Robust Output Tracking of Uncertain Large-Scale Input-Delay Systems via Decentralized Fuzzy Sliding Mode Control

This paper deals with the robust output tracking problem of uncertain large-scale systems with input delay and the time-delay interconnections. Due to the information transmission between subsystems, time delays are often encountered in large-scale systems and lead to the source of system instability. First, the original nonlinear time-delay systems can be represented by the Takagi-Sugeno fuzzy model, which combines some simple local linear time-delay systems with their linguistic description. Then, a feasible and systematic design scheme is presented to synthesize the decentralized fuzzy-model-based sliding mode controller. The adaptive fuzzy approach is proposed to approximate the upper bound of the uncertainties including the time-delay interconnections and the input delay. Based on the Lyapunov stability theorem, the proposed control scheme can not only guarantee the robust stability of the whole closed-loop system with input delay and time-delay interconnections, but also obtain the good tracking performance. Finally, simulation results are given to confirm the effectiveness of the proposed controller in this paper.