Longitudinal wheel-slip control for four wheel independent steering and drive vehicles

In this paper, a longitudinal wheel-slip controller for four wheel independent steering and drive (4WISD) vehicles is proposed to suppress longitudinal wheel slip in varying road conditions. Different from conventional methods that consider single driving source and zero steering angle, the proposed controller considers all independent traction sources from each driving wheel and omnidirectional steering command so as to eliminate slip detection errors in 4WISD vehicles. The proposed controller requires low cost sensing equipment, including merely wheel speed sensor and accelerometer, which makes the system practical to be utilized. The proposed wheel-slip controller can be applied to vehicles with arbitrary quantity of driving wheels and different steering configurations such as traditional two-front-wheel steering and two-rear-wheel steering. Numerical simulation results are presented to demonstrate the efficiency of the proposed longitudinal wheel-slip controller.