Skip to main content
main-content
Top

About this book

The introduction of mechatronic components for the powertrain, steering and braking systems opens the way to automatic driving functions. Together with internal and environmental sensors, various driver assistance systems are going to be developed for improving driving comfort and safety.
Automatic driving control functions suppose a well-designed vehicle behavior. In order to develop and implement the software-based control functions mathematical vehicle models for the stationary and dynamic behavior are required.
The book first introduces basic theoretically derived models for the tire traction and force transfer, the longitudinal, lateral, roll and pitch dynamic behavior and related components, like suspensions, steering systems and brakes.
These models have to be tailored to allow an identification of the many unknown parameters during driving, also in dependence of different road conditions, velocity and vehicle load. Based on these mathematical models drive dynamic control systems are developed for semi-active and active suspensions, hydraulic and electromechanical brakes including ABS, traction and steering control. Then driver assistance systems like adaptive cruise control (ACC), electronic stability control (ESC), electronic course control and anti-collision control systems are considered. The anti-collision systems are designed and tested for emergency braking, emergency steering and avoiding of overtaking accidents.
The book is dedicated to automotive engineers as well as to graduate students of mechanical, electrical and mechatronic engineering and computer science.

Table of Contents

Frontmatter

Chapter 1. Introduction

Abstract
The increasing electrification and electronification is a dominant feature of modern automotive developments. This is demonstrated by an increasing part of electrics/electronics (E/E) of the manufacturing costs from about \(20 \%\) in 1995 to more than \(35 \%\) in 2020. The electrics comprise primarily the electrical energy flows to the consumers through the energy board net. Frequently, former mechanical, pneumatic, or hydraulic actuated components of the chassis and the powertrain are replaced by electrical ones. The electronics are primarily used for the operation, and control and diagnosis functions. This enables the introduction of many new functions for the chassis and the powertrain, for driver-assistance systems and automatic driving.
Rolf Isermann

Electronic Architectures and Control Structures

Frontmatter

Chapter 2. Electrical and Electronic Architectures of Automobiles

Abstract
In the frame of vehicle electrification and electronic management of the chassis and the powertrain, the structures of the electrical and electronic architecture have a significant influence on the realization of functions. Therefore, this chapter briefly considers the types of networks, the communication networks and bus systems, and the software structure of the electronic control units (ECU).
Rolf Isermann

Chapter 3. Vehicle Control Structures

Abstract
Because of the increasing complexity of vehicle control functions, a unified structure eases the understanding and development. Therefore, this chapter summarizes vehicle control structures and the model-based design workflow with different simulation tools.
Rolf Isermann

Modeling of Drive Dynamics

Frontmatter

Chapter 4. Vehicle Dynamics Modeling

Abstract
Vehicle dynamics is concerned with the movements of the vehicle on a road surface. The stationary and dynamic behavior is based on the forces on the vehicle via the tires, gravitation, and aerodynamics. These forces act on the body, the tires, and the wheels.
Rolf Isermann

Chapter 5. Tire Traction and Force Transfer

Abstract
The transfer of the forces and  torques between the tire and the road surface is fundamental for all longitudinal and lateral motions of a vehicle. The physical effects of the force transfer depend on local properties at the contact patch. The amount of forces is a function of the frictional properties between the tire and the road surface.
Rolf Isermann

Chapter 6. Longitudinal Vehicle Behavior

Abstract
The longitudinal behavior of automobiles is a characteristic property which all drivers recognize immediately during acceleration, continuous driving, coasting, and braking. As will be shown in this chapter, many components from the combustion engine or electric motor through the torque converter and elastic drive train to the driven wheels act together. In order to understand their interactions and for the design of automatic control systems like anti-locking control (ABS), automatic velocity control (AVC), or adaptive cruise control (ACC) or automatic driving in general, static and dynamic process models are required. After summarizing the corresponding drive train components, the respective models are derived and compiled together with different kinds of granularity.
Rolf Isermann

Chapter 7. Lateral Vehicle Behavior

Abstract
In order to describe and analyze the stationary and dynamic behavior of driving vehicles, the motions in horizontal and vertical directions and around the three axes have to be considered. Regarding the lateral behavior, first a one-track model is considered, where the two wheels of an axle are concentrated in one middle wheel to result in a most simple approach. This begins with kinematic models, considering geometric relations. Then, the dynamic behavior is treated with steering angles as inputs and yaw rate, slip angle and lateral velocity as outputs. These one-track models allow to analyze some main properties with regard to steering.
Rolf Isermann

Chapter 8. Vertical Vehicle Behavior

Abstract
The vertical behavior of driving cars is mainly determined by the suspension systems of the individual wheel’s respective axles and the road roughness. The suspension systems characterize the driving comfort of the passengers and have a significant influence on driving safety. Therefore, firstly, a measure for driving comfort is considered, which is followed by a description of suspension components and mathematical models of passive suspensions which are also required for lateral two-track models, rolling and pitching behavior. Active suspensions are treated in Chap. 15.
Rolf Isermann

Chapter 9. Roll and Pitch Dynamic Behavior

Abstract
The roll and pitch behavior is already included in the basic dynamic equations (7.​3.​4)–(7.​3.​8) of the two-track models; see also Fig. 7.​17. In the following, the roll and pitch dynamic behavior is considered separately by neglecting the couplings between the motions around the roll and pitch axis. The resulting models are required to obtain simplified models and as a basis for the estimation of the various parameters.
Rolf Isermann

Chapter 10. Parameter and State-Estimation Methods for Vehicle Dynamics

Abstract
The derived mathematical models of vehicle dynamics are mostly based on theoretical physical models and contain parameters \(\boldsymbol{\theta }\) which are partially known or not known at all. Therefore, they have to be determined experimentally by measurements of input and output signals and parameter identification or parameter-estimation methods have to be applied; see Fig. 10.1.
Rolf Isermann

Chapter 11. Parameter Estimation (Identification) of Vehicle Dynamics

Abstract
The application of parameter-estimation methods to determine the unknown vehicle model parameters is treated for a selection of dynamic and static vehicle or vehicle component models. Herewith, the methods of Sect. 10.​1 are used, either in continuous or discrete time, in non-recursive or recursive form. In general, one tries to use series on-board sensors only depending on the standard equipment of the vehicle, (Robert Bosch GmbH 2018). However, in some cases also additional sensors are applied which are used for research vehicles. Compare the discussion of available sensors and measurement systems discussed in the introduction to Chap 10.
Rolf Isermann

Chapter 12. State Estimation of Vehicles

Abstract
The determination of not or not precisely measurable driving state variables as velocity over ground, slip angle, yaw, rolling, and pitch angle can be reconstructed by state estimation methods with kinematic or dynamic vehicle models. The estimation of some parameters may also be integrated in a state estimation procedure.
Rolf Isermann

Dynamic Control of Chassis Components

Frontmatter

Chapter 13. Braking Control

Abstract
In the frame of active vehicle safety, the optimal function of brake systems has one of the highest priorities. In the long history of the development of mechanical, hydraulic, and pneumatic brake systems, the improvements of the braking performance by electronic control since the introduction of ABS-brake control around 1978 play a dominant role for automotive control.
Rolf Isermann

Chapter 14. Steering Control Systems

Abstract
The steering system translates the rotation of the steering wheel through the steering shaft, a steering gear, tie rods steering arms, and the wheel carrier to a turn of the steered wheels; see Fig. 14.1. The required steering forces are generated by muscular forces of the driver and are transferred to the wheels without power assistance for very small cars.
Rolf Isermann

Chapter 15. Suspension Control Systems

Abstract
The basic behavior of suspension systems, their relevance for driving comfort and safety, their components, and linear and nonlinear mathematical models for passive suspensions were treated in Chap. 8. It was shown that ride quality and driving safety are conflicting properties and that an adaptation to changing road and load conditions can be reached with active suspensions. Therefore, this chapter considers semi-active as well as active hydraulic suspensions. A further topic is the indirect tire pressure monitoring based on wheel velocity and suspension sensors.
Rolf Isermann

Driver-Assistance Systems

Frontmatter

Chapter 16. On Driver-Assistance Systems

Abstract
Advanced driver-assistance systems (ADAS) support the driver during driving or parking. They are pretended to alert, automate, adapt, and enhance vehicle systems to improve safety, comfort, and driving.
Rolf Isermann

Chapter 17. Advanced Driver Assistance Systems for Longitudinal and Lateral Guidance

Abstract
Based on the book parts II “Modeling of Drive Dynamics” and III “Dynamic Control of Chassis Components” control-oriented advanced driver assistance systems (ADAS) are briefly described in this chapter.
Rolf Isermann

Automatic Driving

Frontmatter

Chapter 18. Classification of Automatic Driving Functions

Abstract
The driver assistance systems until about 2008 were developed sequentially to improve firstly safety and secondly comfort and are characterized by automatic control and warning functions; see Winner et al. (2016). They can be seen as steps toward automatic driving.
Rolf Isermann

Chapter 19. Longitudinal Vehicle Control

Abstract
Automatic driving control of vehicles can be divided into longitudinal and lateral driving control. Figure 19.1 shows some basic maneuvers without obstacles like driving with constant velocity, with acceleration or braking, straightline driving on roadways, cornering, and lane change. Figure 19.2 depicts a roadway with two lanes, one for each direction, with lanewidth B. Usually, the vehicle is driven in the center of a lane, such that the lateral distance to the right lane marking is \(y = B/2 = D_\mathrm {y}\).
Rolf Isermann

Chapter 20. Lateral Vehicle Control

Abstract
Roads are usually built from elements of circles, clothoids with intermediate connections, and straight lines; see RAA (2008). Curves have curvatures which develop steadily, such that driving without lateral jerk is possible.
Rolf Isermann

Chapter 21. Anticollision Control Systems

Abstract
Automotive safety is one of the high-priority issues in the design of vehicles, construction, and equipment to minimize the occurrence and consequence of accidents. The improvements in automobile and roadway design have steadily reduced injury and death rates in developed countries. This positive development was supported by measures of passive and active safety systems.
Rolf Isermann

Chapter 22. Automatic (Autonomous) Driving

Abstract
The driver assistance systems described in Chaps. 17 (TCS, ESC, LKA) and 19 (ACC) assist and control the vehicle in special cases and the driver performs continuously the driving task. These driver assistance systems (DAS, ADAS) are dedicated to level 1 of the automatic driving degrees in Table 18.​1. For vehicles with partial automation, level 2, tasks of longitudinal and lateral driving are automatic (ACC-FR, LKA, LKC) but the driver has to be attentive all the time, to monitor the correct functioning, and to perform all remaining tasks.
Rolf Isermann

Backmatter

Additional information

Premium Partner

    Image Credits