CityMobile PRT Commission Research

EUROPEAN COMMISSION DG RESEARCH SIXTH FRAMEWORK PROGRAMME THEMATIC PRIORITY 1.6 SUSTAINABLE DEVELOPMENT, GLOBAL CHANGE & ECOSYSTEMS INTEGRATED PROJECT – CONTRACT N. 031315

Preliminary system definition

Deliverable no.

3.1.1

Dissemination level

PP, Restricted to other program participant (including the Commission services)

Work Package

3.1 Cybercars and advanced city car design

Author(s)

Adrian Zlocki (IKA)

Co-author(s)

Giancarlo Alessandretti (CRF), Ahmed Benmimoun (IKA), Joseph Canou (ROBOSOFT), Renzo Cicilloni (CRF), Jan Schomerus (DLR)

Status (F: final, D: draft)

F (07.02.07)

File Name

CITYMOBIL_D.3.1.1_070207.doc

Project Start Date and Duration

01 May 2006 - 30 April 2011

TABLE OF CONTENTS 1

Executive Summary

4

2

Introduction

5

3

Description of scenarios

6

3.1

Selection of scenarios

6

3.2

Town Centre

7

3.3

Principal urban roads with an equipped lane (called „e-lane“)

8

3.4

Inner city centre

9

3.5

Shared traffic space with automated buses and dual mode vehicles

4

Requirements of scenarios

12

4.1

Requirements for the town centre scenario

12

4.2

Requirements for principal urban roads with an equipped lane (called „e-lane“) scenario

14

4.3

Requirements for the inner city centre scenario

17

4.4

Requirements for shared traffic space with automated buses and dual mode vehicles scenario

20

4.4.1 Traffic management system 4.4.2 Requirements for automated buses, cybercars and dual- mode vehicles 4.4.3 Requirements on infrastructure

20 22 25

Comparison of requirements

25

4.5 5

10

Preliminary system definition

28

5.1

Sensors

28

5.2

Actuators

29

5.3

ECUs

29

5.4

Communication devices

29

5.5

HMI technology

30

6

Conclusions

31

7

Appendix

32

7.1

Detailed description of scenarios – Town centre

32

7.1.1 A concept for vehicle functionalities 7.1.2 Conditions for use of the vehicles in the protected area 7.1.3 Specific capabilities – Town centre

32 33 36

Detailed description of scenarios – Principal urban roads with an equipped lane

36

7.2.1 7.2.2 7.2.3 7.2.4

36 37 37 40

7.2

7.3

7.4

Environment for e-lanes Vehicles used in e-lanes Conditions for use of the vehicles in e-lanes Specific capabilities – Principal urban roads with an equipped lane

Detailed description of scenarios – Inner city

40

7.3.1 Condition for the use of cybercars in the dedicated area 7.3.2 Specific capabilities – Inner city

40 43

Detailed description of scenarios – Shared traffic space with automated buses and dual mode vehicles

44

7.4.1 7.4.2 7.4.3 7.4.4

44 46 48 51

Traffic management and vehicle functionalities Infrastructure and basic conditions Conditions for use of the vehicles on dedicated lanes Specific capabilities – Shared traffic space with automated buses and dual mode vehicles

Preliminary system definition

2

8

Acknowledgement

52

9

Sources

53

9.1

53

Reference List

TABLES Table 1: Stopping distances at 5 m/s2 ................................................................................................ 23 Table 2: Comparison of scenarios ..................................................................................................... 26 Table 3: Basic Conditions – Town centre............................................................................................. 33 Table 4: Driving – Town centre.......................................................................................................... 34 Table 5: Traffic – Town centre........................................................................................................... 35 Table 6: Basic Conditions – Principal urban roads with an equipped lane .................................................. 38 Table 7: Driving – Principal urban roads with an equipped lane ............................................................... 39 Table 8: Traffic – Principal urban roads with an equipped lane ................................................................ 40 Table 9: Basic Conditions – Inner city................................................................................................. 41 Table 10: Driving – Inner city ............................................................................................................ 42 Table 11: Traffic – Inner city ............................................................................................................. 43 Table 12: Basic Conditions – Shared traffic space with automated buses and dual mode vehicles.................. 49 Table 13: Driving – Shared traffic space with automated buses and dual mode vehicles............................... 50 Table 14: Traffic – Shared traffic space with automated buses and dual mode vehicles ................................ 51

FIGURES Figure 3-1: View of the historical town centre in Genova .......................................................................... 8 Figure 3-2 Representative data of Genova town centre ........................................................................... 8 Figure 3-3: Use of e-lanes as UML activity diagram ................................................................................ 9 Figure 3-4: Adapted inner city for automated transportation system.......................................................... 10 Figure 7-1: Concept for assisted guidance in a curve ............................................................................ 32 Figure 7-2: Typical road scene in Genova ........................................................................................... 35 Figure 7-3: DLR test track in Berlin-Adlershof, a possible site for e-lanes .................................................. 37 Figure 7-4: Possible inner city automated transportation scene (NancyCab from the French MobiVip project)... 43 Figure 7-5: Example for an automated bus, Phileas in Eindhoven, Netherlands.......................................... 45 Figure 7-6: Road network of the automated high-tech buses system in Eindhoven, Netherlands.................... 47 Figure 7-7: Dedicated lanes for automated high-tech buses systems in Eindhoven, Netherlands ................... 48

Preliminary system definition

3

Preliminary system definition 1 Executive Summary Technological issues of advanced urban transport systems are addressed in sub-project 3 of the CityMobil project. The first step in this sub-project is to develop working scenarios, which represent different transport areas of advanced urban transport systems with objective to identify the main challenges regarding the technological requirements.

The four different considered scenarios are a “Town centre”, “Principal urban roads with an equipped lane (called ”e-lane”), an “Inner city centre” with cybercars and a “Shared traffic space with automated buses and dual mode vehicles”.

The scenarios can be distinguished by the type of the vehicles, which are utilized within each scenario, the environment in which the vehicles are operated and the operating mode.

The “Town centre” provides a dedicated area in which the driver manoeuvres dual-mode vehicles and is surrounded by pedestrians, bicycles, mopeds, small delivery vehicles and possibly private vehicles. He is assisted by the vehicle in his driving task.

The “Inner city centre” also provides a dedicated area, but in this case for cybercars, which are operated driverless. Surrounding traffic is given by means of pedestrians, bicycles and low speed vehicles.

Dual-mode vehicles are operated on dedicated lanes in the “e-lane” scenario by the driver or fully autonomous. In this case the lanes are shared by dual-mode vehicles and ordinary traffic.

The “Shared traffic space with automated buses and dual mode vehicles” is also given by dedicated lanes. In this scenario the lanes are shared between high-tech buses, dual-mode vehicles and cybercars.

The requirements focused on technological aspects, which are derived from the functionality are described in detail for each of the four different scenarios. Based on these identified requirements the preliminary system definitions are given in order to fulfil the requirements. A detailed design of system definition will be conducted in following work packages of subproject 3.

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2 Introduction In sub-project 3 of CityMobil the technological issues of advanced urban transport systems are addressed.

The main objective of this sub-project is to identify technological solutions in order to introduce advanced urban transport systems on a large-scale. Specific vehicle architectures are developed and the basic subsystems for cybercars and advanced city cars are defined to achieve this objective within the sub-project. A dual-mode platform is developed within SP3 and optimum solutions for human-machine interfaces and information systems are proposed.

Furthermore specific obstacle detection systems and navigation techniques, focusing on wireless communication for high throughput are evaluated.

In order to study the described technological issues, working scenarios have been developed, which represent different transport areas in modern city life and provide possible solutions for future deployment of innovative transport systems. The scenarios offer a good level of generality and potentiality for the CityMobil sub-project. Functions, such as automatically moving in dedicated lanes, entering and exiting a parking area automatically and joining and leaving a formation of cybercars, have to be considered within those scenarios.

The resulting scenarios have future implications on the following work packages in the subproject 3. They represent the working base for the work packages 3.2 “human factors”, 3.3 “obstacle detection and avoidance” and 3.4 “cooperative vehicles and navigation”.

The selected working scenarios are described in the present report, with a focus on basic requirements. Based on the derived requirements, the main technological challenges for the applications are identified, which allow the subproject to address them in WP3.2 – Human factors, WP 3.3 - Obstacle detection and avoidance and WP3.4 – Cooperative vehicles and navigation.

As a result, preliminary system definitions are given in form of a description of the vehicles and their components with the necessary additional infrastructure belonging to the system in different scenarios. The preliminary system definitions are sub-divided into sensors, actuators, ECUs and HMI technology, which is needed for the above described scenarios.

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3 Description of scenarios Within this chapter the presented scenarios are described. Basic conditions such as the general characteristics of the area and how to use the advanced vehicles are given. A more detailed description of the environment, the infrastructure and the traffic situation is included in the Appendix.

The selected scenarios are as follows: • Town centre • Principal urban roads with an equipped lane (called „e-lane) • Inner city centre scenario with cybercars • Shared traffic space with automated buses and dual mode vehicles As described in the next section, these cases have been chosen due to the good level of generality and the potentiality for effective applications of advanced transport systems, such as those studied in the CityMobil project.

3.1

Selection of scenarios

The definition of preliminary system requirements for cybercars and advanced city car design is strongly dependent upon the application area of these systems, and in particular the transport mission, the service offered to the users and the environment.

Therefore, four basic scenarios have been chosen, in order to focus on selected application fields on the one hand, and provide a widespread coverage of different levels of transport modes, automation and urban integration on the other hand. The objective of this scenario generation is the determination of the upcoming challenges regarding the technological requirements. Therefore other aspects like the management of fleets, toll collecting etc. are not treated in detail.

In the process of scenario selection the following aspects have been considered, as far as possible. Besides these aspects the defined cases should not represent long-term future scenarios, but should be realisable by adaptation of available technology and know-how.

•

Automatic vehicles moving on dedicated lanes

•

Vehicles entering and exiting automatically from a parking area

•

Dual-mode vehicles joining and leaving a formation of cybercars

•

Problems of inner city traffic in combination with pedestrians

•

Integration of advanced urban transport systems into existing infrastructure

•

Increase of the automation level for future transport systems:

•

o

On one hand, by sophisticated person transport systems, which move within an unprotected environment, interacting with other traffic participants

o

And on the other hand by conventional vehicles, where driving tasks are partly or totally automated by means of advanced driver assistance systems.

Coverage of various forms of traffic and categories of road users.

In order to cover most of the given criteria, different scenarios have to be considered. The results of this selection process are four different scenarios, in which different levels of automation and different technological aspects are regarded. In the following section the selection of the scenarios is described.

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The first scenario deals with partly automated dual mode vehicles/advanced city cars in a historical town centre, the second with a combination of cybercars and dual mode vehicles (mixed traffic) and the third scenario with cybercars in a city area. The last scenario describes automated high-tech buses on dedicated lanes, which are shared with dual mode vehicles and cybercars.

3.2

Town Centre

Mobility in urban areas, especially in historical town centres, is a complex subject, dealing with conflicting issues like meeting transport demand, accessibility, use of available spaces, environmental effects. A delicate equilibrium involving social, economic and environmental aspects must be preserved in the area.

However, these conditions can offer a number of interesting opportunities for new transport solutions, based on advanced systems, and with a potential to improve the attraction of the city areas. Hence a “Town Centre” scenario has been chosen as one of the reference cases for the present study within CityMobil.

The “Town Centre” scenario here defined considers an historical area, inside the city structure but often not well connected to the surrounding districts, and characterised by a complex and intricate network of small roads. This situation can be found in a large number of Mediterranean towns in Europe. 1 In the following, the case of Genova is considered as an emblematic reference case, for different reasons, including: • Considerable extension, among the widest in Europe.

• Significant architectural heritage, with important initiatives for urban qualification launched in recent years by the political authorities.

• Despite the investments, the area remains a decreasing real estate resource, and population is decreasing, mostly for the difficulties related to transport.

• The area is too wide for a total restriction to pedestrians, and too compact for conventional mobility tools; experience has shown that traditional public and collective vehicles cannot satisfy all the transport needs.

• Mobility requirements are varied, and vital for the development of the area; they are related to the needs of inhabitants, visitors, commercial and service operators and include for instance: mobility of elderly and families, transport of baggage, supply of goods to the shops, connection to public lines in the neighbouring roads, spaces for either temporary or permanent stops.

Some indicative data, with reference to the present context in Genova (Figure 3-2), can be found in the following box.

Even if the study has been focused on such an example, it is clear that requirements coming from this scenario can be extended to a large number of cases among European cities.

1 For various historical reasons, a different situation is found in most cities of continental and northern

Europe, where smaller traditional city centres remain today, often providing better links to the modern areas around, so that penetration is easier, and traffic limitation in pedestrian areas is practicable.

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Figure 3-1: View of the historical town centre in Genova

Figure 3-2 Representative data of Genova town centre Genova Historical Town Centre: some representative data Surface: 113 ha Number of living units (apartments): 12804 Population at 1956: 70000 inhabitants Population at 2001: 18000 inhabitants Overall theoretical estate value: present: 1 Billion Euros possible with improved conditions: 4-5 Billions Existing traffic rules: ZTL (limited traffic zone) and ZSL (limited parking zone), with different conditions for residents or for other users Width of roads: in most cases between 1.5 and 5 m a few smaller and larger roads are present Source: Urban Mobility Council - Genova

3.3

Principal urban roads with an equipped lane (called „e-lane“)

Constantly rising commuter traffic in large cities has been a long time challenge for urban development. The enhancement of existing roads and expressways is often limited by the available space or undesirable for various other reasons. While public transportation can help solving some of the traffic problems, many people still prefer using their own vehicles. More efficiency in individual transportation, especially on highly frequented commuter roads, is therefore a key element for the 21st century traffic. Advanced driver assistance and automation systems can make a major contribution to this goal as they provide good means for governing the flow of traffic in order to avoid traffic jams and congestion. Other benefits of assistance and automation include higher safety and improved travelling comfort.

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Figure 3-3: Use of e -lanes as UML activity diagram While these advantages of automation and assistance are well-known and even most of the technical problems are solved, the development towards more highly automated individual traffic to date lags behind the advances in the public transportation sector, e.g. in automated

underground railways. One of the reasons might be that impressive progress in single fields like ACC, lane keeping assistance or traffic management, to name a few, remain patchy and cannot tap their full potential as long as they are not interconnected in the right way. The challenges in this puzzle are not restricted to technical problems but include also bringing different entities such as authorities, research organisations, car manufacturers and suppliers together. This integration can only be done with small and realistic enough condensation kernels and with thinking in migration paths. Instead of starting with a potentially unrealistic clean slate design, we start with the real world, identify first entrance points and plan the potential migration from there towards more highly automated traffic. The entrance point for this scenario is a especially equipped and certified lane where especially equipped but otherwise conventional vehicles can drive with automation.

Such an e-lane concept, particularly, if it is developed and designed by an international consortium consisting of a variety of different institutions, can make significant progress on the road towards the individual traffic of the future.

The following paragraphs sketch the technical details of a first stage e-lane scenario.

Wherever possible, proven and existing technology will be employed in a flexible way that allows the whole system to be upgraded as soon as advances in the different domains are available.

3.4

Inner city centre

The “Inner city centre� scenario involves an automated transportation system where the use of cybercars is made in a taxi-type application (individual or small group of persons -4,5-, on demand and point to point). The user can enter the vehicles at defined access points and has the possibility to choose the destination on pre-defined tracks.

The environment considered in this scenario is a specific urban area dedicated to pedestrian or semi-pedestrian and cybercars circulation. This specific urban area is a delimited area, which can receive a high density of persons who need to travel relatively short distances.

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Semi-pedestrian means that only bicycles or very low speed vehicles (like garbage collection vehicle or cleaning machine) will interact with people or cybercars.

Figure 3-4: Adapted inner city for automated transportation system

A - Lyon, France

B - Nijmegen, Netherlands

The automated transportation solution used in the inner city scenario will apply a set of technological innovations, which will bring flexibility and comfort both for the end-user and the system manager: -

-

-

-

A fleet of automated vehicles. These automated vehicles will have autonomous movement capabilities like localisation, navigation communication. Platooning and corresponding off-tracking management is also considered to allow the formation of a train of vehicles and multi-trailers cybercars in a safe way (safety and integrity of vehicles).

A fleet management system. This system will have the capabilities of real time vehicle’s movement optimisation. It will take into account the information of the surrounding environment (vehicle network state, client’s reservation, programmed events etc.)

Man-machine-interfaces for interaction between users and vehicle (information about the situation of the vehicle etc.) or the global transportation system (access point, information panels etc.)

Mobile communication system. This will allow communication between the cybercars and the fleet manager, but it will also allow end-users to access for example a website dedicated to the transportation system status.

This automated transportation system will also bring several levels of security allowing circulation of cybercars in a pedestrian site: speed limitations, obstacle detection and avoidance systems, manual and automatic emergency braking.

Moreover some capabilities must be considered to manage cybercars when they are not in use by end-users: batteries recharging, maintenance, vehicles dispatching etc.

3.5

Shared traffic space with automated buses and dual mode vehicles

Based on the historical development of modern cities, space and free land for traffic infrastructure such as parking spaces and new road systems is limited. Furthermore the congestion of available roads is a growing problem, which will increase even more in the near future.

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In order to cope with the resulting traffic congestion a growing number of cities indicate interest in introducing high-tech buses systems. A high-tech buses system is a public transport system, which connects various districts of a city and allows people to travel from their homes to work or to the city centre on a given time table without being influenced by traffic jams or road congestions and independent of their own vehicle.

These high-tech buses systems offer a large number of advantages such as environmental friendliness, independence of personal vehicles, fixed schedules, smoother traffic flow etc.

The systems are operated on dedicated bus lanes. These are often lined by attractive shoulders, typically covered by grass or trees, separating the dedicated lanes from the normal city traffic. Furthermore true high-tech buses system should have the capability of automatic guidance and automatic docking to the associated bus stop.

In order to increase the road saturation of the dedicated bus lanes for the automated hightech buses system in the future, the scenario “shared traffic space with automated buses and dual mode vehicles� not only consists of automated bus systems on the lanes, but also dual mode vehicles and cybercars, which are supposed to travel on the same driving lanes by means of automated guidance. This seems to be a satisfying solution for the integration of innovative transport concepts (cybercars, dual mode vehicles etc.) in urban area considering that the necessary traffic space and infrastructure are already available in the cities, where a high-tech buses system is installed.

In the recent past a growing number of cites have already successfully introduced high-tech buses systems with dedicated lanes. Examples of such cities are: Paris, Rouen and Nice (France), Amsterdam, Utrecht and Eindhoven (Netherlands), Bradford, Edinburgh and Leeds (United Kingdom). Cities like Eindhoven and Las Vegas (North America) have already introduced automated guided bus systems.

The detailed scenario description in the annex is based on high-tech buses systems with autonomous guided buses, like the one introduced in Eindhoven, Netherlands. The existing system is to be enhanced by dual mode vehicles and cybercars, which share the already existing dedicated lanes with the bus system. The necessary adaptation of the existing infrastructure as well as the organisation of such a scenario is given.

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4 Requirements of scenarios In order to identify the necessary technology, which is used in the four scenarios, requirements have to be derived from the functionality. At the end of the chapter a comparison of the four different scenarios is given, which focuses on the distinct characteristics and the main challenges of each scenario.

4.1

Requirements for the town centre scenario

The following aspects should be considered for the realisation of a town centre scenario: Information acquisition •

Amount of information First class of information needed for automatic or semiautomatic manoeuvres is related to the vehicle position in the controlled scenario. In particular the lateral position of the vehicle relative to the lane or path, the longitudinal position relative to mapped points and the direction of movement are the necessary information.

Second class of information is related to the surrounding environment, in particular the information of relative speed, distance and direction from other vehicles or standing obstacles are requested.

Finally the information needed by the fleet manager is related to vehicle’s positioning and vehicle’s status.

•

Accuracy and resolution of information For the first class of information it is necessary to achieve a 10 cm precision for the lateral position and a 1 m precision for longitudinal position.

For second class of information it is necessary to detect all type of obstacles, like vehicles, pedestrian, cyclist and motorcycles. The accuracy, depending on the type of vehicle, is similar to the above ones.

•

Range Vehicle position information must be guaranteed on the whole area in which the vehicle moves.

Obstacle detection information should provide distance range of 100 m at least for moving obstacles and 50 m for standing obstacles. This will allow stopping the vehicle by using a value of deceleration of about 5 m/s 2 in case of collision avoidance.

•

Update rate Depending on the class of information, this can vary from 10 ms to 100 ms.

Higher values need to be investigated before using them.

•

Reliability Reliability is a key factor for the acceptance of the system, and guarantees the safety of the transportation system.

The reliability needed for the positioning system, obstacle detection system, and the navigation system can be reached with redundancy of sensors and actuators. When the redundancy cannot be guaranteed, system failure that could cause malfunction must be detected.

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•

Communication The communication channel, necessary for the management and safety reasons, has to satisfy the same requirements of the sensorial system. The quantity of information to be exchanged is related to the number of services provided by the system.

Information processing •

Longitudinal and lateral guidance functions In the automatic or in the assisted mode the vehicle is longitudinally and laterally controlled. Starting from the navigation information (maps and localisation) and considering the surrounding objects (information from sensors) a speed profile and a trajectory is calculated. The vehicle controller will consequently calculate a steering torque, an engine torque and a brake deceleration to command the vehicle actuators.

The driver of dual mode vehicles is always present and will be able to override the system in any moment. The driver may take control of vehicle, because he has the responsibility of driving and should be able to operate in the case of risky situations.

•

Behaviour in abnormal situations Depending on the severity of the abnormal situation, the system should be able to drive the vehicle to a stopping place, or to smoothly stop the vehicle in the normal path. After this manoeuvres, and if it is possible, the driver will be asked to take over the control of the vehicle.

System reaction •

Minimum and maximum velocity The minimum cruise speed is set to 15 km/h in order to control the vehicle in a comfortable way. This value is low enough to guarantee a continuous control from near 0 km/h (1.5 km/h is roughly one third of walking speed). It is a stringent requirement, because it can be met only with electric traction or with ICE and automatic transmission; automated transmissions do not allow continuous operation at such a low speed, which can be controlled using clutch for a short time.

The maximum cruise speed is set to 50 km/h according to traffic law (as the cybercars are applied in town centres, most of which vehicle speed limitation is at 50 km/h), and in order to perform an emergency braking on standing obstacles.

•

Minimum and maximum acceleration/deceleration The acceleration and deceleration constrains are mainly given from driveability and comfort target.

The maximum deceleration for emergency braking should be around 0.8 g.

•

Human-Machine-Interface The HMI (Human-Machine Interface) serves as the medium by which the driver of the vehicle can interact with the Dual Mode function. It provides switches for the driver to input requests into the Dual Mode function and feeds back the status of the Dual Mode function to the driver via a series of visual

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•

and audible icons. Whilst the system is ON, it shall always provide information to the driver to indicate what state it is operating in. This shall include: - System ON feedback; - System ACTIVE feedback; - System FAULTY feedback; - System in Driver Override Mode; - Automatic system OFF feedback; Management issues

•

Entering a controlled area, the driver of the dual mode vehicles have to leave the control of the vehicle to the system. In this phase the management centre has to accept the vehicle in the system and the vehicle has to accept to be controlled. The same should happen when the vehicle leaves the controlled area.

Security tools: Protection of sensitive data, which is exchanged between the vehicle and a management centre, is necessary.

4.2

Requirements for principal urban roads with an equipped lane (called „elane“) scenario

The e-lane scenario has been designed as a system mostly based on existing technology in terms of sensors, actuators, communications systems and control units in order to create a show case of what is possible if some of the most advanced hardware available is combined.

Instead of completely defining a scenario and subsequently deriving a set of rigorous requirements that possibly cannot be satisfied by any technology available today, in the elane scenario the available technology sets the limits for the application of the system. As improved technology is introduced, certain system limits such as maximum speed or road constraints can be lifted accordingly. The following section outlines the requirements for the implementation of a first-stage version of the e-lane scenario as it could be developed and implemented using state-of-the-art technology in commercial or prototype state today.

Information acquisition •

Amount of information (position, velocity, surrounding vehicles and objects, topography, signs, environmental conditions etc.)

For lateral and longitudinal guidance, the vehicle must acquire information about its own position relative to the lane, the longitudinal position in the lane as well as distance, direction and relative speed of surrounding vehicles and other obstacles. Up-to-date information about the road, e.g. topography, speed limits, and construction sites must be available. Information about environmental conditions that could affect the proper functionality of the system is also necessary.

All information about the vehicle status as it is available from any modern passenger vehicle’s own control units, such as speed, steering angle, outside temperature, etc. must be accessible. o

Accuracy and resolution of information Position information must be better than 10 cm at all times to allow lateral guidance. Information about surrounding vehicles should have the same accuracy in the near range. For distant obstacles (i.e. more than 25 m) the lateral resolution should be still good enough to allow distinction between adjacent lanes.

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•

Range When travelling at the maximum speed of 120 km/h, the system must be able to come to a complete stop in case a static obstacle on the road ahead is detected. Commercially available long-range radar sensors, which accomplish the range of about 150 - 200 m, are therefore necessary. If the stopping distance is increased significantly due to adverse road surface conditions such as ice, snow or hydroplaning, the maximum speed should be reduced accordingly.

•

Update rate The update rates and time lags of all sensors must be high enough for the proper operation of control algorithms for lateral and longitudinal guidance.

Crisp requirements cannot be stated in a preliminary definition as the parameters of different sensors influence each other and are also dependent on the actuator dynamics. Experiences with DLR’s test vehicles suggest that sensors with update rates less than 20Hz and time lags of more than 50ms should be generally not considered as primary sources to calculate set-points for lateral and longitudinal guidance controllers.

•

Reliability Vital information, such as the position of the host vehicle and positions of obstacles, must be obtained by redundant sensors. The system need not be entirely fail-safe, but any failure that could cause malfunction must be detected and hence the system must safely transfer into an operation state that is not affected by the failure (“graceful degradation”).

•

Communication Vehicles and infrastructure must be equipped with a suitable communication system to exchange information about road conditions, construction sites, accidents, etc. For cost reduction, the infrastructure communication equipment does not have to provide a continuously available communication channel but can be limited to access points at certain distances, which depend on the level of service and the complexity of the road environment. Generally, there should be at least one access point located at every road entry and exit.

Information processing •

Longitudinal and lateral guidance functions If working in the higher automated mode, the system provides both longitudinal and lateral guidance. The system processes information from sensors, the infrastructure and possibly also from a static database on board of the vehicle. The system architecture is divided in different levels, starting with a discrete state machine and going down via path planning algorithms to the low-level controllers for lateral and longitudinal guidance. Even if the vehicle is in the higher-automated mode, the human driver receives a continuous haptic feedback at the vehicle controls and can take over the driving task at any time.

•

Behaviour in abnormal situations (system failure, disturbances, driver misuse etc.)

The primary backup strategy of the system in situations that it cannot handle or in case of failures is to transfer authority back to the human driver. This is only possible if the driver constantly maintains a certain level of situation awareness. Designing a haptic and audiovisual human machine interface,

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which ensures this and allows a safe transition between manual and automated driving modes is a key research issues of the e-lane scenario.

If the driver is disabled, the system will choose from a set of contingency procedures that could involve emergency braking in case of an imminent accident or bringing the vehicle to a full stop, if possible moving the vehicle out of the traffic and switching on the hazard warning lights.

System reaction •

Minimum and maximum velocity There is no minimum velocity. The maximum velocity has been set to 120 km/h as this covers the maximum speed on most principal urban roads in Europe.

•

Minimum and maximum acceleration/deceleration No special requirements except that the base vehicles must be standard passenger vehicles with official approval and homologation for road service.

The brake-by-wire interface must allow reaching full breaking power (activation of ABS on dry road) within less than 0.5 seconds. The drive-by-wire interface must allow full acceleration. These requirements mean especially that standard interface of ACC systems does not fulfil the requirements.

•

Minimum and maximum steering angle and steering angle velocity No special requirements except that the base vehicle must be a standard passenger vehicle with official approval and homologation for road service.

The dynamics of the steering actuator must be sufficient for lateral guidance.

While precise requirements cannot be given yet, our experiences point that an electric actuator, which provides a torque of 10 Nm (and has a negligible moment of inertia compared to the vehicle’s steering system) suffices for this purposes if combined with the power steering of any modern vehicle.

•

Human-Machine-Interface Haptic feedback must be possible at least at the steering wheel and accelerator pedal. There should be a high-resolution display in the instrument cluster (as is already standard in many modern automobiles) that allows displaying messages in text or symbolic form. Among others, these messages include the availability of an e-lane, the system status and the end of an elane. Directed acoustic signals to warn or inform the driver in urgent situations must be possible. The detailed content and mode of the information provided to the driver will be decided with input from WP3.2.

•

Management issues The scenario involves individual vehicles operated and taken care of by their respective owners so there is no need for particular fleet management.

However, the system involves specially certified and equipped infrastructure, so there is a need for maintenance and administration. If the system is going to be implemented in a larger scale a business plan must be developed in order to provide financing for these tasks.

The vehicle registration process via the car to infrastructure communication system provides also a possible way to generate invoice data for any other purpose, e.g. when a pay-per-kilometre policy has been chosen.

•

Security and privacy aspects

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The communication system between the infrastructure and each vehicle using an e-lane must provide encryption and secure authentication in order to avoid sabotage acts and protect the driver’s privacy.

Due to the nature of the system, the infrastructure system collects sensitive information, e.g. data that allows creating movement profiles. This information must be protected from any unauthorized access and treated according to data protection laws.

4.3

Requirements for the inner city centre scenario

The following aspects should be considered for the realisation of an “inner city centre” scenario: Information acquisition •

Amount of information The information needed by the vehicle is relative to position, velocity, surrounding vehicles, obstacles and vehicle status. This information is needed to allow fully autonomous movement in a safe way.

The position information will be used for navigation of the vehicles.

Regarding the obstacle detection, this detection characterization of obstacle as being static or mobile.

should

allow

the

If mobile obstacles are detected, the vehicle should be informed about the speed and direction of the obstacle movement.

The information needed by the fleet manager is relative to vehicle’s positioning and vehicle’s status.

•

Accuracy and resolution of information For navigation of the vehicle the positioning system should be able to give decimetre information or better.

For obstacle detection the system must be able to detect all type of obstacles, from very fine object (like a pavement) to objects such as vehicles, people, balls (children) or buildings. The accuracy should be similar to the positioning system accuracy when possible. However all information about possible obstacles (dangerous situation) will be used to ensure safety even if accuracy is low.

•

Range The positioning information and accuracy must be available on the whole area in which the vehicle moves.

There is no minimum range for obstacle detection but the maximum range for obstacle detection depends on the vehicle’s speed. In the best case the detection of obstacle should allow the vehicle to be stopped by using a comfortable value of deceleration (e.g.: at 5 m/s for a max deceleration of – 1 m/s 2 the range of detection should be at least of 6m).

In normal case a range of 150 m should be considered to allow anticipation manoeuvres (reducing speed in a comfortable way…).

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•

Update rate The update rate of positioning information and obstacle detection should allow navigation of the vehicle with reactive capabilities. It should ensure safety of movement.

•

Reliability Reliability is the most important quality of measurement. The safety of the transportation system depends directly on the reliability of sensors information.

The reliability is needed for the positioning system, obstacle detection system, and the navigation system.

Redundancy and preventive maintenance will help to ensure reliability of the system.

•

Communication Reliable communication capabilities should be available to allow constant communication with the fleet manager.

Information processing •

Longitudinal and lateral guidance functions These capabilities are needed to allow the following of predefined or prelearned tracks.

In addition with these functions, off-tracking management for train or multitrailers cybercars must be taken into account in the control laws to enforce safety of movement and plan safe trajectories and movements.

•

Behaviour in abnormal situations As they are moving in an autonomous way, cybercars must be able to handle abnormal situations. This abnormal situation must be considered as external to the vehicle (like an obstacle on the followed track) but also as internal (sensor or system failure).

The possibility for user intervention must be available (emergency brake).

System reaction •

Minimum and maximum velocity There is no minimum velocity. The speed must be adapted to the environment.

However, navigation of vehicle should be made without reverse movement.

The maximum speed should respect the local law (for example in France the speed in inner city must be lower than 30km/h).

•

Minimum and maximum acceleration/deceleration There is no minimum acceleration or deceleration.

Regarding acceleration, the maximum value should allow comfortable transportation for user (~1 m/s 2).

Regarding deceleration, the maximum value of a controlled action (normal movement) should also be around –1 m/s 2. In emergency case there is no maximum value because the most important thing is to stop the vehicle. This

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is possible because cybercars move at a low speed. The maximum deceleration that can be performed by the vehicle braking system is –3 m/s 2.

•

Human-Machine-Interface It should consist of 2 main parts: the embedded HMI for vehicle’s user information and also HMI located in the users access points.

In the vehicle: Where I am & where I go (selection & information about destination – estimated time- etc.)

What am I doing now? (Did I see the obstacle, is the vehicle behaviour a normal behaviour) Security control (emergency stop, dangerous movements of user (human factors)) The followed path What is the situation of: The considered cybercar: Case of normal situation (time to reach the different destinations, etc.)

Case of abnormal situation (vehicle failure, traffic…)

The other cybercars in the network The cybercars network status Out of the vehicle: - Advanced Information points with: Real time status of network - Availability of cybercars Possibility to do a request for a cybercar Management issues -

•

o

Fleet management

o

Efficient communication between central system and cybercars or vehicle to vehicle.

Real time localisation of cybercars Real time management: Function of users’ information & request Function of programmed events (maintenance, booking by users, programmed events…)

If existing traffic signal: knowledge of this signal to manage the vehicles - Management of “virtual” signals Maintenance management -

- Reserved docking areas for pick-up and drop-off passengers must exist.

- Maintenance places should exist also.

- Possibility of batteries charging in the docking areas.

•

Security tools: Software: reliability Hardware: (sensors redundancy, detection of sensor failures) Security of people (in & out the vehicle) Vehicle signalisation (sound and/or light signals, lane visibility…)

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4.4

Requirements for shared traffic space with automated buses and dual mode vehicles scenario

The requirements for the scenario “shared traffic space with automated buses and dual mode vehicles” are classified into three different sections. Firstly the requirements of the overall traffic management and the corresponding components are considered. Secondly the specific requirements for all three types of vehicles, namely buses, dual mode vehicles and cybercars are given. The requirements on the infrastructure (e.g. dedicated lanes, the entrance and the exits, the lane crossings, intersections and the bus stops) are covered last.

4.4.1 Traffic management system The traffic management system consists of three main components, a computer system, a system to determine the exact position of all vehicles on the track and a vehicle-toinfrastructure-communication. All components are considered in the following.

Traffic management computer The main tasks of the traffic management computer are: •

velocity control of all vehicles on dedicated lanes

•

management of bus stop procedure

•

management of pedestrian crossings

•

management of intersections with ordinary road users

•

management of bus and cybercars schedule

•

management of entrances and exits of dedicated lanes for dual mode vehicles

•

parking of automated buses and cybercars

•

providing information and instruction to the driver (e.g. switching into automated mode)

In order to ensure safe and accident free transport, the traffic management computer has to track the vehicles on the dedicated lanes and therefore the vehicle’s position (see section: positioning determination system). In addition to the tracking the management system monitors and controls intersections, pedestrian crossings and bus stops. In case of an approach to an intersection the system calculates the distance and the crossing arrival time and regulates the traffic on the dedicated approach lanes according to its calculations. This means that all vehicles have to come to defined stopping positions. As all vehicles are equipped with distance sensors (see sub-chapter 4.4.2) the positioning of the vehicles must have an accuracy within the metre range in the longitudinal direction. Besides the positioning system the distance between two vehicles is also measured with distance sensors, which provide a more exact positioning behind another vehicle. The most critical stopping position is given for the first vehicle stopping at an intersection or a pedestrian crossing. In this case a stopping zone of 2-3 m needs to be taken into account.

The timing of the stop command has to be considered in order to assure a comfortable braking manoeuvre prior to the intersection or pedestrian crossing. Comfortable acceleration ranges are within 2-2.5 m/s 2. At a maximum velocity of 80 km/h the distance to the intersection should add up to 109.9 m (with a 0.5 s time span for system reaction) at which point the stop signal should initialise a stopping. This results in a necessary time of about 9.4 s.

The vehicles have to reply to the traffic management system by means of vehicle-toinfrastructure communication in order to acknowledge the commands.

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The traffic management system is in charge of the entrances and exits to the dedicated lanes for dual mode vehicles. Once a driver approaches an entrance he has to insert his destination by the human-machine interface in his vehicle (see sub-chapter 4.4.2 for details).

The vehicle has to be registered within the management system and the driving course on the dedicated lanes until the exit is to be calculated. Knowing the position of each vehicle on the track the management system has to provide a suitable timing for the dual mode to enter the dedicated lanes safely. The driver will be requested to switch into automated driving mode.

Before an exit the management system also signals the driver to take over the driving task from the system and leave the tracks at the designated exit.

Besides the traffic management the system has to manage the bus stop procedures like stop the bus, open doors, wait until passengers enter the bus, close doors and leave the bus stop.

The schedule for buses and cybercars as well as the usage of either buses or cybercars (depending on rush hours, time of day etc.) is provided by the system as well.

The traffic management system runs fully automated. Nevertheless abnormal situations, like system failure, disturbances, driver misuse, etc might occur in everyday life. Therefore the system has to be monitored and serviced by trained personnel.

Information acquisition Monitoring and managing the traffic situation requires some form of communication between the vehicles on the track and the traffic management system. The type of communication in the scenario “shared traffic space with automated buses and dual mode vehicles” is vehicleto-infrastructure communication.

•

Amount of information In order to choose the dimension of the communication network, the amount of information has to be considered. The information, which will be transmitted by the vehicle, includes the vehicle position, the vehicle velocity and information for the driver like upcoming intersections or lane exits.

•

Range The communication range depends on the infrastructure and the number of installed transmitters. Ranges of at least 100 m should be taken into account to reduce the number of infrastructure-based transmitters.

•

Transfer rate The transfer rate has to meet those demands. Transfer rates of 1 MBit/s seem to be appropriate and can be provided by communication technologies like GMS, WLAN, Bluetooth etc.

•

Update rate An update rate of 0.1 s is necessary as the vehicles move with a maximum velocity of 80 km/h and therefore an update occurs every 2.22 m. As 80 km/h is the maximum possible velocity only allowed on chosen parts of the dedicated lanes without critical situations like intersections and bus stops, the value seems to meet the requirement on the positioning system, which is also in the metre range (see the next section for details).

•

Reliability The reliability of the communication system is of importance in critical situations.

Therefore all vehicles transmit a control signal, which helps the management system to check for reliability.

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•

Security The signal transmission as well as the communication protocol has to be secure against hacker attacks from the outside.

Information processing •

Positioning determination system The exact determination of each vehicle position on the dedicated lanes is an essential part of the traffic management system. The accuracy has to be within the range of one metre in order to guarantee a safe track determination of each vehicle. The reliability of the information has to be guaranteed at any time. A stationary correction signal improves the accuracy and provides stability and good data quality.

4.4.2

Requirements for automated buses, cybercars and dual-mode vehicles

High-tech buses system The requirements for automated buses on dedicated lanes shall be adapted to already existing systems such as the Phileas-program in Eindhoven/Veldhoven. Here all issues regarding automated buses and their automated lateral and longitudinal guidance, obstacle detection, emergency braking or surveillance of the vehicle, are available. Further information can be obtained on the Phileas-homepage (http://www.phileas.nl). In addition to the sensors used in the Phileas bus system a distance sensor is required as shared traffic predominates in the dedicated lanes. Braking vehicles in front of the high-tech buses have to be considered as drivers of dual mode vehicles have the possibility to interfere in the automated driving task at any time.

Dual mode vehicles The dual mode vehicles are ordinary cars, which are enhanced with a lateral and longitudinal guidance system, a human-machine interface, car-to-infrastructure communication system and an obstacle detection system. While the vehicle is operating in automated mode the driver is monitoring the system and therefore able to intervene in dangerous situations.

Information acquisition (obstacle detection) •

Range To determine the required detection range of the sensors, the stopping distance of the vehicle has to be estimated. Therefore the vehicle velocity, the deceleration and the delay time (computing time + build-up time of the brake system) are needed.

The minimum deceleration of a motor vehicle should be 5 m/s 2 as for example given by German law (§41, 4 StvZO). For build-up time a time span of 0.5 s can be estimated (Rössler, B. et. Al., 2005). With these values the stopping distance can be calculated according to Equation 1.

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Equation 1: Stopping distance

D=

v2 + t⋅v 2⋅a

By inserting different velocities in Equation 1 the following table can be created: Table 1: Stopping distances at 5 m/s2 velocity v in [km/h]

stopping distance D in [m]

10

2.16

30

11.11

50

26.23

70

47.53

80

60.49

Assuming that the maximum velocity of the vehicle does not exceed 80 km/h, the minimum detection range must be 60.4 m for an emergency braking situation at a maximum deceleration of 5 m/s 2 in 0.5 s. As given above, the detection range should be between 100 and 150 m for comfortable decelerations of 2.5 m/s 2 at a maximum velocity of 80 km/h. This can be provided by today’s modern ACC-sensors.

•

Angular field The distance sensor is used to determine the correct stopping distance behind another vehicle at bus stops, intersections and pedestrian crossings.

Furthermore the sensor increases the safety in case an object is detected in front of the vehicle. As the driver is present and monitors the system the angular field of detection is sufficient to be within the range of modern far-field ACC-sensors of 8 ° to each side.

•

Acquisition rate The acquisition rate must be suitable for detecting even fast moving targets, which can reach velocities up to 80 km/h as this is the maximum speed on the dedicated lanes. The requirements for the update rate are limited to 10-15 Hz (as an usual threshold for modern vision systems) depending on the applied sensor.

•

Obstacle Classification In case obstacles are identified in front of the vehicle, following actions of the guidance system are dependent on the type of the recognised target.

Therefore the obstacle detection system must identify the position, the relative velocity, the relative acceleration and the dimension of appearing obstacles.

With this data it should be able to classify the target as moving vehicles, stationary vehicles etc. so that the system is able to react in a proper way.

Feedback about the obstacle detection is sent to the traffic management system. In case of dual mode vehicles, the traffic management must decide whether the driver can manually overtake the obstacle or has to wait behind it.

This decision is based upon the traffic situation and the location (bus stop, intersection, higher velocity section etc.).

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Information processing •

Longitudinal guidance functions The velocity of the dual mode vehicle on the dedicated lanes is determined by the traffic management system, e.g. in dense traffic, at speed limits or at intersections. For higher safety the vehicles are equipped with distance or obstacle detection sensors. These sensors detect all obstacles in front of the vehicle, even if those obstacles are not monitored by the traffic management system (ghost-drivers, broken down vehicles etc.). The data from the distance sensor is classified with a higher priority in the longitudinal vehicle guidance compared to the data from the traffic management system, providing safety in case of braking cars in front of the vehicle or sudden appearance of obstacles.

•

Lateral guidance functions A possibility of lateral guidance for dual mode vehicles is the adoption of the automated guiding system used in the high-tech buses system. Other possibilities for lane recognition devices can also be implemented into the vehicle. To provide proper guidance the lane detection equipment must achieve a lane keeping accuracy of a maximum of 40 cm deviation between the middle of the dedicated lane and the middle of the vehicle. This is the average value for a human driver in urban traffic. The lane keeping system must provide this accuracy in order to prevent collision with oncoming traffic.

The vehicles have to follow the dedicated lanes on the track designed for buses. The average steering wheel angle has to be 200 ° as no parking manoeuvres and no narrow curves are present in the scenario.

System reaction •

Minimum and maximum velocity The average velocity for dual mode vehicles should be 50 km/h, if no leading vehicle is present, e.g. automated buses, which are regularly stopping at bus stops. The maximum velocity is limited to 80 km/h on the dedicated track.

•

Minimum and maximum acceleration/deceleration The maximum acceleration and deceleration is set to 2.5 m/s 2 in order to provide a comfortable ride. In emergency cases the maximum deceleration must be as large as the maximum deceleration of the automated buses. The minimum required maximum deceleration is 5 m/s 2. For modern buses the maximum possible deceleration is set to 9.5 m/s 2.

•

Human-Machine-Interface The human-machine interface (HMI) has the function to provide ongoing information about the driving conditions to the driver (in case of stopping at an intersection, entering or exiting the dedicated lanes) or about the control mode, which the driver has to activate (manual/ automated). Via the HMI the driver is able to operate the navigation system in which he can enter the planned route on the dedicated lanes at the access. Furthermore the driver is informed about the system status, critical situations, abnormalities and travel information.

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In general the tasks of the HMI are: Informing the driver about the driving situation (accelerating, braking, stopping) o

Informing the driver about the driving route

o

Handle the transfer of the driving task between manual and automatic

o

Provide the traffic management system with the desired driving destination

o

Inform the driver about critical and abnormal system behaviour

Cybercars The requirements for cybercars, which should drive fully automated with no driver present, are similar to the requirements on automated buses, although more strict. The reliability needs to be higher and the accuracy more detailed. Especially the reliability on the sensor signals is critical as there is no human driver monitoring the system from within the vehicle.

4.4.3 Requirements on infrastructure The conditions of the dedicated lane have to match the intended purpose. Therefore the lanes have to be wide enough, the curvature must not be to narrow and the gradient should not be great for the lanes that must accommodate bus traffic. For the lane width the default value is 3.5 m and the curvature should hold a minimum radius of 12 m [RĂ–S05] as specified for example on urban roads according to German law. The gradient of the lanes should meet the available engine power of buses, which lies approximately at 35 % (e. g. MAN Omnibusse), and therefore this limit must not be exceeded. To meet the requirements of the lateral guidance system, the lanes have to feature certain equipments (guidelines, transponder, clear markings etc.).

For the traffic on the dedicated lanes, two driving lanes, one for each direction, are sufficient as overtaking is not possible in this scenario. In case of obstacles on the dedicated lanes, which are blocking the driveway for cybercars, there is no possibility for the cybercars to overtake. The obstacle has to be removed by service personnel.

In order to offer all passengers a comfortable ride, the road must be in good conditions.

The limits of the dedicated lanes can consist of curb stones, a shoulder, which is covered by grass or trees or bright and white markings at intersections with public traffic, to ensure a safe separation between public and automated traffic. It should be impossible for ordinary traffic to enter the dedicated lanes except for the entrances, which are clearly marked prohibiting ordinary vehicles from entering.

For lateral guidance of the automated traffic a guidance system must be integrated into the dedicated lanes. This system has to consist of either magnetic nails or an electric wire, which are integrated into the driving lane. Other possibilities are visible road markings painted on the driving lane, which meet the demands of modern vision systems for lane keeping algorithms.

4.5

Comparison of requirements

In the following sub-chapter a comparison between the four scenarios is given. The most relevant and characteristics requirements with respect to the state of the art are highlighted.

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Table 2: Comparison of scenarios Scenario

Vehicles

Environment

Traffic

Pedestrians, bicycles, mopeds, small delivery vehicles and possibly private vehicles

Operating Operation mode

Dual-mode vehicles

Dedicated area

E-Lane

Dual-mode vehicles

Dual-mode vehicles on the Dedicated lanes track and ordinary traffic at intersections

Inner City Centre

Cybercars

Dedicated area

High-tech busessystems, dual-mode vehicles, cybercars

High-tech busessystems, dualmode vehicles, cybercars and Driver/ frequent Dedicated lanes pedestrians and autonomous bicycles on the dedicated lanes and public traffic at intersections

Town Centre

Dedicated lanes

Pedestrians, bicycles and low speed vehicles

Driver

Assisted driving inside (difficult manoeuvres, speed limits and parking) and manual driving outside the dedicated areas

Autonomous operation from low to high Driver/ speed inside autonomous the dedicated area otherwise manual driving Driverless

Autonomous operation at low speed Autonomous/ assisted driving up to max. velocity (about 80 km/h) on and manual driving of the dedicated lanes

The main challenges for each single scenario are: •

•

•

Town Centre: o Complex environment (road users, safety, speed) o Interventions on the infrastructure should be limited o Dual mode operation and mixed control (driver, system) Principal urban roads with an equipped lane (called „e-lane“): o Dual mode operation and transition manoeuvres o High speed o Interactions with ordinary traffic Inner city centre: o Level of service, information, journey time o Obstacle detection

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•

Shared traffic space with automated buses and dual mode vehicles: o Mixed control (driver, system) o Coordination of mixed traffic by an infrastructure-based traffic management system o Obstacle detection

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5 Preliminary system definition Based on the identified requirements, preliminary solutions to fulfil these requirements are given in this chapter. These are only preliminary definitions. In the following phase of the project (Task 3.1.2) a detailed design and system definition will be conducted.

The focus is set on the identified technological gaps compared to the state of the art, which have to be addressed within the other following work packages in SP3 of CityMobil.

5.1

Sensors •

•

•

•

Obstacle detection and longitudinal guidance - Lidar or - Radar or - Camera (image based system) The sensors have a range of about 150 m and a horizontal opening angle of about 16 °.

Lateral guidance - Camera (image based system) to detect bright lane markings or - Sensors for detection of magnetic/ electromagnetic field e.g. guide wire / magnetic nails - GNSS trajectory (see below “Position determination”) Position determination - GNSS, with an accuracy within the meter range or (e.g. DGPS) - Triangulation between communication bases along the track - Inertial measurement system - Laser based positioning - Odometer - Image based system Digital map - State of the art digital map for navigation systems - Next generation digital map with detailed information about the signage, the curvatures and street layout.

- High level digital map with very detailed information about the track, including landmarks, tunnels, bridges, parameters of the road sections (number of lanes, lane width, curvatures etc.) with an accuracy in the range of centimetres.

Depending on the complexity of the environment different requirements regarding the sensors for obstacle detection have to be fulfilled. In the protected environments of the scenarios “Principal urban roads with an equipped lane (called „e-lane)” and “Shared traffic space with automated buses and dual mode vehicles” only radar or lidar sensors will be utilised to detect obstacles on the own lane. In the scenario “Inner city centre scenario with cybercars” the interaction with pedestrians has to be considered. Therefore sensors with a higher coverage area like laser scanners are needed. The most complex environment is given in the scenario “Town centre”, where lidar, radar and camera based sensors are needed to detect obstacles like pedestrian, other vehicles, objects on the road etc.

Regarding the lateral guidance it is sufficient to equip the vehicles with camera based sensors, if bright lane markings are given, like in the scenarios “e-lane” and “shared traffic Preliminary system definition

28

space”. For the latter also the already existing guide wire/magnetic nails system can be used, instead of a camera. In inner city areas lane markings cannot be expected, therefore the lateral guidance has to be based in these cases on a GNSS-system in combination with a digital map, where the possible trajectories for the cybercars are described. In case the signal quality is too low because of buildings, other techniques such as RFID can be used. In case of the “Town centre” also continuous and ideal markings cannot be expected. Due to the more complex environment and limited traffic space, a more detailed and accurate digital map with information about the environment is needed for a GNSS-based lateral guidance.

5.2

Actuators • • •

Brake actuator (brake booster, electro-mechanical brake, brake-by-wire) Steering actuator (active steering, by-wire-steering) Throttle actuator (controls the engine output)

For dual mode vehicles utilised in the scenarios “town centre”, “e-lane” and “shared traffic space” all three mentioned actuators fulfil the requirements and can be used. In case of the brake booster it has to be considered that the device provides a sufficient deceleration capability also for emergency braking. In case of the cybercars the already existing and utilised actuators are not sufficient. Cybercars are not able to drive 50 km/h. The maximum velocity is 20 km/h as the actuators and brakes are only sufficient for up to 20 km/h.

5.3

ECUs • •

ECUs to pursue the different sensors e.g. position detection, obstacle detection and vehicle guidance (microcontroller, in-car PC) ECUs to operate actuators (microcontroller, in-car PC)

The state of the art ECUs fulfil the requirements for alls scenarios. In some cases it will be necessary to have redundant ECUs.

5.4

Communication devices

A communication with the infrastructure has to be established. Possible communication protocols are: • • •

WLAN UMTS GSM

The most suitable layout depends on the necessary range, reliability and the amount of data that has to be exchanged. By now WLAN (IEEE 802.11) solutions are already in operation, e.g. BMW Connected Drive and fit the necessary requirements.

WLAN uses the ISM band (Industrial, Scientific and Medical) for which the maximum transmitting power is limited by the Federal Communications Commission (FCC) as regulatory authority of the USA. For wave bands the frequencies 902 to 928 MHz, 2400 to 2483.5 MHz, 5150 to 5350 MHz and 5725 to 5825 MHz are available. The standard IEEE 802.11 defines two different transmission procedures on the Physical Layer (2.4 GHz frequency band). First the Frequency Hopping Spread Spectrum (FHSS) and second the Direct Sequence Spread Spectrum (DSSS). As alternative an Infrared interface can be used, which provides a data rate of 1 to 2 MBit/s. Furthermore a modem with a transfer rate of Preliminary system definition

29

20 MBit/s to 5 GHz/s has been specified for the Unlicensed National Information Infrastructure (U-NII) by the FCC. One of the main characteristics of the WLAN system is the transparent data communication between the mobile stations among each other or with stationary fixed network stations. The protocols are specified for slow moving stations, which are normally connected to each other (Ad-hoc-mode), e.g. in buildings, or to other stations outside the direct range by use of an available infrastructure (Infrastructure Mode) that communicate package oriented.

Communication with other vehicles is not needed for most of the scenarios. Only in case of the scenario “Inner city centre” communication with the cybercars could be needed for the fleet management. The most important aspect is the communication with the infrastructure for the acquisition of updated information like in the e-lane scenario (construction sites, road condition etc.) and fleet and vehicle management. For the scenario “Shared traffic space” vehicle-infrastructure communication is essential, because the dual-mode vehicles are not equipped with digital maps. All necessary information is provided by the traffic management system by means of communication.

As the communication is often time critical and therefore has to be fast and reliable GMS does not suit for this application, whereas both UMTS and WLAN meet the most requirements. Additional adaptations of these communication technologies are needed to meet also the requirements regarding reliability and security.

5.5

HMI technology •

Screen for presenting track information to the driver in terms of symbols, scripts, pictures, voice commands, animations or films

•

Input device (touch screen, keyboard), to enter or change the desired destination

•

Microphone and speakers, to allow a two way communication (e.g. emergency call with the control centre)

•

Possibility to activate emergency functions (emergency stops / calls)

•

User identification and billing of the journey (e.g. by fingerprints/ ID-Cards or electronic cash)

The interface to the driver is a very important aspect in all scenarios. Especially in the scenarios, where dual mode vehicles or assisted vehicles are utilised it is important to provide the driver information about the status of the systems, as he is responsible for monitoring the system. The driver can therefore always intervene and overrule the system in case of dangerous situations or malfunctions. Principally the HMI concepts for driver assistances system can be utilised for these vehicles. Visual, acoustical and haptical interfaces and control elements for the driver to activate/deactivate and overrule the systems are state of the art.

In case of the cybercars input device (touch screen, keyboard) to enter or change the desired destination, microphone and speakers, to allow a two-way communication (e.g. emergency call with the control centre) are needed. In case of emergency situations the passenger should also have the possibility to activate emergency functions (emergency stops / calls).

Besides this HMIs for user identification and billing of the journey (e.g. by fingerprints/ IDCards or electronic cash) are also necessary for cybercars.

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6 Conclusions The objective of CityMobil sub-project 3 is the analysis of vehicles and technological issues for the achievement of a more effective organisation of urban transport systems. Investigations and research of vehicles layout, system architecture, communication systems and further technological aspects are the focus of the first work package.

The first step in sub-project 3 is the consideration of four different working scenarios. These are selected based on today’s available adoption of technology and know-how. In principle four different scenarios are considered, which cover these aspects.

The first scenario “Town centre” deals with partly automated dual mode vehicles/advanced city cars in a historical town centre. The second scenario is a combination of cybercars and dual mode vehicles (mixed traffic) “Principal urban roads with an equipped lane (called „elane)”. In third scenario, “Inner city centre”, cybercars are operated within a city area. The last scenario (“Shared traffic space with automated buses and dual mode vehicles “) describes automated high-tech buses on dedicated lanes, which are shared with dual mode vehicles and cybercars.

The main identified challenges for the town centre scenario are on one side the complex environment (road users, safety, speed) and dual mode operation respectively mixed control of the vehicles. On the other side modifications of the infrastructure should be minimised to obtain the historical town centre. The e-lane scenario is characterised by dual mode operation on dedicated lanes, where interaction with ordinary traffic at high speed has to be considered. In the inner city centre scenario the application of cybercars is extended.

Pedestrians and other slow-moving traffic participants have to be taken into account. The last scenario “shared traffic space” the main challenge is represented by the mixed control of the vehicles on one side and on the other side by the mixed traffic participants (buses, dual mode vehicles, cybercars).

Generally the main requirements for these scenarios can be classified into three groups: •

Detection of obstacles: As the vehicles in the four scenarios do not move in a protected environment only, other traffic participants and obstacles have to be detected. Therefore environmental sensors like radar, lidar and camera-based technologies have to be utilised and adapted to the detailed needs of each of the scenarios. Depending on the level of interaction with other traffic participants partly the state of the art sensing technology is sufficient.

•

Vehicles guidance: For autonomous or assisted longitudinal and lateral guidance information about the surrounding environment is needed. Especially in complex areas, as given in the town centre scenario, the acquisition of this information by sensing technologies is difficult. A solution for this challenge is presented by GNSS and detailed digital maps with the necessary information about the attributes of the surrounding road sections.

•

Communication with other traffic participants and infrastructure is an essential aspect for all four scenarios. The communication has to be secure, reliable and allow high data rates. State of the art communication technologies fulfil already many of these requirements. However modifications of these technologies are necessary.

The requirements on actuators (except for Cybercars for higher speed), ECUs and HMIs can be fulfilled by the technologies, which are already available.

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7 Appendix 7.1

Detailed description of scenarios – Town centre

7.1.1 A concept for vehicle functionalities The vehicles considered for this scenario are able to travel both outside and inside the historical town centre. In the first case, they are inserted in ordinary traffic and normally driven, while in the protected area they exploit advanced functions and a strong compatibility with the special environment.

To this purpose, the potentialities of CityMobil vehicles with on-board intelligence are relevant. The assisted vehicles will be parked around the zone and allowed to drive in a dedicated network of roads. In particular, the following functions are considered: • Dual mode operation, with possibility for both manual and assisted/automatic driving.

• Speed control, according to the conditions of the site.

• Assisted driving, especially in difficult or narrow passages, in order to follow a fixed trajectory (e.g. in a right angle curve) or to stop at precisely defined places: these characteristics permit the use of the vehicle also by “non-expert” drivers, enlarging the number of potential users. (Figure 7-1).

• Possible extension of such assisted route following, when accessing a parking place or even a private area.

• Obstacle detection for increased safety of the other road users, especially pedestrians.

• Specific control logics for the power-train in the protected area, for a significant reduction of unwanted emissions.

• Capability of use in platoon, where the first vehicle is manually driven and a second one is linked automatically, for instance in order to pick up a vehicle or bring it to a user.

Figure 7-1: Concept for assisted guidance in a curve

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Such a scheme can be effectively coupled to a “car-sharing� approach, allowing mobility for the residents according to their individual needs, and avoiding at the same time some of the disadvantages connected to the ownership of a vehicle.

This approach is related to the lack of stopping and travelling areas, and the need to limit the circulating fleet of vehicles. Telematic functions are therefore important to maintain the vehicle and the user in contact with a control centre, for functions such as service management, security, diagnostics, logistics and maintenance.

7.1.2 Conditions for use of the vehicles in the protected area The following conditions take into account the situation of Genova: they can represent several similar Cities especially in Southern Europe.

Table 3: Basic Conditions – Town centre Environmental Topology

Historical town centre with a surface of 113 Ha, very compact and with a structure / street layout limiting vehicle access and halting places. The assisted vehicles will be parked around the zone and allowed to drive in a dedicated network of roads. Total length (for a first feasibility study) can be 12 km.

Road gradient Small in the selected area (future extension possible) Environment

Mediterranean town Average monthly rain between 27mm (July) and 153 mm (October) Average minimum temperature between 5 deg (January) and 21 deg (August) Average maximum temperature between 11 deg (January) and 27 deg (August)

Lane layout Surface structure

Mostly paved with slabs or stones (see figure 2)

Number of lanes

One lane, with often one way and partly two way circulation

Lane width

Small roads (3 - 5 m typical)

Lane limits

Buildings (presence of main doors, shop windows, entrances to private areas)

Curvature

Down to 4 m radius; feasibility of assisted manoeuvres to be investigated

Tunnels, bridges

Absent

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Lane markings Turning arrows

No

Marking conditions

Marking not present

Construction marking

Marking not present

Field of vision Occlusion by high curvatures

Frequent (crossings, junctions)

Occlusions by Frequent (buildings) buildings, trees Occlusion by other users

Frequent (pedestrians, cycles, small vehicles)

Tunnels, bridges

No

Sun glare

Limited

Infrastructure Traffic lights

No (if necessary, a vehicle/infrastructure communication could be used)

Signs

Present; in particular: stop and yield, one way roads, no entry

Intersections

Several

Table 4: Driving – Town centre Velocity Limitations

To be defined according to road layout and safety

Average velocity

10 km/h (preliminary)

Maximum velocity

30 km/h (preliminary)

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Level of assistance Longitudinal guidance

For difficult manoeuvres (sharp curves and narrow passages) + speed limit

Lateral guidance

For difficult manoeuvres (sharp curves and narrow passages)

Platooning

Possible for picking up a vehicle or bringing it to somebody (to be investigated)

HMI

Driver should understand the interventions of the assistant and also know when she/he is entering the zone with assisted driving

Table 5: Traffic – Town centre Traffic situation (see Figure 7-2) General

Local traffic for inhabitants (elderly, families, transport of heavy loads, services, emergency etc.) operators working in the area, and owners of small shops (supply and delivery of goods)

Oncoming traffic

Mostly pedestrians, cycles and moped, small delivery vehicles; some private cars are present

Interaction with other users

Frequent with pedestrians, cycles and small vehicles

Figure 7-2: Typical road scene in Genova

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7.1.3 Specific capabilities – Town centre In comparison with the other scenarios chosen, the selected case of the “town centre” is characterised by the following aspects, especially requiring innovative technological solutions.

First of all, the vehicle characteristics, even if specialised for urban trips, should allow both manual and assisted driving. A standard production car should be the base platform, equipped with additional assistance functions, which can be introduced when needed. This combination has received less attention in the past, compared to fully autonomous vehicles.

The Human Machine Interface solutions require special consideration, since the driver should be always well aware if the vehicle is inside or outside the protected zone. Moreover, well-accepted and safe solutions should be developed regarding the interaction between manual and automatic controls, when following a predefined trajectory during difficult manoeuvres.

Obstacle detection and avoidance poses a number of challenges: these are due to the presence of several road users in limited spaces, the high number of lateral entrances into the lane and obstructions which can limit the view of potential obstacles. Innovative technologies have a great potential in this field, but the constant supervision and control by the driver should be envisaged.

7.2

Detailed description of scenarios – Principal urban roads with an equipped lane

7.2.1 Environment for e-lanes In a first-stage implementation, e-lanes should be restricted to such roads that prevent the existence of pedestrians or cyclists on the road by constructive measures. The reason is that at the selected speed range of 0-120 km/h at present no suitable technology exists that could detect such obstacles early enough with an appropriate level of reliability.

Level crossings introduce a much higher level of complexity and probably require additional technical equipment in the infrastructure as well as the participating vehicles, e.g. to transmit the traffic light status to the vehicles. Therefore the basic e-lane has been defined for roads free of level crossings.

In order to meet all these preconditions, urban expressways provide the ideal environment for first real applications of e-lanes. Due to the limitations, especially the call for the absence of level crossings, e-lanes implemented on other types of urban roads will be probably too short to be really useful in terms of traffic flow or travel comfort, but will suffice for testing and demonstration purposes.

A car to infrastructure communication system is a vital part of the e-lane scenario. For cost reasons, this system can consist of frequently spaced access points instead of a system with a constant connection. Every vehicle on the e-lane has to obtain clearance from the infrastructure system before transferring to the higher automated mode. Clearance will be denied, if there are adverse conditions or accident sites on the road section. The infrastructure system receives information about road conditions from its own sensors and from passing vehicles.

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Figure 7-3: DLR test track in Berlin-Adlershof, a possible site for e -lanes

7.2.2 Vehicles used in e -lanes The base vehicle for an e-lane scenario can be any off-the shelf road vehicle. In the design of the e-lane scenario mainly passenger vehicles of medium and smaller sizes were considered since these are widely used for urban passenger transport. The main purpose for the basic scenario was to make use of serial-production systems wherever possible and get by with as few additional sensors and actuators as possible.

Looking at the actuator side, most of today’s modern vehicles already provide a good basis for the necessary drive-by-wire- interfaces, e.g. electrically powered steering assistance. For the detection of obstacles such as other vehicles, a wide range of sensors, notably based on RADAR and LIDAR technology, are on the market. For suffic ient reliability, a redundant system of two different sensor systems should be considered.

Similar to obstacle detection, the positioning system should have at least two independent ways of determining the vehicle position. One way to achieve this is to combine a differential GPS receiver with an optical lane detection system.

7.2.3 Conditions for use of the vehicles in e-lanes The following conditions are necessary for the operation of dual use vehicles as proposed for the use on e-lanes. Most European inner city expressways meet these conditions.

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Table 6: Basic Conditions – Principal urban roads with an equipped lane Environmental Topology

Principal urban roads with several lanes per direction and structural segregation from pedestrian areas. One or more of these lanes are dedicated e-lanes with mixed traffic between manually driven cars and vehicles in more highly automated driving modes.

Road gradient No high gradients that make special demands to the vehicles Environment

Practically no temperature limits, except for the operation limits of standard passenger vehicles System might not be operational in extremely heavy rain System might not be operational when streets are snow covered

Lane layout Surface structure

Paved road

Number of lanes

Two or more lanes in each direction

Lane width

Typical lane width 3.5 m or more

Lane limits

Clearly visible markings

Curvature

No strong curvature

Tunnels, bridges

Present, sufficient illumination necessary

Lane markings Turning arrows

No

Marking conditions

Clearly visible markings

Construction marking

Clearly visible and unambiguous markings or system temporarily disabled in construction areas

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Field of vision Occlusion by high curvatures

No

Occlusions by No buildings, trees Occlusion by other users

Possible

Tunnels, bridges

Possible

Sun glare

Limited tolerance for sun glare

Infrastructure Traffic lights

No (possible in later stages)

Signs

Present

Intersections

No level intersections (possible in later stages)

Table 7: Driving – Principal urban roads with an equipped lane Velocity Limitations

Speed limits for manual traffic applies also for dual mode vehicles

Average velocity

Depending on road type

Maximum velocity

120 km/h (preliminary)

Level of assistance Longitudinal guidance

Yes (similar to ACC with haptic feedback)

Lateral guidance

Yes (similar to Honda LKAS)

Platooning

No (possible in later stages)

HMI

Driver receives haptic and audiovisual feedback when in higher-automated mode

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Table 8: Traffic – Principal urban roads with an equipped lane Traffic situation (see Figure 7-2) General

Mainly commuter and commercial traffic

Oncoming traffic

No oncoming traffic due to structural segregation of the carriageways

Interaction with other users

No pedestrians, no bicycles. Motorcycles, passenger and commercial vehicles present

7.2.4 Specific capabilities – Principal urban roads with an equipped lane One of the challenges in the e-lane scenario is the fact that highly automated vehicles are operated in a mixed traffic environment together with manually driven passenger vehicles.

However, to maintain a reasonable level of complexity, it was chosen to start with inner city expressways in the first stage of the scenario. This provides an environment free of obstacles such as pedestrians and bicycles, which are difficult to track using today’s sensor technology.

Therefore the obstacles to be detected include motorcycles, passenger vehicles and larger commercial vehicles. In principle, these types of obstacles can be detected safely by state-ofthe-art sensor technology, however to achieve a sufficient level of reliability, a combination of two different sensors such as RADAR and LIDAR should be employed.

The car to infrastructure communication systems allows interchanging information in either direction. When the automation system in a vehicle notices adverse road conditions such as ice or snow, it can inform the infrastructure system via the next access point. This reduces the necessary efforts for sensors such as video cameras on the infrastructure side.

The Human Machine Interface is crucial for the functionality and safety of the system as the transfer of authority from the automation back to the human driver is one of the back-up strategies in case of technical failures or a situation that the automation cannot deal with.

This is only feasible if the driver receives continuous feedback about the vehicle status in order to keep him in the driving loop. The HMI will include multi-modal interaction with the driver via the haptic and audiovisual channels. Driver actions will be monitored and warnings will be issued, e.g. if the driver leaves his place and therefore becomes unable to take over the vehicle controls quick enough in case of a system failure.

7.3 7.3.1

Detailed description of scenarios – Inner city Condition for the use of cybercars in the dedicated area

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Table 9: Basic Conditions – Inner city Environmental Topology

Inner City area. No specific surface area but short length course (~1 km).

Possibility of reserved places for cybercars parking. Width of road should allow pedestrian (or bicycle) and cybercars to use simultaneously this road in a secure way. Possibility of bottleneck road (no place for overtaking or park places).

Road gradient Usually low gradient/slope.

Maximum 10% in both direction for the considered cybercars Environment

Temperature should be less than 50°C because of batteries and electronic system of cybercars.

No specific rain conditions (IP65).

Lane layout Surface structure

Asphalt-like and paved road, must respect 10cm ground clearance.

Number of lanes

Road usually made of 2 lanes for both directions.

Lane width

No specific lane width: from large circulation area to narrow street.

Possibility of 2 ways on one lane (restricted access to only 1 vehicle at the same time).

However road width should allow simultaneous passing of cybercars and other users (pedestrian, bicycle)

Lane limits

Buildings, bicycle parking places, shops or terraces, pedestrian zone marker.

Except these physical limits, lane width will be defined by cybercars’s width and a security coefficient.

Curvature

Should be more than 4 m regarding the cybercars characteristics.

Tunnels, bridges

Possible presence of tunnels and bridges.

Lane markings Turning arrows

No arrows marking

Marking conditions

Lane marking if necessary for vehicle guidance.

Construction marking

No construction marking.

Lane marking possible to allow pedestrian and others to know where cybercars circulate.

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Field of vision Occlusion by high curvatures

Sometimes (crossings, junctions)

Occlusions by Frequent (buildings, trees, kiosk) buildings, trees Occlusion by other users

Frequent: pedestrians, bicycles. Less frequent: small vehicles (garbage collection, cleaning machine)

Tunnels, bridges

Possible

Sun glare

Can occur

Infrastructure Traffic lights

Specific circulation signals should be treated by the supervisor and the fleet management system and by vehicle to vehicle communication, not by a modification of infrastructure.

If existing, system should be able to get signals information.

Signs

Used to inform people of cybercars circulation.

Reserved park places for cybercars.

Special maintenance and supply dock position.

Special passenger loading station and access points.

Intersections

Yes. Can be T-crossing, X-crossing or roundabout.

Lanes can be merged or separate.

Table 10: Driving – Inner city Velocity Limitations

To be defined according to road layout and safety

Average velocity

10 km/h

Maximum velocity

30 km/h

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Level of assistance Longitudinal guidance

Totally automated transportation system on predefined tracks Off-tracking management for navigation of a train of vehicles or multi-trailers Cybercars (safety and integrity of vehicles).

Obstacle avoidance, obstacle bypassing

Lateral guidance

Is part of totally automated transportation system on predefined tracks

Platooning

For picking up a vehicle or bringing it to park places or users For several vehicles following the same track Passenger needs to understand the Cybercars comportment

HMI

Table 11: Traffic – Inner city Traffic situation (see Figure 7-2) General

No motor vehicles except garbage collection and cleaning machine (low speed vehicles).

Pedestrian zone. Example is given in Figure 7-4.

Oncoming traffic

Mostly pedestrians, bicycles. Rarely services vehicles (garbage, cleaning).

Interaction with other users

Frequent with pedestrians and bicycles.

Figure 7-4: Possible inner city automated transportation scene (NancyCab from the French MobiVip project)

7.3.2

Specific capabilities – Inner city

Compared to other scenarios, the inner city scenario is dedicated to fully autonomous vehicles moving between pedestrians and bicycles in a dedicated area. The realisation of this scenario will need to apply a set of technological innovations bringing flexibility, comfort and security to users.

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The most “important” technological innovation is relative to security and autonomous capabilities for handling abnormal situations. As cybercars are moving autonomously between pedestrian and bicycles the obstacle detection and avoidance capabilities should be developed with the intention to limit the human (Cybercars users) intervention to “zero” (even if a hardware emergency stop is mandatory).

In addition to “direct” obstacle detection and avoidance, off-tracking management for navigation of a “train” of cybercars or multi-trailers cybercars must be developed. Indeed, in the case of platooning, this off-tracking management is mandatory to ensure safety and integrity on the path followed by the vehicles. It will guarantee the integrity of vehicles and collision avoidance.

Cybercars users will be confident in the system only if they are constantly informed and understand the vehicle’s behaviour. If they see an obstacle on the vehicle trajectory they must be informed that it has also been detected by the obstacle detection system.

Moreover, the HMI won’t be only embedded in the cybercars but will also be part of cybercars access points to inform about the transportation system status.

On top of the transportation system a fleet manager should be implemented to handle all users’ inquiries and information about each vehicle. The computation of this information will allow routing and timing optimisation for each vehicle in the network of cybercars. By taking into account users needs and delays, the fleet manager will be able to re-plan the whole system in real time.

7.4

Detailed description of scenarios – Shared traffic space with automated buses and dual mode vehicles

7.4.1 Traffic management and vehicle functionalities The scenario includes three different types of vehicles, the automated high-tech buses system, dual mode vehicles and cybercars. As soon as the vehicles are travelling on dedicated lanes all three types of vehicles will be guided automatically. For a safe flow of traffic a highly developed traffic management system is necessary. In the following these four elements are described in detail.

1. Traffic management system The traffic management system monitors the traffic on the dedicated driving lanes. It controls the entrances for dual mode vehicles, regulates the procedure at bus stops and intersections and guides the dual mode vehicles to their designated exits.

In total the main tasks of the traffic management system are: • • • • •

Monitor the position of each vehicle on the dedicated driving lanes Provide comfortable entrance possibilities for dual mode vehicles Conduct stopping manoeuvre for automated buses at bus stops Control all vehicles at pedestrian crossings and intersections Guide dual mode vehicles to designated exits

Further possible and imaginable tasks and applications like calculating toll fees or informing the driver about the traffic situation at the destination are of secondary importance and should not be discussed in detail at this point.

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The traffic management system consists of a computer system, an infrastructure based vehicle-to-infrastructure-communication and a human-machine interface within the dual mode vehicles, automated buses and cybercars.

The traffic management monitors each situation at bus stops, pedestrian crossings or intersections. Therefore the system needs to be informed about the number of vehicles and their position on the dedicated driving lane at the entrance of the vehicles onto the track by means of vehicle-to-infrastructure-communication.

At bus stops and at pedestrian crossings all vehicles come to a full stop and have to wait. In order to come to a comfortable full stop, all vehicles have to be equipped with vehicle-toinfrastructure communication devices. In case the dedicated driving lane needs to be crossed by pedestrians or other traffic, the management system coordinates the traffic signals and initialises a stop of all automated vehicles near the intersection. This manoeuvre can therefore be initialised by the system not just in time, in order to stop vehicles abruptly, but well in advanced of the place to stop, so that a comfortable deceleration of the vehicle is achieved.

The human-machine interface informs the driver of dual mode vehicles and cybercars, when they have to switch back to manual mode, when they are allowed to enter the dedicated driving lane and when they have to leave the lanes at their destination.

The traffic management computer knows the number of vehicles and their position on the dedicated driving lanes. Therefore the entrance of additional vehicles can be easily coordinated not just by number of vehicles, but also by the timing of the entrance.

2. High-tech buses system Although the high-tech buses guidance system is fully automated and even approaches all bus stops in automated mode, a driver is on board at any time in order to monitor the system and to ensure that the route is being followed safely. Therefore the systems have to be operated in normal and in automated modus. An example of such a vehicle is given in Figure 7-5, which shows the Phileas high-tech buses system in Eindhoven.

Figure 7-5: Example for an automated bus, Phileas in Eindhoven, Netherlands

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The vehicle is equipped with sensors for driving lane detection to provide lateral guidance. In the longitudinal direction the vehicle velocity is also provided by an automated control system. Today’s automated bus systems such as the Phileas are not equipped with a headway sensor. Combined traffic on shared lanes demand a sensor system to detect obstacles in front of the vehicles in case of intersections or manually initiated stopping manoeuvres. Furthermore infrastructure-to-vehicle communication systems have to be mounted in the vehicles to exchange information (e.g. vehicle position and vehicle velocity) between the buses and the traffic management system.

The average velocity of the high-tech buses is within the range of 0-50 km/h. Longer distances between two bus stops allow higher velocities of up to a maximum of 80 km/h. The driver, who monitors the system throughout the drive, can intervene at every point in time in critical and dangerous situations.

The number of necessary buses, which are needed to operate the system, is dependent upon the length of the driving route. A frequency of every 10 minutes is the target during rush hours (the Phileas bus passes a bus stop every 10 minutes).

3. Dual mode vehicles and cybercars The dual mode vehicles and cybercars are also equipped with sensor systems for longitudinal and lateral control. Those types of vehicles need to communicate with the traffic management system as well (vehicle position, vehicle velocity, etc.). The vehicles are able to perform automated stop and go manoeuvres at bus stops, intersections and pedestrian crossings.

Before entering the dedicated driving lane the driver enters the destination to a man-machine interface. As soon as the traffic management system accepts the information and receives the vehicle position, the driver is allowed to enter the lane. Once on the lane he will be requested to switch into automated driving mode. Before leaving the lane he is notified by the man-machine interface to take over the driving task again and leave at the next exit. During the travel the driver himself only has to monitor the system and interact in dangerous and critical situations. The dual mode vehicles and the cybercars follow the buses on the lane and do not have the opportunity to overtake them.

Cybercars do not leave the designated lanes and have the same driving route as automated buses. In principle there are only two differences between cybercars and automated buses.

The number of people that can be transported by cybercars is much lower and they do not require a driver on board. Therefore cybercars are considered as more advanced high-tech buses systems within this scenario. Given those considerations cybercars are preferably introduced during nighttime instead of automated buses as the need for mass transportation is lower and the lack of human driver helps to lower costs.

7.4.2 Infrastructure and basic conditions The infrastructure for the scenario “City with dedicated lanes for automated buses (lanes shared with dual mode vehicles and cybercars)� is based on already existing dedicated road networks. Figure 7-6 shows the road network created to connect the airport with the central train station and other parts of the city in Eindhoven, Netherlands.

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The requirements regarding the layout (e.g. curve radiuses and turning possibilities at intersections) of the road network have to be suitable for buses. Tunnels and bridges do not cause any problems as long as a safe vehicle-to-infrastructure communication is available and therefore the position of each vehicle on the dedicated lane is known to the traffic management system.

Figure 7-6: Road network of the automated high-tech buses system in Eindhoven, Netherlands

1 km

The dedicated bus lanes provide one lane per travel direction. The lane surface structures are of good quality. The width of the lane is suitable for vehicles and especially for buses.

Driving lanes equipped with magnets can serve for lateral guidance in the automated systems of the high-tech buses. A shoulder separates the dedicated lane from the ordinary road network. Typically the shoulder is covered by grass or trees, but the separation can already be realised by curbstones or visible lane markings as well.

The field of vision must not allow occlusions of the driving way in front of the vehicles as the driver in each vehicle still has the responsibility to monitor the system and intervene in dangerous situations. Therefore occlusion in curves should also still allow the driver to have a good overview over the driving track and react appropriately in dangerous situations.

Lane markings are present on the driving lane surface to indicate pedestrian crossings, intersections of upcoming bus stops. These have to be in good conditions to provide good visibility to the driver, who is monitoring the system and has to be informed about upcoming situation changes well in advance. Furthermore pedestrian crossings, intersections and bus stops have to be equipped with infrastructure-to-vehicle communication. Lane markings could also serve as orientation markings for the lateral guidance of the vehicles. An example of a typical driving lane layout for this scenario is given in Figure 7-7.

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The entrances onto the driving track are regulated by traffic lights. A vehicle is allowed to enter the lane after the traffic management computer is informed and the GPS position is allocated by the system. The computer calculates a safe entrance time and switches the traffic lights.

Figure 7-7: Dedicated lanes for automated high-tech buses systems in Eindhoven, Netherlands

Construction sites and construction markings must not be present on the driving lanes, as no automated traffic will be possible during construction work.

Bus stops are located at regular distances along the entire route. The stops are constructed on raised platforms, which allow the passengers to get on and off the bus without having to climb steps. This is an advantage for older and disabled people. The bus stop is being approached in fully automated mode by the electronic guidance system. The bus stop information system informs the traveller about the arrival time of the bus in minutes.

Infrastructure-to-vehicle-communication stations are located next to the driving lane to provide good communication quality. The number of stations and distances between them are based upon the communication range of the vehicles and the stations.

7.4.3

Conditions for use of the vehicles on dedicated lanes

The following conditions are necessary for the operation of high-tech buses systems, dualmode vehicles and cybercars on dedicated lanes in urban areas.

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Table 12: Basic Conditions – Shared traffic space with automated buses and dual mode vehicles Environmental Topology

An urban area with no specific attributes is foreseen. Separate parking spaces for cybercars and buses at the bus station should be provided. The construction of overtaking bays is not necessary, because the vehicles follow each other.

Road gradient Usually low gradient, suitable for buses.

Environment

No specific weather conditions (Continental weather).

Lane layout Surface structure

Concrete road to reduce flange groove.

Number of lanes

Road with 2 lanes, one for each direction.

Lane width

Road width should be suitable for buses (Lane width 4 m).

Lane limits

The lane limits should consist of curbed stones, visible lane markings or shoulders covered by grass or trees.

Curvature

The minimal curvature should be 12 m in order to be suitable for buses.

Tunnels, bridges

Tunnels and bridges can be present on the track.

Lane markings Turning arrows

In necessary

Marking conditions

Specific lane markings for the lateral guidance (depending on the guiding system used in the high-tech buses) are necessary. Lane markings to distinguish e.g. pedestrian crossings or other intersections and to define the dedicated lanes must be clearly visible for camera systems.

Construction marking

No construction site allowed in automated driving mode

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Field of vision Occlusion by high curvatures

The radiuses of the curves are optimised for buses and therefore an occlusion of the field of vision is unlikely.

Occlusions by As the lanes are designed to fit buses occlusions by trees and buildings are buildings, unlikely. trees Occlusion by other users

Crossings and intersections need to be free of buildings and trees so that there is no occlusion present in dangerous and critical situations.

Tunnels, bridges

Possible in case tunnels occur.

Sun glare

Can appear.

Infrastructure Traffic lights

Can occur on the dedicated lanes to control the interaction between traffic on the dedicated lanes and public traffic and to give way to swinging in traffic.

Signs

Dedicated lanes are marked clearly. Bus stops and intersections as well as pedestrian crossings have to be marked for driver of dual-mode vehicles.

Intersections

Can occur at contact points with public traffic.

Table 13: Driving – Shared traffic space with automated buses and dual mode vehicles Velocity Limitations

To be defined according to road layout and safety.

Average velocity

50 km/h

Maximum velocity

80 km/h

Level of assistance Longitudinal guidance

Fully automated transportation system on predefined tracks

Lateral guidance

Totally automated transportation system on predefined tracks

Platooning

No platooning available

HMI

HMI to inform the passenger about the behaviour and actions of the vehicles

Obstacle avoidance

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Table 14: Traffic – Shared traffic space with automated buses and dual mode vehicles Traffic situation (see Figure 7-2) General

Cybercars, dual-mode vehicles and high-tech buses-systems

Oncoming traffic

High-tech buses, cybercars, dual-mode vehicles

Interaction with other users

Pedestrians and bicycles at crossings, public traffic at intersections

7.4.4

Specific capabilities – Shared traffic space with automated buses and dual mode vehicles The scenario “shared traffic space with automated buses and dual mode vehicles” is dedicated to the interaction of high-tech buses-systems, cybercars and dual-mode vehicles among each other and with other road users, e.g. pedestrians and bicycles on a dedicated lane. The implementation of this scenario in an urban environment will base upon technologies, which allow a safe and comfortable ride with a simultaneous good availability.

The core of the dedicated lane scenario will be represented by the guiding systems of the vehicles and the fleet management. Because of the autonomous movements of the vehicles on the dedicated lanes and the individual choice of dual-mode vehicles, the routing of the traffic plays a decisive role. Due to the possibility of suddenly appearing obstacles (broken down vehicles, pedestrians) an additional on board control system has to be developed.

The traffic management technology has to control all autonomous vehicles, manage the interaction of the traffic on the dedicated lanes with public traffic at intersections or pedestrian crossings and adopt the navigation for all vehicles. The traffic management regards all possible situations and incorporate them into its calculations. To guarantee a safe ride an onboard control system has to be integrated, which is capable of vehicle-to-infrastructure communication and includes an obstacle detection system that is able to detect obstacles in front of the vehicle.

Passengers are informed about the status of the vehicles, its actions and behaviour.

Therefore the autonomous vehicles have to be equipped with a HMI, which provides information e.g. about oncoming traffic and detected obstacles or other abnormal situations.

To assure an easy use another HMI system has to be mounted at the bus stops e.g. to inform the passenger about the arrival of the next bus or to enable the user to call or reserve a cybercar.

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8 Acknowledgement Chapter 4.1 and 7.1 is written with significant support of researchers from the Urban Mobility Council in Genova. Special thanks are due to Prof. Vittorio Garroni Carbonara, Prof.ssa M.Benedetta Spadolini and Dr.ssa Silvia Pericu from the Faculty of Architecture in Genova University.

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9 Sources 9.1

Reference List

RĂ–SSLER, B. et. Al., 2005. SP Deliverable - D40.4 - Requirements for intersection safety applications, In: Preventive and Active Safety Applications, Integrated Project, Contract number FP6-507075

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