Sliding mode control for anti-lock brake system of passenger vehicles featuring electrorheological valves

Abstract

This paper presents a sliding mode control for a new anti-lock brake system (ABS) of a passenger vehicle using electrorheological (ER) valves. The Bingham model of an ER fluid is empirically obtained as a function of electric fields, and it is incorporated with the dynamic model of ER valves. The design parameters of the ER valves such as electrode gap are appropriately determined by considering braking forces required for a small-sized passenger vehicle. An electrically controllable ABS using the ER valves is then proposed and its governing equations of motion are derived. Subsequently, sliding mode controllers are formulated for wheel slip control as well as yaw rate control. In the formulation of the sliding mode controllers, the friction force which is difficult to measure in real time is estimated via a sliding mode observer associated with the fuzzy algorithm. Computer simulations for braking performance and steering stability under various road conditions are undertaken in order to demonstrate the effectiveness of the proposed ABS.