Sliding mode controller for wheel-slip control of anti-lock braking system

The anti-lock braking system is a technology for passengers´ safety in recently developed sophisticated vehicles. It is a part of the braking system of a vehicle which exhibits controlled braking torque to prevent the wheels from locking whenever a hard brake is applied. The highly non-linear dynamics of longitudinal tire force and the uncertain parameters of the vehicle and friction coefficient of the road motivate to use a non-linear robust controller. An efficient sliding mode controller has been proposed here to maintain the slip ratio to an optimum value so that the vehicle stopping without skidding is ensured within minimum possible distance. The non-linear Dugoff´s friction model for the wheel has been taken for modeling the quarter car. The chattering phenomena caused by sliding mode have been minimized with an efficient technique. Slip-tracking performance and the robust performance of the proposed controller have been compared with the recent existing non-linear controller.