Observer-based adaptive fuzzy output constrained control for uncertain nonlinear multi-agent systems

In this paper, consensus control problem is studied for uncertain nonlinear multi-agent systems with output constraint. Fuzzy logic systems (FLSs) and fuzzy state observer are employed to approximate unknown nonlinear functions and estimate unmeasured states, respectively. Barrier Lyapunov Function (BLF) is introduced to handle with the problem of output constraint. By combining adaptive backstepping and dynamic surface control (DSC) technique, a distributed adaptive fuzzy output feedback control scheme is proposed. It is proved that the semi-globally uniformly ultimately boundedness (SGUUB) of all the signals in the closed-loop can be guaranteed and all followers' outputs can be well synchronized to the leader's output while maintaining consensus tracking errors to be bounded. The simulation example is provided to show the effectiveness of the presented control method. (C) 2018 Elsevier Inc. All rights reserved.