A reduced-order-observer based variable structure controller with finite reaching time

In this paper, a finite reaching time reduced-order observer based output feedback controller are proposed for both the matched and mismatched uncertainty variable structure systems. The result is a reduced-order observer (ROO) based output feedback controller which guarantees the existence of the sliding mode in finite time. The problem of the ROO design of the system is also addressed. Moreover, the implications of the use of the ROO in the design of the controller are pointed out. In the sliding mode, the stability of the equivalent reduced-order system is assured under certain conditions.