A ROBUST QFT CONTROL APPROACH FOR AUTOMOBILE ENGINE IDLE SPEED SYSTEMS: MODELING, DESIGN AND SIMULATION by TONY JOY Submitted in partial fulfillment of the requirements for the degree of Master of Science Electrical Engineering and Computer Science CASE WESTERN RESERVE UNIVERSITY August, 2016 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of Tony Joy candidate for the degree of Master of Science *. Committee Chair Mario Garcia-Sanz Committee Member Vira Chankong Committee Member Marija Prica Date of Defense 05/05/2016 *We also certify that written approval has been obtained for any proprietary material contained therein. 1 Table of Contents LIST OF FIGURES .......................................................................................................... 4 LIST OF TABLES ............................................................................................................ 6 NOMENCLATURE ......................................................................................................... 7 ABSTRACT ...................................................................................................................... 9 ACKNOWLEDGEMENTS ........................................................................................... 10 CHAPTER 1: INTRODUCTION ................................................................................. 11 1.1 MOTIVATION .............................................................................................................. 11 1.2 INTERNAL COMBUSTION ENGINE ............................................................................... 11 1.2.1 Engine Operation ................................................................................................... 13 1.2.2 Engine Sensors ....................................................................................................... 15 1.2.3 Engine Control Loops ............................................................................................ 18 1.2.4 Engine Operating Modes ....................................................................................... 21 1.2.5 Engine Management Systems ................................................................................ 22 1.2.6 Maps and Look-up tables ....................................................................................... 24 1.3 IDLE SPEED CONTROL PROBLEM ................................................................................ 26 1.3.1 Control Variables ................................................................................................... 27 1.3.2 Disturbances ........................................................................................................... 29 CHAPTER 2: MODELING .......................................................................................... 31 2.1 HISTORY .................................................................................................................... 31 CHAPTER 3: SIMULATOR DESIGN ........................................................................ 36 2 CHAPTER 4: ROBUST CONTROL DESIGN. .......................................................... 39 4.1 QUANTITATIVE ROBUST CONTROL. ........................................................................... 41 4.2 DESIGN PROCESS ....................................................................................................... 42 4.2.1 Plant Definition ...................................................................................................... 42 4.2.2 Specifications: ........................................................................................................ 43 4.2.3 Controller Design: .................................................................................................. 45 4.2.4 Analysis: ................................................................................................................ 46 4.3 CONTROL HIERARCHY ............................................................................................... 49 CHAPTER 5 SIMULATION ........................................................................................ 51 5.1 PERFORMANCE SPECIFICATIONS ................................................................................. 51 5.2 NO - LOAD CONDITION ............................................................................................... 51 5.3 LOAD CONDITIONS ..................................................................................................... 56 5.4 IGNITION TIMING. ...................................................................................................... 59 5.5 HIGHER SPEED TO IDLE MODE. .................................................................................. 60 CHAPTER 6: CONCLUSION ...................................................................................... 63 CHAPTER 7: FUTURE WORK................................................................................... 64 7.1 ENGINE START STOP SYSTEM ..................................................................................... 64 7.2 HYBRID / ALL ELECTRIC VEHICLES ........................................................................... 65 REFERENCES ............................................................................................................... 66 3 List of Figures Figure 1 Cylinder piston mechanism ............................................................................... 13 Figure 2 Four strokes of the engine ................................................................................. 14 Figure 3 Basic Components of an EMS .......................................................................... 23 Figure 4 Example of engine maps ................................................................................... 25 Figure 5 Typical Idle Speed Control System .................................................................. 26 Figure 6 Throttle body ..................................................................................................... 27 Figure 7 Piston positions ................................................................................................. 28 Figure 8 Inputs, outputs and disturbances to the idle speed system. .............................. 29 Figure 9 Mean-value engine model ................................................................................. 31 Figure 10 Engine model in Simulink .............................................................................. 36 Figure 11 Change in engine speed with throttle angle .................................................... 36 Figure 12 Change in engine speed with crank angle ....................................................... 37 Figure 13 Change in engine speed with AFR ratio ......................................................... 38 Figure 14 Control systems with noise and uncertainties ................................................. 40 Figure 15 linearizing the model ....................................................................................... 42 Figure 16 Plant definition window .................................................................................. 43 Figure 17 Nichols plot in Specification window ............................................................. 44 Figure 18 Bode diagram of output disturbance rejection ................................................ 45 Figure 19 Controller design window ............................................................................... 46 Figure 20 Stability Analysis in frequency domain .......................................................... 47 Figure 21 Analysis of disturbance rejection in frequency domain .................................. 48 Figure 22 Time domain analysis: Unit step response ...................................................... 49 4 Figure 23 Controller hierarchy ........................................................................................ 50 Figure 24 PID Control Design ......................................................................................... 52 Figure 25 Engine output speed with PID Control ........................................................... 53 Figure 26 Engine speed output with PID, AFR and ignition timing ............................... 54 Figure 27 Controller design with anti - windup .............................................................. 55 Figure 28 Engine output speed with anti -windup .......................................................... 55 Figure 29 Engine output speed under no load ................................................................. 56 Figure 30 Engine speed drop with load ........................................................................... 57 Figure 31 PID control with Load map ............................................................................. 58 Figure 32 Engine output speed with Load map ............................................................... 58 Figure 33 Proportional control for ignition timing .......................................................... 59 Figure 34 Engine speed output with Ignition map .......................................................... 60 Figure 35 High speed to Idle speed mode ....................................................................... 61 Figure 36 Engine speed output from high RPM to idle mode under load ....................... 62 Figure 37 Mazda I-Stop system. .....................................................................................