Modeling and Simulation of a Hybrid Electric Vehicle for the Challenge X Competition Submitted to: The Engineering Honors Committee 119 Hitchcock Hall College of Engineering The Ohio State University Columbus, OH 43210 By Michael Arnett 4091 Millsboro Rd W Mansfield, OH 44903 Dr. Giorgio Rizzoni, Advisor May 20, 2005 Abstract: As the market shifts toward larger vehicles and growing concerns regarding petroleum consumption and emissions emerge, automakers have begun to explore new vehicle propulsion solutions. General Motors and The Department of Energy have joined together to create the Challenge X competition to explore hybrid-electric vehicles as one such solution. Seventeen teams across the United State will experience “real-world” HEV development over the three year competition. This process begins with vehicle architecture selection, modeling and simulation. A dynamic model of a hybrid-electric powertrain is developed here. This model is then implemented into two Simulink based simulators: the quasi-static cX-SIM, the dynamic cX-DYN. These simulators are used to validate the control strategy being developed for the Challenge X vehicle. Verification will include optimal performance in regards to fuel consumption, battery state-of-charge, and drivability. Techniques of validating the model and simulators using a rolling chassis are also being implemented. Preliminary data from the quasi-static simulator and the rolling chassis is presented herein. Acknowledgements: I would like to thank Dr. Giorgio Rizzoni, Joe Morbitzer, Osvaldo Barbarisi, Kerem Koprubasi, Jason Disalvo, John Neal and Christopher C. Mabry, for all of the help and support they have given me throughout the duration of this research. ii Table Contents CHAPTER 1: INTRODUCTION ............................................................................................................... 6 1.1 MOTIVATION ....................................................................................................................................... 6 1.2 VEHICLE ARCHITECTURE................................................................................................................... 8 1.2.1 Classifications of HEVs .............................................................................................................. 8 1.2.2 Vehicle Components.................................................................................................................. 10 1.2.3 Modes of Operation................................................................................................................... 11 CHAPTER 2: MODELING....................................................................................................................... 14 2.1 MODEL OF THE DRIVELINE .............................................................................................................. 14 2.1.1 Dynamic Equations of the Front Driveline.............................................................................. 15 2.1.2 Dynamic Equations of Rear Driveline ..................................................................................... 17 2.1.3 Dynamic Equation of the Vehicle............................................................................................. 17 2.2 DYNAMIC SIMULINK MODEL OF THE FRONT DRIVELINE ................................................................ 18 2.2.1 ICE Model ................................................................................................................................. 19 2.2.2 Clutch Model............................................................................................................................. 19 2.2.3 Front Gearbox Model ............................................................................................................... 20 2.2.4 Transmission ............................................................................................................................. 21 2.2.5 Front Axle ................................................................................................................................. 22 2.2.6 Front Brakes ............................................................................................................................. 23 2.2.7 Front Wheels............................................................................................................................. 24 2.3 DYNAMIC SIMULINK MODEL OF THE REAR DRIVELINE .................................................................. 25 2.3.1 Electric Motor ........................................................................................................................... 25 2.3.2 Rear Gearbox ............................................................................................................................ 26 2.3.3 Rear Axle................................................................................................................................... 27 2.3.4 Rear Brakes............................................................................................................................... 28 2.3.5 Rear Wheels............................................................................................................................... 29 CHAPTER 3: SIMULATION RESULTS................................................................................................ 31 3.1 CX-SIM ............................................................................................................................................. 31 3.1.1 Driver......................................................................................................................................... 32 3.1.2 HEV Powertrain........................................................................................................................ 33 3.1.3 Vehicle....................................................................................................................................... 34 3.2 CX-DYN ............................................................................................................................................ 34 3.3 CX GRAPHICS .................................................................................................................................... 36 3.3.1 Set Layout for Plots Driver ....................................................................................................... 37 3.3.2 Set Layout for Plots Vehicle...................................................................................................... 38 3.3.3 Set Layouts for Plots Acceleration Test.................................................................................... 39 3.3.4 Set Layout for Plots HEV Operation........................................................................................ 40 3.3.5 Set Layout Plots for Conventional Operation .......................................................................... 41 3.3.6 Set Layout Plots for Electric Powertrain.................................................................................. 42 CHAPTER 4: RESULTS & MODEL VERIFICATION........................................................................ 45 4.1 CX-SIM ............................................................................................................................................. 45 4.2 CX-DYN ............................................................................................................................................ 52 4.3 ROLLING CHASSIS............................................................................................................................. 52 4.3.1 Launch Test............................................................................................................................... 53 4.3.2 Model Verification & Mapping................................................................................................. 57 4.3.3 cX Test ....................................................................................................................................... 60 CHAPTER 5: CONTROL STRATEGY DEVELOPMENT .................................................................. 62 5.1 OVERVIEW......................................................................................................................................... 62 5.2 ECMS................................................................................................................................................ 63 5.3 BATTERY STATE-OF-CHARGE .......................................................................................................... 64 iii 5.4 DRIVABILITY ..................................................................................................................................... 65 REFERENCES ........................................................................................................................................... 67 APPENDIX ................................................................................................................................................. 68 List of Figures: Figure 1. Ohio State Challenge X Vehicle Architecture [5]............................................. 10 Figure 2. Dynamic Model of the Driveline [8]................................................................. 15 Figure 3. Simulink Diagram of ICE & ISA....................................................................... 19 Figure 4. Simulink Diagram of the Clutch. ......................................................................