The Research Of Vehicle TCS Based On Engine Torque Output And Braking Force Control

TCS (Traction Control System) is a kind of initiative security control system of vehicle, with controlling the slip ratio on the vehicle driving wheel, which can prevent driving wheel sliding excessively while the vehicle is starting, accelerating, climbing, and ensure the vehicle taking full advantage of the longitudinal and lateral adhesion coming from ground, at last, which makes the vehicle getting the maximum traction and best handling stability and improving vehicle stability.In Matlab / Simulink software environment, it created a vehicle dynamics model, engine model, tire model, transmission system model and the controller models, and chose the drive wheels slip ratio as the control variables, then adopted two kinds of PID and fuzzy PID control method , based on engine torque and brake torque output means mutual adjustment, the overall simulation model of the car were in the uniform pavement, separating the road surface and docking simulation of the drive slip ratio, driving wheel speed, vehicle speed and other parameters. The simulation results show that two kinds of PID and fuzzy PID control method can keeping driving wheel slip ratio nearby the desired target slip ratio (20%), and it also can inhibit the excessive slip of driving wheel, furthermore, driving wheel speed and vehicle speed raised a lot compared when don't exert control. Which verified the correctness and reasonableness of the used simulation model and control method . what's more, Based on the original TCS controller, this paper further improved the external circuit debugging, including power modules, analog signal processing module, pulse signal processing module, the output driver module. using Code Warrior IDE 4.6 as the development platform, this paper applied the C language to write the program of the system initialization module, data acquisition module, data processing module and control functional modules, and completed debugging all of them. Combined with Fuzzy PID control, It carried out simulation experiments with different duty cycle square wave signal as the wheel speed signal, with calculation of the drive slip ratio. the Fuzzy PID control change the high and low voltage of the electronic throttle drive motor so as to change the position of throttle, and it achieved control of the engine torque. As the real vehicle running, the road conditions such as the outside environment is much more complex, but model simulation just is carried out on ideal circumstances, consequently, in order to verify the reasonable control , This paper presented real vehicle testing program of automobile traction control system, and lays the foundation for further follow-up study. The PID and fuzzy PID control method based on the driving wheel slip ratio, can obtain good traction and passing when vehicle was running on the uniform, separate, docking road, it has some reference value for further study of the vehicle traction control.