IEEE PNEC Perspective Volume 4 â—? Autumn 2012
p.6 Pneumatic Robotic Arm BILAL GAHAUR
p. 3
Introducing the Mecanum Wheel p. 6 Mecanum wheels are used to provide omni-directional capability to the vehicle they are installed to. Read through the article to get to know more about it! ONIB NASIR & M USMAN YOUSUF 7 years of IEEE PNEC p.9 Read through the journey of IEEE PNEC since its inception. Also get to know the comments of the important persons associated with IEEE PNEC since the very beginning. Implementation of PID in a line following robot p.12 Line following robots have great popularity amongst students and hobbyists. What greater way to control them then implementing PID! ADIL FAQAH Robotic Arm Interfaced with the Internet p.14 Learn about the design and fabrication of a robotic arm controlled via the internet which was indigenously developed at PNEC HAMMAD KHALID Women in Engineering: Dearth of Induction & Retention p.15 After carrying out a survey in South Asia, the analysis behind the major reasons of the dearth of induction and retention of women in engineering was done. REHMA JAVED & RABIA KHALID Member News See what the IEEE members have been upto
WWW.IEEEPNEC.ORG
p.17
contents
In the News A synopsis of the events conducted by IEEE PNEC since March
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
2
In The News PNEC outshines everyone at Procom.net 2012!
P
NEC participated in Procom.net 2012. An annual event held in NUCES FAST. This year there were a lot of participants from all across Pakistan. A total of 23 teams from PNEC were participating in this event. The teams from PNEC did a remarkable job and brought back laurels. PNEC won the following competi-
tions: Micro-controller and Interfacing: (Runners up) Logic Quiz: (Winners) and (Runners up) I-Quest: (Runners up) and (3rd position) Hardware Exhibition & Competition: (Runners up) & (3rd position) Circuit Designing: (Winners) and (3rd Position)
Career Counseling IV
C
areer Counseling Seminars are being organized by IEEE PNEC for the past 3 years. This year it was held on 5th April 2012. The following companies were a part of this event:
Schneider Electric, MIT Enterprise Forum, Siemens Pakistan, AINiT, Higher Education Consultancy Firm and Mr. Immaduddin who is a PNEC 2002 Graduate and Avanceon. The representative from Schneider Electric gave detailed explanation about their company and their recruitment procedure. Mr. Athar Rizvi of MIT Enterprise Forum guided the audience about being a successful entrepreneur. Siemens Pakistan, told the students about their recruitment procedures. The representative briefed about the fieldwork and also talked about internships. Mr. Levi, from the AINit, Higher Education Consultancy Firm briefed the students about the benefits of applying to Australia & New Zealand for higher studies. Mr. Immaduddin, who shared a bond with the students of PNEC, told them that having self-awareness of what you can do is a vital factor for a bright future. He explained why PNEC graduates face difficulties in the corporate sector and how it can be minimalized.
Membership Drive 2012
I
EEE PNEC Student Branch held its Membership Drive on 20th April 2012. This drive was conducted basically for the students of Semester 1 to 4, to let them know of the manifested benefit of joining IEEE and to encourage them to be a part of this society. The one and a half hour session consisted of interactive sessions from Hassaan Idrees – the GINI Representative of Region 10 who demonstrated the true benefit of joining IEEE to be an integral part of a family of 400,000+ members., Ms. Rabia Khalid – Pakistan WIE Forum Chairperson and Student Representative for South Asia Gold Committee who presented the various programs of IEEE and their benefits., IEEE PNEC and Mr. Onib Nasir –Chairperson, IEEE PNEC who gave the students a detailed description about the working of IEEE PNEC. He demonstrated the various events held under its banner. By the end of the session students had a better and clear vision of IEEE and seemed enthusiastic to become a part of it.
3.
IEEE PNEC PERSPECTIVE . AUTUMN 2012
WWW.IEEEPNEC.ORG
In The News SPARKLE
I
EEE PNEC continued with its enlightening weekly series of lectures by the name of SPARKLE. On Thursday, 19th April a trio of geniuses - Abdullah Bin Azhar, Waseem Hassan and Usman Rahim from PNEC were invited to SPARKLE to speak about their Final year Project. The Segway, christened Subukraftar, is a self-balancing vehicle for pedestrians and is one of its kind in Pakistan. After the SPARKLE session, everyone present was allowed to ride the special vehicle before being given a fair warning. On 3rd may 2012, IEEE PNEC invited Mr. Bilal Zaki and his group after having won the 2nd best research paper award at the International Engineering Mechnaical Convention to discuss his research on object recognition and its application in goal line technology for football. This session was attended by many football enthusiasts. On 17 th May, Lt. Cdr. Faisal bin Badr conducted a session on Brand Yourself – Become an Entrepreneur. In this session the basics of entrepreneurship was discussed and students of PNEC were encouraged to follow this as a profession and way of living.
180 DEGREES— SCRAP TO GADGET
W
IE-IEEE PNEC organized its first Scrap to Gadget, coined as 180 Degrees, on 18th May 2012. The basic objective was to reproduce a given object with available materials. While some participants came to challenge their creative skills, others came for the sake of 3D Avengers ticket on stake.Each team was given a picture of a tractor and the challenge was to build a 3D model of the tractor. Available material included paper, cardboard, straw, paper cups, glue and other objects merely for distraction! A total of 14 teams participated in the event with 3 members each. A panel of three respectable judges, from varying fields came to decide the winner. It included Dr. Sohaib Zia, Mr. Mustaqeem and S.lt Hina. The points were given on five criteria, innovations, neatness of work, aesthitics of the work, durability of the design and how pragmatic was the design. Judges questioned each team on their plan of execution and how they had entertained all facets of competition.
WWW.IEEEPNEC.ORG
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
4
Innovations Pneumatic Robotic Arm by BILAL GAUHAR
Design Body
T
he body consist of two arms i.e. Primary and secondary arm . Primary arm has two portions inclined with each other at an angle of 120 degrees. Primary arm is attached to the base using screw contact. Base Base is 18 inches long and wide with a height of 3 inches. The sheet metal used is 2mm thick. It also has two vertical supports for primary arm and primary pneumatic cylinder. Bed The bed has length and width of 24 inches and it stands on wooden blocks screwed to it providing it a height of 4 inches. It also has a DC motor attached beneath it which provides rotational force to the base. Gripper The gripper is designed using eight rigid links. Each link is attached with the other using pin joints forming a turning pair.
embedded in the bed provides the base a rotation of 160 degrees max. The gripper pneumatic cylinder extends the gripper arms with the help of links which enables it to hold any object with a cross section of 25 cm 2.
Base is made using the same sheet. Base side panels and support arms are welded using electric arc welding. Primary cylinder is fixed to the support arms using screw contact where as the primary arm is fixed to the supports using ball bearings.
The entire mechanism is joystick opBed is made using 3mm thick sheet erated metal. DC motor is embedded into the Fabrication bed by cutting a patch in it using Two links connect the gripper arms to drills and attached using screws. the gripper pneumatic cylinder. The Body panels are made of 2mm thick Wooden blocks are screwed to all the arms have rubber bushes at the end to sheet metal which is cut using oxyacetylene torch. Both the arms are corners. avoid damaging the objects. Gripper links are milled on a CNC Functioning milling machine. Adjustable pin joints are made on lathe machine. Pneumatic cylinders are provided with compressed air at 8 bar pressure. The primary pneumatic cylinder that connects primary arm with the base provides it with an inclination of 30 degrees from home position. Secondary pneumatic cylinder that connects secondary arm with the primary arm provides it with an inclination of 80 degrees w.r.t primary arm. Both the movements provide the machine with maximum horizontal range of 70cm and maximum vertical range attached with each other using exof 40cm.The tended pin joints providing turning DC m o t o r contact.
5.
IEEE PNEC PERSPECTIVE . AUTUMN 2012
Body and base are spray painted.
Future Scope This project provides an idea for medium weight high speed pick and place mechanisms to be used in manufacturing lines having low setup as well as operating and maintenance cost. This mechanism can also be used for various other purposes in manufacturing industries such as spot welding, TIG and MIG welding, fastening nuts and bolts at specific torque by fixing impact wrench instead of gripper.
WWW.IEEEPNEC.ORG
Innovations Introducing: The Mecanum Wheel by ONIB NASIR & M USMAN YOUSUF
I
n recent years, much work has been done on the omni directional capability of mobile robots to work in constrained areas, overcome the nonholonomic constraints of mobile robots and also to give a greater degree of freedom when working with mobile robots [1] - [3]. Mecanum wheel provide the omni directional capability which allow the robot to move in both x and y directions. Mecanum wheels have rollers attached to the wheel circumference at 45 degree orientation. This wheel was developed by the Swedish inventor, Bengt Ilon in 1973 when he was working with the years has been carried out on controlling the slipping of the Mecanum company Mecanum AB. wheels. Pakpoom Viboochaicheep et al presented a motion control method that considered the exact dynamics of the vehicle using a posiSince its inception, the Mecanum wheel has been used in many application detection device, however he only presented the simulation results tions. It is used to provide maneuverability in constrained areas such as and the experimental data was not presented [4]. Akira Shimada et al working in a manufacturing assembly line where the Mecanum wheel is introduced a position corrective feedback control using a vision sensor. used in the forklift. It is also used in wheelchairs to provide better moveThe vision sensor used is an expensive method it is also not easy to obment and easier tracking. The Mecanum based forklift has been used by tain very accurate results with it [5]. the Mercedes manufacturing facility since 2007 and is also being used by many other companies. We worked on feedback control from XY SINCE its inception, the Mecanum direction quadrature encoders to monitor real The working of the Mecanum wheel is limwheel has been used in many appli- time slipping of the Mecanum wheels. The ited by the holonomic constraints. Slipping shaft encoders used are not directly installed to of the wheels may occur due to the me- cations. It is used to provide maneuthe Mecanum wheels as they would experichanical structure of the Mecanum verability in constrained areas such ence the slipping too; rather they are installed wheel. During movement, the sub roll- as working in a manufacturing ason the three wheel structure omni wheel. The ers attached may slip and deviate the sembly line where the Mecanum quadrature shaft encoder provides the absolute mobile robot away from the planned wheel is used in the forklift position of the mobile robot and rectifies the course. The slipping occurs due to various slipping error by monitoring for any deviations from the planned course reasons and it is not possible for us to overcome those factors rather we for the autonomous mobile robot to follow. The proposed rectification need to monitor the slipping of the Mecanum wheels during operation method to control the slipping of the Mecanum wheel is implemented and control that through a mechanism. The slipping of the Mecanum on a mobile robot, Omni-Droid and the experimental data is presented in wheels occurs due to weight balancing on the mobile robot, alignment of the paper. the wheels in the correct direction, the motor rpm varying for each of the motors installed on one of the four wheels, the surface friction which is a Each Mecanum wheels offers three degree of freedom (x,y,θ). In order characteristic impedance of the surface and also unevenness of the sur- to control slipping of the Mecanum wheel all the three degree of freeface. The slipping occurred can be of two types which is the horizontal dom are to be monitored and rectified. We have employed a novel idea slipping or the rotational slipping. Much research in the previous few of controlling the slipping of the Mecanum wheels by monitoring the WWW.IEEEPNEC.ORG
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
6
Innovations manipuladeviation of the mobile robot from the planned tion is to be course by installing two quadrature shaft encoddone within ers. These encoders are installed on separate constrained omni wheels which are a three wheel structure. environAs the Mecanum wheels experience slipping ments. due to external factors, the encoders would These vehicalculate the aggregate slipping of the entire cles are mobile robot instead of monitoring the individremotel y ual slipping of each Mecanum wheel. One operated encoder would be monitoring the divergence of and conthe mobile robot in the x direction and the other tinuously encoder would be used to monitor the diverreceive gence of the mobile robot in the y direction. θ input from would depend on the direction of the robot that the user and it is moving in and would be monitored by the hence the distance of the robot moved in the x and y di- check is again run on the robot to check and destination is not known so this method would rection. By monitoring and constantly rectify- correct if any deviation has occurred. be very difficult to employ on a vehicle where ing x and y direction, we can control θ. the destination is indefinite.
The hardware design for position rectification includes a set of two shaft encoders which are mounted on the omni wheels and provide constant feedback from these encoders to the controller. The controller decides on the basis of the feedback and compares it with the actual planned course to be followed. It rectifies its position based on the algorithm by changing the speed of the motors in accordance with the error recorded. The motor driver circuit is the hbridge circuitry which is used to get input from the controller and drive the motors. The algorithm that we have employed in OmniDroid to control the slipping and maintain the path and thus provide positional tracking for the mobile robot is for the robot to acquire an initial displacement after it is started in the desired direction. It would then check for slipping by getting the magnitude and direction. The direction obtained would be of the x and y direction from which we would compute angle θ. The direction and magnitude obtained would be compared with the desired magnitude and direction and in case there is an error between the two values, it would be rectified by moving in the opposite direction. After the error is nullified, the robot starts moving again and before stopping the encoder value is checked again and the same procedure of nullifying the error is repeated. After the previous instruction, it moves a small distance before it stops so a final
7.
In case 1, we are moving a straight vertical distance and it is our objective to follow the straight path and hence keep Δx as close to zero as possible during all times of the movement of the robot for no deviations to occur. In case 2, we are moving a straight horizontal distance and we desire to keep Δy as close to zero as possible during all times. In case 3, we are moving a straight hypotenuse line and in this we have to monitor both x and y directions. In this case we obtain θ by computation of equation (to be done above) and keep Δθ as close to zero as possible during all times. Another method that can be employed to rectify the error of the mobile robot is caused by slipping of the Mecanum wheels is by continuously seeking the destination after slipping has occurred or known as the destination seeking method. This method does not rectify the error as it occurs rather computes a new direction and magnitude towards the destination after the slipping. The reason we have not employed this method is since Mecanum wheels have vast applications and are now being used in wheelchairs and fork lift trucks extensively where
IEEE PNEC PERSPECTIVE . AUTUMN 2012
The simulation results that we derived for the slipping of the Mecanum wheel whilst moving in the x and y direction are shown on the next page. These results are the slipping of the Mecanum wheel without any corrective feedback mechanism. Mecanum wheels is a new technology on which much work is being carried out all across the world on controlling the slipping and moving the wheels in the desired direction. We have tried a new approach in controlling the slipping of the Mecanum wheel. By achieving the control of slipping, Mecanum wheels can be used in applications such as forklift, wheelchairs or any vehicle that is to be designed for operations in constraint areas. It is also being experimented in cars for parking in a very confined space as the wheel would be able to do parallel parking in the horizontal configuration. Having introduced this technology in PNEC, we hope many students from PNEC would now work with it and produce a Mecanum based wheelchair and forklift in the near future and also use it to win robotics competitions for PNEC.
WWW.IEEEPNEC.ORG
Innovations
Simulation Results of Moving in x, slipping in y direction
Simulation Results of Moving in y, slipping in x direction
REFERENCES [I] P. F. Muir and C. P. Neuman, "Kinematic Modeling of Wheeled Mobile Robots", Technical Report No. CMU-RI-TR-86-12, The Robotics Institute, Carnegie Mellon University, 1986. [2] P. F. Muir and C. P. Neuman, "Kinematic Modeling of Wheeled Mobile Robots", Journal of Robotic Systems, vol. 4, No.2, 1987, pp 281-340. [3] P.F. Muir and C.P .N euman, "Kinematic Modeling for Feedback Control of an OlIUlidirectional Wheeled Mobile Robot", Proc. IEEE Conference on Robotics and Automation, Raleigh, NC, 1987, pp 1172-1178. [4] Pakpoom Viboonchaicheep, Akira Shimada, and Yuhki Kosaka, "Position Rectification Control for Mecanum Wheeled OlIUlidirectional Vehicles", Proc. the 29th Annual Conference of the IEEE Industrial Electronics Society, Roanoke, VA, USA, 2003, pp. 854859. [5] Shimada A, Yajima S, Viboonchaicheep P, and Samura K, "Mecanumwheel Vehicle Systems Based on Position Corrective Control", the 32nd Annual Conference of IEEE Industrial Electronics Society, 2005, pp. 2077-2082. [6]Stephen L. Dickerson and Brett D. Lapin, "Control of an Omni-directional Robotic Vehicle with Mecanum Wheels", Proc. the National Telesystems Conference, Vol. I, 1991, pp. 323-328. [7] Shinji Kamiuchi and Shoichi Maeyama, "A Novel Human Interface ofan Omnidirectional Wheelchair", Int. Workshop on We pay our acknowledgements to Bilal Gahaur our team coordinator and guided us at every Robot and Human Interactive Communicawho was an integral member of the RoboSprint step. A special thanks to Dr. Attaullah Memon tion, 2004, pp. 101-106.
team and designed and manufactured the robot completely on his own. Without him this would not have had been possible. We also thank the organizing committee of the RoboSprint at CASE, who were extremely helpful and a special mention for Umer Farooq, who acted as WWW.IEEEPNEC.ORG
for motivating us, supporting us and providing whatever we needed and to Robotics and Dynamic Systems Research Lab for funding our project and giving us a place to do all our work.
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
8
Celebrations 7 years of IEEE PNEC Many things when established are not known to progress and advance like IEEE PNEC Student Branch has done in the past 7 years. IEEE PNEC was established on 3 rd September 2005 with the aim to progress as a comprehensive society, responsive to technological change. Since then IEEE PNEC has come a long way in fulfilling the dream of its founders and the efforts have not been subsided to constantly innovate and bring up new ideas for the upbringing of her members and PNEC students.
man Hassan. They organized a series of successful events during their tenure which included the Karachi Section Student Congress, 2nd IEEE International Conference on Computer, Controls & Communication, initiated the Career Counseling Seminar which has become a tradition while also helping students understand life after graduation and also ponder over the heap of options available to them and conducted a fun filled fresher’s week to engage the new batch and provide them an opportunity for interaction with the seniors. Nimra Kazmi also The Student Branch has seen many ups and downs since her successfully initiated the Women in Engineering Affinity beginning. After having been established in 2005, Ali Allawala Group during this period. and Anas Imtiaz took over the branch and came up with a lot of bright ideas which distinguished IEEE PNEC Student Branch The torch was then passed to Syed Ahmed Fuad. IEEE PNEC in a fledgling state from other societies and branches. They set has not looked back since and has travelled a successful uphill about to develop a website for the student branch and also re- journey. He found a dedicated executive committee at his dislease the first issue of the magazine Perspective for which cop- posal that was willing to work and implement new ideas. He set
Celebrating
7 years of excellence ies were distributed to students. They set the tradition and stan- about to focus on different events with technical and nondard for the times to come which the future ex-com’s had to technical events at its forefront. The Career Counseling Semikeep in mind while operating. nar was organized again in his tenure along with Quiztronics, a technical quiz competition. WIE PNEC flourished under his But sadly after the departure of Ali Allawala and Co. the stuleadership and established a name for them in the Karachi Secdent branch saw a trickle in interest and a corresponding detion and in Pakistan as well. They organized a lot of events cline of activities and membership. There was a lack of enthuincluding a trip to Merryville Old Age Home, Women Empowsiasm within the Student Branch coupled with a lack of adminerment Seminar, Bake Sale and also initiated Tech Fest. During istrative support which resulted in the student branch becoming his time, IEEE PNEC found her outstanding stalwart volunteer dormant for a brief period of time. in Dr. Attaullah Memon who became the IEEE PNEC Student But as with all good things, there was somebody to rescue Branch Mentor and has been guiding the activities of the stuIEEE from the abyss and resurrect it into the society it was en- dent branch and also have played a pivotal role in all that the visioned to be. The continued efforts of a dedicated teacher student branch has been able to achieve so far. Yasir Khan along with one ambitious student Syed Ali Asad After the elections for the student branch, power was transRizvi paid off dividends and they were able to revive the stuferred to Rabia Khalid and company. She had phenomenal sucdent branch back to life with some dedicated volunteers such as cess in leading the student branch and IEEE PNEC was able to Nimra Kazmi, Sameed Ahmed Khan, Jahazaib Kakar and Usexplore new horizons and venture into novel thoughts and
9.
IEEE PNEC PERSPECTIVE . AUTUMN 2012
WWW.IEEEPNEC.ORG
Celebrations
ideas. The quite famous weekly SPARKLE sessions were held on every Thursdays and a series of robotics workshop was conducted to promote robotics and its associated technologies. The tech magazine, Perspective was revived and the 2 nd issue was released in January 2012 on the theme of communications. Arguably, the outstanding thing done during the year was the development of the website and making it live. The website has added a new dimension to the student branch and is also representing it and the college online with a global presence. The focus was just not on technical events, rather fun filled activities were conducted alongside. For this purpose, Minute to Win it, Scavenger Hunt, Bake Sale and a few other activities were held. WIE PNEC conducted her flagship event Techfest II and also visited PN Model School to create awareness amongst the next generation of girls about university life. The year ended on a big note with the first ever Annual General Meeting of the student branch being organized where the review of the complete year was presented along with the Annual Report and awards being given to the outstanding volunteers. As of now, Onib Nasir and his executive committee are leading the Student Branch and doing a remarkable job in maintaining the high standards set by the previous executive committees. IEEE PNEC has had a rich tradition of dedicated and enthusiastic volunteers due to which it has been able to achieve such accomplishments. During the journey, IEEE PNEC has also treaded on rutted paths and confronted difficult times but has always emerged victorious. Her history is a telling tale of enthusiasm and hope. The editorial team of Perspective wishes IEEE PNEC even more success and triumphs in the years to come. Stay blessed! ANAS IMTIAZ says ‘My aim of attempting to resurrect a nearly dead and defunct IEEE PNEC student branch was to provide a platform for inspired learning, foster a culture of research and have opportunities to develop and practice interpersonal and leadership skills.’
HASSAAN IDREES says ‘This society was not only the first place where I volunteered a month into when I stepped in at University it was also the only place which connected me to establish a concrete professional network. The society helped me visit places, meet academicians and engineers, learn cross-cultural-collaboration within Pakistan, in Asia and around the world.’
ALI ASAD says ‘The biggest task that we were SYED AHMED FUAD says ‘Each day faced with was to establish IEEE as functioning brought with it new challenges and exciting society in PNEC, a body that was important for scenarios to deal with. From rejuvenating the reasons beyond just mentioning "IEEE Memsociety to rekindling our financial resources; ber" on your CV, and to generate sufficient establishing firm industrial-academic ties and momentum to make the society self-sustaining. to encouraging women in our world of engiAnd today, thanks to the efforts of countless neering. Each event brought more adrenaline excellent volunteers like Nimra Kazmi, Hassan rush than the other.’ Idress, Fuad Ahmed, IEEE PNEC has become RABIA KHALID says ‘IEEE PNEC bethe society that we envisioned.’ cause of its exceptional activities not only has added value to the reputation of the college SHEZANA ZULFIAQAR says ‘Happy 7 years of formation to IEEE PNEC and conbut also brought a lot of credit to it over the gratulations to all the deserving members and past few years. Representatives of IEEE volunteers who contributed in nurturing the PNEC are no doubt acknowledged as incomstudent branch. IEEE-PNEC has set commendparable and extraordinary students in terms of able bars in its infancy. Unity, foresightedness leaderships, professionalism, quality of work and the glint of bringing about a change can and commitment to their duties.’ take it to unimaginable heights. Few areas of DR. ATTAULLAH MEMON says ‘It effort: research opportunities and spread of goes without saying that IEEE PNEC is education.’ the most active and vibrant student society that represents undergraduate students of BILAL ZAKI says ‘IEEE PNEC should focus on building on the memberships. nearly all disciplines at PNEC. What esBeing one of the most functional sentially differentiates it from others is its and vibrant student body in the college, it consummate character that lets its student should also act as a mentor to the other student members freely envision, devise and exebodies lending them support when required to cute an assortment of academic and social make PNEC a more happening place. The activities, which provide for tremendous society should also keenly focus on involving opportunities to strengthen their scholarly talents, enhance their proits alumnus in their plans and events.’ fessional acumen, and raise them as esteemed citizens. ’
WWW.IEEEPNEC.ORG
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
10
Innovations Implementation of PID in a Line Following Robot by ADIL FAQAH
A
mongst the numerous different categories of robots, lines following robots are probably the most popular among both students and robot hobbyists alike.
In implementing line following, the algorithm used is of vital importance to the performance of the robot. Numerous algorithms are available which rely on different number of sensors and their respective positioning on the robot. However most one sensor, two sensor and even three sensor designs fall short in performance – speed is compromised and the robot wobbles too much about the line; wasting both time and battery power. Why does this happen? If we consider a robot with 3 sensors i.e. left, center and right, a basic algorithm that can be implemented for line following would be: If the center sensor sees the line, Go straight. If the left sensor sees the line, Go left. If the right sensor sees the line, Go right. While this algorithm might allow the robot to follow the line somewhat smoothly at low speeds, it quickly starts to lose its efficiency as the speed is increased. The robot starts wobbling about the line and if it is going too fast it may well lose control and stop following the line all together (Figure 1). Furthermore this algorithm has poor efficiency in following angled or arced lines.
Figure 1
All this happens because the algorithm only takes one factor into consideration i.e. is the robot centered over the line? For improved line following, we need to consider 2 more factors i.e. how long the robot has not been centered over the line and how fast the robot is oscillating about the line. Hence, a better and more efficient algorithm is one based on PID control system. A Proportional Integral Derivative controller (PID controller) is a generic widely used control loop feedback mechanism. A PID controller calculates an "error" value as the difference between a measured process variable and a desired set point. The controller then attempts to minimize the error by adjusting the control inputs. Before implementation of the PID controller can be discussed, it is necessary to first go over some of the common terms associated with it with respect to our application. Target position
The ideal position for the robot to be i.e. the center of the line.
Measured position
The current position of the robot with respect to the line.
Error
The difference between the target position and the measured position. Note: Error can be positive, negative or 0.
Proportional
Numerical indication of the extent of deviation of the robot from the center of the line.
Integral
Accumulated error over time.
Derivative
The rate at which the robot is oscillating about the line.
Kp, Ki and Kd
Constant values used to tune the PID controller.
Implementation of PID control also has some hardware requirements. There is no use of implementing PID control in a robot with only 3 sensors. At least 6 to 10 sensors are required. For this example, an 8 sensor design shall be considered (Figure 2).
WWW.IEEEPNEC.ORG
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
12
Innovations A couple things to consider in the sensor design:
A greater number of sensors will give a wider error range.
The distance between individual sensors determines the resolution of the sensor array.
With everything done, it is now possible to actually implement PID control. The algorithm for PID control is as follows: START: error = target_position – measured_position; proportional = error*Kp; integral = integral + (error*dt); integral = integral*Ki; derivative = (error – previous_error)/dt; derivative = derivative*Kd; control = proportional + integral + derivative; previous_error = error; wait(dt); Go to START
The binary readings from the sensors aid in visualizing the po11100111
The robot is centered over the line.
01111111
The robot is to the extreme right of the line.
11111110
The robot is to the extreme left of the line.
After implementing the above algorithm, the value of control sition of the robot over the line. A 0 indicates the line was de- can be used to manage the speed of the motors. In a robot with tected while a 1 indicates otherwise. differential drive, something like the following may be tried: Similarly, a table of all the possible patterns obtainable from the sensor array can be created with a weighted error value as11111110
-6
11111100
-5
11111000
-4
11110001
-3
11110011
-2
11110111
-1
11100111
0 (Target position)
11101111
1
11001111
2
10001111
3
00011111
4
00111111
5
01111111
6
11111111
7 or -7 depending on which extreme sensor was last on the line.
/*The following is done to ensure we never get a negative value of control and that it doesn’t exceed the specified maximum.*/ if (control > max_speed) control = max_speed; if (control < - max_speed) control = -max_speed; left_motor = 80 + control; right_motor = 80 - control; Once PID control has been implemented, it might be observed that the robot still doesn’t follow the line smoothly in fact it may even perform worse than before! This is because the PID constants Kp, Ki and Kd haven’t been tuned as per the environment and the characteristics of the robot. The PID controller may be tuned in the following manner: 1.
Set Ki and Kd to 0 and set Kp to 1. Adjust the value of Kp such that the robot eventually starts to follow the line. If it is too slow, increase the value. If it is too fast decrease it. The robot might still wobble a lot; this will be taken care of.
2.
In order to reduce the wobbling of the robot about the line, start with a Kd value of 1 and gradually increase it to a suitable value.
3.
To tune the integral term, start with a Ki value of 0.1 and try increasing it in very small (ideally 0.01) increments. A low value will have no apparent effect on the movement of the robot however higher values of Ki will make the robot jerk wildly about the line. Pick a suitable value.
signed to each pattern. Note that the following table isn’t stanKeep in mind that it isn’t necessary to utilize all the terms of dard and varies from robot to robot primarily due to spacing the PID controller. Most people find that their robot follows the between the individual sensors. line just fine using PI only. Experiment with different combinaUtilizing the table, the reading from the sensor array can be equ tions and different values to figure out what works best for your robot. -ated to its corresponding weighted value to give a numerical value for error.
13 .
IEEE PNEC PERSPECTIVE . AUTUMN 2012
WWW.IEEEPNEC.ORG
Innovations Design & Implementation of a Robotic Arm Interfaced with the Internet by HAMMAD KHALID
T
he following project was chosen by me, Hammad Khalid and Umar Yoonus, so that the main results of this project would signify that remote monitoring and control of an environment using the internet is not only feasible but also becoming increasingly desirable. With the increasing trend towards ‘information on the move’ where people and services need to be accessed anytime, anywhere, it seems that the next step is to extend this accessibility to include our environment – be that our home, workplace or any location.
We started off by designing the mechanical model on paper and then transferring it on software like AUTO-CAD and CATIA. A rough sketch was designed keeping in mind the four degrees of freedom we planned to provide and calculations of torque and inertia were performed to have the idea of what motors need to be installed and what will be our weight limitation. Of course, when practically implemented these calculations proved to be having slight variations for which we had already kept enough margin. The mechanical design was then ordered for fabrication. Once the mechanical assembly was in our hands, we went to our next phase which was the development of electronic circuitry. Initial testing on breadboard and Veroboards was completed within a month which was an essential aid so that we didn’t mess up in u final PCBs. Control of four motors for the linear, angular, vertical and clamping motion of the robotic arm required the implementation of four Hbridges, a master controller board (AVR ATMEGA16) was used for motor selection, direction and speed control. A power supply board was implemented to supply power to all the boards from one DC battery. Since we needed precision in the linear i.e. forward & reverse motion of the robot and angular movement we self-developed our encoder boards with I.R transmitters so that the motor can stop at a particular number of pulses ad hence on the specified direction.
Our goal was to implement an inexpensive, simple system for use in multi-tasking robotic applications using computer communication or in other words, operating a robot through internet or LAN based architecture. In our project we tried to implement the virtual environment to the user. Different operations on the robotic arm can be done on the real time system (Client-server model). Server-end program manages overall interfacing with the hardware of the robotic arm. Live video streaming is also The next step involved Programming the controller for which we used CodeVisionAVR. Serial Communication had to be available. developed at the slave end between the host computer and the We kept the mechanical design of the robotic arm as simple as robot for which we used Visual Basic. An extensive learning possible since a very complicated mechanical assembly would for this language had to be done since we were totally new to it. have been beyond our scope. But maximum effort is placed on controls and communications. Full emphasis was placed on The same software was used to develop Internet Control by making the experience of our robotic arm control as similar as first designing a control panel (interface) at the master end and possible to the experience of completing a hands-on mission. linking it with our slave end through TCP. For this also Operator should not distinguish between maneuvering the mas- VB.NET proved to be an essential platform. Video Feedback ter device and controlling the actual tool. This is largely de- was provided by an already available software DIGIWATCHER. pendent on computer controlled electro-mechanical interface. WWW.IEEEPNEC.ORG
AUTUMN 2012 . IEEE PNEC PERSPECTIVE .
14
Opinion Women in Engineering: Dearth of Induction & Retention by REHMA JAVED & RABIA KHALID TODAY, more than ever a nation’s growth depends on technological innovation and hence upon engineering. To tap all the talent available in our society, we need to pay particular attention to participation of women in the engineering workforce. However, Engineering and Sciences has always been a man-dominated field. Be it the discouragement faced by women to enter this field, lack of career counseling or the hurdles one has to overcome as engineers the outcome is staggering. As a result of which only a few women choose engineering as a career path. In the last few years, IEEE Women In Engineering has played its role in motivating school-going students to embrace fields of sciences and technology. With various seminars and workshops, it also enables women to develop their professional skills and discover their true potentials. Female Engineers - Why so few?
T
Transition - From a Student to a Professional Engineer
Another major concern is the lack of career counseling. When it comes to making the career choice, it is largely based on trial and error or being inspired by a certain person excelling in his/her profession. As a result women those who choose engineering and those who do not are not aware of the career that would suit them best.
Other reasons included lack of confidence (16%), parental opposition (9%) and to an extent, harassment at work (8%).
I
here have been various discouraging factors when it comes to nternships can teach you more about what you want to do and perusing engineering and foremost is lack of parent’s encourwhat you don’t want to do. It also provides you with invaluable agement. With the strong family setup of our society, parents’ soft skills. For many universities, it is mandatory to intern at at least opinion becomes extremely significant. However, even today one organization before graduating. parents prefer their daughters to opt for medicine. Their concerns con- This is conflicting to the PWF survey result where only 54% of women sists of the small percentage of women in engineering colleges as well as engineers had interned at some organization while pursuing their engilack of career opportunities for women engineers. neering degree. When asked the reason behind the lack of experience, Later when it comes to persuing engineering as a career, guardians are 24% answered that females were not preferred as compared to their reluctant to allow their daughters to do so. This lack of encouragement male counter parts. further decreases the pool of working engineers. According to a survey The survey holds as majority of engineering firms involving fieldwork conducted at University of Michigan, even at a younger age, parents prefer men. Females are generally held to office work and purely whiteprovided more math-supportive environments for sons than they did for collar jobs hence drastically limiting their job opportunities. In Pakistan their daughters. As a result of which sons were more prone to opt for even multi-nationals such as Engro Ltd. discourage women employees technological related fields then daughters later on. [2 ref] on remote-stie locations such as Daharki.
It is also noted that men tend to have better special skills then women. To survive at any organization, one needs to excel at communications, effective in planning and excellent in management. All of which can be improved with workshops and training courses. Therefore, those women lacking in confidence or otherwise need to train themselves in these Understanding the significance of co-curricular activities o achieve professional excellence, one doesn’t just needs to skills if they intend to supersede others in the employment race. hone themselves their technically. Participation in co curricu- As they say, ‘No one is born a leader’. It is an attribute that has to be lar activities is also necessary to develop social skills, which in developed with time. However, when the female engineers were asked if they had any experience in leading a team, 32% replied in negative. turn aid in character building. Pakistan WIE Forum conducted a survey among females enrolled in This could be the result of women not given the opportunity to lead a engineering colleges all over Pakistan. First they were asked which extra team or they themselves being reluctant to stand in the line of fire.
T
curricular activity the female students have mostly been a part of. 64% in Even with excellent academic records but with the lack of leadership, all answered in favor of society memberships like IEEE. However, 23% special and communication skills it eventually becomes difficult for of students answered ‘none’. these women to compete and get hired at respectable firms. The next question targeted the impedances faced by these women while Moral of the story participating in the se activities. The results show that 53% of women e should realize the significance of retaining women in believe that there was a lack of opportunities where they could enroll engineering and encouraging those passionate enough themselves. This is a fair indication that there are not many platforms to to join the field. An emphasis on career counseling enable these female engineers to be dynamic and explore them selves. sessions from a young age should be made. Society on It would be fair to mention that many students willingly do not participate in extra curricular activities. It is necessary to educate these souls that being active in such programs teaches you how to be a leader, work in a team and tackle problems in various situations. This cannot be achieved by solely focusing on your engineering degree.
15 .
IEEE PNEC PERSPECTIVE . AUTUMN 2012
W
the other hand, should accept its share of duties and not bar the fairer sex form entering this profession. One of the major impedances comes due to the general prejudice against women that has been embedded in the minds of the people. Therefore, we should deal with all these factors so that women can establish themselves as leaders in this field too as they have in others including medicine and business administration.
WWW.IEEEPNEC.ORG
Our members make us proud! SHELL ECO MARATHON Kanza Basit, WIE PNEC Chair, led a team in Shell Eco Marathon Asia an annual event hosted by Shell annually at Sepang International Circuit, Malaysia in which students practically apply their engineering knowledge to design and fabricate a fuel efficient vehicle. She led the urban team BOLT. BOLT recorded a 66km/l track run and also got the 10 th position on the leader board. The urban team also won the 2 nd position in communications awards. They represented the college and Pakistan well at the international arena
UN WOMEN CONFERENCE WIE PNEC Chair, Kanza Basit, represented Pakistan in the UN Women Conference hosted by Duksung Women’s University, Seoul, South Korea. The conference was all about gender equality and empowering women. It consisted of 8 different topics under which a total of 96 teams were selected to be a part of the conference from all over Asia and Africa. The team of Kanza Basit participated in the poster design competition. Their idea was to make a smart device application for women which compiles good education and good career opportunities. They got the 2nd position in the poster design competition. The closing of the conference was grand with UN Secretary General, Ban Ki Moon, being the chief guest along with Seoul Mayor. It was good to hear his supporting and acknowledging words for women of the world. This marked the end of the conference followed by a Korean Pop concert.
ASIA PACIFIC REGION 10 SPMP COMMITTEE The Asia Pacific Region 10 of IEEE has recently initiated a new project ‘Student Professional Mentorship Program’ which would be acting as a bridge between students and professionals to help student members get professional mentorship, help and advice for their technical queries. Rabia Khalid, previously the Chairperson IEEE PNEC was appointed as the Student Representative for the Committee. The student committee was recently finalized and Onib Nasir, the current Chairman IEEE PNEC has been selected as one of the ten students from Pakistan, India, Bangladesh and Sri Lanka. We congratulate Onib Nasir on his selection and wish him well.
ROBOSPRINT ‘12 RoboSprint is an annual robotics competition organized by CASE University, Islamabad with an aim of promoting robotics and its associated technologies amongst the students of Pakistan to make them at par with the current progress in robotics and automation in the world. The IEEE members, Onib Nasir, M Usman Yousuf and Osama Amjad Ansari represented PNEC in the robotics competition. They won the Performance Award at the competition and also impressed many of the participants with their pneumatic systems, the only team to used pneumatic systems in the competition.
17 .
IEEE PNEC PERSPECTIVE . AUTUMN 2012
WWW.IEEEPNEC.ORG
The IEEE RAS Society strives to advance innovation, education, and fundamental and applied research in Robotics and Automation. Robotics focuses on systems incorporating sensors and actuators that operate autonomously or semi-autonomously in cooperation with humans. Robotics research emphasizes intelligence and adaptability to cope with unstructured environments. Automation research emphasizes efficiency, productivity, quality, and reliability, focusing on systems that operate autonomously, often in structured environments over extended periods, and on the explicit structuring of such environments. The Robotics and Dynamic Systems Lab has recently been setup in PNEC by Dr. Attaullah Memon with the aim of promoting robotics and its associated technologies amongst the students of PNEC and providing them with a platform to develop and fabricate robotic systems indigenously. The lab aims to work on research problems and innovative projects that extend the start of the art in robotics. In a short span of time, RDS Lab has already developed many platforms including the first Segway to be manufactured in Pakistan, industrial robotic welding arm, mecanum wheel based robot and many other projects.
Editor in Chief
Editor
Assistant Editor
Creative Director
Production Manager
Syed Onib Nasir
Rehma Javed
Rabia Jamal
Adil Faqah
Asim Ahmed
IEEE PNEC STUDENT BRANCH Pakistan Navy Engineering College National University of Sciences & Technology sb.pnec@ieee.org www.ieeepnec.org