Simulation And Research On ESP Of Automobile

Electronic Stability Program (ESP) has become the focus of the study in the field of automotive active safety in recent years. Not only does it has the features of ABS and ASR which are able to control the stability of the car driving lengthways, but also is able to control the stability in more complex conditions. Like the ABS which has gradually transformed as the car's standard equipment in recent decades, the ESP also is gradually becoming the standard equipment of the automotive.First, a two degree of freedom vehicle dynamics models base on the H.B.Pacejka tyre model (magic formula) has been built in this dissertation, and the ideal linearity two degree of freedom vehicles model has been brought forward. Then by using of the software ADAMS to simulate analysis the responding with a step input of the steering wheel in the limit working condition, and ascertains the yaw rate and the side slip angle as the control target. Using the method of direct yaw-moment control, it has researched the control algorithm of two different control strategies based on the PID (Proportion Integral Differential) control theory and fuzzy control theory, and the controllers have been built. The fuzzy PID controller has been built based on the comparison of the two control theories in both superior and inferior, and has carried out simulation analysis with three kinds of controllers under the representative working condition. At last, by using of the hardware in the loop simulation system dSPACE to carry out the slalom test with the outside signal source,and the results of the simulation has been analyzed.Results indicated that, all controllers have obvious effects to the automobile stability, but the fuzzy PID controller is the best. Considering this dissertation focuses on the research of control theory and the design of controller, so the vehicle model is simplified partly. The feedback control quantity has imposed on the vehicle center of mass by the form of torque, and this lead to the controller worse control effect on the side slip angle in the limit working condition. The controller real-time simulation speed of response is sensitive, and it has good effect on automobile stability with the different outside entering, and off-line simulation results are approximately the same. The realization of hardware in the loop simulation has established a basis for further accurate model building-up and the improvement of the control strategy, and it is a technical support to the code compiling of ECU.