Vehicle ABS control system design via integral sliding mode

Abstract

An active braking system is a very vital electro-mechanical system, which greatly improves the safety of a vehicle in extreme circumstances since it can maximise the longitudinal tyre-road friction while keeping large lateral forces that ensure vehicle drivability. In this paper, the integral sliding mode control was applied for an optimised design of the vehicle ABS system. The controller objective was to maximise the deceleration of the braking force by forcing the slip ratio to attain the maximum value. According to the integral sliding mode control concept, the system state is initiated at the switching manifold, where the uncertainty and the disturbances are compensated during braking via a discontinuous control term that strongly exists in braking dynamics. This feature enabled to design a continuous controller named as the ideal control during sliding motion and from the first instant. Consequently, the braking action is optimised with the desired dynamic characteristics. The validity and applicability of the proposed controller are verified by the numerical simulations based on MATLAB/Simulink programs for simulating the ABS system under various road conditions.