Robust quadratic stabilization tracking control for mobile robot with nonholonomic constraint

A robust hybrid tracking control scheme, which combines a computed torque control (CTC) method with a robust hybrid compensator, is proposed for nonholonomic mobile robot with parametric uncertainties and disturbances. CTC acts as the main controller to control the nominal model of the robot. The robust hybrid compensator consists of variable structure control (VSC) and H ∞ optimal control approaches, where the VSC is utilized to eliminate the effect of the parametric uncertainties and ensure the stability of the close-loop system, while H ∞ approach is designed to achieve a certain tracking performance. In addition, to reduce the conservatism of the robust control method, a quadratic stability approach is derived to separate the parametric uncertainties. According to the Lyapunov stability theorem, it is proved that all signals in the closed-loop are bounded. Simulation examples on a typical wheeled mobile robot are presented to show the efficiency of the proposed robust hybrid tracking control method.