On robust bounded control of the combined wheel slip with integral compensation for an autonomous 4WS4WD vehicle

Abstract

This paper presents a robust bounded controller that prevents an autonomous 4WS4WD vehicle from wheel skidding in presence of uncertainties of both tire/road condition and aerodynamic drag. For eliminating the steady-state error of path tracking, this control scheme incorporates integral compensation into a robust low-and high-gain technique, which in our earlier work has been introduced to achieve the anti-skidding. In comparison, this new proposed scheme ensures the path-tracking error can vanish asymptotically without incurring high-frequency chattering in the control signals. Simulation shows that, under the uncertainty effects, the proposed controller effectively limits the combined wheel slip and achieves the asymptotic path tracking. Moreover, the control inputs of wheel torque and wheel steering are coordinated well in response to this new control scheme.