Optimal design of a hybrid controller for antilock braking systems

Antilock braking systems (ABS) have been developed to reduce tendency of wheel lock and to improve vehicle control during sudden braking especially on slippery road surfaces. The objective of such control is to increase wheel tractive force in the desired direction while maintaining adequate vehicle stability and steerability and also reducing the vehicle stopping distance. In this paper, an optimized hybrid controller using a fuzzy system is proposed for antilock braking systems. The objective function is defined to maintain wheel slip to a desired level so that maximum wheel tractive force and maximum vehicle deceleration are obtained. All components of fuzzy system are optimized using a genetic algorithm and error based optimization technique. The error based global optimization approach is used for fast convergence near optimum point. Simulation results show fast convergence and good performance of the controller for different road conditions