Variable structure control for discrete-time singular system based on reaching law with dynamic disturbance compensator

Synthesis problem of variable structure control (VSC) for discrete-time singular system (DSS) with internal parameter perturbation and external disturbance is considered in this paper. The dynamic switching function which is used to guarantee the stability of the control system in the switching band is provided. The discrete singular reaching law with dynamic disturbance compensator is designed to eliminate the restriction of the system uncertainties is bounded and the satisfaction of matching conditions compared with conventional VSC. Essential condition of sliding mode which can cross the switching plane step by step is considered. The discrete singular variable structure controller is designed by applying the reaching law, which can guarantee the system to reach the switching plane in finite time, decrease the system chattering effectively and enhance the dynamic quality of the control system. Simulation results illustrate the feasibility and validity of the proposed approach.