Robust soft variable structure control of perturbed singular systems with constrained input

This paper investigates the robust soft variable structure (RSVS) control technique for perturbed singular systems with constrained input control. The aim of the RSVS control law, in addition to achieving desirable control performance for the constrained input, is the robust stability of the closed-loop system in the presence of perturbation. In this paper, the RSVS control for perturbed singular systems is designed for two cases. First, it is assumed that the perturbation term vanishes at the origin. In this case, the proposed RSVS controller leads to asymptotic stabilization of the perturbed singular system. In the second case, the perturbed singular systems with non-vanishing perturbation are considered and the robustness of RSVS is also investigated. In this situation, the proposed controller guarantees practical stability of the perturbed singular system. Finally, computer simulations are provided for two examples to verify the theoretical results.