Modeling and Control of Engines and Drivelines

Lars Eriksson is an Associate Professor of Vehicular Systems at Linköping University with main responsibility for the engine control laboratory. Since 1994, he has been working as a researcher in the field of modeling and control of engines and drivelines with research that is performed in close collaboration with industry. This provides good contact with practicing engineers and who are then able to offer their input when new research results are integrated into course curriculums. As a teacher he has developed and taught several courses on this subject, both at the university and for industry. At Linköping University he is responsible for the course “Modeling and Control of Engines and Drivelines” which has been given on the subject since 1998 and he is also a regular lecturer for the module "Basics of SI engine control" on the Powertrain Engineering Programme at IFP School in Paris.Since 1992, Lars Nielsen has been a Professor of Vehicular Systems holding the Sten Gustafsson chair at Linköping University. His main research interests are in automotive modeling, control, and diagnosis, and he has been active in all aspects of this field during its expansion and growth since the nineties. His supervision has led to thirty graduate exams, in many cases with significant industrial participation. The collaboration aspect has also been strong in his role as center director for two large centers of excellence (ECSEL 1996-2002, LINK-SIC 2010- ). In the international research community, he was the Chairman of Automotive Control within the International Federation of Automatic Control (2002-2005), and then the Chairman of all Transportation and Vehicle Systems (2005-2011). Selected national commissions of trust are Board Member of the Swedish Research Council-NT (2001-2006), and vice chair in IVA II - the electrical engineering division of the Royal Swedish Academy of Engineering (2010-).

• Preface xvii Series Preface xixPart I VEHICLE – PROPULSION FUNDAMENTALS1 Introduction 31.1 Trends 41.1.1 Energy and Environment 41.1.2 Downsizing 41.1.3 Hybridization 61.1.4 Driver Support Systems and Optimal Driving 61.1.5 Engineering Challenges 81.2 Vehicle Propulsion 81.2.1 Control Enabling Optimal Operation of Powertrains 91.2.2 Importance of Powertrain Modeling and Models 101.2.3 Sustainability of Model Knowledge 111.3 Organization of the Book 112 Vehicle 152.1 Vehicle Propulsion Dynamics 152.2 Driving Resistance 162.2.1 Aerodynamic Drag 172.2.2 Cooling Drag and Active Air-Shutters 182.2.3 Air Drag When Platooning 192.2.4 Rolling Resistance – Physical Background 202.2.5 Rolling Resistance–Modeling 212.2.6 Wheel Slip (Skid) 242.2.7 Rolling Resistance – Including Thermal Modeling 252.2.8 Gravitation 272.2.9 Relative Size of Components 282.3 Driving Resistance Models 282.3.1 Models for Driveline Control 292.3.2 Standard Driving Resistance Model 302.3.3 Modeling for Mission Analysis 312.4 Driver Behavior and Road Modeling 322.4.1 Simple Driver Model 322.4.2 Road Modeling 332.5 Mission Simulation 342.5.1 Methodology 342.6 Vehicle Characterization/Characteristics 342.6.1 Performance Measures 352.7 Fuel Consumption 362.7.1 Energy Density Weight 362.7.2 From Tank to Wheel – Sankey Diagram 372.7.3 Well-to-Wheel Comparisons 382.8 Emission Regulations 392.8.1 US and EU Driving Cycles and Regulations 393 Powertrain 453.1 Powertrain Architectures 453.1.1 Exhaust Gas Energy Recovery 473.1.2 Hybrid Powertrains 473.1.3 Electrification 483.2 Vehicle Propulsion Control 503.2.1 Objectives of Vehicle Propulsion Control 503.2.2 Implementation Framework 513.2.3 Need for a Control Structure 523.3 Torque-Based Powertrain Control 523.3.1 Propagation of Torque Demands and Torque Commands 523.3.2 Torque-Based Propulsion Control – Driver Interpretation 543.3.3 Torque-Based Propulsion Control – Vehicle Demands 553.3.4 Torque-Based Propulsion Control – Driveline management 553.3.5 Torque-Based Propulsion Control – Driveline–Engine Integration 553.3.6 Handling of Torque Requests – Torque Reserve and Interventions 563.4 Hybrid Powertrains 583.4.1 ICE Handling 583.4.2 Motor Handling 593.4.3 Battery Management 593.5 Outlook and Simulation 603.5.1 Simulation Structures 603.5.2 Drive/Driving Cycle 603.5.3 Forward Simulation 613.5.4 Quasi-Static Inverse Simulation 613.5.5 Tracking 613.5.6 Inverse Dynamic Simulation 623.5.7 Usage and Requirements 643.5.8 Same Model Blocks Regardless of Method 65Part II ENGINE – FUNDAMENTALS4 Engine – Introduction 694.1 Air, Fuel, and Air/Fuel Ratio 694.1.1 Air 694.1.2 Fuels 704.1.3 Stoichiometry and (A/F) Ratio 714.2 Engine Geometry 734.3 Engine Performance 744.3.1 Power, Torque, and Mean Effective Pressure 744.3.2 Efficiency and Specific Fuel Consumption 754.3.3 Volumetric Efficiency 764.4 Downsizing and Turbocharging 774.4.1 Supercharging and Turbocharging 785 Thermodynamics and Working Cycles 815.1 The Four-Stroke Cycle 815.1.1 Important Engine Events in the Cycle 845.2 Thermodynamic Cycle Analysis 855.2.1 Ideal Models of Engine Processes 865.2.2 Derivation of Cycle Efficiencies 895.2.3 Gas Exchange and Pumping Work 915.2.4 Residual Gases and Volumetric Efficiency for Ideal Cycles 935.3 Efficiency of Ideal Cycles 985.3.1 Load, Pumping Work, and Efficiency 995.3.2 (A/F) Ratio and Efficiency 1005.3.3 Differences between Ideal and Real Cycles 1035.4 Models for In-Cylinder Processes 1055.4.1 Single-Zone Models 1055.4.2 Heat Release and Mass Fraction Burned Analysis 1075.4.3 Characterization of Mass Fraction Burned 1095.4.4 More Single-Zone Model Components 1115.4.5 A Single-zone Cylinder Pressure Model 1135.4.6 Multi-zone Models 1145.4.7 Applications for Zero-dimensional Models 1176 Combustion and Emissions 1196.1 Mixture Preparation and Combustion 1196.1.1 Fuel Injection 1196.1.2 Comparing the SI and CI Combustion Process 1206.2 SI Engine Combustion 1216.2.1 SI Engine Cycle-to-Cycle Variations 1216.2.2 Knock and Autoignition 1226.2.3 Autoignition and Octane Number 1246.3 CI Engine Combustion 1266.3.1 Autoignition and Cetane Number 1266.4 Engine Emissions 1286.4.1 General Trends for Emission Formation 1286.4.2 Pollutant Formation in SI Engines 1306.4.3 Pollutant Formation in CI Engines 1346.5 Exhaust Gas Treatment 1376.5.1 Catalyst Efficiency, Temperature, and Light-Off 1376.5.2 SI Engine Aftertreatment, TWC 1396.5.3 CI Engine Exhaust Gas Treatment 1406.5.4 Emission Reduction and Controls 142Part III ENGINE – MODELING AND CONTROL7 Mean Value Engine Modeling 1457.1 Engine Sensors and Actuators 1467.1.1 Sensor, System, and Actuator Responses 1467.1.2 Engine Component Modeling 1497.2 Flow Restriction Models 1497.2.1 Incompressible Flow 1517.2.2 Compressible Flow 1547.3 Throttle Flow Modeling 1567.3.1 Throttle Area and Discharge Coefficient 1577.4 Mass Flow Into the Cylinders 1597.4.1 Models for Volumetric Efficiency 1597.5 Volumes 1627.6 Example – Intake Manifold 1667.7 Fuel Path and (A/F) Ratio 1687.7.1 Fuel Pumps, Fuel Rail, Injector Feed 1687.7.2 Fuel Injector 1697.7.3 Fuel Preparation Dynamics 1717.7.4 Gas Transport and Mixing 1747.7.5 A/F Sensors 1747.7.6 Fuel Path Validation 1787.7.7 Catalyst and Post-Catalyst Sensor 1787.8 In-Cylinder Pressure and Instantaneous Torque 1807.8.1 Compression Asymptote 1807.8.2 Expansion Asymptote 1827.8.3 Combustion 1837.8.4 Gas Exhange and Model Compilation 1847.8.5 Engine Torque Generation 1847.9 Mean Value Model for Engine Torque 1867.9.1 Gross Indicated Work 1877.9.2 Pumping Work 1907.9.3 Engine Friction 1907.9.4 Time Delays in Torque Production 1927.9.5 Crankshaft Dynamics 1937.10 Engine-Out Temperature 1937.11 Heat Transfer and Exhaust Temperatures 1967.11.1 Temperature Change in a Pipe 1967.11.2 Heat Transfer Modes in Exhaust Systems 1977.11.3 Exhaust System Temperature Models 1977.12 Heat Exchangers and Intercoolers 2037.12.1 Heat Exchanger Modeling 2047.13 Throttle Plate Motion 2067.13.1 Model for Throttle with Throttle Servo 2108 Turbocharging Basics and Models 2118.1 Supercharging and Turbocharging Basics 2118.2 Turbocharging Basic Principles and Performance 2148.2.1 Turbochargers in Mean Value Engine Models 2148.2.2 First Law Analysis of Compressor Performance 2168.2.3 First Law Analysis of Turbine Performance 2188.2.4 Connecting the Turbine and Compressor 2198.2.5 Intake Air Density Increase 2198.3 Dimensional Analysis 2208.3.1 Compressible Fluid Analysis 2218.3.2 Model Structure with Corrected Quantities 2238.4 Compressor and Turbine Performance Maps 2238.4.1 The Basic Compressor Map 2238.4.2 The Basic Turbine Map 2258.4.3 Measurement Procedures for determining Turbo Maps 2268.4.4 Turbo Performance Calculation Details 2278.4.5 Heat Transfer and Turbine Efficiency 2308.5 Turbocharger Models and Parametrizations 2328.5.1 Map Interpolation Models 2328.6 Compressor Operation and Modeling 2328.6.1 Physical Modeling of a Compressor 2338.6.2 Compressor Efficiency Models 2378.6.3 Compressor Flow Models 2398.6.4 Compressor Choke 2418.6.5 Compressor Surge 2448.7 Turbine Operation and Modeling 2498.7.1 Turbine Mass Flow 2498.7.2 Turbine Efficiency 2528.7.3 Variable Geometry Turbine 2538.8 Transient Response and Turbo Lag 2548.9 Example – Turbocharged SI Engine 2558.10 Example – Turbocharged Diesel Engine 2579 Engine Management Systems – An Introduction 2639.1 Engine Management System (EMS) 2639.1.1 EMS Building Blocks 2649.1.2 System for Crank and Time-Based Events 2659.2 Basic Functionality and Software Structure 2669.2.1 Torque Based Structure 2669.2.2 Special Modes and Events 2679.2.3 Automatic Code Generation and Information Exchange 2679.3 Calibration and Parameter Representation 2679.3.1 Engine Maps 2689.3.2 Model-Based Development 27010 Basic Control of SI Engines 27110.1 Three Basic SI Engine Controllers 27210.1.1 Production System Example 27310.1.2 Basic Control Using Maps 27410.1.3 Torque, Air Charge, and Pressure Control 27510.1.4 Pressure Set Point from Simple Torque Model 27510.1.5 Set Points from Full Torque Model 27610.1.6 Pressure Control 27710.2 Throttle Servo 27910.2.1 Throttle Control Based on Exact Linearization 28010.3 Fuel Management and Control 28210.3.1 Feedforward and Feedback Control Structure 28310.3.2 Feedforward Control with Basic Fuel Metering 28310.3.3 Feedback Control 28410.3.4 Fuel Dynamics and Injector Compensation 28910.3.5 Observer Based Control and Adaption 29010.3.6 Dual and Triple Sensor Control 29310.4 Other Factors that Influence Control 29410.4.1 Full Load Enrichment 29510.4.2 Engine Overspeed and Overrun 29610.4.3 Support Systems that Influence Air and Fuel Calculation 29610.4.4 Cold Start Enrichment 29810.4.5 Individual Cylinder -control 29810.5 Ignition Control 29910.5.1 Knock Control – Feedback Control 30110.5.2 Ignition Energy – Dwell Time Control 30410.5.3 Long-term Torque, Short-term Torque, and Torque Reserve 30510.6 Idle Speed Control 30610.7 Torque Management and Idle Speed Control 30710.8 Turbo Control 30810.8.1 Compressor Anti-surge Control 30810.8.2 Boost Pressure Control 30910.8.3 Boost Pressure Control with Gain Scheduling 31210.8.4 Turbo and Knock Control 31410.9 Dependability and Graceful Degradation 31511 Basic Control of Diesel Engines 31711.1 Overview of Diesel Engine Operation and Control 31711.1.1 Diesel Engine Emission Trade-Off 31811.1.2 Diesel Engine Configuration and Basics 31911.2 Basic Torque Control 32011.2.1 Feedforward Fuel Control 32211.3 Additional Torque Controllers 32211.4 Fuel Control 32311.4.1 Control signal – Multiple Fuel Injections 32411.4.2 Control Strategies for Fuel Injection 32611.5 Control of Gas Flows 32711.5.1 Exhaust Gas Recirculation (EGR) 32811.5.2 EGR and Variable Geometry Turbine (VGT) 32911.6 Case Study: EGR and VGT Control and Tuning 33211.6.1 Control Objectives 33311.6.2 System Properties that Guide the Control Design 33411.6.3 Control Structure 33611.6.4 PID Parameterization, Implementation, and Tuning 34011.6.5 Evaluation on European Transient Cycle 34311.6.6 Summing up the EGR VGT Case Study 34611.7 Diesel After Treatment Control 34612 Engine–Some Advanced Concepts 34912.1 Variable Valve Actuation 34912.1.1 Valve Profiles 35112.1.2 Effects of Variable Valve Actuation 35212.1.3 Other Valve Enabled Functions 35412.1.4 VVA and Its Implications for Model Based Control 35512.1.5 A Remark on Air and Fuel Control Strategies 35512.2 Variable Compression 35612.2.1 Example – The SAAB Variable Compression Engine 35712.2.2 Additional Controls 35812.3 Signal Interpretation and Feedback Control 36112.3.1 Ion-sense 36112.3.2 Example – Ion-sense Ignition Feedback Control 36512.3.3 Concluding Remarks and Examples of Signal Processing 369Part IV DRIVELINE – MODELING AND CONTROL13 Driveline Introduction 37313.1 Driveline 37313.2 Motivations for Driveline Modeling and Control 37313.2.1 Principal Objectives and Variables 37413.2.2 Driveline Control vs. Longitudinal Vehicle Propulsion Control 37513.2.3 Physical Background 37513.2.4 Application-driven Background 37513.3 Behavior without Appropriate Control 37613.3.1 Vehicle Shuffle, Vehicle Surge 37613.3.2 Traversing Backlash–shunt and Shuffle 37713.3.3 Oscillations After Gear Disengagement 37713.4 Approach 38013.4.1 Timescales 38013.4.2 Modeling and Control 38014 Driveline Modeling 38114.1 General Modeling Methodology 38114.1.1 Graphical Scheme of a Driveline 38214.1.2 General Driveline Equations 38214.2 A Basic Complete Model – A Rigid Driveline 38414.2.1 Combining the Equations 38514.2.2 Reflected Mass and Inertias 38614.3 Driveline Surge 38614.3.1 Experiments for Driveline Modeling 38614.3.2 Model with Driveshaft Flexibility 38714.4 Additional Driveline Dynamics 39114.4.1 Influence on Parameter Estimation 39114.4.2 Character of Deviation in Validation Data 39214.4.3 Influence from Propeller-shaft Flexibility 39314.4.4 Parameter Estimation with Springs in Series 39414.4.5 Sensor Dynamics 39514.5 Clutch Influence and Backlash in General 39614.5.1 Model with Flexible Clutch and Driveshaft 39614.5.2 Nonlinear Clutch and Driveshaft Flexibility 40014.5.3 Backlash in General 40314.6 Modeling of Neutral Gear and Open Clutch 40414.6.1 Experiments 40414.6.2 A Decoupled Model 40514.7 Clutch Modeling 40614.7.1 Clutch Modes 40914.8 Torque Converter 40914.9 Concluding Remarks on Modeling 41114.9.1 A Set of Models 41114.9.2 Model Support 41114.9.3 Control Design and Validating Simulations 41215 Driveline Control 41315.1 Characteristics of Driveline Control 41415.1.1 Inclusion in Torque-Based Powertrain Control 41415.1.2 Consequence of Sensor Locations 41515.1.3 Torque Actuation 41515.1.4 Transmissions 41615.1.5 Engine as Torque Actuator 41715.1.6 Control Approaches 41815.2 Basics of Driveline Control 41915.2.1 State-Space Formulation of the Driveshaft Model 41915.2.2 Disturbance Description 42015.2.3 Measurement Description 42015.2.4 Performance Output 42015.2.5 Control Objective 42115.2.6 Controller Structures 42115.2.7 Notation for Transfer Functions 42215.2.8 Some Characteristic Feedback Properties 42215.2.9 Insight from Simplified Transfer Functions 42515.3 Driveline Speed Control 42715.3.1 RQV control 42715.3.2 Formulating the Objective of Anti-Surge Control 42915.3.3 Speed Control with Active Damping and RQV Behavior 43015.3.4 Influence from Sensor Location 43515.3.5 Load Estimation 43615.3.6 Evaluation of the Anti-Surge Controller 43815.3.7 Demonstrating Rejection of Load Disturbance 43915.3.8 Experimental Verification of Anti-Surge Control 44015.3.9 Experiment Eliminating a Misconception 44315.4 Control of Driveline Torques 44315.4.1 Purpose of Driveline Torque Control for Gear Shifting 44415.4.2 Demonstration of Potential Problems in Torque Control 44415.4.3 Approaches to Driveline Torque Control for Gear Shifting 44715.5 Transmission Torque Control 44815.5.1 Modeling of Transmission Torque 44815.5.2 Transmission-Torque Control Criterion 45215.5.3 Gear-shift Condition 45215.5.4 Final Control Criterion 45415.5.5 Resulting Behavior–Feasible Active Damping 45415.5.6 Validating Simulations and Sensor Location Influence 45615.6 Driveshaft Torsion Control 45915.6.1 Recalling Damping Control with PID 46015.6.2 Controller Structure 46015.6.3 Observer for Driveshaft Torsion 46115.6.4 Field Trials for Controller Validation 46415.6.5 Validation of Gear Shift Quality 46415.6.6 Handling of Initial Driveline Oscillations 46615.7 Recapitulation and Concluding Remarks 46715.7.1 General Methodology 46715.7.2 Valuable Insights 46815.7.3 Formulation of Control Criterion 46815.7.4 Validation of Functionality 46815.7.5 Experimental Verification of Torque Limit Handling 46915.7.6 Benefits 469Part V DIAGNOSIS AND DEPENDABILITY16 Diagnosis and Dependability 47316.1 Dependability 47416.1.1 Functional Safety–Unintended Torque 47416.1.2 Functional Safety Standards 47616.1.3 Controller Qualification/Conditions/Prerequisites 47716.1.4 Accommodation of Fault Situations 47816.1.5 Outlook 47816.1.6 Connections 47916.2 Basic Definitions and Concepts 47916.2.1 Fault and Failure 48016.2.2 Detection, Isolation, Identification, and Diagnosis 48116.2.3 False Alarm and Missed Detection 48116.2.4 Passive or Active (Intrusive) 48216.2.5 Off-Line or On-Line (On-Board) 48216.3 Introducing Methodology 48216.3.1 A Simple Sensor Fault 48216.3.2 A Simple Actuator Fault 48316.3.3 Triple Sensor Redundancy 48316.3.4 Triple Redundancy Using Virtual Sensors 48516.3.5 Redundancy and Model-Based Diagnosis 48616.3.6 Forming a Decision–Residual Evaluation 48816.3.7 Leakage in a Turbo Engine 49116.4 Engineering of Diagnosis Systems 49416.5 Selected Automotive Applications 49416.5.1 Catalyst and Lambda Sensors 49516.5.2 Throttle Supervision 49616.5.3 Evaporative System Monitoring 49716.5.4 Misfire 50116.5.5 Air Intake 50716.5.6 Diesel Engine Model 51716.6 History, Legislation, and OBD 52016.6.1 Diagnosis of Automotive Engines 52016.7 Legislation 52116.7.1 OBDII 52116.7.2 Examples of OBDII Legislation Texts 523A Thermodynamic Data and Heat Transfer Formulas 527A.1 Thermodynamic Data and Some Constants 527A.2 Fuel Data 528A.3 Dimensionless Numbers 528A.4 Heat Transfer Basics 529A.4.1 Conduction 535A.4.2 Convection 536A.4.3 Radiation 537A.4.4 Resistor Analogy 537A.4.5 Solution to Fourth-order Equations 539References 541Index 555