Adaptive fuzzy sliding mode controller for wheel slip control in antilock braking system

Safety features like antilock braking systems (ABSs) have become an essential feature of road vehicles now a days. ABSs are designed for the purpose of maintaining the wheel slip in the required value during sudden braking to ensure the vehicle steerablility and non-skidding. Uncertain factors such, as type of road surface, tyre pressure, vehicle mass, etc., cause the required wheel slip to be continuously changing. Hence, controlling the wheel slip remains a difficult task always. This situation leads to a need for design of a controller, which will be capable of dealing with these uncertainties. One of the controllers which can effectively deal with the parametric and modeling uncertainties is sliding mode controller (SMC). Fuzzy logic is a knowledge based system which is very much useful in handling the systems whose models are not developed fully or accurately or information about the system is uncertain. In this paper, a robust and adaptive Fuzzy sliding mode controller (FSMC) is proposed for a laboratory ABS model by combining fuzzy logic with sliding mode controller. The performance of the proposed FSMC is assessed through digital simulations for various initial conditions of vehicle velocity and road surface conditions.