Adaptive output tracking of MIMO nonlinear systems with unknown non-symmetric dead-zone

This paper is devoted to the adaptive output tracking for a class of multi-input multi-output nonlinear systems with unknown non-symmetric dead-zone. Under the assumption that the signs of leading principal minors of the control gain matrix are known, an adaptive dynamic surface control scheme is proposed. The proposed scheme is able to avoid the explosion of complexity problem in backstepping design and guarantee the L_∞ performance of the tracking error. Moreover, only one parameter needs to be updated online at each design step, which significantly reduces the computational burden. It is proved that all signals of the closed-loop system are semi-globally uniformly bounded. Simulation results are given to illustrate the effectiveness of the proposed scheme.