Integral sliding mode control for interconnected descriptor systems based on a reduced-order observer

In this paper, a reduced-order observer-based integral sliding mode controller is designed for a class of interconnected descriptor systems. First, the observer matching condition is used to transform the interconnected descriptor system into an interconnected normal system. Based on the canonical form, a reduced-order observer is then designed to estimate the state variables of the interconnected descriptor system. In terms of the measurable output variables and the state variables of the proposed reduced-order observer, a sliding mode control scheme is developed to drive the state trajectories of the system to the sliding surface in a finite time and maintain a sliding motion thereafter. It is shown that at the existence of unknown matched disturbances, the proposed observer-based integral sliding mode control scheme can still ensure the asymptotic stability of the resultant closed-loop system. This is an obvious improvement of the existing observer-based sliding mode control methods in descriptor systems fields. Finally, an example is given to verify the effectiveness of the proposed method.