Vehicle Traction Control System: Sliding Mode Control and Computer Graphics Simulation

Wheel spin is a phenomenon which may occur while a car starts or runs on a slippery road. As the slip between the tires and road increases, the traction force decreases and most drivers may not be able to steer the car properly. Traction control system (TCS) can help improve driving stability and safety by restricting the slip of the driven wheels. The slip restriction is usually achieved by exerting brake torque or reducing the torque generated by the engine.

In this thesis, to cope with the strong nonlinearity of the friction-slip curve, the uncertainty caused by the aero dynamics, and the complex actuator dynamics, a tire slip controller based on the sliding mode method is designed for a TCS. Although the controller is designed by taking the actuator model as a simple gain, the simulation results show the robustness of the controller when a detailed actuator model is included.

Furthermore, animation based on computer graphics is made to compare the acceleration performance and directional stability of TCS-equipped cars with those of non TCS-equipped cars. In the animation process, texture mapping and billboarding techniques are adopted to make the simulation scenario much more realistic.