Adaptive H∞ control of nonholonomic systems with strong nonlinear drifts

In this paper, adaptive H_∞ control is considered for uncertain nonholonomic systems in chained form with external disturbances and strong nonlinear drifts. The state-scaling and backstepping technique are applied to design the global adaptive controller and a switching strategy is developed to eliminate the phenomenon of uncontrollability. The proposed controller guarantees the effect from external disturbance to the system output in sense of L₂ gain arbitrarily small. Without the presence of the disturbance, the system states are asymptotically regulated to the origin. An simulation example shows the effectiveness of the proposed control schemes.