Modeling and control of engines and drivelines

Content: Preface xvii Series Preface xix Part I VEHICLE - PROPULSION FUNDAMENTALS 1 Introduction 3 1.1 Trends 4 1.1.1 Energy and Environment 4 1.1.2 Downsizing 4 1.1.3 Hybridization 6 1.1.4 Driver Support Systems and Optimal Driving 6 1.1.5 Engineering Challenges 8 1.2 Vehicle Propulsion 8 1.2.1 Control Enabling Optimal Operation of Powertrains 9 1.2.2 Importance of Powertrain Modeling and Models 10 1.2.3 Sustainability of Model Knowledge 11 1.3 Organization of the Book 11 2 Vehicle 15 2.1 Vehicle Propulsion Dynamics 15 2.2 Driving Resistance 16 2.2.1 Aerodynamic Drag 17 2.2.2 Cooling Drag and Active Air-Shutters 18 2.2.3 Air Drag When Platooning 19 2.2.4 Rolling Resistance - Physical Background 20 2.2.5 Rolling Resistance-Modeling 21 2.2.6 Wheel Slip (Skid) 24 2.2.7 Rolling Resistance - Including Thermal Modeling 25 2.2.8 Gravitation 27 2.2.9 Relative Size of Components 28 2.3 Driving Resistance Models 28 2.3.1 Models for Driveline Control 29 2.3.2 Standard Driving Resistance Model 30 2.3.3 Modeling for Mission Analysis 31 2.4 Driver Behavior and Road Modeling 32 2.4.1 Simple Driver Model 32 2.4.2 Road Modeling 33 2.5 Mission Simulation 34 2.5.1 Methodology 34 2.6 Vehicle Characterization/Characteristics 34 2.6.1 Performance Measures 35 2.7 Fuel Consumption 36 2.7.1 Energy Density Weight 36 2.7.2 From Tank to Wheel - Sankey Diagram 37 2.7.3 Well-to-Wheel Comparisons 38 2.8 Emission Regulations 39 2.8.1 US and EU Driving Cycles and Regulations 39 3 Powertrain 45 3.1 Powertrain Architectures 45 3.1.1 Exhaust Gas Energy Recovery 47 3.1.2 Hybrid Powertrains 47 3.1.3 Electrification 48 3.2 Vehicle Propulsion Control 50 3.2.1 Objectives of Vehicle Propulsion Control 50 3.2.2 Implementation Framework 51 3.2.3 Need for a Control Structure 52 3.3 Torque-Based Powertrain Control 52 3.3.1 Propagation of Torque Demands and Torque Commands 52 3.3.2 Torque-Based Propulsion Control - Driver Interpretation 54 3.3.3 Torque-Based Propulsion Control - Vehicle Demands 55 3.3.4 Torque-Based Propulsion Control - Driveline management 55 3.3.5 Torque-Based Propulsion Control - Driveline-Engine Integration 55 3.3.6 Handling of Torque Requests - Torque Reserve and Interventions 56 3.4 Hybrid Powertrains 58 3.4.1 ICE Handling 58 3.4.2 Motor Handling 59 3.4.3 Battery Management 59 3.5 Outlook and Simulation 60 3.5.1 Simulation Structures 60 3.5.2 Drive/Driving Cycle 60 3.5.3 Forward Simulation 61 3.5.4 Quasi-Static Inverse Simulation 61 3.5.5 Tracking 61 3.5.6 Inverse Dynamic Simulation 62 3.5.7 Usage and Requirements 64 3.5.8 Same Model Blocks Regardless of Method 65 Part II ENGINE - FUNDAMENTALS 4 Engine - Introduction 69 4.1 Air, Fuel, and Air/Fuel Ratio 69 4.1.1 Air 69 4.1.2 Fuels 70 4.1.3 Stoichiometry and (A/F) Ratio 71 4.2 Engine Geometry 73 4.3 Engine Performance 74 4.3.1 Power, Torque, and Mean Effective Pressure 74 4.3.2 Efficiency and Specific Fuel Consumption 75 4.3.3 Volumetric Efficiency 76 4.4 Downsizing and Turbocharging 77 4.4.1 Supercharging and Turbocharging 78 5 Thermodynamics and Working Cycles 81 5.1 The Four-Stroke Cycle 81 5.1.1 Important Engine Events in the Cycle 84 5.2 Thermodynamic Cycle Analysis 85 5.2.1 Ideal Models of Engine Processes 86 5.2.2 Derivation of Cycle Efficiencies 89 5.2.3 Gas Exchange and Pumping Work 91 5.2.4 Residual Gases and Volumetric Efficiency for Ideal Cycles 93 5.3 Efficiency of Ideal Cycles 98 5.3.1 Load, Pumping Work, and Efficiency 99 5.3.2 (A/F) Ratio and Efficiency 100 5.3.3 Differences between Ideal and Real Cycles 103 5.4 Models for In-Cylinder Processes 105 5.4.1 Single-Zone Models 105 5.4.2 Heat Release and Mass Fraction Burned Analysis 107 5.4.3 Characterization of Mass Fraction Burned 109 5.4.4 More Single-Zone Model Components 111 5.4.5 A Single-zone Cylinder Pressure Model 113 5.4.6 Multi-zone Models 114 5.4.7 Applications for Zero-dimensional Models 117 6 Combustion and Emissions 119 6.1 Mixture Preparation and Combustion 119 6.1.1 Fuel Injection 119 6.1.2 Comparing the SI and CI Combustion Process 120 6.2 SI Engine Combustion 121 6.2.1 SI Engine Cycle-to-Cycle Variations 121 6.2.2 Knock and Autoignition 122 6.2.3 Autoignition and Octane Number 124 6.3 CI Engine Combustion 126 6.3.1 Autoignition and Cetane Number 126 6.4 Engine Emissions 128 6.4.1 General Trends for Emission Formation 128 6.4.2 Pollutant Formation in SI Engines 130 6.4.3 Pollutant Formation in CI Engines 134 6.5 Exhaust Gas Treatment 137 6.5.1 Catalyst Efficiency, Temperature, and Light-Off 137 6.5.2 SI Engine Aftertreatment, TWC 139 6.5.3 CI Engine Exhaust Gas Treatment 140 6.5.4 Emission Reduction and Controls 142 Part III ENGINE - MODELING AND CONTROL 7 Mean Value Engine Modeling 145 7.1 Engine Sensors and Actuators 146 7.1.1 Sensor, System, and Actuator Responses 146 7.1.2 Engine Component Modeling 149 7.2 Flow Restriction Models 149 7.2.1 Incompressible Flow 151 7.2.2 Compressible Flow 154 7.3 Throttle Flow Modeling 156 7.3.1 Throttle Area and Discharge Coefficient 157 7.4 Mass Flow Into the Cylinders 159 7.4.1 Models for Volumetric Efficiency 159 7.5 Volumes 162 7.6 Example - Intake Manifold 166 7.7 Fuel Path and (A/F) Ratio 168 7.7.1 Fuel Pumps, Fuel Rail, Injector Feed 168 7.7.2 Fuel Injector 169 7.7.3 Fuel Preparation Dynamics 171 7.7.4 Gas Transport and Mixing 174 7.7.5 A/F Sensors 174 7.7.6 Fuel Path Validation 178 7.7.7 Catalyst and Post-Catalyst Sensor 178 7.8 In-Cylinder Pressure and Instantaneous Torque 180 7.8.1 Compression Asymptote 180 7.8.2 Expansion Asymptote 182 7.8.3 Combustion 183 7.8.4 Gas Exhange and Model Compilation 184 7.8.5 Engine Torque Generation 184 7.9 Mean Value Model for Engine Torque 186 7.9.1 Gross Indicated Work 187 7.9.2 Pumping Work 190 7.9.3 Engine Friction 190 7.9.4 Time Delays in Torque Production 192 7.9.5 Crankshaft Dynamics 193 7.10 Engine-Out Temperature 193 7.11 Heat Transfer and Exhaust Temperatures 196 7.11.1 Temperature Change in a Pipe 196 7.11.2 Heat Transfer Modes in Exhaust Systems 197 7.11.3 Exhaust System Temperature Models 197 7.12 Heat Exchangers and Intercoolers 203 7.12.1 Heat Exchanger Modeling 204 7.13 Throttle Plate Motion 206 7.13.1 Model for Throttle with Throttle Servo 210 8 Turbocharging Basics and Models 211 8.1 Supercharging and Turbocharging Basics 211 8.2 Turbocharging Basic Principles and Performance 214 8.2.1 Turbochargers in Mean Value Engine Models 214 8.2.2 First Law Analysis of Compressor Performance 216 8.2.3 First Law Analysis of Turbine Performance 218 8.2.4 Connecting the Turbine and Compressor 219 8.2.5 Intake Air Density Increase 219 8.3 Dimensional Analysis 220 8.3.1 Compressible Fluid Analysis 221 8.3.2 Model Structure with Corrected Quantities 223 8.4 Compressor and Turbine Performance Maps 223 8.4.1 The Basic Compressor Map 223 8.4.2 The Basic Turbine Map 225 8.4.3 Measurement Procedures for determining Turbo Maps 226 8.4.4 Turbo Performance Calculation Details 227 8.4.5 Heat Transfer and Turbine Efficiency 230 8.5 Turbocharger Models and Parametrizations 232 8.5.1 Map Interpolation Models 232 8.6 Compressor Operation and Modeling 232 8.6.1 Physical Modeling of a Compressor 233 8.6.2 Compressor Efficiency Models 237 8.6.3 Compressor Flow Models 239 8.6.4 Compressor Choke 241 8.6.5 Compressor Surge 244 8.7 Turbine Operation and Modeling 249 8.7.1 Turbine Mass Flow 249 8.7.2 Turbine Efficiency 252 8.7.3 Variable Geometry Turbine 253 8.8 Transient Response and Turbo Lag 254 8.9 Example - Turbocharged SI Engine 255 8.10 Example - Turbocharged Diesel Engine 257 9 Engine Management Systems - An Introduction 263 9.1 Engine Management System (EMS) 263 9.1.1 EMS Building Blocks 264 9.1.2 System for Crank and Time-Based Events 265 9.2 Basic Functionality and Software Structure 266 9.2.1 Torque Based Structure 266 9.2.2 Special Modes and Events 267 9.2.3 Automatic Code Generation and Information Exchange 267 9.3 Calibration and Parameter Representation 267 9.3.1 Engine Maps 268 9.3.2 Model-Based Development 270 10 Basic Control of SI Engines 271 10.1 Three Basic SI Engine Controllers 272 10.1.1 Production System Example 273 10.1.2 Basic Control Using Maps 274 10.1.3 Torque, Air Charge, and Pressure Control 275 10.1.4 Pressure Set Point from Simple Torque Model 275 10.1.5 Set Points from Full Torque Model 276 10.1.6 Pressure Control 277 10.2 Throttle Servo 279 10.2.1 Throttle Control Based on Exact Linearization 280 10.3 Fuel Management and Control 282 10.3.1 Feedforward and Feedback Control Structure 283 10.3.2 Feedforward Control with Basic Fuel Metering 283 10.3.3 Feedback Control 284 10.3.4 Fuel Dynamics and Injector Compensation 289 10.3.5 Observer Based Control and Adaption 290 10.3.6 Dual and Triple Sensor Control 293 10.4 Other Factors that Influence Control 294 10.4.1 Full Load Enrichment 295 10.4.2 Engine Overspeed and Overrun 296 10.4.3 Support Systems that Influence Air and Fuel Calculation 296 10.4.4 Cold Start Enrichment 298 10.4.5 Individual Cylinder -control 298 10.5 Ignition Control 299 10.5.1 Knock Control - Feedback Control 301 10.5.2 Ignition Energy - Dwell Time Control 304 10.5.3 Long-term Torque, Short-term Torque, and Torque Reserve 305 10.6 Idle Speed Control 306 10.7 Torque Management and Idle Speed Control 307 10.8 Turbo Control 308 10.8.1 Compressor Anti-surge Control 308 10.8.2 Boost Pressure Control 309 10.8.3 Boost Pressure Control with Gain Scheduling 312 10.8.4 Turbo and Knock Control 314 10.9 Dependability and Graceful Degradation 315 11 Basic Control of Diesel Engines 317 11.1 Overview of Diesel Engine Operation and Control 317 11.1.1 Diesel Engine Emission Trade-Off 318 11.1.2 Diesel Engine Configuration and Basics 319 11.2 Basic Torque Control 320 11.2.1 Feedforward Fuel Control 322 11.3 Additional Torque Controllers 322 11.4 Fuel Control 323 11.4.1 Control signal - Multiple Fuel Injections 324 11.4.2 Control Strategies for Fuel Injection 326 11.5 Control of Gas Flows 327 11.5.1 Exhaust Gas Recirculation (EGR) 328 11.5.2 EGR and Variable Geometry Turbine (VGT) 329 11.6 Case Study: EGR and VGT Control and Tuning 332 11.6.1 Control Objectives 333 11.6.2 System Properties that Guide the Control Design 334 11.6.3 Control Structure 336 11.6.4 PID Parameterization, Implementation, and Tuning 340 11.6.5 Evaluation on European Transient Cycle 343 11.6.6 Summing up the EGR VGT Case Study 346 11.7 Diesel After Treatment Control 346 12 Engine-Some Advanced Concepts 349 12.1 Variable Valve Actuation 349 12.1.1 Valve Profiles 351 12.1.2 Effects of Variable Valve Actuation 352 12.1.3 Other Valve Enabled Functions 354 12.1.4 VVA and Its Implications for Model Based Control 355 12.1.5 A Remark on Air and Fuel Control Strategies 355 12.2 Variable Compression 356 12.2.1 Example - The SAAB Variable Compression Engine 357 12.2.2 Additional Controls 358 12.3 Signal Interpretation and Feedback Control 361 12.3.1 Ion-sense 361 12.3.2 Example - Ion-sense Ignition Feedback Control 365 12.3.3 Concluding Remarks and Examples of Signal Processing 369 Part IV DRIVELINE - MODELING AND CONTROL 13 Driveline Introduction 373 13.1 Driveline 373 13.2 Motivations for Driveline Modeling and Control 373 13.2.1 Principal Objectives and Variables 374 13.2.2 Driveline Control vs. Longitudinal Vehicle Propulsion Control 375 13.2.3 Physical Background 375 13.2.4 Application-driven Background 375 13.3 Behavior without Appropriate Control 376 13.3.1 Vehicle Shuffle, Vehicle Surge 376 13.3.2 Traversing Backlash-shunt and Shuffle 377 13.3.3 Oscillations After Gear Disengagement 377 13.4 Approach 380 13.4.1 Timescales 380 13.4.2 Modeling and Control 380 14 Driveline Modeling 381 14.1 General Modeling Methodology 381 14.1.1 Graphical Scheme of a Driveline 382 14.1.2 General Driveline Equations 382 14.2 A Basic Complete Model - A Rigid Driveline 384 14.2.1 Combining the Equations 385 14.2.2 Reflected Mass and Inertias 386 14.3 Driveline Surge 386 14.3.1 Experiments for Driveline Modeling 386 14.3.2 Model with Driveshaft Flexibility 387 14.4 Additional Driveline Dynamics 391 14.4.1 Influence on Parameter Estimation 391 14.4.2 Character of Deviation in Validation Data 392 14.4.3 Influence from Propeller-shaft Flexibility 393 14.4.4 Parameter Estimation with Springs in Series 394 14.4.5 Sensor Dynamics 395 14.5 Clutch Influence and Backlash in General 396 14.5.1 Model with Flexible Clutch and Driveshaft 396 14.5.2 Nonlinear Clutch and Driveshaft Flexibility 400 14.5.3 Backlash in General 403 14.6 Modeling of Neutral Gear and Open Clutch 404 14.6.1 Experiments 404 14.6.2 A Decoupled Model 405 14.7 Clutch Modeling 406 14.7.1 Clutch Modes 409 14.8 Torque Converter 409 14.9 Concluding Remarks on Modeling 411 14.9.1 A Set of Models 411 14.9.2 Model Support 411 14.9.3 Control Design and Validating Simulations 412 15 Driveline Control 413 15.1 Characteristics of Driveline Control 414 15.1.1 Inclusion in Torque-Based Powertrain Control 414 15.1.2 Consequence of Sensor Locations 415 15.1.3 Torque Actuation 415 15.1.4 Transmissions 416 15.1.5 Engine as Torque Actuator 417 15.1.6 Control Approaches 418 15.2 Basics of Driveline Control 419 15.2.1 State-Space Formulation of the Driveshaft Model 419 15.2.2 Disturbance Description 420 15.2.3 Measurement Description 420 15.2.4 Performance Output 420 15.2.5 Control Objective 421 15.2.6 Controller Structures 421 15.2.7 Notation for Transfer Functions 422 15.2.8 Some Characteristic Feedback Properties 422 15.2.9 Insight from Simplified Transfer Functions 425 15.3 Driveline Speed Control 427 15.3.1 RQV control 427 15.3.2 Formulating the Objective of Anti-Surge Control 429 15.3.3 Speed Control with Active Damping and RQV Behavior 430 15.3.4 Influence from Sensor Location 435 15.3.5 Load Estimation 436 15.3.6 Evaluation of the Anti-Surge Controller 438 15.3.7 Demonstrating Rejection of Load Disturbance 439 15.3.8 Experimental Verification of Anti-Surge Control 440 15.3.9 Experiment Eliminating a Misconception 443 15.4 Control of Driveline Torques 443 15.4.1 Purpose of Driveline Torque Control for Gear Shifting 444 15.4.2 Demonstration of Potential Problems in Torque Control 444 15.4.3 Approaches to Driveline Torque Control for Gear Shifting 447 15.5 Transmission Torque Control 448 15.5.1 Modeling of Transmission Torque 448 15.5.2 Transmission-Torque Control Criterion 452 15.5.3 Gear-shift Condition 452 15.5.4 Final Control Criterion 454 15.5.5 Resulting Behavior-Feasible Active Damping 454 15.5.6 Validating Simulations and Sensor Location Influence 456 15.6 Driveshaft Torsion Control 459 15.6.1 Recalling Damping Control with PID 460 15.6.2 Controller Structure 460 15.6.3 Observer for Driveshaft Torsion 461 15.6.4 Field Trials for Controller Validation 464 15.6.5 Validation of Gear Shift Quality 464 15.6.6 Handling of Initial Driveline Oscillations 466 15.7 Recapitulation and Concluding Remarks 467 15.7.1 General Methodology 467 15.7.2 Valuable Insights 468 15.7.3 Formulation of Control Criterion 468 15.7.4 Validation of Functionality 468 15.7.5 Experimental Verification of Torque Limit Handling 469 15.7.6 Benefits 469 Part V DIAGNOSIS AND DEPENDABILITY 16 Diagnosis and Dependability 473 16.1 Dependability 474 16.1.1 Functional Safety-Unintended Torque 474 16.1.2 Functional Safety Standards 476 16.1.3 Controller Qualification/Conditions/Prerequisites 477 16.1.4 Accommodation of Fault Situations 478 16.1.5 Outlook 478 16.1.6 Connections 479 16.2 Basic Definitions and Concepts 479 16.2.1 Fault and Failure 480 16.2.2 Detection, Isolation, Identification, and Diagnosis 481 16.2.3 False Alarm and Missed Detection 481 16.2.4 Passive or Active (Intrusive) 482 16.2.5 Off-Line or On-Line (On-Board) 482 16.3 Introducing Methodology 482 16.3.1 A Simple Sensor Fault 482 16.3.2 A Simple Actuator Fault 483 16.3.3 Triple Sensor Redundancy 483 16.3.4 Triple Redundancy Using Virtual Sensors 485 16.3.5 Redundancy and Model-Based Diagnosis 486 16.3.6 Forming a Decision-Residual Evaluation 488 16.3.7 Leakage in a Turbo Engine 491 16.4 Engineering of Diagnosis Systems 494 16.5 Selected Automotive Applications 494 16.5.1 Catalyst and Lambda Sensors 495 16.5.2 Throttle Supervision 496 16.5.3 Evaporative System Monitoring 497 16.5.4 Misfire 501 16.5.5 Air Intake 507 16.5.6 Diesel Engine Model 517 16.6 History, Legislation, and OBD 520 16.6.1 Diagnosis of Automotive Engines 520 16.7 Legislation 521 16.7.1 OBDII 521 16.7.2 Examples of OBDII Legislation Texts 523 A Thermodynamic Data and Heat Transfer Formulas 527 A.1 Thermodynamic Data and Some Constants 527 A.2 Fuel Data 528 A.3 Dimensionless Numbers 528 A.4 Heat Transfer Basics 529 A.4.1 Conduction 535 A.4.2 Convection 536 A.4.3 Radiation 537 A.4.4 Resistor Analogy 537 A.4.5 Solution to Fourth-order Equations 539 References 541 Index 555