Design of antilock braking system based on variable structure control

Antilock braking system (ABS) is an important part to improve the automobile´s active safety. In general, ABS is designed to achieve maximum negative acceleration by preventing the wheels from locking. Researches show that the friction between road and tire is a nonlinear function of wheel slip. In this paper, to deal with the strong nonlinearity in the design of ABS controller, a variable structure controller has been designed and index reaching law and integral switching surface with saturation function methods are used to reduce chattering. In the simulations, several situations such as braking in dry road, wet road and snow road are considered.