Algorithm Research And Simulation Analysis For Control System Of ABS&TCS

Control system of ABS&TCS can balance three factors such as traction capability, braking capability and stability through controlling wheel moment and engine output moment. Now, control system of ABS&TCS is the international research focus in the vehicle active safety field, and some relevant products are gradually equipped to the moderate and top cars. While in china, the research in this field is at very beginning. The dissertation is divided into six chapters and describes the algorithm research of ABS&TCS, the development of vehicle dynamics simulation software and off-line simulation analysis based on research achievement of overseas. In Chapter One, the function and the construction of ABS&TCS are introduced, the history of control system and its present status are discussed, the contents of the dissertation are put forward. In Chapter Two is about the research of algorithm of ABS control system. There are many concepts and methods put forward such as the strategy and target of control system of ABS&TCS, the threshold of wheel pressure decrease model and wheel pressure hold model of ABS control system and PID method of ABS control system. Meanwhile, there are analysis of pressure decrease model, pressure hold model and the influence of PID gains to ABS control system. ABS control system can guarantee the stability and braking capability during braking through the integration control of threshold method and PID method. In Chapter Three is about the research of algorithm of TCS control system. Primary control models of TCS control system are put forward, and signal process model and PID control model analysed. The calculation method of wheel speed, wheel acceleration, wheel spin slip and vehicle reference speed are decided and the identification method of road surface put forward through the analysis of signal process model. The wheel change at every stage during vehicle acceleration is defined and different PID gains will be used according to the definition of every wheel speed stage through the analysis of PID control model. TCS control system can guarantee the stability and traction capability during vehicle acceleration. In Chapter Four, dynamics simulation software of ABS&TCS is compiled. A vehicle model can describe the vehicle non-linear characteristics under limit condition is needed for simulating vehicle stability control system. This chapter adopts GIM tire model in tire's ISO coordinate, in which the tire's longitudinal slip property and lateral slip property are considered. Except for tire model, the dynamics simulation software is a 7-DOF vehicle model, which including engine model, brake model, driveline model, vehicle model and driver model. Finally, Simulink model of dynamics simulation software and graphics user interface based on Matlab are worked out. In Chapter Five is about off-line simulation and analysis of ABS&TCS control system. The correctness and practicability of threshold method and PID method of ABS&TCS control system are validated and sets the foundation for further research through off-line simulation and analysis. Chapter Six is the summary and conclusion of the dissertation. The following conclusions can be derived from the simulation study of ABS&TCS control system. 1. The threshold method and PID method are validated through the research of control algorithm of ABS&TCS control system. The threshold and PID gains under...