quality system and by further upgrading of the system. REFERENCES 1) Law on State Survey and Cadastre “RS Official Gazette”, no. 72/09, as amended; 2) Law on Planning and Construction “RS Official Gazette, no. 72,/09, as amended; 3) Main design of Highway on Corridor 10, Section 3: Crvena reka-Ciflik, from km 40+965,00 to km 50+945,64: Design of surveying works, Main traverse, Analysis of Geodetic Survey, Design of Geodetic Marking, Land Acquisition Design, Geoput d.o.o. Belgrade, 2010; 4) Main design of Highway on Corridor 10, Section 2: Grabovnica-Grdelica, from km 868+166,10 to km 873+700,00: Design of surveying works, Main traverse, Analysis of Geodetic Survey, Design of Geodetic Marking, Land Acquisition Design, Geoput d.o.o. Belgrade, 2010; 5) Master design, Preliminary Design and Main Design of Niksic-Savnik-Zabljak trunk road, section: Savnik-Grabovica, L=8,1 km, Geoput d.o.o. Belgrade, 2008; 6) Technical control of TECHNICAL DOCUMENTATION: Main design of E-75 Novi SadBelgrade Highway (Surveying analysis, Design of geodetic marking, Land acquisition design), section: LOT 1.1. from km 108+000 to km 120+000, Geoput d.o.o. Belgrade, 2008. Paper sent to revision: 28.07.2011. Paper ready for publication: 05.09.2011.

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Paper number: 9(2011)3, 205, 401 - 410

INTERCITY BUS USERS VIBRATION COMFORT ANALYSIS THROUGH AN OSCILLATORY MODEL WITH SEVEN DOF USING ADAMS/VIEW SOFTWARE MSc Dragan Sekuliü * University of Belgrade, Faculty of transport and traffic engineering, Belgrade, Serbia Dr Vlastimir Dedoviü University of Belgrade, Faculty of transport and traffic engineering, Belgrade, Serbia An analysis of the vibration comfort of the users of an intercity bus IK-302 is carried out. Evaluation of the vibrations effect is made through criteria of comfort for means of public transport, defined in the international standard ISO 2631. The plane longitudinal model of the bus, with seven degrees of freedom (DOF) is created in the module ADAMS/View. Comfort is considered with the places of driver and passengers, in the middle part of the bus as well as on the rear overhang. Vertical seats accelerations of users were analyzed for two actual excitations: asphalt-concrete in bad condition and the same in good condition. The results of the simulation show that the vibrations mostly endanger the comfort of passengers in the rear end of the bus, and driver’s comfort is not threatened. Key words: bus comfort, ISO 2631, road roughness, simulation, ADAMS/View INTRODUCTION During driving the drivers and passengers in the vehicle are exposed to vibration from ground excitation. Vibration raise a sense of discomfort, reduces working ability, and in the long term action can endanger the health [02, 03]. Particularly risky groups are the drivers of construction machinery, agricultural machines, heavy trucks and buses [08]. Researches [08, 12, 13] have shown that the bus drivers can be exposed to high intensity vibration. The most frequent diseases of drivers due to long-term exposure to high levels of vibration are related to the musculo-skeletal disorders (pain in the lower back, neck, shoulders and knees), psychological disorders (tiredness, tension, mental fatigue), disorders of sleep and others [17, 01]. In order to minimize the negative impact of vibrations and protect the health at work, the European Union adopted in June 2002. the Directive 2002/44/EC. In this Directive the whole human body allowable levels of vibration exposure at work are defined, and in accordance, clearly highlighted the obligations of working organization for taking the appropriate safety measures [11]. A timely response, in order to prevent the dis-

ease of the bus driver as well as of the passengers, requires continuous monitoring of the vibration levels that they are exposed. That means frequent measuring of the intensity of vibrations to which the vehicle users are exposed in actual circumstances of bus service. Except by the measurements, it is possible to make an analysis by simulation through the oscillatory models of vehicles. Simulations get in importance in cases when the measurements, due to of various restrictions, are rarely carried out. In this paper the oscillatory comfort of the users is analyzed using a plane oscillatory model of the intercity bus IK-302 with seven DOF. Oscillatory comfort of bus driver and passengers is evaluated after the procedure and criteria prescribed by the Standard ISO 2631 [07]. Oscillatory model of the bus is made in the module ADAMS/View of the software pack ADAMS (Version MD ADAMS M3). The oscillatory model is excited by two signals registered on actual road surface: asphaltconcrete in bad condition and the same in good condition. BUS OSCILLATORY MODEL The analysis is carried out using an oscillatory model of the intercity bus IK-302 with seven DOF, made using the module ADAMS/View of

* Faculty of transport and trafﬁc engineering, Vojvode Stepe 35, Belgrade, Serbia, e-mail: d.sekulic@sf.bg.ac.rs

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Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

the ADAMS software pack - Figure 1. Figure 2. shows a schematic representation of the oscillatory model. The independent motions of concentrated masses of the mechanical oscillatory system are: vertical motions of driver’s body, of the bodies of the passenger in the middle of the bus (passenger1) and the passenger on the bus rear overhang (passenger 2), of the bus Center of gravity (CG), of the CG of front and rear axle as well as the angular motion of bus suspended mass around the y-axis.

The oscillatory mod of the bus IK-302 is made in ADAMS/View module with eight stiff bodies with freedom limited by means of appropriate connections. The driver, the passenger1 and the passenger2 are deﬁned as three stiff bodies connected to the bus body through three translational joints. The translational joints allow translational motion of stiff bodies only in vertical direction. The bus body is also deﬁned as a stiff body connected to GROUND by two joints - Inline Primitive Joint and Parallel Axes Primitive Joint. The combination of

Figure 1. Plane oscillatory model of the bus in ADAMS/View

Figure 2. Schematic representation of the plane oscillatory model of the bus

402

Journal of Applied Engineering Science 9(2011)3, 205

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

these allows translational motion of the bus body in vertical direction and angular motion around transversal CG axis. Front and rear axles are deﬁned as two stiff bodies joined to GROUND by translational joints that also allow translational motion of the axles only in vertical direction. To realize the motion in the point of contact between the tire and pavement, two virtual stiff bodTable 1. Geometry parameters of the bus Geometry parameter

ies are introduced, connected to the GROUND by translational joints. The actual road roughness is introduced to these joints by means of CUBSPL function. Suspension system of the bus, driver’s seat, passengers’ seats and tires are deﬁned as SPRINGDAMPER elements with appropriate stiffness and damping (Table 3). Table 2. Masses parameters of the bus

Value [m]

Masses parameter

Value

l - distance between axles

5.65

mv - mass of the driver and the seat

100 [kg]

a - distance from the front axle to CG of the loaded bus

3.55

mp1 - mass of the passenger 1 and the seat

90 [kg]

b - distance from the rear axle to CG of the loaded bus

2.10

mp2 - mass of the passenger 2 and the seat

90 [kg]

pp – front overhang of the bus

2.82

zp – rear overhang of the bus lu - total length of the bus

m - suspended mass of the loaded bus 15400 [kg] mt1 - mass of the front axle

746 [kg]

3.392

mt2 - mass of the rear axle

1355 [kg]

11.862

Jy - inertia moment of the suspended mass related to transversal axis

rs - distance from the driver’s seat to the front axle

1.30

d - distance from the driver’s seat to bus CG

4.85

p1 - distance from the passenger 1 seat to bus CG

0.5

p2 - distance from the passenger 2 seat to bus CG

4.2

150000 [kgm2]

The meanings of labels in Figure 2. are given in tables (1-3). Tables also show all values of parameters used in simulation, taken from available sources [09].

Table 3. Oscillatory parameters of the bus

Oscillatory parameter

Value

Oscillatory parameter

Value

cs - driver’s seat spring stiffness

25000 [N/m]

816350 [N/m]

bs - driver’s seat damping

1000 [Ns/m]

cZ - equivalent stiffness of rear axle pneumatic suspension elements

cp1, cp2 - passengers’ seat spring stiffness

40000 [N/m]

b2 - damping of one rear axle hock absorber

22500 [Ns/m]

220 [Ns/m]

bz - equivalent damping of rear axle shock absorbers

91839 [Ns/m]

c1 - one front axle pneumatic suspension element stiffness

175000 [N/m]

cpn - front and rear tire stiffness (pertire)

1000000 [N/m]

cp - equivalent stiffness of front axle pneumatic suspension elements

350000 [N/m]

cpp - equivalent front axle tires stiffness

2000000 [N/m]

b1 - one front axle shock absorber damping

15000 [Ns/m]

czz - equivalent rear axle tires stiffness

4000000 [N/m]

bp - front axle shock absorbers equivalent damping

60000 [Ns/m]

bpn - front and rear tire damping (pertire)

150 [Ns/m]

bpp - equivalent front axle tires damp ing

300 [Ns/m]

bzz - equivalent rear axle tires damping

600 [Ns/m]

bp1, bp2 - passengers’ seat damping

c2 - one rear axle pneumatic suspension element stiffness

20000 [N/m]

Journal of Applied Engineering Science 9(2011)3, 205

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Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

The equivalent stiffness of air springs and equivalent damping of dampers on rear axle are calculated by using expressions 1 and 2 from [15]. Figure 3. shows the eigenvalues for oscillatory

parameters and mass parameters of the bus. All real parts of eigenvalues are negative, so the equilibrium position of the oscillatory system is stable.

Figure 3. Eigenvalues for the deﬁned oscillatory model Table 4. Modes of oscillation of the oscillatory system Mode number

Undamped natural frequency

Damping ratio

1.134706E+000

0.457225E+000

-5.188163E-001 +/- 1.009152E+000

1.345294E+000

0.428959E+000

-5.770759E-001 +/- 1.215237E+000

2.561561E+000

0.328449E+000

-8.413420E-001 +/- 2.419451E+000

3.363872E+000

0.058918E+000

-1.981937E-001 +/- 3.358028E+000

3.392065E+000

0.061392E+000

-2.082473E-001 +/- 3.385667E+000

7.951542E+000

0.819930E+000

-6.519709E+000 +/-4.551968E+000

8.886907E+000

0.629679E+000

-5.595898E+000 +/-6.903842E+000

A pair of imaginary numbers corresponds to each real part of eigenvalues. It follows that the motion of the system around the equilibrium position has an oscillatory character. Table 4. presents the oscillatory modes of the oscillatory system. Natural oscillation frequencies of the system correspond to typical frequencies of the bus oscillation [04]. BUS EXCITATION The paper analyses the oscillatory comfort of the bus users which is the consequence of the reactions of the vehicle model to excitation by two signals recorded on actual pavements - asphaltconcrete in bad condition and asphalt-concrete in good condition (Figures 4(a) and 4(b)). Road

404

Real

Imaginary

roughness is taken from [06], and it is recorded by means of measurement vehicle K. J. Law Engineers on the road sections of the length of 161 m, with vehicle speeds of 72 km/h and 80 km/h. Longitudinal road roughness is random function that contains different wave lengths and different roughness amplitudes. Not all roughness wave lengths have the same level of outcome to the oscillatory behavior of the vehicle. For example, the roughnesses with very short wave length (up to 1 m) produce major effect to the interior noise in the vehicle. On the opposite, the roughnesses with long wave length indicate the longitudinal road proﬁle character and have no signiﬁcant effect to oscillatory motion of the vehicle. For the analysis of the vehicle oscillatory behavior, the range of excitation frequencies between 1 Hz and 30 Hz is the most important [16]. The conJournal of Applied Engineering Science 9(2011)3, 205

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

nection between roughness wave length, vehicle velocity and road frequency is represented by expression:

where: - is road roughness wave length (m); V - is vehicle velocity (m/s) and f - is road roughness frequency (Hz).

Figure 4. Road roughness recorded on (a) asphalt-concrete in bad condition (b) asphalt-concrete in good condition

The ranges of roughness wave lengths from 20.00 m to 0.67 m and 22.22 to 0.74 m correspond to the frequency range for vehicle velocities of 72 km/h and 80 km/h, respectively. That’s why the recorded signals were filtered using Moving average filter in the software pack ProVal 2.73 [05]. The Figures 5(a) and 5(b) show filtered and averaged signals of road roughness on the left and right wheel as function of time. ANALYSIS OF THE RESULTS

I3 is used for numerical integration. GSTIFF integrator uses backwards differentiation formula and Newton-Raphson algorithm for numerical integration of differential equations [10]. The time sequence of 7 s is chosen. The acceleration signals of vehicle users are sampled at each 0,001 s. Simulation is carried out in a way that the oscillatory model is ﬁrst brought in the equilibrium, using the command “Find static equilibrium“, and only after that the dynamic simulation is completed.

Gear Stiff (GSTIFF) integrator with formulation

Vertical accelerations of bus users for two types

Figure 5. Filtered and averaged road roughness of (a) asphalt-concrete in bad condition (b) asphalt-concrete in good condition Journal of Applied Engineering Science 9(2011)3,205

405

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

Figure 6. Vertical acceleration of the bus user body for the excitation from asphalt-concrete in bad condition and bus speed 72 km/h Table 5. Statistical parameters for vertical user’s body acceleration, for the excitation from asphalt-concrete in bad condition and bus speed 72 km/h User’s body acceleration 2

Driver [m/s ]

Maximum value

Minimum value

Mean value

RMS value

1.9195

-1.9247

-0.0163

0.746

1.8221

-1.7446

0.0004

0.7137

2.7324

-3.0992

0.0112

1.0681

Passenger 1 [m/s ] Passenger 2 [m/s ]

Figure 7. Bus user vertical acceleration for the excitation from asphalt-concrete in good condition and bus speed 80 km/h Table 6. Statistical parameters for vertical user’s body acceleration, for the excitation from asphalt-concrete in good condition and bus speed 80 km/h User’s body acceleration 2

Driver [m/s ]

Minimum value

Mean value

RMS value

0.7041

-0.8065

-0.0006

0.2665

1.1207

-1.0524

0.0001

0.4097

1.6516

-1.374

0.0015

0.5448

Passenger 1 [m/s ] Passenger 2 [m/s ]

406

Maximum value

Journal of Applied Engineering Science 9(2011)3, 205

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

of excitation are shown in ﬁgures 6. and 7. In the tables 5 and 6 the important statistical parameters of the users’ accelerations are given, by means of “plot-tracking” command in ADAMS/ PostProcessor. Vertical accelerations of users have greater values when the bus is excited from asphalt-concrete in bad condition than when excited from asphalt-concrete in good condition. The maximum value of vertical acceleration, for both excitations, abides the passenger in the rear of the bus (passenger 2). The peak value of the acceleration of the passenger 2 on the worse pavement is about -3.0 m/s2, and on the better one is 1.65 m/s2. Peak values of the acceleration for driver and passenger in the middle of the bus (passenger1) on the worse pavement are almost the same (table 5). On the good pavement the peak vertical accelerations of driver and passenger 1 are about -0.8 m/s2 and 1.12 m/s2 respectively. The evaluation of the effect of vibrations to the bus user comfort is made through procedures prescribed by the International Standard ISO 2613-1 (1997) [11]. This standard prescribes the total root mean square value of weighted acceleration as the basic value for the evaluation of effect of vibrations to the comfort, expression 1.

where: - is total root mean square value of weighted acceleration on the seats of bus users [m/s2]; - are root mean square values of weighted acceleration for x, y, z axis [m/s2]; - are multiplying factors for acceleration RMS for x, y, z axis; Values of multiplying factors kx, ky, kz for acceleration RMS, for the assessment of the vibrations effect to the comfort, are equal to 1. This comfort analysis is carried out regarding the calculated root mean square value of weighted vertical accelerations on the driver’s and passengers’ seats, expression 2.

where: - is root mean square value of weighted vertical acceleration on the users’ seats [m/s2]; - is the i-th sample of weighted vertical acceleration on the users’ seats [m/s2]; N - is the number of samples of the signal of weighted vertical acceleration on the users’ seats;

Figure 8. Filters for weighting the acceleration on users’ seats

Number of samples of the signals of vertical acceleration N is equal to 7001. A specific program is made in software pack Matlab® for the weighting of vertical acceleration of bus users. Within this program, according to Standard ISO 2631-1, the filter Wk is defined to weight vertical acceleration of users on their seats (Fig. 8). Journal of Applied Engineering Science 9(2011)3, 205

Figure 8. shows also the filter Wd for weighting horizontal accelerations on the users’ seats (accelerations for x- and y- axis). Filters Wk and Wd are used for evaluation of effect of vibrations to comfort, work ability and health of users [11]. The same figure shows also filter Wf for weighting vertical accelerations on seats for low frequencies excitation, i.e. for evaluation of the

407

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

effect of vibrations to appearance of motion sickness with users. The weighting ﬁlters describe the sensitivity of human body to vibrations of different frequencies. For example, human body is the most sensitive to vertical accelerations in frequency range of 4 to 8 Hz, and out of this range the sensitivity decrease, both with frequencies lower than 4 Hz and higher than 8 Hz. That is

why the modulus of the transfer function of the ﬁlter Wk for frequencies 4 to 8 Hz is equal to 1, i.e. 0 dB. The comfort evaluation is made by comparing of the root mean square values of weighted vertical acceleration of bus users obtained by simulation (table 7), with limit comfort criteria for means of public transport (table 8), according the Standard ISO 2631-1 (1997).

Figure 9. Vertical acceleration and weighted vertical acceleration on bus driver’s seat for the excitation from asphalt-concrete in bad condition and bus speed of 72 km/h Table 7. Root mean square values of weighted vertical acceleration of bus users Type and state of pavement

Bus speed [km/h]

Asphalt-concrete (bad) Asphalt-concrete (good)

Root mean square values of weighted vertical acceleration [m/s2] driver

passenger 1

passenger 2

0.4099

0.5737

0.7190

0.1732

0.3453

0.4337

Table 8. Comfort criteria for the means of public transport Vibration intensity

Comfort experience

< 0.315 [m/s2]

not uncomfortable

0.315 - 0.63 [m/s2]

a little uncomfortable

0.5 - 1.0 [m/s2]

fairly uncomfortable

0.8 - 1.6 [m/s2]

uncomfortable

1.25 - 2.5 [m/s2]

very uncomfortable

> 2.0 [m/s2]

extremely uncomfortable

As an example, ﬁgure 9. shows the vertical acceleration and weighted vertical acceleration on driver’s seat, for asphalt-concrete in bad condition excitation and vehicle speed of 72 km/h. For the excitation from asphalt-concrete in bad condition, root mean square value of weighted

408

acceleration of driver and passenger1 is greater than 0.315 m/s2, so that vibrations, after the evaluation criteria, have the effect on their comfort designated as “a little uncomfortable”. Root mean square value of weighted acceleration of passenger2 is 0.719 m/s2, and the comfort desigJournal of Applied Engineering Science 9(2011)3, 205

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

nation is “fairly uncomfortable”. For the excitation from asphalt-concrete in good condition, root mean square value of weighted acceleration of driver is 0.1732 m/s2. After the standard, the vibrations do not have effect to his comfort. For the same excitation, the vibrations inﬂuence the comfort of both passengers, after the criterion of ISO 2631, are designated with notion “a little uncomfortable”. Root mean square values of weighted vertical

acceleration of users, from table 7., are represented also graphically, in Figure 10. The graph shows that, for both excitements, the passenger 2 exposed to higher RMS values of weighted acceleration compared with the driver and passenger1. In opposite to the passenger 2, the lowest RMS value of weighted acceleration, and accordingly the highest comfort, is on the driver’s seat. The effective values of weighted vertical acceler-

Figure 10. Root mean square values of weighted vertical acceleration of users for the excitement from (a) asphalt-concrete in bad condition and (b) asphalt-concrete in good condition

ation of the driver, obtained by simulation for the excitation from asphalt-concrete in good condition, are comparable with effective acceleration values measured in earlier researches [09]. CONCLUSION The bus driver and passengers are exposed to negative effect of vibrations excited from road roughness and ﬁltered through the bus to their bodies. The research presented shows that bus drivers are exposed to vibrations that intensities may exceed the allowed values prescribed. Understanding of the intensity of vibrations that bus drivers and passengers are exposed is important for proper acting to reduce negative effect of vibrations to their comfort, and which is even more important, to their health. The paper analyzed the effect of vibrations to the comfort of intercity bus IK-302 users, applying an oscillatory model with seven DOF and two actual excitations: asphalt-concrete in bad condiJournal of Applied Engineering Science 9(2011)3, 205

tion and asphalt-concrete in good condition. The velocities of test vehicle during recording were almost the same. Actual excitement on asphaltconcrete in bad condition was recorded at 72 km/h, and on asphalt-concrete in good condition at 80 km/h. The analysis shows that the vibration effect to the users comfort for a certain velocity and pavement depends on pavement state. The users comfort decrease on pavements with low quality. Vibrations affect mostly the comfort of passengers in rear end of the bus, and at least the bus driver comfort. The results of simulation show that the passenger on the rear overhang of the bus abides highest values of vertical acceleration on asphalt-concrete in bad condition pavement. Root mean square value of weighted vertical acceleration of this passenger is 0.719 m/s2. For the excitement from asphalt-concrete in good condition, root mean square value of weighted vertical acceleration is more favorable and

409

Dragan Sekuliü and etc. - Intercity bus users vibration comfort analysis through an oscillatory model with seven DOF using ADAMS/VIEW software

amounts 0.4337 m/s2. For the same excitement, root mean square value of weighted vertical acceleration of the driver, calculated by simulation, is 0.1732 m/s2, which means that the vibrations due to this pavement do not affect the driver’s comfort.

10) Negrut, D., Dyer, A., ADAMS/Solver Primer, Ann Arbor, (2004).

REFERENCES

12) Okunribido, O. O., Shimbles, S.J., Magnusson, M., Pope, M., City bus driving and low back pain: A study of the exposures to posture demands, manual materials handling and whole-body vibration, Applied Ergonomics, 38 (1), 29-38, (2007).

11) Nelson, C., Brereton, P., The European Vibration Directive, Industrial Health, 43 (3), 472-479, (2005).

1) Alperovitch-Najenson, D., Low Back Pain among Professional Bus drivers: ergonomic and Occupational-Psychosocial risk Factors, Israel Medical Association Journal, 12 (1), 2631 (2010). 13) Picu, A., Whole body vibration analysis for bus drivers, SISOM 2009 and Session of 2) Dedoviü, V., Mladenoviü, D., Dinamika vozila the Commission of Acoustics, Bucharest. - praktikum, Beograd: Saobraüajni fakultet u (2009). Beogradu (1999).

3) Demiü, M. ,A contribution to design of semiac- 14) Sekuliü, D., Dedoviü, V., Simulation of the oscillatory behavior of buses equipped with a tive vehicle suspension system, Journal of Apclassic and active suspension system, Jourplied Engineering Science, 3 (9), 7-16. (2005). nal of Applied Engineering Science, 6 (20), 4) Demiü, M., Diligenski, Ĉ., Projektovanje auto23-32, (2008). busa, Kragujevac: Mašinski fakultet Univerz15) Sekuliü, D., Dedoviü, V., Analiza oscilatoriteta u Kragujevcu (2003). nog komfora vozaþa autobusa simulacijom 5) http://www.roadprofile.com/data/proval/ pomoüu modela sa šest stepeni slobode, download/ ProVAL-2.73.0032.zip XXIII Meÿunarodni nauþno-struþni skup: Nauka i motorna vozila, Specijalna konfer6) http://www.sintraonline.net/rr_win95.zip encija za Zapadni Balkan, Beograd, (2011). 7) ISO 2631, Mechanical vibration and shockEvaluation of human exposure to whole-body 16) Simiü, D., Dinamika motornih vozila - oscilacije i vešanje automobila, Kragujevac: vibration, 2nd edition, (1997). Mašinski fakultet u Kragujevcu, (1975) 8) Kompier, M.A.J., Bus drivers: Occupational stress and stress prevention, Leiden: Depart- 17) Whitelegg, J., Health of professional drivers, A Report for Transport & General Workers, ment of Work and Organizational Psychology, Lancaster: Union, Eco-Logica Ltd.,(1995). University of Nijmegen, (1996). 9) Mladenoviü, D., Istraživanje uticaja konstrukcionih parametara na oscilatorno ponašanje autobusa, Magistarski rad, Beograd: Saobraüajni fakultet u Beogradu (1997).

410

Paper sent to revision: 01.07.2011. Paper ready for publication: 07.09.2011

Journal of Applied Engineering Science 9(2011)3, 205

MSc Nenad Paviü and etc. - Drivers age as the dominant demographic factor in trafﬁc accident

Paper number: 9(2011)3, 206, 411 - 416

DRIVERS AGE AS THE DOMINANT DEMOGRAPHIC FACTOR IN TRAFFIC ACCIDENT MSc Nenad Paviü * Delta Generali Insurance, Belgrade, Serbia Dr Vladimir Popoviü University of Belgrade, Faculty of mechanical engineering, Belgrade, Serbia Miloš Vasiü Institute for research and design in commerce & industry, Belgrade, Serbia Elements that makes the traffic system, environment, vehicles and human, also represents integral part of any resulting accident. In addition to numerous improvements of vehicles, expansions and improvement of road infrastructure, the number of accidents have been increasing. The main culprit, human, who, with the participation of 57% (when combined with other factors accounts for more than 90%) of accidents, is the weakest link in the chain. This work covered and explains numerous human factors at which we can affect. The new Law on Traffic safety was taken in consideration. Analysis of accidents in function of the drivers age was conducted. The goal of measures, which have been proposed for suppression and prevention, is declining and reducing negative trends. Key words: traffic accidents, drivers age, human factors INTRODUCTION Increasing number of vehicles on the roads, improving performance and higher average speed have affected that the last decades great importance been given to improved the system of active, passive and catalytic motor vehicle safety. Despite considerable technical progress, it seems that the number of accidents continues to rise. Reports of the World Health Organization show that at 2002. the number of casualties in the middle-income countries was 550.000 while in 2008. this number amounted 940.000 [09]. Traffic accidents occurring as a factor of road, vehicles and humans (Figure 1. [19]).

Figure 1. Trafﬁc factors

Several conducted studies have shown that 57 % of all crash cases were due soley to human factor, while in combination with others percentage greater than 90 [02]. HUMAN FACTORS Distraction One of the prerequisites for safe driving is attention. When mental resources are not sufﬁcient to meet all the imposed tasks, the driver will see only a limited set of information which he will use for decision making and response to the demanding task. Other information will go unnoticed and be deleted from memory [03]. The causes of obstruction may be varied ; this time we shall focus our attention on two most important: talking with a passengers and cell phone. Simultaneous vehicle steering and conversation with the passenger leads to processing additional informations, which inevitably brings to reduction of concentration, particularly among young and inexperienced drivers. Four studies have shown that risk of an accident increases with the number of teens passengers ride with young driver only one almost doubles the risk of accidents, while two or more increase

* Delta Generali Insurance, Milentija Popoviüa 7b, New Belgrade, Serbia, e-mail: nenad_pavic@live.com

411

MSc Nenad Paviü and etc. - Drivers age as the dominant demographic factor in trafﬁc accident

the risk to ﬁve times than driving alone [20]. Form of auditory input, cell phone conversation while driving, greatly contributes to increased risk of accidents. Conducted research have found that older adults (65 to 74) increased time of breaking, following distance and time necessary to reach the previous velocity. On the other hand, young people (18 to 25 years) degraded reaction time to the same level as older who drive without use of cell phone [18].

Fatigue As a result of physical and (or) mental effort, which occurs during the driving, depending on the intensity, are manifest through: slow reaction and decision making, slow movement control, reduced tolerance for other road users, hallucinations ... Figure 2. [07]. Men under 30 made up about 50% of all accidents that occurred under the inﬂuence of fatigue [05]. The importance of this factor is perhaps

Figure 2. Dependency risks of accidents from fatigue

best illustrated by the fact that the organism after 17 to 19 hours without sleep is in the same condition as when it comes to blood alcohol level of 0.05g/100ml [21]. The most commonly given responses in the ﬁght against fatigue and continuing driving are grouped in Table 1. [13]. Table 1. Obtained answers in testing the driver’s habits to combat fatigue The obtained answers

Opening a window / turn up air conditioning

Stop and a short walk

Listening to the radio / CD

Talk with a travel companion

Drink Coffee

Other

At Loughborough University in Great Britain found that the only effect, which is effective more than 10 -15 minutes of these obtained answers, gives caffeine intake of at least 150 mg or ﬁfteen minutes of sleep [06]. Reaction Time In the narrow sense, corresponds to time of a mental process and represented time required to register and select the type of response [02].

412

As this is a complex process, for better understanding we can separated it on four main factors [15]: 1. Detection It begins when driver see object ahead. He can, due to fatigue, deconcentration, poor visibility ... be in sight even before. 2. Identiﬁcation Data collection (the object is stationary or moving, estimating the speed ...) and their selection by priorities. 3. Decision After information collected, it is necessary to decide, whether and how to react. 4. Reply Moment beginning of decision implementation, ie. contact with the command brakes or turning the steering wheel, which represents the end of the reaction time. The perception of an objects has a direct inﬂuence. It has been found that TTC (time to contact), which can be measured experimentally to study the degree of perception, at elderly adults overestimated, in case of smaller and underestimated in case of higher speed [04,01]. ReacJournal of Applied Engineering Science 9(2011)3, 206

MSc Nenad Paviü and etc. - Drivers age as the dominant demographic factor in trafﬁc accident

tion times in the function of drivers age shown in Figure 3 [15]. Factors that may additionally prolong reaction time are fatigue, stress, tension, alcohol consumption and (or) other opiates ... when the risks of accidents exponentially increases.

Visibility With age, the quality of vision decreases. Amount of light, which photoreceptors of eye for people over 60 years can register, are two thirds less than for those in their twenties. As a result of adaptation to new situation and the need to maintain the level of visibility, contrast sensitivity decreases.

Figure 3. Reaction times in the function of drivers age

At night, when eyes have adjusted to dark, headlights of incoming vehicles, due to sudden changes in light intensity, cause glare. Weakened accommodation at older population, as well as mentioned inﬂuence (decreasing the registered amount of light and increased contrast), led to scattering of light and short blindness.

Also, the width of the visual ﬁeld is reduced which has a direct impact on visibility. Comes to increase the necessary amount of time and heavier spotting a pedestrian on other side of the road, parking, inclusion of vehicles from adjacent streets... [08]. Factors and their impacts are shown in Table 2 [16].

Table 2. Visual factors and potential risks Visual factor

Definition

Related driving tasks

Accommodation

Change in the shape of the lens to bring images into focus

Changing focus from dashboard displays of the roadway

Static visual acuity

Ability to see small details cleary

Reading dashboard displays

Adaptation

Change in sensitivity to different levels of light

Adjust to changes in the light upon entering a tunnel in daylight

Angular movment

Seeing objects moving across the ﬁeld of view

Judging speed of cars crossing our path of travel

Movment in depth

Detecting changes in size of the image on the eye

Judging speed of an approaching vehicle

Color

Discrimination of different colors

Identiﬁcation of colors of signals

Contrast sensivity

Seeing objects thet are similar in brightness to their background

Detection of dark-clothed pedestrians at night

Depth percepcion

Judgment of the distances of objects

Passing on two lane roads with oncoming trafﬁc

Dynamic visual acuity

Ability to see objects that are in motion relative to us

Reading trafﬁc signs while moving

Eye movment

Changing the direction of gaze of the eyes

Scanning the road for hazards

Glare Sensitivity

Ability to resist and recover from the effect of glare

Reduction in visual performance due to headlight glare

Journal of Applied Engineering Science 9(2011)3, 206

413

MSc Nenad Paviü and etc. - Drivers age as the dominant demographic factor in trafﬁc accident

Other factors Alcohol is one of the biggest causes of traffic accidents. Depending on the entered quantities, it affects on vision (reduction acuity and constriction of visual field ), concentration, reasoning ... The same goes for drugs - reaction time decreasing, weakening motor functions, assessment ... Most accidents under these influences is among young people. In contribution to this speaks exploring from 2009. by the U.S. government for road safety, showing that concetration of alcohol and / or drugs while driving by persons from 21 to 25 years is the most common, 24.8%, after which followed gradual decline [14]. Difficulties at detecting some drugs in the body and false images which occur are serious problem. Smoking marijuana cigarette leaves low level of trace after three to four hours, while the effect lasts for the next twelve or more. [16]. MATERIAL AND ANALYSIS From previous studies of human factors which were presented in this paper and their impact on ability to drive, we can conclude that age, to a lesser or greater extent, represents the common denominator. The study group comprised 200 persons - drivers, selected with method of random choice who had in period of six months at Delta Generali insurance reported accidents as a damaged /

harmful side. The group consisted from males and females, aged 18 to 75 years. It was expected that data demonstrate a degree of compliance with other tests where, direct or indirect, demographic features was included in the analysis. The results are shown graphically (Figure 4). The largest share is among people aged 18 to 30 years, after which number of accidents decreases. Young people, although naturally predisposed to be a better drivers-thanks to shorter reaction time, better coordination of movement, psychomotor skills ... because the lack of social responsibility, maturity and experience in trafﬁc, are participants in a larger number of accidents. Excessive security, risky driving style and inability to recognize and react in dangerous situation made pretty dangerous combination. Jump that occurs at people over 65 years of age are caused by numerous consequences that were mentioned in previous discussion with reference to the section that follows. DISCUSSION Exposed research, statistics and facts that been presented in this paper should drawn attention to the seriousness of the issues which in public haven’t got attention to the extent it deserves. The current situation is such, that predictions, Figure 5, has not encouraged. [22].

Figure 4. Participation of trafﬁc accidents in the function of the drivers age

It is necessary to investing more in scientiﬁc research, for the sake of detecting the causes and suggestions for their prevention, and trafﬁc regulations which will adequately, through the implementation of these informations into new or existing legislation, lead to reducing the number

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of trafﬁc accidents. Implement more active trafﬁc education for children and young people through educational institutions, acting through media, with emphasis on those who are most represented among young - television and internet ... Journal of Applied Engineering Science 9(2011)3, 206

MSc Nenad Paviü and etc. - Drivers age as the dominant demographic factor in trafﬁc accident

Training of drivers in driving schools, in addition to acquiring basic skills and knowledge, must provide more. Introduce and show how to react in emergency situations; predicting, spotting mistakes of other road users and adequate responses to them. Conducted Republic research indicated that just over 1% of rear-seat passengers used seat belts [11].

Importance of preventive measures through the demonstration is one of the best ways to individual understand, how rules and laws are not there to kept him limited or hindered. A good example of this can be activitie of the National driving academy and use simulators for frontal impact and rollover.

Figure 5. Projected deaths for selected causes to 2030

What about elderly people (over 65)? Regulations, governing what kind of health condition must be a driver, was written at 1982. Studies speak in favor that it would be desirable to introduce a ban on cell phone use, in a manner anticipated with new Law on traffic safety for novice drivers [23,12]. Also, driving at night, for reasons already explained, significantly increases the risk. The introduction of the test, which would checked the ability of potential collisions during the necessary controls required for driver license extension [01]. CONCLUSION It is necessary to pay more attention and resources to testing and implementation of preventive measures. Also, seen from the point of cost-effectiveness, presented proposals along conducting detailed analysis and working on their application and implementation is significantly more cost-effective than the amount of material costs that result from accidents, with a reminder that life has no price.

Journal of Applied Engineering Science 9(2011)3, 206

REFERENCES 1) DeLucia, R., Bleckley, K., Meyer, E., Bush, M. (2003). Judgments about collision in younger and older drivers. Transportation Research Part F: Trafﬁc Psychology and Behaviour, No 1, Vol 6, pp. 63-80 2) Ĉuriü, P., Filipoviü, D.(2009). Reakciono vreme vozaþa izazivaþa saobraüajnih nesreüa. Medicinski pregled, No 3-4, Vol 62, pp. 114-119. 3) Ĉuriü, P., Mikov M. (2008). Neke osobine vozaca izazivaca saobracajnih nesreca. Medicinski pregled, No 9-10, Vol 61, pp. 464-469. 4) Hancock, A., Manser, P. (1997). Time-to contact: More than tau alone. Ecological Psychology, No 4, Vol 9, pp. 265-297 5) Horne, J., Reyner, L. (1995). Sleep Related Vehicle Accidents, British Medical Journal Vol.310, pp. 565-567. 6) Horne, J., Reyner, L. (2000). Sleep Related Vehicle Accidents, Sleep Research Laboratory, Loughborough University

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7) http://www.commerce.wa.gov.au/WorkSafe/ PDF/Bulletins/, retrieved on July 18th, 2011 8) http://www.visualexpert.com/why.html, retrieved on July 20th, 2011 9) http://www.who.int/healthinfo/en/, retrieved on July 29th, 2011 10) Kaplanoviü, S., Petroviü, J., Ivkoviü I. (2009). Economic instruments in function of sustainable development of road transportation. Istraživanja i projektovanja za privredu, No 25, Vol 7, pp. 17-22. 11) Lipovac K, Buliü Ĉ, Vemiü D. (2002). Upotreba sigurnosnih pojaseva u Republici Srbiji. Prevencija saobraüajnih nezgoda na putevima. VI simpozijum sa meÿunarodnim uþešüem, Zbornik radova Novi Sad, pp. 287-92. 12) Mather, R. (2007). Age and Driving Behavior: Contributions from Human Factors. Journal of Scientific Psychology, pp. 24-31. 13) Maycock, G. (1995). Driver Sleepiness as a Factor in Car and HGV Accidents, Transport Research Laboratory, TRL Report 169. 14) National Highway Traffic Safety Administration. (2010). Drug Involvement of Fatally Injured Drivers. U.S. Department of Transportation Report No. DOT HS 811 415. 15) Olson, P., Dewar, R. (2002) Driver Perception-Response Time, Human factors in traffic safety, Tucson: Lawyers & Judges Publishing Company, pp. 43-77. 16) Olson, P., Dewar, R. (2002) Human factors in traffic safety, Tucson: Lawyers & Judges Publishing Company

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17) Paviü, N., Popoviü, V., Vasiü, M. (2011). Održavanje sistema osiguranja motornih vozila pod uticajem prevara. XXXVI Nauþno struþni skup održavanje mašina i opreme, Zbornik radova Beograd, pp. 109-114. 18) Strayer, L., Drews, A. (2003). Effects of cell phone conversations on younger and older drivers. Proceedings of the Human Factors and Ergonomics Society 47th Annual Meeting, pp.1860-1864. 19) Todoroviü, J., Vujoviü, R., Šotra, D., Cakiü, I. (2001). Preventiva i štetni dogaÿaji kao bitan actor osiguranja motornih vozila u drumskom saobraüaju. Preventivno Inženjerstvo, No 1, Vol 9, pp. 30. 20) Triplett, W. (2005). Teen Driving. The CQ Researcher, No 1, Vol 15, pp. 8. 21) Williamson, A. (2000). Moderate Sleep Deprivation Produces Impairments in Cognitive and Motor Performance Equivalent to Legally Prescribed Levels of Alcohol Intoxication. Occupational and Environmental Medicine, No 10, Vol 57, pp. 649-655. 22) World health statistics (2007). World Health Organization, pp.12. 23) Yannis, G., Papadimitriou, E., Papantoniou,P., Petrellis, N. (2010). Cell phone use and trafﬁc characteristics. 12th World Conference on Transport Research; Lisbon, Portugal.

Paper sent to revision: 08.06.2011. Paper ready for publication: 13.09.2011.

Journal of Applied Engineering Science 9(2011)3, 206

Paper number: 9(2011)3, 207, 417 - 423

SOME BASES FOR DEFINING CORRELATIONS BETWEEN CHANGES IN A SEA PORT ORGANIZATON AND CHANGES OF PRODUCTIVITY Dr Deda Ĉeloviü * The Port of Bar, Bar, Montenegro Mr Dijana Medenica Mitroviü Faculty of Bussines Studies, Bar, Montenegro Process of selecting port organizational model is characterized by high level of complexity and has to be based on previously clearly defined objectives to be achieved. Some from the group of main objectives are: improvement of productivity, rationalization of port structure, etc. After general considerations referred on port transformation process and principal theoretical approaches to this thematic, paper is focused on analyzing some important bases for defining correlations between made organizational changes in a sea port and changes of productivity in the cargo handling process. Key words: sea port, organizational changes, productivity. INTRODUCTION Contemporary organizations are placed in a very complex, unstable and dynamic environment. One of the basic tasks they are encountering is a constant adapting to changes as to provide for compatibility with the environment. Organizational change implies only the change of such variables which make the content of an organization as a process [10,12]. According to some authors an organizational change implies any change in the organization leading to a higher level of efficiency and effectiveness in functioning, including standards and methods of their measurement [06]. The following may be identified as the content of organisational changes [06,05,01]: changes in organizational structure (including implementation of the different organisational models and appropriate decision support systems), changes in management structure, changes in business processes, activities and tasks, changes in organizational systems, changes in technology, changes in organizational culture and changes in people. Different authors define the organizational transformation in various ways. So, according to Collins and Porras organizational transformation implies “a group of theories, values, strategies and techniques of science of behavior, focused on the planned change of the organizational vi-

sion and regulation of work, with the intention of generating alpha, beta, gamma A and gamma B changes in the awareness of the members of the organization, for the purpose of promoting paradigmatic changes which assist the organization to adapt to the existent or create a desirable future environment” [07,08]. The main feature of this definition is the one that insists on behaviorist content of the organizational transformation. According to the definition given by Gouillart and Kelly [11], organizational transformation views the organization as a living organism, which due to serious deficiencies in itself, must initiate a complete “medical” treatment, and transformation should be initiated as a radical and complete “therapy” which consists of: redirecting – change in the perception of what the organization is and what it may be; restructuring – changes in organizational structure; revitalization – achievement of growth through improvement of relations with the environment; renewal – change of the spirit of the organization, i.e. affecting the human factor in the organization through application of the model for development of personality and relations within the organization. The process of organizational transformation is very complex and like in the case of other concepts of organizational changes, there is no universal model for its implementation.

* Port of Bar, Obala 13. jula b.b., 85 000 Bar, Montenegro, e-mail: deda.djelovic@lukabar.me

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Dr Deda Ĉeloviü and etc. - Some bases for deﬁning correlations between changes in a seaport organization and changes of productivity

ELEMENTS DETERMINING NECESSITY FOR ORGANIZATIONAL CHANGES IN THE SEAPORTS

(tons)

In the circumstances characterized by intensifying of exchange of goods, rapid development of science, technique and technology, problems to be resolved also change as well as the elements of the environment to which the port needs to adapt. Therefore, it is frequently necessary to also modify organizational structure of the port through improvement of the existent or introduction of a completely new one. Organizational model should fully respect the fact that traditional role of ports has signiﬁcantly evolved and that ports are no longer selected only for their natural hinterland but for being the best centers for adding value to goods and nodes in overall transport chain of goods [09]. The process of selection of a port organizational

3500

model is, as well, complex and there is no perfect methodology for its implementation. The process of improvement of the existent or introduction of a new organizational model, or process of selecting of the port organizational model, should be based on previously clearly defined goals to be achieved. Some from the group of main goals are: improvement of productivity, rationalization of port structure, orientation towards the processes for the purpose of creating the base for competitive positioning in the free market, attracting private capital, etc. After defining the goals, options and alternatives should be developed and assessed. Particularly, it is necessary to analyze results arising from selecting any specific option. A useful instrument for planning the process of selecting the port organization model (selecting the optimal options) is the decision tree.

B efore port res truc turing - 1993

3000

2500

After port res truc turing - 1996

2500

1700

2000 1500 1000

800

500

750

500 0 P roduc tivity (tons per em ploy ee per y ear) in A rgentina

Tons per ves s el per day Tons per ves s el per day for D ry B ulk c argoes in for general c argoes in C olom bia C olom bia Indic ator of produc tivity

Figure 1. - Indicators od productivity before and after port organization transformation [15]

CHARACTER OF TRANSFORMATION EFFECTS ON THE PRODUCTIVITY LEVEL In order to illustrate general effects of adequately modeled and realized process of port reform (organizational transformation, ...) on productivity in the cargo handling process, with Figure 1 are presented some data referred on ports in Columbia and Argentina before and after the restructuring process [15]. The level of productivity is quantiﬁed through the application of various indicators: for ports in Argentina – tons per employee per annum; for ports in Columbia – tons per vessel per day for dry bulk cargoes and tons per vessel per day for general cargoes.

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In accordance with the results of the relevant researches, it may be stated that one of the principal objectives of the organizational changes (and restructuring in general) is increasing productivity in the cargo handling process (through fulﬁlling the organizational prerequisites, fulﬁlling preconditions for optimization of the investment intensity in the domain of the cargo handling technologies etc.). Correlation between the productivity in the cargo handling process and the ship service time Productivity improving process is realized through following basic phases: identifying bases for proJournal of Applied Engineering Science 9(2011)3, 207

Dr Deda Ĉeloviü and etc. - Some bases for deﬁning correlations between changes in a seaport organization and changes of productivity

ductivity improving, identifying elements of cargo handling technology where improvements are possible, detailed analysis of identified improving possibilities, realization of improvements. Some of the very important bases of productivity improving process are: cost analyses for previous periods, analyses of technological problems appeared during the cargo handling process, analyses of available resources (workers, port machinery, lifting accessories …), etc. Possible domains of productivity improving are: domain of workers (additional training, specializations...), domain of port machinery (introducing new port machinery with higher efficiency degree, reconstruction and modernization of existing port machinery …), domain of lifting accessories (introducing new lifting accessories with better performances …), domain of infrastructure objects, domain of internal transport flows, etc. Increasing productivity has positive impact to very wide range of parameters that characterize realization of the cargo handling process in a port. There is a direct correlation between increased productivity and reduction of ship service time in a port (components of ship service time related to handling operations). Some results of related researches authors presented in the paper [02], [03].

Influential factors on ship loading/unloading time Influential factors on ship loading/unloading time are numerous and of very different nature and influence intensity. Starting from basic structure of ship loading/unloading process model, implementing cause-effect (Ishikava) method, key groups of mentioned influential factors are identified (Figure 2) [04]. Key groups of influential factors on ship loading/ unloading time are [04]: • • •

• • • •

factors referred on management of ship loading/unloading process, F1; factors which are determined by ship (which is loaded/unloaded) characteristics, F2; factors which are determined by cargo (which is the object of manipulation) characteristics, F3; factors referred on manipulation type and its implemented variant, F4; factors referred on workers engaged during the loading/unloading process, F5; factors referred on used port machinery, F6; factors referred on used lifting accessories, F7; etc.

Figure 2. Cause – effect diagram

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Dr Deda Ĉeloviü and etc. - Some bases for deﬁning correlations between changes in a seaport organization and changes of productivity

Factors referred on port machinery, F6 All identified groups of influential parameters have complex structure and are consisted of several elements. Group of influential parameters referred on port machinery, F6, involve following elements: • port machinery coefficient of effective utilization during the loading/unloading process, F61; • duration of loading/unloading process interruptions caused by used port machinery failure, F62; • degree of used port machinery technological adequacy, F63; • number of port machinery working cycles achieved during the loading/unloading process, F64; • coefficient of port machinery capacity utilization, F65; etc. In order to define “mechanism” of influence of these parameters on ship loading/unloading time, a research of influence of port machinery technological adequacy on ship loading/unloading time is done in the next paper segment.

Influence of port machinery technological adequacy degree on ship loading/unloading time Port machinery technological adequacy degree (A) can be defined as a degree of coordination between its exploitation performances and technological requirements generated in the process of cargo handling – ship loading/unloading (where port machinery in question is engaged). Starting from hypothesis that there is a correlation between used port machinery technological adequacy degree and values of ship loading/unloading time, an analysis (investigation), whose results are presented here, is done. Definitions Technologically adequate port machinery, Ta: Port machinery with performances which are totally in accordance with technological requirements appeared in the process of its exploitation. Technologically inadequate port machinery, Tal: Port machinery (with smaller capacity than Ta) which can replace port machinery Ta in the cargo handling process;

Table 1. - Input data of investigation Cargo No type

Manipulation with cargo

Ta (used in the warehouse)

Tal (used in the warehouse)

Tah (used in the warehouse)

Bags (50 kg)

Ship to warehouse

Forklift – capacity 2 t Forklift – capacity 1,5 t Forklift – capacity 3 t

Palette

Ship to warehouse

Forklift – capacity 2 t Forklift – capacity 1,5 t Forklift – capacity 3 t

Big bags

Ship to warehouse

Forklift – capacity 2 t Forklift – capacity 1,5 t Forklift – capacity 3 t

Sawn timber

Ship to warehouse

Forklift – capacity 2 t Forklift – capacity 1,5 t Forklift – capacity 3 t

Technologically inadequate port machinery, Tah: Port machinery (with higher capacity than Ta) which can replace port machinery Ta in the cargo handling process; Input data of investigation Input data of this investigation (which was performed in The Port of Bar, in the period from 2005 to 2009) [14] are systematized in Table 1. Parameters of working process with some characteristic cargo types are taken into consideration.

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Technologically adequate port machinery (forklifts) which can match technological requirements appeared during the process of cargo handling in warehouse, Ta, was replaced with technologically inadequate port machinery Tal or Tah in following cases: • when the number of technologically adequate forklifts, according to deﬁned cargo handling technologies, was not enough to satisfy all customers demands (all forklifts from the group Ta were engaged); • when some of forklifts from the group Ta were in “down time” status;

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Dr Deda Ĉeloviü and etc. - Some bases for deﬁning correlations between changes in a seaport organization and changes of productivity

Results of investigation - Inﬂuence of used port machinery adequacy degree on ship unloading time Graphs of correlations between ship unloading time and used port machinery adequacy degree, based on chosen cargo quantity in a ship, values of productivity per hour and assumption that during the complete unloading process only a gang

per ship is engaged, are deﬁned here. Systematization of previously mentioned elements is done by Table 2., where and some important relations between characteristic parameters are given also. Symbols in Table 2 have following meanings: i = 1, 2, 3, 4 – number of cargo types analyzed; j = 1, 2, 3 – number of port machinery categories (j = 1: Ta; j = 2: Tal; j = 3: Tah);

Table 2. - Systematization of investigation elements N0

Cargo type Bags (50 kg)

Palette

Big bags

Sawn timber

Manipulation with cargo

Cargo quantity, Q (t)

Ship to warehouse

Productivity , Pij (t/h)

Ship loading/unloading time, Utij (h)

P11

Ut11

Ta1

P12= P11

Ta1

Ut12 = Ut11

Tah

P13 = P11

Tah

Ut13 = Ut11

P21

Ut21

Ta1

P22 < P21

Ta1

Ut22 > Ut21

Tah

P23 = P21

Tah

Ut23 = Ut21

P31

Ut31

Ta1

P32 < P31

Ta1

Ut32 > Ut31

Tah

P33 = P31

Tah

Ut33 = Ut31

P41

Ut41

Ta1

P42 < P41

Ta1

Ut42 > Ut41

Tah

P43 = P41

Tah

Ut43 = Ut41

As well, using appropriate mathematical methods [13], concrete mathematical relations which adequately describe correlations between ship unloading time, Ut, and cargo quantity, Q, for analyzed cargo types and manipulation, are deﬁned Palette

70 60

40 30

Ta = Tal = Tah

20 10

unloading time, Tu (h)

Graphic Utij = f (Qi)

Bags (50 kg)

unloading time, Tu (h)

Cargo

Tal Ta = Tah

50 40 30 20 10

Correlation Utij = f (Qi)

ca rg o q ua ntity ( x 1 0 0 0 ) (t)

When port machinery Ta or Tal or Tah is used:Ut = 0.008Q

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0 1

cargo quantity ( x 1000) (t)

When port machinery Ta or Tah is used: Ut = 0.0076Q + 0.016 When port machinery Tal is used: Ut = 0.01Q + 0.05

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Dr Deda Ĉeloviü and etc. - Some bases for deﬁning correlations between changes in a seaport organization and changes of productivity

Cargo

Bags (50 kg)

Palette

60 unloading time, Tu (h)

Graphic Utij = f (Qi)

unloading time, Tu (h)

35 30 25 20 15 10

T al

T a = T ah

50 40 30 Tal 20

Ta = Tah

5 10

0 1

Correlation Utij = f (Qi)

4 5 6 7 cargo quantity ( x 1000) (t)

0 1

When port machinery Ta or Tah is used: Ut = 0.0044 Q When port machinery Tal is used: Ut = 0.0055 Q

5 6 7 cargo quantity ( x 1000) (t)

When port machinery Ta or Tah is used: Ut = 0.0075Q – 0.02 When port machinery Tal is used: Ut = 0.011Q – 1.5

Results comment

CONCLUSION

Results of analyses of correlations between port machinery technological adequacy degree and ship unloading time conﬁrm that ship unloading time intensively depend on port machinery technological adequacy degree. Here two characteristic things can be pointed out: when port machinery Ta and Tah are used in the unloading process than optimal values of ship unloading time are identiﬁed. Case when port machinery of category Tal is included in the working process is characterized by bigger values of ship unloading time. Here and an “additional” conclusion becomes obvious – although in certain cases instead of forklifts from group Ta were used forklifts from category Tah (with higher capacity) productivity remain at the same level because other technological elements (workers, lifting accessories, …) are not adjusted with this change in implemented cargo handling technology.

By considerations done in this paper, some aspects of the complex thematic referred on the correlations between organizational changes and changes in productivity during the cargo handing process in a sea port were elaborated. It was stated that one of the principal objectives of the port organizational transformation is improvement of productivity what lead to the increased level of the port customer satisfaction level (increased level of port services quality), primarily through optimizing ship service time (its components related to loading/unloading operations). Mechanism through which correlations between organizational changes and level of productivity are concretized are numerous: enabling new investments in port machinery, enabling new investments in lifting accessories, … what is highlighted (partially) when an analysis of complex relations between productivity in the cargo process, ship service time (loading/unloading time) and inﬂuential parameters on ship loading/unloading time was done.

Deﬁned mathematical correlations between characteristic parameters could be used as a base for researching, through an “bottom – up” approach, and correlations between made organizational changes in a port organization and changes in the cargo handling process productivity. Ship service time could be used here as the optimal indicator.

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REFERENCE 1) Coulter, M., (2010) Strategic managment in practice (translation in Serbian), Data status, Belgrade. 2) Delovic, D., Medenica Mitrovic, D., (2010) An Approach to the Selection of Optimal Transformation Strategy in Seaports, Trafﬁc and Transportation, Vol. 22, no. 3, 219 - 228. 3) Delovic, D., (2005) Inﬂuential Factors on Ship Loading/Unloading Time in a Multipurpose Port Terminal, Symposium on Ship Operations, Management and Economics, Proceedings, Athens, (www.sname.org/sections/greece/symposium.htm). 4) Delovic, D., (2004) Level of hourly productivity of a »working gang« in the cargo handling process (in Serbian), Journal of Applied Engineering Science, No. 3, Belgrade. 5) Dess, et al., (2007) Strategic Management, III edition (translation in Serbian), Data status, Belgrade. 6) Jasko,O., (2000) Design and managment of the organizational changes, Ph. D. thesis (in Serbian), Faculty of the organizational science, Belgrade. 7) Murphy, R., M., (2003) Managing Strategic Change: An Executive Overview, Unite States Army War College, www.carlisle.army.mil/ usawc/dclm/pdf/MurphyMgtText03.pdf.

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8) Murphy, R., M., (2003) Strategic Leadership vs. Strategic Management: Untying The Gordian Knot, United States Army College, www. sba.muohio.edu/abas/2000/RMurphy.pdf. 9) Niekerk, H., (2002) Ports restructuring, policy and regulation: The South African case, IAME Panama 2002, Conference Proceedings, http://www.eclac.cl/Transporte/. 10) Simic, I., (1999) The role of the management in the process of a comapany organizational transformation (in Serbian), Economics Faculty, Nis. 11) Stojkovic D., (2006) Models of the speciﬁc organization restructuring, Ph. D. thesis, Faculty of organizational sciences, Belgrade. 12) Stoner, J. F., et al., (2000) Management, Zelnid, Belgrade. 13) Vukadinovic, S., (1986) Elements of probability theory and mathematical statistics (in Serbian), Privredni pregled, Belgrade. 14) * * *, An Analysis of cargo handling process parameters for period 2005 – 2009, The Port of Bar, 2010. 15) * * *, World Bank Port Reform Toolkit www. worldbank.org/html/fpd/transport/.

Paper sent to revision: 18.07.2011. Paper ready for publication: 22.08.2011.

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EVENTS REVIEW

Scientific conference MAINTENANCE OF MACHINERY AND EQUIPMENT OMO 2011 June 16th, Faculty of Mechanical engineering, Belgrade In cooperation with the Society of Technical System Maintenance DOTS, IIPP Institute continued a thirty-year tradition of scientific conference OMO “Maintenance of machinery and equipment” (Održavanje Mašina i Opreme). The scientific conference is held every year in order to improve the function of maintenance of technical systems in all industry sectors with purpose to promote the value of maintenance. XXXVI scientific conference “Maintenance of machinery and equipment OMO 2011, was held on 16 June 2011 at Faculty of Mechanical Engineering. As in previous years and this year was held under the patronage of the Ministry of Education and Science of Republic of Serbia. On behalf of the Institute IIPP moderator of the conference was Nada Stanojeviü.

Invited lectures were held by: Prof. dr. Gradimir Danon, leading expert in the field of maintenance and operation of the tires with 30 years experience (Belgrade faculty of forestry). Professor Danon spoke on the topic: PROACTIVE TYRE MAINTENANCE Miloš Tucakoviü, a leading expert in the field of HR and Director of the Belgrade office of one of the 10 most influential global companies in this area (Stanton Chase) presented the topic: HUMAN RESOURCES - HR management. During the scientific conference, diplomas were presented to the best trainees of internal audits ISO 9000 and Quality school trainings.

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ANNOUNCEMENT OF EVENTS IIPP MAINTENANCE MANAGEMENT SCHOOL Maintenance Management School presents practical experience in combination with adopted theoretical knowledge, thus creating maintenance management experts capable to perform and coordinate the maintenance of complex technical systems. Use unique opportunity to expand knowledge in the field of technical systems maintenance. During fourdays training focus will give to the following topics: • Corporate/Company Environment • Maintenance Objectives and Policies • Work Planning • Maintenance Concepts • Team Working and Communications • Maintenance Terminology • Information Technology • Laws and Regulations • Quality Assurance (Systems) • Condition Monitoring • Environment and Occupational Health and Safety • Fault Finding Techniques • Spare Part Management The school program merges best local knowledge and experience modernized and harmonized with the recommendations of European Federation of National Maintenance Societies. Since Maintenance Management School connected and unified local tradition and experience in the maintenance process with the European norms and requirements, it’s result is thus twofold - to all who signed up gives a chance to gain national certificate ’’Expert for maintenance management” and to those who can and want more, Maintenance management school opens the possibility of obtaining the International certificate “European maintenance manager”. Result: More than 240 national certificates and 16 internationally recognized certificates: European Maintenance Manager. Time and location: 19.11.2011. (first part) – Faculty of Mechanical Engineering, Belgrade 24-26.11.2011. (second part) -Hotel Aleksandar, Vrnjaþka Banja

VII symposium “RESEARCH AND DESING FOR INDUSTRY” 2011 Editorial board of scientific journal Applied Engineering Science in cooperation with Faculty for mechanical engineering in Belgrade, organize VII simposium Research and design for industry, which is traditionally held during the month of December. The areas covered by the symposium are: planning and execution of projects in a wide range of industruial sectors such as transport, energy, construction, telecommunications, maintenance of technical systems, public sector enterprises, financial sector, IT sector etc.. Symposium primarily present the results of initiated or realized projects in the domestic economy, as well as the knowledge, methods and techniques, standards and software tools that have contributed or could contribute to their better implementation. The symposium IIPP, as in previous years, will have plenary sessions, invited lecturers, software demonstrations, magazines and books promotions..... The authors are invited to submitt their papaers to the Organizing Committee no later than 31/11/2011. (web site www.iipp.rs or by filling out the application and sending to the fax number: 011/6300751 011/3302-450 ) The accepted papers, whose authors timely paid registration fee, will be published in the Proceedings before the symposium. Proceedings will be published in the electronic edition and will be distributed to all participants at the Symposium. Details: www.iipp.rs, 011 / 6300750 Journal of Applied Engineering Science 9(2011)3

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ANNOUNCEMENT OF EVENTS IIPP QUALITY MANAGEMENT SCHOOL Considering business conditions of European market, quality has a significant role, not only in providing new markets, but also in maintaining the existing ones. Nowadays, customers do not only expect a quality product, but they require a proof that the company is capable to produce high quality products and provide quality services. Obtaining of this evidence should be the first goal for each company that has high aspirations when it comes to new markets but also standard’s procedure in order to maintain its reputation. Implementation is not complete if employees are not familiar with standards. With the aim to closer inform the employees of the meaning and significance of ISO standards, Institute for research and design in commerce & industry – IIPP organize training “School of Quality”. During the training participants will: • expend their knowledge about implementation of ISO standards, • learn how to maintain and improve quality level of companies • learne how to verify and improve business performance of companies Training will be held during four days in two locations. First lectures will be held at the Faculty of Mechanical Engineering in Belgrade, while the final lecture and the test will take place in attractive location in Serbia - Vrnjaþka Banja. Programme • Fundamentals of quality concepts, definitions, approaches • Standards, review and interpretation • Management Responsibility • System and process approach • Data management, information system • Statistical methods (engineering methods, quality management methods) • RISK, FMEA, FTA • Supply and storage, evaluation of supplier • Maintenance • Evaluation, audit, certification • Examples, practice, Deming management experiment • PAS 99 - Integrated Management Systems Result After implemented training, Qiipp consultant is able to assume responsibility for independent work in the following fields of activity: • Implementation of quality standards • Maintaining a high level of quality • Constant improvement of the quality system • Assessment and audits of own companies and their suppliers Candidates who passe the test will get a diploma “Qiipp consultant for implementation, maintenance, analysis, evaluation and testing, design and improvement of the quality system”. Time and location: 19.11.2011. (first part) – Faculty of Mechanical Engineering, Belgrade 24-26.11.2011. (second part) -Hotel Aleksandar, Vrnjaþka Banja Institute for research and design in commerce & industry Phone: 011/6300750; Fax: 011/6300751; E-mail: office@iipp.rs; web: www.iipp.rs

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BOOK RECOMMENDATION THE SCIENTIFIC METHODS AND TECHNICAL DEVELOPMENT By Miroslav Demiü Monograph “The scientific methods and technical development” is relevant and important, because of its modern approach in presentation of scientific methods for a wide range of scientific fields. Special attention was paid to the social, natural and technical sciences. Bearing in mind that in our country exists unjustifiably rigid division between basic and applied science, where often is implied that basic science deserve a higher status in relation to the applied, equal relations and access to the aforementioned science creates an attempt in balancing “contradictions” between them. The significance of this approach is emphasized by the fact that applied sciences are expected to get our country out of poverty and “clutches of globalization” also. The monograph contains nine chapters and each chapter is devoted to some of the problems accompanying the scientific work. In order to intro duce readers to the theme of the book, the definition of science and its classification are given in the first chapter, while in the second chapter attention is paid to the historical development of science, from the old era to the present, noting the most significant scientific contributions and their creators in different fields of science. The third chapter deals with issues of relationship between science and society, from prehistory to the present, emphasizing the importance and necessity of strengthening the connection of science and society in the interests of more rapid progress of civilization. The fourth chapter in details present the scientific and professional sources of information and their importance in the design and implementation of research and product development. A very wide range of scientific methods, which are used in natural, social, technical and other sciences, is shown in the fifth chapter of the book. Bearing in mind that technical development is also the subject of book, a more importance is given to those scientific methods which are the basis for scientific research in technical sciences and technical product development. The sixth chapter of the book is devoted to human factors in scientific researchers, while special emphasis is given to attributes that should have and develop students. Seventh chapter speaks of the proper selection and directing potential researchers in their education. The eighth chapter is devoted to technical development, one of the pillars that should create a strong and competitive economic resources. It gives a description of both traditional, as well as systemic processes in product development, with special emphasis on methods based on the application of computers during the product development process. It should be noted that the views and clarification of a significant number of practical examples represents a precious material that facilitates involvement in theprocess of technical development. The ninth chapter deals with the problems of writing scientific publications for the purpose of putting achieved results to the scientific insight – to the professional community, in order that they be adequately evaluated. The book has nearly 300 pages and contains almoust 50 well-chosen pictures, diagrams, illustrations and tables. Extensive and well-systematized bibliographical information are given at the end of each chapter. In understandable and acceptable manner book shows the results of researchs in the world and in our country, along with comprehensive and quality comments , so it provides to a wieder readership audience knowledge and guidance necessary for independent implementation of research activities, especially to younger scientists. Prof. dr Branislav Rakiüeviü Publisher: Faculty of mechanical engineering, Kragujevac, Serbia Published: 2011; Format: B5; Pages: 295; ISBN: 978-86-86663-75-7 Journal of Applied Engineering Science 9(2011)3

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BOOK RECOMMENDATION SERBIAN ENERGY - YESTERDAY, TODAY AND TOMORROW By Nenad Ĉajiü Author of the monograph, prof. dr. Nenad Ĉajiü belongs to the narrowest circle of leading researchers and experts in our country, internationally recognized in the field of energy, sustainable development, spatial planning and design of energy facilities and infrastructure. He has been an official of the World Council for Energy and the Head of the Center for Energy at faculty for Mining and Geology in Belgrade. The monograph consists of seven chapters. Chapter 1 discuss the importance of energy and outlines the basic definitions and concepts used within the monograph. Chapter 2 gives an analysis of previous energy development in the world with consideration of the current situation and its impact on the development of economy and society. Different scenarios for development of the world’s energy in the XXI century were also analysed. In the next chapter, which refers to the energy sources of Serbia, the author analyzes the conventional and renewable sources of energy (potential of coal, oil and natural gas, hydro potential, the potential of oil shale, nuclear raw materials and new renewable energy sources) along with plenty of recent data. Chapter 4 shows the Serbian energy development in three important periods: the period till 1990 and the disintegration of SFR Yugoslavia, then in the period since 1990 till 1995, since 1995 till 2000, i.e., the period of sanctions, economic blockade and bombing of Serbia. In Chapter 5 energetic of Serbia in the period since 2000 till 2009 was examined with a special focus to the sectors of coal, oil, gas, electric power, electric transition, renewable energy, utility and industrial energy. Chapter 6 refers to sustainable energy development of Serbia in the period up to 2021.godine, based on existing Strategy for longterm Energy Development of Serbia and Spatial Development Plan of the Republic of Serbia, energy acts, whose author is also professor Ĉajiü. Last section describes recommendations and measures related to sustainable energy development in Serbia. In my opinion, the monograph represents high quality work, because, in very complex way, considers so far development and current prospects of our country’s energy system. It includes energy, economic and environmental aspects of energy development in Serbia. Within the monograph, also, are presented the problems of sustainable development of mankind, which has been in many works of similar themes left out to a large extent, and therefore it allows a more realistic assessment of development opportunities of new technologies and renewable sources in substitution to conventional energy sources. This monograph represents a valuable research and teaching materials and as such is a significant contribution to the further development of energy in our country. It is written clearly and understandably, with enough information, explanations and illustrations to allow the reader to understand and accept the process of energy development of the world and our country. The monograph is very useful reading material for all interested in energy development, students of mechanical, mining and geological, electrical, technological and other faculties, as well as engineers and professionals working in different energy organizations. Therefore, I strongly recommend it to all interested parties in order to enrich their knowledge in the energy sector in general and in particular Serbia. Based on years of scientific experience and expertise, author analyzed energy development in Serbia in particularly analytical and studious way. It is hard to find more competent author for the monograph on Energy of Serbia. This is confirmed by the fact that from over then 250 cited references, 2/3 belongs to the author himself. In conclusion, with great pleasure I find monograph “SERBIAN ENERGY-YESTERDAY, TODAY AND TOMORROW” by prof. N. Ĉajiü, the most comprehensive reference in the energy sector of Serbia, published to date. Prof. dr Miroljub Adžiü

Publisher: Academy of Engineering Sciences of Serbia Published: 2011; Format: B5; Pages: 238; ISBN: 978-86-87035-03-4

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SADRŽAJ

OD UREĈIVAýKOG ODBORA

Dr Nenad Ĉajiü UVODNIK

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REZIMEI RADOVA Mr Jasna Glišoviü, Dr Miroslav Demiü, Mr Danijela Miloradoviü PRIKAZ PRIMENE VIRTUELNE STVARNOSTI U CILJU SMANJENJA VREMENA I TROŠKOVA RAZVOJNOG CIKLUSA VOZILA

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Dr Zoran Nikoliü, Dr Zlatomir Živanoviü RAZVOJ, KARAKTERISTIKE I MOGUûNOSTI ELEKTRIýNIH VOZILA

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Dr Ĉorÿe Vukeliü, Dr Igor Budak, Dr Branko Tadiü, Dr Ognjan Lužanin, Dr Miodrag Hadžisteviü, Dr Peter Krizan AUTOMATIZOVANO GENERISANJE ŠEMA BAZIRANJA RADNOG PREDMETA PRILIKOM PROJEKTOVANJA PRIBORA

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Mr Miroslav Kuburiü, Mr Mladen Lero RADOVI MERENJA PRI PROJEKTOVANJU I IZGRADNJI PUTEVA

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MSc Dragan Sekuliü, Dr Vlastimir Dedoviü ANALIZA UTICAJA VIBRACIJA NA KOMFOR KORISNIKA MEĈUGRADSKOG AUTOBUSA POMOûU OSCILATORNOG MODELA SA SEDAM STEPENI SLOBODE KORIŠûENJEM ADAMS/VIEW SOFTVERA

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MSc Nenad Paviü, Dr Vladimir Popoviü, Miloš Vasiü STAROST VOZAýA KAO DOMINANTAN DEMOGRAFSKI FAKTOR SAOBRAûAJNIH NEZGODA

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Dr Deda Ĉeloviü, Mr Dijana Medenica Mitroviü OSNOVE ZA DEFINISANJE KORELACIJA IZMEĈU ORGANIZACIONIH PROMENA U MORSKOJ LUCI I PROMENA PRODUKTIVNOSTI

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OD UREĈIVAýKOG ODBORA

Srbija se danas nalazi na putu za prikljuþenje Evropskoj uniji, pri þemu je energetika, potpisivanjem sporazuma o Energetskoj zajednici Jugoistoþne Evrope pre nekoliko godina, veü napravila znaþajan korak u tom pravcu. Tome je doprinelo i ranije donošenje Zakona o energetici iz 2004. godine (koji je ove godine promenjen i usvojen sa znaþajnim promenama) i Strategije dugoroþnog razvoja energetike Republike Srbije do 2015.godine iz 2005. godine (pri þemu se nova priprema), dokumenata koji su opredelili evropski put energetike. Prof. dr Nenad Ĉajiü

Novi Zakon o energetici Republike Srbije usklaÿuje nas sa zahtevima EU u domenu energetike i omoguüuje:

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sigurnost i kvalitet snabdevanja ;

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tržišnu konkurenciju ;

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stvaranje atraktivnih i stabilnih uslova za razvoj energetskog sektora;

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unapreÿenje energetske eﬁkasnosti ;

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stvaranje uslova za stimulisano korišüenje obnovljivih izvora energije i kogeneraciju ;

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unapreÿenje zaštite životne sredine ;

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deﬁnisanje povlašüenih proizvoÿaþa energije,itd.

Postojeüa Strategija dugoroþnog razvoja energetike Republike Srbije do 2015. godine, uraÿena je 2005.godine, da saglasno ranijem Zakonu o energetici usvoji osnovne ciljeve nove energetske politike, utvrdi prioritetne pravce razvoja u energetskim sektorima, i odobri program donošenja odgovarajuüih instrumenata, kojim se omoguüuje realizacija kljuþnih prioriteta u radu, poslovanju i razvoju celine energetskog sistema (u sektorima proizvodnje i potrošnje energije) Srbije. Osnovna premisa pri izboru ciljeva, utvrÿivanju prioriteta i odgovarajuüih instrumenata, zasnovana je na politiþkom opredeljenju zemlje za racionalno usklaÿivanje razvoja celine energetike sa privrednoekonomskim razvojem zemlje i njenom ukljuþivanju u evropske integracije. Meÿutim, mora se danas konstatovati da su brojna planska opredeljenja deﬁnisana u Strategiji dugoroþnog razvoja energetike Srbije u periodu do 2015. godine bila bazirana na mnogo pretpostavki koje se iz objektivnih razloga do sada nisu mogle ostvariti: •

nije došlo do predviÿenog privrednog, posebno industrijskog, razvoja Srbije;

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ne ostvaruje se intenzivnije istraživanje energetskih potencijala,

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uvozna zavisnost se ne smanjuje;

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bez veüih pozitivnih pomaka u agregatnoj energetskoj eﬁkasnosti;

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potrošnja energije, posebno elektriþne, i dalje je veoma neracionalna;

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ekonomski položaj energetske privrede se bitno nije poboljšao, a ekonomski kriterijumi kao osnova kontrole energetskog sektora su nedovoljno prisutni, pre svega, u oblastima politike cena;

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cene energije nisu ekonomske i realno se ne poveüavaju bar do nivoa koji obezbeÿuje prostu reprodukciju;

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politika cena energenata je pod velikim uticajem socijalnih problema i kontrole inﬂatornih kretanja;

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aktivnosti na restrukturiranju i transformaciji energetskih preduzeüa nisu završene, itd.

Takoÿe, nisu bili predviÿeni sporazumi sa stranim kompanijama, ostvareni tokom proteklih godina (RWE, SECI Energia S.p.A, Gasprom, Gaspromneft, Komiko i dr.), u privatizaciji i izgradnji novih energetskih objekata.

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OD UREĈIVAýKOG ODBORA Samim tim i predviÿanja razvoja energetike data u Strategiji nisu mogla biti ostvarena. Zbog toga se svake druge godine pravi Program ostvarivanja Strategije gde se realnije sagledavaju moguünosti razvoja energetike u kratkoroþnom periodu. Prošle godine završena je izrada drugog Programa ostvarivanja te Strategije kojim je detaljno obrazložen sadržaj i dinamika realizacije Prioritetnih programa razvoja energetskog sektora u periodu do 2012. godine. Program se usklaÿuje prema realnim potrebama za energijom i energentima, þime je omoguüena izmena i aktuelizacija Strategije razvoja energetike Republike Srbije. Meÿutim zbog navedenih aktuelnih promena koje se dešavaju u energetici naše zemlje (i sveta) neophodna je izrada nove Strategije dugoroþnog razvoja energetike, koja treba da se realizuje što pre. Po mom mišljenju novu Strategiju je potrebno doneti za .period do 2030.godine sa vizijom do 2050.godine. Buduüi da se energetski objekti grade dugo (4 do 7 godina, pa i duže) i da je vek njihove eksploatacije optimalno od 25 do 30 godina, a sa revitalizacijom i do 40 godina, da uvoÿenje novih tehnologija i obnovljivih izvora zahteva duži period, da üe u toku narednih 20 do 30 godina biti zaposednuta sva ležišta fosilnih goriva, da ne raspolažemo veüim rezervama nafte i prirodnog gasa, to je veoma korisno da se sagleda potreban razvoj za duži vremenski period. Time bi se uskladili i sa strategijama razvoja energetike uraÿenih od strane razvijenih zemalja sveta i EU za sopstveni razvoj i meÿunarodnih energetskih agencija, koje su sve donesene najþešüe do 2030 godine , mada ih ima i do polovine ovog veka. Vizija do 2050.godine je neophodna da se uradi, jer prema uraÿenim analizama za prostorne planove rudarskih basena Kolubare i Kostolca, može se oceniti da üe njihove rezerve biti najveüim delom iscrpljene do tada, a to pretstavlja najveüi deo naših energetskih potencijala ( ne raþunajuüi potencijale na Kosovu i Metohiji koji nam za sada nisu raspoloživi). Kroz tu viziju moramo se pripremati za period kada üe praktiþno biti iscrpljene sve naše rezerve fosilnih goriva i kada üe nam na raspolaganju ostati samo obnovljivi izvori energije.

Prof. dr Nenad Ĉajiü

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REZIMEI RADOVA Broj rada: 9(2011)3, 201 PRIKAZ PRIMENE VIRTUELNE STVARNOSTI U CILJU SMANJENJA VREMENA I TROŠKOVA RAZVOJNOG CIKLUSA VOZILA Mr Jasna Glišoviü Univerzitet u Kragujevcu, Mašinski fakultet u Kragujevcu, Kragujevac, Srbija Dr Miroslav Demiü Univerzitet u Kragujevcu, Mašinski fakultet u Kragujevcu, Kragujevac, Srbija Mr Danijela Miloradoviü Univerzitet u Kragujevcu, Mašinski fakultet u Kragujevcu, Kragujevac, Srbija Proces razvoja vozila danas karakterišu poveüani zahtevi za bržim i jeftinijim razvojnim ciklusima, uz smanjenje potrošnje goriva. Ukupni zahtevi u toku razvoja novog vozila obuhvataju potrebu za izradu brzih prototipova i procenu trajnosti kako bi se postigao ubrzamn proces razvoja. Danas, takoÿe postoji konvergencija tržišta i tehniþkih promena koja direktno utiþe na razvoj vozila. Postoji jasni trend u automobilskoj industriji da proizvoÿaþi finalnog proizvoda ustupaju sve više razvojnih aktivnosti kooperantima. Zbog toga, ukupan kvalitet završnog proizvoda, zavisiüe od toga koliko uspešno su krajnji proizvoÿaþ vozila i svi dobavljaþi radili zajedno u toku razvoja. Nedostatak sinhronizacije izmeÿu kooperanata i finalne automobilske kompanije, kao i izmeÿu razliþitih razvojnih odeljenja proizvoÿaþa, dovode do vrlo skupih grešaka. Iako se istraživanja u virtuelnoj stvarnosti (VR) odvijaju više od 20 godina, tek pre nekoliko godina neakademski svet poþeo je da ceni njenu primenu u cilju rešavanja problema u realnom svetu. Izmeÿu ostalih, automobilska industrija je dobro ocenila njen potencijal za konstrukciju, razvoj i proizvodne procese. U stvari, automobilska industrija, kao i njeni dobavljaþi, su bili meÿu prvima koji su poþeli da primenjuju VR. Oþekivane prednosti korišüanje virtuelnih tehnologija (smanjenje vremena razvoja, smanjene troškova razvoja, bolja konstrukcija kroz virtuelnu proveru, manje izmena i poveüanje kvaliteta) su prikazane u ovom radu. Kljuþne reþi: virtuelna realnost, vozilo, razvojni ciklus Broj rada: 9(2011)3, 202 RAZVOJ, KARAKTERISTIKE I MOGUûNOSTI ELEKTRIýNIH VOZILA Dr Zoran Nikoliü Institut “Goša”, Beograd, Srbija Dr Zlatomir Živanoviü Institut “Vinþa”, Beograd, Srbija U radu su predstavljeni razvoj, prednosti i mane elektriþnih vozila. Buduünost elektriþnih vozila uveliko zavisi od cene nafte na svetskom tržištu, životne sredine i tehniþkih karakteristika pogonskog sistema elektriþnog vozila. Kao rezultat prve naftne krize, sedamdesetih godina prošlog veka, poþela su prva razmišljanja o elektriþnim vozilima i u našoj zemlji. Prvo elektriþno vozilo napravljeno je u nekadašnjoj Jugoslaviji, pod voÿstvom akademika A. Despiüa. Danas su uglavnom sve elektiþne komponente, potrebne za vožnju, visokog kvaliteta i imaju visok stepen efikasnosti, tako da je ukupna efikasnost pogona putniþkih elektriþnih sistema (baterija) oko 75 %. Najveüi problem i dalje ostaje “ rezervoar energije”. ýak i najbolje baterije danas poseduju gustinu energije po masi do 200 Wh/kg, tako da se elektriþna vozila u pogledu performansi ni danas ne mogu porediti sa konvencionalnim vozilima. Odgovarajuüi baterijski sistem sa 1700 Wh/kg biüe spreman da obezbedi performanse koje se mogu porediti i time omoguüi prelazak na potpuno þista vozila. Dok istraživaþi ne osmisle bateriju takvog tipa, koristiüemo hibridna elektriþna vozila kao rešenje za smanjenje izduvne emisije i potrošnje goriva sa ciljem da se postepeno smanji zavisnost od uvoza nafte. Kljuþne reþi: elektriþna vozila, hibridna vozila, elektriþni pogon, baterije, Li-air, TAM 2001 - E

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REZIMEI RADOVA Broj rada: 9(2011)3, 203 AUTOMATIZOVANO GENERISANJE ŠEMA BAZIRANJA RADNOG PREDMETA PRILIKOM PROJEKTOVANJA PRIBORA Dr Ĉorÿe Vukeliü Univerzitet u Novom Sadu, Fakultet tehniþkih nauka, Novi Sad, Srbija Dr Igor Budak Univerzitet u Novom Sadu, Fakultet tehniþkih nauka, Novi Sad, Srbija Dr Branko Tadiü Univerzitet u Kragujevcu, Mašinski fakultet, Kragujevac, Srbija Dr Ognjan Lužanin Univerzitet u Novom Sadu, Fakultet tehniþkih nauka, Novi Sad, Srbija Dr Miodrag Hadžisteviü Univerzitet u Novom Sadu, Fakultet tehniþkih nauka, Novi Sad, Srbija Dr Peter Krizan Tehnološki univerzitet u Slovaþkoj, Mašinski fakultet, Bratislava, Slovaþka U radu je predložena metodologija koja ima za cilj da popuni prazninu u oblasti automatizovanog projektovanja pribora. Prisup je zasnovan na detaljnom razmatranju, analizi i sintezi svih operativnih zahteva vezanih za automatizovano deﬁnisanje moguüih šema baziranja radnog predmeta u toku mašinske obrade. U radu je prikazana koncepcija sistema, njegovo funkcionisanje i studija sluþaja. Kljuþne reþi: pribor, baziranje, greška baziranja.

Locirɚnje cilindriþnog rɚdnog komɚdɚ ɚ) ogrɚniþenje od 4 stepenɚ slobode, b) ogrɚniþenje od 5 stepeni slobode, c) ogrɚniþenje od 6 stepeni slobode

Broj rada: 9(2011)3, 204 RADOVI MERENJA PRI PROJEKTOVANJU I IZGRADNJI PUTEVA Mr Miroslav Kuburiü Geoput d.o.o, Beograd, Srbija Mr Mladen Lero Geoput d.o.o, Beograd, Srbija U radu je prikazan pregled geodetskih radova u vezi sa razvojem tehniþke dokumentacije u toku izgradnje puteva (autoputeva, magistralnih puteva itd.). Poseban akcenat je stavljen na potrebe, ciljeve i znaþaj geodetskih radova, kao i na obim i nivo detalja neophodne tehniþke dokumentacije. Kljuþne reþi: dizajn geodetskog obeležavanja, geodetske mape, projektovanje geodetskih zapažanja, dizajn kupovine zemljišta Journal of Applied Engineering Science 9(2011)3

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REZIMEI RADOVA Broj rada: 9(2011)3, 205 ANALIZA UTICAJA VIBRACIJA NA KOMFOR KORISNIKA MEĈUGRADSKOG AUTOBUSA POMOûU OSCILATORNOG MODELA SA SEDAM STEPENI SLOBODE KORIŠûENJEM ADAMS/VIEW SOFTVERA MSc Dragan Sekuliü Univerzitet u Beogradu, Saobraüajni fakultet, Beograd, Srbija Dr Vlastimir Dedoviü Univerzitet u Beogradu, Saobraüajni fakultet, Beograd, Srbija U radu je izvršena analiza uticaja vibracija na komfor korisnika meÿugradskog autobusa IK-302. Vrednovanje dejstva vibracija je sprovedeno prema kriterijumima udobnosti u sredstivma javnog prevoza koji su propisani u meÿunarodnom standardu ISO 2631. Za potrebe analize deﬁnisan je ravanski podužni oscilatorni model autobusa sa sedam stepeni slobode u modulu ADAMS/View. Komfor je odreÿen za mesto vozaþa, putnika u srednjem delu autobusa i putnika na zadnjem prepustu autobusa. Analizirana su vertikalna ubrzanja na mestima korisnika za dve realne pobude: asfalt-beton u lošem stanju i asfalt-beton u dobrom stanju. Rezultati simulacije pokazuju da vibracije najviše ugrožavaju komfor putnika u zadnjem delu autobusa, dok je komfor vozaþa najmanje ugrožen. Kljuþne reþi: komfor autobusa, ISO 2631, neravnost kolovoza, simulacija, ADAMS/View

Vertikɚlno ubrzɚnje na mestima korisnika zɚ pobudu: ɚsfɚlt-beton u dobrom stɚnju i brzinɚ autobusa od 80 km/h

Broj rada: 9(2011)3, 206 STAROST VOZAýA KAO DOMINANTAN DEMOGRAFSKI FAKTOR SAOBRAûAJNIH NEZGODA MSc Nenad Paviü Delta Generali Osiguranje, Beograd, Srbija Dr Vladimir Popoviü Univerzitet u Beogradu, Mašinski fakultet, Beograd, Srbija Miloš Vasiü Institut za istraživanja i projektovanja u privredi, Beograd, Srbija Elementi sistema koji þine saobraüaj, okolina, vozilo i þovek, predsatvljaju i sastavni deo svake nastale nezgode. Pored mnogobrojnih inovacija i unapreÿenja vozila, širenja i poboljšanja putne infrastrukture, broj nesreüa se poveüava. Glavni krivac je þovek koji, sa uþešüem u 57 % ( dok u kombinaciji sa ostalim faktorima þini preko 90 % ) nezgoda, predstavlja najslabiju kariku u lancu. Radom su obuhvaüeni i objašnjeni brojni ljudski faktori koji þine uzroþnike na koje možemo uticati. U obzir su uzete mere obuhvaüene novim Zakonom o bezbednosti saobraüaja. Izvršena je analiza nezgoda u funkciji godina starosti vozaþa. Predložene mere za suzbijanje i prevenciju imaju za cilj smanjenje i opadanje negativnih trendova. Kljuþne reþi: saobraüajne nezgode, godine vozaþa, ljudski faktori

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Journal of Applied Engineering Science 9(2011)3

REZIMEI RADOVA Broj rada: 9(2011)3, 207 OSNOVE ZA DEFINISANJE KORELACIJA IZMEĈU ORGANIZACIONIH PROMENA U MORSKOJ LUCI I PROMENA PRODUKTIVNOSTI Dr Deda Ĉeloviü Luka Bar, Bar, Crna Gora Mr Dijana Medenica Mitroviü Fakultet za poslovne studije, Bar, Crna Gora Proces izbora modela organizacije luke se karakteriše visokim stepenom složenosti i mora da bude zasnovan na prethodno precizno deﬁnisanim ciljevima koji se trebaju postiüi. Neki iz skupa glavnih ciljeva procesa su: povišenje produktivnosti, racionalizacija strukture luke, itd. Nakon opštih razmatranja vezanih za proces transformacije luka i osvrta na osnovne teorijske pristupe rješavanju problema iz ovog domena, Rad je fokusiran na analizu kljuþnih korelacija izmeÿu organizacionih promjena u morskim lukama i promjena produktivnosti u procesu pretovara tereta. Kljuþne rijeþi: morska luka, organizacione promjene, produktivnost.

Uzroþno - poslediþni dijagram

Journal of Applied Engineering Science 9(2011)3

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INDEXING Starting from 2006th, only three years since the launch of the journal Istraživanja i projektovanja za privredu (Journal of Applied Engineering Science), all published articles are indexed in international ELSEVIER database through SCOPUS service. In this way, the work and results of the local scientiest are widely available as the SCOPUS is the largest database of abstracts and citations in terms of scientiﬁc publications and quality web sources which, above all, give the results of research in various ﬁelds.This database provides excellent information necessary for further work and scientists training with extensive search capabilities.

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CIP - Katalogizacija u publikaciji Narodna biblioteka Srbije, Beograd 33 Istraživanja i projektovanja za privredu = Journal of Applied Engineering Science: nauþno-struþni þasopis / glavni urednik Jovan Todoroviü; odgovorni urednik Predrag Uskokoviü. - God. 1, br. 1 (2003) Beograd (Vatroslava Lisinskog 12a): Institut za istraživanja i projektovanja u privredi, 2003 - (Beograd: Beograﬁka). - 29 cm Tromeseþno Drugo izdanje na drugom medijumu: Istraživanja i projektovanja za privredu (Online) = ISSN 1821-3197 ISSN 1451-4117 = Istraživanja i projektovanja za privredu COBISS.SR-ID 108368396 Journal of Applied Engineering Science 9(2011)3