Disturbance rejection of singularly perturbed switched systems subject to actuator saturation

This paper addresses the disturbance rejection problem for singularly perturbed switched systems subject to actuator saturation. We focus our attention on the synthesis of feedback control laws to achieve disturbance rejection for the systems. By using the average dwell-time approach together with the piecewise Lyapunov function technique, sufficient conditions for the existence of a controller are derived in terms of LMIs, which are independent of the singular perturbation parameter ε. Some convex optimization problems are formulated to get a larger estimate of the basin of attraction and a better disturbance rejection ability. The state-feedback controller depends on the singular perturbation parameter ε, but it is shown to be well posed for all ε∈(0,ε₀]. In addition, if ε is sufficiently small, the ε-dependent controller can be reduced to an ε-independent one. Finally, a hydraulic servoposition system is used to show the feasibility and effectiveness of the obtained results.