Graduation Design of Wuhan University of Technology

Design handling stability control system for four axis vehicle

School: International Education Institute

Specialty amp; Class: vehicle gj1303

Student name: Liu Chang

Tutor: Pei Xiaofei

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Abstract

In recent years, the automobile market in our country had a large development, the electronic stability program has been widely popularized in the passenger car market. However, in commercial vehicle market, there are few heavy trucks equipped with electronic stability program. heavy goods vehicle is easy to make automobile side skidding, braking swerve or other dangerous conditions, because it has characteristics of high quality, high center of gravity, length of body is too large. The handling and stability of heavy goods vehicle has a direct influence on the driver's life and property security. Meanwhile, the ESP system can improve the handling and stability of heavy goods vehicle, and also can effectively reduce the risk of the occurrence of these dangerous conditions. The designed of the handling and stability control system of multi axle vehicle can make the truck operated effectively under the steering condition, improve the steady state steering characteristics and the severability of the vehicle. This paper select a suitable automobile model in trucksim through the study of a four axle heavy freight car, and set up the working conditions required for the simulation experiment.

This paper select a suitable automobile model in trucksim through the study of a four axle heavy freight car, and set up the working conditions required for the simulation experiment. In the Simulink environment, this paper built an Electronic Stability Program based on yaw speed control and an Electronic Stability Program based on both yaw rate and sideslip angle coordination control. In the Simulink environment, this paper built an Electronic Stability Program based on yaw speed control and an Electronic Stability Program based on both yaw rate and sideslip angle coordination control ，this paper also design a kind of PID control system . And put the vehicle which is in software of trucksim model into the Simulink environment, carry out a joint simulation experiment. The experimental results verify the effectiveness of ESP system design for the four axis vehicle stability, improves the safe capability of vehicles.

Key Words ：ESP; four axle vehicle; PID control; yaw rate; sideslip angle

Content

Chapter 1 Introduction 1

1.1 Introduction to ESP 1

1.2 Key technologies of ESP 1

1.3 Research status at domestic and abroad 2

1.4 Research content of this paper 3

Chapter 2 The control principle of ESP 5

2.1 Structure of ESP system 5

2.2 working process of ESP 5

2.3 The basic idea and work characteristics of ESP control 6

2.4 Conclusion 6

Chapter 3 Establishment of vehicle's dynamic model 7

3.1 Two degrees of freedom car model 7

3.2 plane dynamics model of vehicle 8

3.3 tire model 9

Chapter 4 Design of ESP for four axle vehicle 11

4.1 Design idea of four axle automobile ESP 11

4.1.1 The progress of Electronic Stability Program control 11

4.1.2 The choice of work strategy for Electronic Stability Program 11

4.2 PID controller 12

4.2.1 The principle of PID control 12

4.2.2yaw rate control 13

4.2.3 Design of combined ESP of yaw rate and sideslip angle 14

4.2.4 Selection of PID parameters 16

4.3 Calculation of ideal parameters 16

4.3.1 Calculation of ideal yaw angular velocity 16

4.3.2 Calculation of the sideslip angle 17

4.4 The distribution of braking force 18

4.5 Conclusion 19

Chapter 5 Joint simulation between trucksim and Simulink 21

5.1Joint simulation overview 21

5.2 Model of joint simulation 21

5.3 Double lane change simulation 22

5.3.1 Double lane change simulation conditions 22

5.3.2 Simulation analysis of single yaw rate control 23