UNIVERSITY OF CINCINNATI Date: 8-Nov-2010 I, Kovid Mathur , hereby submit this original work as part of the requirements for the degree of: Master of Science in Mechanical Engineering It is entitled: Conversion of a Hybrid Electric Vehicle to Drive by Wire Status Student Signature: Kovid Mathur This work and its defense approved by: Committee Chair: Manish Kumar, PhD Manish Kumar, PhD Ernest Hall, PhD Ernest Hall, PhD Janet Dong, PhD Janet Dong, PhD 11/11/2010 1,200 Conversion of a Hybrid Electric Vehicle to Drive by Wire Status A thesis submitted to the Division of Research and Advanced Studies of the University of Cincinnati In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In the Department of Mechanical Engineering of the College of Engineering 2010 By Kovid Mathur Bachelor of Engineering (Mechanical Engineering) Visvesvaraya Technological University, 2005 Committee Chair: Dr Manish Kumar Abstract With advancements in the automotive driving and safety technology the new age is looking to redefine transportation as we know it. The thrust area of study at the Center for Robotics Research at University of Cincinnati is building technology for autonomous vehicles and it has made considerable advancements over the years to building the future car. In summer 2006, Defense Advanced Research Projects Agency announced the third Grand Challenge which would feature ground vehicles executing “simulating military supply missions safely and effectively in a mock urban area”. The center entered the competition with a team of students and researchers to achieve this goal with generous contributions from Tank Automotive Research Development and Engineering Center (TARDEC), Applied Research Associates Inc (ARA) and the University of Cincinnati amongst others. An all terrain hybrid electric vehicle built by Cal Motors as an economical non tactical base transport vehicle was used as the competition entry, which was donated as per a Co-operative Research and Development Agreement (CRADA). This thesis presents the drive by wire solution along with the custom changes which were made on the vehicle in order to put the till now theories into practice. The design solution introduced control of linear actuators by more responsive and energy efficient servo motors which were driven by a Galil™ motion controller. Each axis of the controller was responsible for the control of electronic braking, steering and speed control systems respectively. The process involved some metal fabrication to incorporate the positioning of components for improved space usage and definite mounting, after which the iii systems were calibrated for optimum functioning. A series-hybrid approach was introduced for the ATV to provide longer hours of operation. Before the vehicle was allowed to ply on city streets it was brought to Ohio state law standards and in addition underwent a thousand mile durability test. The result of the research and development was a robust and effective system which could control by wire the all terrain vehicle (ATV) and met all primary goals of the project. iv v Acknowledgement My thesis work at the University of Cincinnati is the amalgamation of many people’s effort all through my life. I consider myself very fortunate to have really good advisors and teachers to whom I owe this work. They have at every step helped me build a broader perspective and have provided me with many opportunities to enhance my talent for engineering and design. I would like to acknowledge the following people for their effort towards this work: Dr Ernest Hall for his remarkable direction and constant encouragement which got me through even in the toughest of times. Dr Manish Kumar and Dr Janet Dong for their unprecedented encouragement and support. Saurabh Sarkar , Scott Reynold and Ray Scott who as friends and colleagues helped me in my undertakings and decision making. Gaurav, Hem and Shuchi Mathur my immediate family, who believed in my abilities and supported me all through my education. Vishal Mathur, my cousin without whose love and support, I would have never achieved my goals. Finally I would like to express my profound appreciation for my fiancé Marietta for her encouragement, understanding, and patience even during hard times of this study. vi Table of Content Abstract…………………………………………………………………………………………………………………………………….iii Acknowledgements …………………………………………………………………………………………………………………vi 1. Introduction…………………………………………………………………………………………………………………………1 2. Literature survey………………………………………………………………………………………………………………….6 2.1. By wire system……………………………………………………………………………………………….……….…….6 2.2. Braking system……………………………………………………………………………………………….…………….9 2.3. Steering system…………………………………………………………………………..………………………………12 2.4. Future developments…………………………………………………….……………………………………………16 3. Reverse Engineering…………………………………………………..………………………………………………………17 3.1. The Hyrider…………………………………………………………………………………………………………………18 3.2. The Structure………………………………………………………………………………………………………………21 3.3. Batteries…………………………………………………..…………………………………………………………………23 3.4. Battery charger……………………………………………………………………………………………………………25 3.5. Suspension system………………………………………………………………………………………………………25 3.6. Traction motors..…………………………………………………………………………………………………………26 3.7. The Brakes……………………………………………………………..……………………………………………………26 3.8. Hybrid conversion……………………………………………………………………….………………………………28 3.9. Street legal..………………………………………………………………………………………………..………………31 3.10. Lighting…………………………………………………………………………………..………………………………35 4. The thousand mile test………………………………………………..…………………….………………………………39 5. Steer by wire solution………………………………………………………………………………………………………..43 5.1. The design…………………………………………………………………………………………………………………..43 5.2. Computer control of steering………………………………………………………………………………………50 6. Brake by wire solution……………………………………………………………………………………………………….53 6.1. The design…………………………………………………………………………………………………………………..55 6.2. Computer control of brakes………………..………………………………………………………………………57 7. Conclusion………………………………………………………….………………………………………………………………61 vii 8. References……………………………………………………………..………………………………………………………….63 9. Appendix A…………………………………………………………………………………………………………………………67 9.1. Jeep electrical wiring documentation……………….…………………………………………………………67 viii List of Figures Figure 1: Figure 1: Multiple redundancy schematic..………………………………………………………………….8 Figure 2: View of chassis without top body…..………………………………………………………………………….20 Figure 3: Modular construction of the chassis. ………………………………………………………………………..20 Figure 4: Heavy duty Batteries…………………………………………………………………………………………………21 Figure 5: The suspension system and traction motor……………………………………………………………….26 Figure 6: A schematic diagram showing routing of brake lining. ………………………………………………27 Figure 7: The two master cylinders coupled into one single unit. …………………………………………….27 Figure 8: Parallel configuration for hybrid vehicles. …………………………………………………………………29 Figure 9: Schematic diagram showing charging of battery pack with a generator…………………….31 Figure 10: General Street legal requirements as per Ohio DMV……………………………………………….34 Figure 11: Installation of a battery stand and an electrical box. ………………………………………………36 Figure 12: Installation of a cooling fan for electrical box. …………………………………………………………36 Figure 13: Wiring schematic of lighting systems. …………………………………………………………………….37 Figure 14: Part 1- The thousand mile test on the city roads……………………………………………………..39 Figure 15: Part 2- The thousand mile test on the city roads……………………………………………………..40 Figure 16: Odometer reading before and after the thousand mile test…………………………………….41 Figure 17: Schematic diagram for steer by wire (design A) ………………………………………………………44 ix Figure 18: Engineering drawings for steer by wire (design A) ………………………………………………….45 Figure 19: Schematic diagram for steer by wire (design B) ………………………………………………………46 Figure 20: CAD drawing for Steering bracket (0.5” thick steel) ………………………………………………..47 Figure 21: Images to show the mounting of steering bracket…………………………………………………..48 Figure 22: Schematic diagram showing the electrical connections for the steer by wire………….51 Figure 23: Two master cylinders with two outputs for respective wheel set…………………………….54 Figure 34: 3/16” dia brake adapters…………………………………………………………………………………………55 Figure 35: Tools used for creating new brake lining………………………………………………………………….56 Figure 36: Using blow torch to assist flaring of brake tube……………………………………………………….56 Figure 37: Components introduced for brake by wire solution…………………………………………………57 Figure 38: Schematic diagram of electrical connections for electronic control of brakes………….58 Figure 39: Schematic diagram for computer control of braking by wire……………………………………60 x List of Tables Table 1: Technical specifications of the batteries……………………………………………………………………..22 Table 2: Battery charging specifications……………………………………………………………………………………22 Table 3: Charging time specifications……………………………………………………………………………………….23 Table 4: Battery charger technical specifications……………………………………………………………………..24 Table 5: Log sheet for the thousand mile test ………………………………………………………………………….41 Table 6: Values defining numerical position on each control unit…………………………………………….52 Table 7: Values on system corresponding to braking force requirement………………………………….59 Table 8: Dashboard to J1 - female Duel Row Header………………………………………………………………..65 Table 9: Fuze to J2 - female 2 P Single Inline Row…………………………………………………………………….65 Table 10: J1 to "Jeep" - male Duel Row Header………………………………………………………………………..66 Table 11: J2 to Jeep, Single Inline Row……………………………………………………………………………………..66