The study of anti-lock braking system based on sliding mode variable structure control

摘要

The friction characteristic between road surface and tire makes the anti-lock braking system (ABS) take on the properties of nonlinearity, time variation and uncertainties. The sliding mode variable structure controller (SMVSC) has strong robust ability in dealing with uncertainties including the model error and unknown interference, so SMVSC is used in ABS extensively. In order to achieve expected performance, SMVSC has to identify the road characteristics in real time. The mathematical model of ABS is established, and the application of SMVSC in ABS is realized. One kind of estimation algorithm of optimal slip ratio based on the shape of mu-lambda curve is proposed. By computer simulation, the feasibility and validity of SMVSC based on optimal slip ratio is verified.