Automotive Anti-lock Braking System (abs) Controller

In this paper, the development, configuration and operation principle of the anti-lock braking system, i.e. ABS, is first briefly introduced, then the basic research is focused on the application of adaptive sliding mode control in ABS. In order to provide safety and obtain desired longitudinal vehicle motion, a robust sliding mode controller is designed to maintain the reference input wheel slip. The design strategy investigated is based on a sliding surface that only contains the error between the reference input wheel slip and the actual wheel slip. The design strategy uses continuous switching, in the form of a saturation or a Ambrosino function, to reduce chattering in the system response. To get the precise approximation of the tire force and the vehicle speed, the sliding mode control theory is proposed in observers, which bring about good effect. The paper also discusses the PID control and nonlinear PID control in the ABS and compares their performance with the sliding mode control'. It is shown in the simulation that sliding mode control can guarantee the stability and robustness while vehicle is braking even if ABS operates at the instability region of the adhesion coefficient and wheel slip curve or the surface condition changes, which is better than the PID control and nonlinear PID control.