Preface	5
	Contributors	6
	Contents	8
	1 Introduction and Fundamentals	23
	1.1 History, Definition, Function, and Significance	24
	1.1.1 History	24
	1.1.2 Definition and Scope	29
	1.1.3 Purpose and Significance	30
	1.2 Chassis Design	31
	1.2.1 Vehicle Classification	31
	1.2.2 Powertrain Configurations	32
	1.2.3 Chassis Composition	35
	1.2.4 Trends in Chassis Composition	35
	1.3 Chassis Layout	37
	1.3.1 Chassis Requirements	38
	1.3.2 Layout of Suspension Kinematics	40
	1.3.3 Suspension Kinematics	40
	1.3.3.1 Suspension Parameters Relative to Vehicle	40
	1.3.3.2 Roll and Pitch Center	42
	1.3.3.3 Wheel Travel	42
	1.3.3.4 Wheel Travel Parameters	43
	1.3.3.5 Steering Kinematic Parameters	46
	1.3.3.6 Kinematic Parameters of Current Vehicles	50
	1.3.3.7 Wheel Travel Curves	50
	1.3.3.8 Wheel Kinematic Calculation Software	53
	1.3.4 Elastokinematics and Component Compliances in Suspension Design	53
	1.3.5 Target Parameter Values	54
	1.3.6 Suspension Composition	55
	2 Driving Dynamics	57
	2.1 Driving Resistances and Energy Requirements	57
	2.1.1 Driving Resistances	57
	2.1.1.1 Rolling Resistance	57
	2.1.1.2 Effect of Road Surface on Rolling Resistance FR,Tr	62
	2.1.1.3 Aerodynamic Drag FA	65
	2.1.1.4 Climbing Resistance FC	66
	2.1.1.5 Inertial Resistance FI	67
	2.1.1.6 Total Driving Resistance	68
	2.1.2 Crosswind Response Behavior	68
	2.1.3 Performance and Energy Requirements	71
	2.1.4 Fuel Consumption	72
	2.2 Tire Traction and Force Transfer to the Roadway	74
	2.2.1 The Physics of Tire Traction and Force Transfer	76
	2.2.1.1 Acceleration and Braking	79
	2.2.1.2 Cornering	80
	2.2.2 Detailed Tire Forces	85
	2.3 Longitudinal Dynamics	87
	2.3.1 Acceleration and Braking	87
	2.3.1.1 Anti-Dive	87
	2.3.1.2 Anti-Lift (Anti-Squat)	88
	2.3.1.3 Load Changes During Straightline Driving	89
	2.4 Vertical Dynamics	89
	2.4.1 Springs	89
	2.4.1.1 Spring Ratio	90
	2.4.1.2 Natural (Eigen) Frequencies	90
	2.4.2 Vibration Dampers	91
	2.4.3 Excitations from the Roadway	92
	2.4.3.1 Harmonic Excitations	92
	2.4.3.2 Periodic Irregularities	93
	2.4.3.3 Stochastic (Random) Irregularities	93
	2.4.3.4 Spectral Density of Road Surface Irregularities	94
	2.4.3.5 Measured Road Surface Irregularities	95
	2.4.4 Tires as Spring/Damper Elements	95
	2.4.5 Suspension Models	96
	2.4.5.1 Single-Mass System	96
	2.4.5.2 Dual-Mass System	97
	2.4.5.3 Expansion of the Model to Include Seat Suspension Effects	97
	2.4.5.4 Single-Track Suspension Model	98
	2.4.5.5 Two-Track Suspension Model	99
	2.4.6 Parameter Variation	101
	2.4.7 The Roadway/Vehicle Connection	103
	2.4.7.1 Spectral Density of Vehicle Body Accelerations	104
	2.4.7.2 Spectral Density of Dynamic Wheel Loads	106
	2.4.8 Human Oscillation Evaluation	106
	2.4.9 Conclusions from the Fundamentalsof Vertical Dynamics	108
	2.5 Lateral Dynamics	108
	2.5.1 Handling Requirements	108
	2.5.2 Steering Kinematics	109
	2.5.2.1 Static Steering Layout	109
	2.5.2.2 Dynamic Steering Layout	110
	2.5.3 Vehicle Modeling	111
	2.5.3.1 Simple Single-Track (Bicycle) Model	111
	2.5.3.2 Simple Vehicle Dynamics	112
	2.5.3.3 Understeer and Oversteer	115
	2.5.3.4 Expanded Single-Track Model with Rear-Wheel Steering	116
	2.5.3.5 Nonlinear Single-Track Model	117
	2.5.3.6 Analysis of Transient Behavior Using the Simple Single-Track Model	119
	2.5.3.7 The Vehicle as Part of a Closed-Loop System	121
	2.5.3.8 Dynamic Behavior of the Vehicle as Part of a Closed-Loop System	122
	2.5.3.9 Slip Angle Compensation Using Rear-Wheel Steering	125
	2.5.3.10 Investigation of Frequency Response for Varied Vehicle Configurations	127
	2.5.3.11 Dual-Track Model	128
	2.5.3.12 Parameter Variation	131
	2.6 General Vehicle Dynamics	135
	2.6.1 Interactions between Vertical, Longitudinal, and Lateral Dynamics	135
	2.7 Chassis Control Systems	140
	2.7.1 Definition of Terms	140
	2.7.2 Limitations of the Passive Vehicle – Basic Goal Conflicts	140
	2.7.3 The Driver-Vehicle Control Loop	141
	2.7.4 Division of Chassis Control Systems into Domains	142
	2.7.4.1 Longitudinal Dynamics	142
	2.7.4.2 Lateral Dynamics	143
	2.7.4.3 Vertical Dynamics	143
	2.7.5 Requirements for Chassis Control Systems	143
	2.8 Handling Characteristics	144
	2.8.1 Handling Evaluation	144
	2.8.2 Driving Maneuvers	146
	2.8.3 Parameter Range of Maneuvers	146
	2.8.4 Tuning Procedures	149
	2.8.4.1 Tuning Procedures forSteady-State Steering Behavior	149
	2.8.5 Subjective Handling Evaluation	149
	2.8.5.1 Evaluation Methods and Representation	152
	2.8.5.2 Acceleration (Driveoff) Behavior	152
	2.8.5.3 Braking Behavior	152
	2.8.5.4 Steering Behavior	154
	2.8.5.5 Cornering Behavior	156
	2.8.5.6 Straightline Driving Behavior	156
	2.8.5.7 Ride Comfort	158
	2.8.6 Objective Handling Evaluations	159
	2.8.6.1 Measurement Parameters	159
	2.8.6.2 Acceleration (Driveoff) Behavior	159
	2.8.6.3 Braking Behavior	160
	2.8.6.4 Steering Behavior	161
	2.8.6.5 Cornering Behavior	163
	2.8.6.6 Straightline Driving Behavior	165
	2.8.6.7 Ride Comfort	167
	2.9 Active and Passive Safety	167
	3 Chassis Components	170
	3.1 Chassis Structuring	170
	3.1.1 Classification by Function	170
	3.1.2 Modular Chassis Structure	171
	3.1.3 Chassis Components	171
	3.2 Drivetrain	172
	3.2.1 Configurations	172
	3.2.2 Axle Drives	172
	3.2.2.1 Differentials	172
	3.2.2.2 Locking Differentials	172
	3.2.2.3 Active Differentials	174
	3.2.2.4 Torque Vectoring	174
	3.2.3 Four-wheel-drive (All-wheel-drive)	175
	3.2.4 Control Strategies	176
	3.2.5 Half-shafts	177
	3.3 Wheel Brakes and Braking	178
	3.3.1 Fundamentals and Requirements	178
	3.3.2 Types of Braking Systems	179
	3.3.2.1 General Requirements	180
	3.3.3 Legal Regulations	181
	3.3.4 Brake System Design	181
	3.3.4.1 Brake Force Distribution	181
	3.3.4.2 Dimensioning	183
	3.3.5 Braking Torque and Dynamics	183
	3.3.5.1 Braking Torque	183
	3.3.5.2 Braking Dynamics	184
	3.3.6 Brake System Components	185
	3.3.6.1 Brake Calipers	185
	3.3.6.2 Brake Discs	189
	3.3.6.3 Brake Linings	190
	3.3.6.4 Drum Brakes	190
	3.3.6.5 Brake Fluid	193
	3.3.6.6 Brake Force Booster	193
	3.3.6.7 Tandem Master Cylinder	194
	3.3.6.8 Human-Machine Interface (HMI)	194
	3.3.7 Electronic Braking Control Systems	198
	3.3.7.1 Brake Assistant (MBA, EBA, HBA)	198
	3.3.7.2 Wheel Speed Sensors	201
	3.3.7.3 Electronic Braking System Functions	202
	3.3.7.4 Electrohydraulic Brake (EHB)	208
	3.3.7.5 Electromechanical Brake (EMB)	209
	3.3.7.6 Networked Chassis	211
	3.4 Steering Systems	212
	3.4.1 Requirements and Designs	212
	3.4.2 Hydraulic Rack and Pinion Steering	215
	3.4.2.1 Technology and Function	215
	3.4.2.2 Design and Components	218
	3.4.3 Steering Tie Rods	221
	3.4.4 Steering Driveline and Steering Column	224
	3.4.4.1 Components and Function Modules	224
	3.4.4.2 Design and Testing	226
	3.4.4.3 Crash Requirements and Energy Absorption Mechanisms	227
	3.4.4.4 Future Prospects and Modularization	230
	3.4.5 Electromechanical Steering Systems	230
	3.4.5.1 Design Concepts	230
	3.4.5.2 Configuration and Advantages	233
	3.4.6 Active Steering and Superposition Steering	236
	3.4.6.1 Functional Principles and Configuration	236
	3.4.6.2 Functions – Present and Future	238
	3.4.7 Rack and Pinion Power Steering with Torque and Angle Actuators	240
	3.4.8 Rear-wheel and Four-wheel Steering Systems	241
	3.4.9 Steer-by-wire and Single-wheel Steering Systems	243
	3.4.9.1 System Configuration and Components	244
	3.4.9.2 Technology, Advantages, Opportunities	246
	3.5 Springs and Stabilizers	247
	3.5.1 The Purpose of the Spring System	247
	3.5.2 Design and Calculation of Steel Springs	247
	3.5.2.1 Leaf Springs	248
	3.5.2.2 Torsion Bar Springs	251
	3.5.2.3 Stabilizers	252
	3.5.2.4 Coil Springs	260
	3.5.3 Spring Materials	268
	3.5.4 Steel Spring Manufacture	270
	3.5.4.1 Hot Forming	270
	3.5.4.2 Heat Treating Hot Formed Springs	272
	3.5.4.3 Cold Forming	272
	3.5.4.4 Shot Peening	273
	3.5.4.5 Plastification	274
	3.5.4.6 Corrosion Protection	274
	3.5.4.7 Final Inspection and Marking	275
	3.5.5 Roll Control Using Stabilizers	275
	3.5.5.1 Passive Stabilizers	275
	3.5.5.2 Switchable Off-Road Stabilizers	276
	3.5.5.3 Switchable On-Road Stabilizers	276
	3.5.5.4 Semi-Active Stabilizers	276
	3.5.5.5 Active Stabilizers	278
	3.5.6 Springs for use with AutomaticLeveling Systems	278
	3.5.6.1 Purpose and Configurations	278
	3.5.6.2 Leveling Using a Gas Spring	279
	3.5.7 Hydropneumatic Springs	282
	3.5.7.1 Self-Pumping Hydropneumatic Spring/Damper Elements	282
	3.5.8 Air Springs	285
	3.6 Damping	287
	3.6.1 The Purpose of Damping	287
	3.6.2 Telescopic Shock Absorber Designs	291
	3.6.2.1 Twin-Tube Shock Absorbers	291
	3.6.2.2 Monotube Shock Absorbers	292
	3.6.2.3 Comparison of Damper Types	292
	3.6.2.4 Special Designs	293
	3.6.3 Coilover Shock Absorber and Strut	293
	3.6.4 Shock Absorber Calculations	295
	3.6.5 Additional Damper Features	296
	3.6.5.1 Rebound and Compression Bump Stops	296
	3.6.5.2 Stroke-Dependent Damping	298
	3.6.5.3 Amplitude-Selective Damping	300
	3.6.6 Damper End Mounts	301
	3.6.7 Semi-Active Damping and Spring Functions	302
	3.6.8 Alternative Damping Concepts	306
	3.6.8.1 Magneto-Rheological (MRF) Dampers	306
	3.6.8.2 Conjoined Damping	307
	3.6.8.3 Load-Dependent Damping (PDC)	307
	3.7 Wheel Control	308
	3.7.1 Purpose, Requirements, and System Structure	308
	3.7.2 Suspension Links: Purpose, Requirements, and System Structure	309
	3.7.2.1 Control Arms (Control Links)	310
	3.7.2.2 Support Links	311
	3.7.2.3 Auxiliary Links	311
	3.7.2.4 Suspension Link Requirements	312
	3.7.2.5 Suspension Link Materials	312
	3.7.2.6 Suspension Link Manufacturing Processes	313
	3.7.2.7 Manufacturing Methods for Aluminum Suspension Links	319
	3.7.2.8 Configuration and Optimization of Suspension Links	321
	3.7.2.9 Integration of the Joints into the Link	321
	3.7.3 Ball Joints	322
	3.7.3.1 Purpose and Requirements	323
	3.7.3.2 Types of Ball Joints	323
	3.7.3.3 Ball Joint Components	324
	3.7.3.4 Bearing System (Ball Race, Grease)	327
	3.7.3.5 Sealing System (Sealing Boot, Retaining Ring)	330
	3.7.3.6 Suspension Ball Joints	333
	3.7.3.7 Preloaded Ball Joints	334
	3.7.3.8 Cross Axis Ball Joints	335
	3.7.4 Rubber Bushings	337
	3.7.4.1 Purpose, Requirements, and Function	337
	3.7.4.2 Types of Rubber Bushings	339
	3.7.5 Pivot Joints	341
	3.7.6 Rotational Sliding Joints (Trunnion Joints)	342
	3.7.7 Chassis Subframes	343
	3.7.7.1 Purpose and Requirements	343
	3.7.7.2 Types and Designs	343
	3.8 Wheel Carriers and Bearings	346
	3.8.1 Types of Wheel Carriers	346
	3.8.2 Wheel Carrier Materials and Manufacturing Methods	348
	3.8.3 Types of Wheel Bearings	349
	3.8.3.1 Bearing Seals	352
	3.8.3.2 Lubrication	352
	3.8.3.3 ABS Sensors	353
	3.8.4 Wheel Bearing Manufacturing	355
	3.8.4.1 Rings and Flanges	355
	3.8.4.2 Cages and Rolling Elements	356
	3.8.4.3 Assembly	356
	3.8.5 Requirements, Design, and Testing	356
	3.8.5.1 Bearing Rotational Fatigue Strength	358
	3.8.5.2 Component Strength and Tilt Stiffness	360
	3.8.5.3 Verification by Testing	362
	3.8.6 Future Prospects	363
	3.9 Tires and Wheels	367
	3.9.1 Tire Requirements	367
	3.9.1.1 Properties and Performance	367
	3.9.1.2 Legal Requirements	369
	3.9.2 Types, Construction, and Materials	370
	3.9.2.1 Tire Types	370
	3.9.2.2 Tire Construction	371
	3.9.2.3 Tire Materials	371
	3.9.2.4 The Viscoelastic Properties of Rubber	372
	3.9.3 Transmission of Forces between the Tire and the Road Surface	373
	3.9.3.1 Supporting Force	373
	3.9.3.2 Adhesion Behavior and Lateral Force Buildup	374
	3.9.3.3 Tangential Forces: Driving and Braking	375
	3.9.3.4 Sideslip, Lateral Forces, and Aligning Moments	375
	3.9.3.5 Sideslip Stiffness	376
	3.9.3.6 Tire Behavior under Slip	378
	3.9.3.7 Tire Uniformity	379
	3.9.4 Tire Simulation Models	379
	3.9.4.1 Tire Models for Lateral Dynamics	379
	3.9.4.2 Tire Models Using Finite Elements (FEM)	381
	3.9.4.3 Tire Models for Vertical Dynamics	381
	3.9.4.4 Tire Vibration Modes	382
	3.9.4.5 Cavity Natural Frequencies	382
	3.9.4.6 Full Tire Models	383
	3.9.5 Modern Tire Technologies	385
	3.9.5.1 Tire Sensors	385
	3.9.5.2 Run-Flat Tires	387
	3.9.5.3 Tires and Control Systems	388
	3.9.5.4 High Performance (HP) and Ultra High Performance (UHP) Tires	389
	3.9.6 Vehicle Testing and Measurement	390
	3.9.6.1 Subjective Test Procedures	390
	3.9.6.2 Objective Test Procedures for Longitudinal Adhesion	391
	3.9.6.3 Objective Test Procedures for Lateral Adhesion	392
	3.9.6.4 Acoustics	393
	3.9.7 Laboratory Testing and Measurement Methods	393
	3.9.7.1 Basic Tire Test Rig Designs	393
	3.9.7.2 Strength Tests	394
	3.9.7.3 Measuring Tire Characteristics Using a Test Rig	394
	3.9.7.4 Measuring Tire Characteristics Using a Vehicle-Mounted Test Rig	394
	3.9.7.5 Measuring Tire Rolling Resistance	395
	3.9.7.6 Measuring Uniformity and Geometry	395
	3.9.7.7 Roadway Measurement and Modeling	397
	3.9.7.8 Power Loss Analysis	397
	3.9.7.9 Tire Temperature Measurement	398
	3.9.8 The Future of Tire Technology	399
	3.9.8.1 Material Developments	399
	3.9.8.2 Energy Saving Tires	399
	4 Axles and Suspensions	403
	4.1 Rigid Axles	405
	4.1.1 The De Dion Driven Rigid Axle	407
	4.1.2 Rigid Axles with Longitudinal Leaf Springs	407
	4.1.3 Rigid Axles with Longitudinal and Lateral Links	408
	4.1.4 Rigid Parabolic Axles with a Central Joint and Lateral Control Links	409
	4.2 Semi-Rigid Axles	409
	4.2.1 Twist Beam Axles	410
	4.2.1.1 Torsion-Type Twist Beam Axles	411
	4.2.1.2 Standard Twist Beam Axles	411
	4.2.1.3 Coupling-Type Twist Beam Axles	412
	4.2.2 The Dynamic Twist Beam Axle	412
	4.3 Independent Suspension	413
	4.3.1 Independent Suspension Kinematics	413
	4.3.2 The Advantages of Independent Suspension	415
	4.3.3 Single-Link Independent Suspension Systems	415
	4.3.3.1 Trailing Link Independent Suspension	416
	4.3.3.2 Semi-Trailing Link Independent Suspension	417
	4.3.3.3 Screw-Link Independent Suspension	418
	4.3.4 Two-Link Independent Suspension	418
	4.3.4.1 Lateral-Longitudinal Swing Axles	418
	4.3.4.2 Trapezoidal Link with One Lateral Link (Audi 100 Quattro)	419
	4.3.4.3 Trapezoidal Link with One Flexible Lateral Link (Porsche Weissach Axle)	419
	4.3.5 Three-Link Independent Suspension	419
	4.3.5.1 Central Link Independent Suspension	419
	4.3.5.2 Double Wishbone Independent Suspension	420
	4.3.6 Four-Link Independent Suspension	422
	4.3.6.1 Rear Axle Multi-Link Independent Suspension	422
	4.3.6.2 Multi-Link Suspension with Two Lower Two-Point Links	423
	4.3.6.3 Trapezoidal (Integral) Link Suspension	423
	4.3.6.4 Two Longitudinal and Two Lateral Links	424
	4.3.6.5 One Longitudinal and Three Lateral Links	424
	4.3.6.6 One Diagonal and Three Lateral Links	425
	4.3.7 Five-Link Independent Suspension	426
	4.3.7.1 Five-Link Front Suspension (SLA with two Decomposed 3-Point Links)	426
	4.3.7.2 Five-Link Rear Suspension	426
	4.3.8 Strut-Type Suspension Systems	427
	4.4 Front Axle Suspension	430
	4.4.1 Front Axle Suspension System Requirements	430
	4.4.2 Front Axle Components	432
	4.4.3 Front Axle Suspension Types	432
	4.4.3.1 McPherson with Upper Strut Brace	432
	4.4.3.2 McPherson withOptimized Lower Control Arm	432
	4.4.3.3 McPherson withDecomposed Lower Control Arm	432
	4.4.3.4 McPherson with Two-Piece Wheel Carrier	433
	4.4.3.5 Double Wishbone with Decomposed Control Arms	433
	4.5 Rear Axle Suspension	434
	4.5.1 Rear Axle Suspension Requirements	434
	4.5.2 Rear Axle Components	434
	4.5.3 Rear Axle Suspension Types	434
	4.5.3.1 Non-Driven Rear Axles	434
	4.5.3.2 Driven Rear Axles	434
	4.5.4 ULSAS Rear Axle Benchmark	435
	4.6 Design Catalog for Axle Type Selection	436
	4.7 The Chassis as a Complete System	436
	4.7.1 Front / Rear Axle Interaction	436
	4.8 Future Suspension Systems	438
	4.8.1 Axles of the Past 20 Years	438
	4.8.2 Relative Popularity of Various Current Axle Designs	438
	4.8.3 Future Axle Designs (Trends)	438
	5 Ride Comfort and NVH	441
	5.1 Fundamentals: NVH and the Human Body	441
	5.1.1 Concepts and Definitions	441
	5.1.2 Sources of Vibrations, Oscillations, and Noise	442
	5.1.3 Limits of Human Perception	443
	5.1.4 Human Comfort and Well-Being	444
	5.1.5 Mitigation of Oscillation and Noise	445
	5.2 Bonded Rubber Components	446
	5.2.1 Bonded Rubber Component Functions	446
	5.2.1.1 Transferring Forces	446
	5.2.1.2 Enabling Defined Movements	446
	5.2.1.3 Noise Isolation	447
	5.2.1.4 Vibration Damping	448
	5.2.2 The Specific Definition of Elastomeric Components	449
	5.2.2.1 Force-Displacement Curves	449
	5.2.2.2 Damping	449
	5.2.2.3 Setting	450
	5.3 Engine and Transmission Mounts	451
	5.4 Chassis and Suspension Mounts and Bushings	455
	5.4.1 Rubber Bushings	455
	5.4.2 Sliding Bushings	456
	5.4.3 Hydraulically-Damped Bushings (Hydro Bushings)	457
	5.4.4 Chassis Subframe Mounts	460
	5.4.5 Upper Strut Bearings and Damper Mounts	461
	5.4.6 Twist Beam Axle Mounts	463
	5.5 Future Component Designs	464
	5.5.1 Sensors	465
	5.5.2 Switchable Chassis Mounts	465
	5.6 Computation Methods	466
	5.7 Acoustic Evaluation ofBonded Rubber Components	467
	6 Chassis Development	469
	6.1 The Development Process	469
	6.2 Project Management (PM)	475
	6.3 The Planning and Definition Phase	475
	6.3.1 Target Cascading	476
	6.4 The Concept Phase	477
	6.5 Computer-Aided Engineering	477
	6.5.1 Multi-Body Simulation (MBS)	478
	6.5.1.1 MBS Chassis and Suspension Models in ADAMS/Car	478
	6.5.1.2 CAD Chassis Models and Multi-Body Systems	478
	6.5.1.3 Multi-Body Simulation with Rigid and Flexible MBS	479
	6.5.1.4 Multi-Body Simulations Using Whole-Vehicle, Chassis, and Axle Models	480
	6.5.1.5 Effects of Manufacturing Tolerances on Kinematic Parameters	481
	6.5.2 Finite Element Method (FEM)	482
	6.5.2.1 Classification of Analyses	482
	6.5.2.2 Strength Analyses	483
	6.5.2.3 Stiffness Analyses	483
	6.5.2.4 Natural Frequency Analyses	483
	6.5.2.5 Service Life and Durability Analyses	484
	6.5.2.6 Crash Simulations	484
	6.5.2.7 Topology and Shape Optimization	484
	6.5.2.8 Simulations of Manufacturing Processes	486
	6.5.3 Whole-Vehicle Simulations	486
	6.5.3.1 Vehicle Handling and Dynamic Simulations	486
	6.5.3.2 Kinematics and Elastokinematics	486
	6.5.3.3 Standard Load Cases	487
	6.5.3.4 MBS Model Verification	488
	6.5.3.5 NVH	488
	6.5.3.6 Loads Management (Load Cascading from Systems to Components)	490
	6.5.3.7 Whole-Vehicle Durability Simulations	494
	6.5.3.8 Whole-Vehicle Handling Fingerprint	494
	6.5.3.9 Specification of Elastokinematics Using Control-System Methods	495
	6.5.4 3D Modeling Software (CAD)	496
	6.5.5 Integrated Simulation Environment	497
	6.5.5.1 Kinematic Analysis Using ABE Software	497
	6.5.5.2 The Virtual Product Development Environment (VPE)	500
	6.6 Series Development and Validation	502
	6.6.1 Design	502
	6.6.1.1 Component Design	503
	6.6.1.2 Package Volume	504
	6.6.1.3 Failure Mode and Effects Analysis (FMEA)	505
	6.6.1.4 Tolerance Investigations	505
	6.6.2 Validation	505
	6.6.2.1 Prototypes	505
	6.6.2.2 Validation Using Test Rigs	505
	6.6.2.3 Roadway Simulation Test Rig	508
	6.6.3 Whole-Vehicle Validation	509
	6.6.4 Optimization and Fine-Tuning	510
	6.7 Development ActivitiesDuring Series Production	510
	6.8 Summary and Future Prospects	511
	7 Chassis Control Systems	513
	7.1 Chassis Electronics	513
	7.2 Electronic Chassis ControlSystems	513
	7.2.1 Domains	513
	7.2.2 Longitudinal Dynamic Control Systems – Wheel Slip Regulation	514
	7.2.2.1 Braking Control	514
	7.2.2.2 Electronically-Controlled Center Differentials	514
	7.2.2.3 Torque-On-Demand Transfer Cases	514
	7.2.2.4 Electronically-ControlledAxle Differentials	515
	7.2.2.5 Axle Drive for Lateral Torque Distribution	516
	7.2.3 Lateral Dynamic Control Systems	517
	7.2.3.1 Electric Power Steering Systems (EPS)	517
	7.2.3.2 Superimposed Steering	518
	7.2.3.3 Active Rear-Wheel Steering	518
	7.2.3.4 Active Rear-Axle Kinematics	519
	7.2.4 Vertical Dynamic Control Systems	519
	7.2.4.1 Variable Dampers	519
	7.2.4.2 Active Stabilizers	521
	7.2.4.3 Active Leveling Systems	521
	7.2.5 Safety Requirements	522
	7.2.6 Bus Systems	523
	7.2.6.1 CAN	523
	7.2.6.2 FlexRay	523
	7.3 System Networking	523
	7.3.1 Vehicle Dynamic Control (VDC)	523
	7.3.2 Torque Vectoring	525
	7.3.3 Vertical Dynamic Management	526
	7.4 Functional Integration	526
	7.4.1 System Architecture	526
	7.4.2 Standard Interfaces	527
	7.4.3 Smart Actuators	528
	7.5 Chassis Control System	528
	7.5.1 Simulation Models	529
	7.5.2 Hardware-in-the-Loop Simulation	530
	7.6 Mechatronic Chassis Systems	531
	7.6.1 Longitudinal Dynamics	531
	7.6.1.1 Powertrain Systems	532
	7.6.1.2 Braking Systems	534
	7.6.2 Lateral Dynamics	536
	7.6.2.1 Front-Wheel Steering Systems	536
	7.6.2.2 Rear-Wheel Steering Systems	537
	7.6.2.3 Roll Stabilization Systems	540
	7.6.2.4 Active Kinematics	543
	7.6.3 Vertical Dynamics	546
	7.6.3.1 System Requirements	546
	7.6.3.2 Classification of Vertical Dynamic Systems	546
	7.6.3.3 Damping Systems	547
	7.6.3.4 Active Leveling Systems	551
	7.6.3.5 Current Active Spring Systems	552
	7.6.3.6 Fully Active Integrated Suspension Systems	555
	7.6.3.7 Pivots (Bushings, Joints, Mounts)	557
	7.7 X-by-wire	559
	7.7.1 Steer-by-wire	559
	7.7.2 Brake-by-wire	560
	7.7.2.1 Electrohydraulic Braking (EHB)	561
	7.7.2.2 Electromechanical Braking(EMB) Systems	561
	7.7.2.3 The ContiTeves Electromechanical Brake	562
	7.7.2.4 Radial (Full-Contact) Disc Brakes	562
	7.7.2.5 Wedge Brake	564
	7.7.3 Leveling-by-wire	565
	7.8 Driver Assistance Systems	565
	7.8.1 Braking Assistance Systems	565
	7.8.1.1 Safety-Relevant Braking Assistance	566
	7.8.1.2 Comfort-Oriented Braking Assistance	567
	7.8.1.3 Braking Assistance System Requirements	567
	7.8.2 Distance Assistance Systems	568
	7.8.3 Steering Assistance Systems	569
	7.8.3.1 Steering Assistance Using Adaptive Assistance Torques	569
	7.8.3.2 Steering Assistance Using Additional Steering Torque	569
	7.8.3.3 Steering Assistance Using a Supplemental Steer Angle	570
	7.8.3.4 Summary	571
	7.8.4 Parking Assistance Systems	571
	7.8.4.1 Introduction	571
	7.8.4.2 Parking Space Recognition	571
	7.8.4.3 Parallel Parking	573
	7.8.4.4 Steering Actuators	574
	8 The Future of Chassis Technology	577
	8.1 Chassis System Concepts – Focus on Customer Value	577
	8.1.1 Choosing Handling Behavior	577
	8.1.2 Diversification of Vehicle Concepts – Stabilization of Chassis Concepts	579
	8.1.2.1 Front Suspension as of 2004	579
	8.1.2.2 Rear Suspension as of 2004	580
	8.1.3 The Future of Chassis Subsystems and Components	580
	8.1.3.1 The Future of Axle Drive Units	580
	8.1.3.2 The Future of Braking Systems	581
	8.1.3.3 The Future of Steering Systems	581
	8.1.3.4 The Future of Suspension Spring Systems	581
	8.1.3.5 The Future of Dampers	581
	8.1.3.6 The Future of Wheel Control Components	581
	8.1.3.7 The Future of Wheel Bearings	581
	8.1.3.8 The Future of Tires and Wheels	581
	8.2 Electronic Chassis Systems	581
	8.2.1 Electronic Assistance Systems and Networking	581
	8.2.2 Networking Chassis Control Systems	582
	8.2.2.1 Peaceful Coexistence	582
	8.2.2.2 Integral Control	583
	8.2.2.3 Networked Control	583
	8.2.2.4 Performance / Efficiency	584
	8.2.2.5 System Safety	584
	8.2.2.6 The Development Process	584
	8.2.2.7 Data Transmission Requirements	585
	8.2.2.8 Summary	585
	8.3 The Future of X-by-Wire Systems	585
	8.4 Intelligent and Predictive Future Chassis Systems	586
	8.4.1 Sensors	587
	8.4.2 Actuators	587
	8.4.3 Predictive Driving	588
	8.5 Hybrid Vehicles	590
	8.6 The Rolling/Driving Chassis	591
	8.7 The Vision of Autonomous Vehicle Control	592
	8.8 Future Scenarios for Vehicle and Chassis Technology	593
	8.9 Outlook	596
	Index	599