Distributed adaptive output consensus tracking for high-order nonlinear time-varying multi-agent systems with output constraints and actuator faults

Abstract

This paper studies the problem of adaptive output consensus tracking for a class of high-order nonlinear time-varying multi-agent systems with output constraints, actuator faults and external disturbances. The upper bounds concerning the disturbances and the time-varying stuck faults, and the time-varying parameters are assumed to be unknown. Most importantly, the nonlinear state-dependent function (NSDF) is provided to solve the tracking problem with output constraints, and the dynamic surface control (DSC) technique is used to overcome the iterative derivative of virtual controllers caused by the backstepping design scheme. Next, by modeling the failure of the actuators for all nonlinear subsystems, the actuator faults of all nonlinear subsystems are properly handled. Furthermore, a distributed adaptive controller is proposed to guarantee that the tracking error converges to a small adjustable neighborhood of the origin, and the output constraints are not violated for any nonlinear subsystem. It is also shown that the signals of the closed-loop nonlinear subsystems are bounded. Finally, simulation results illustrate the effectiveness of the proposed control method.