Robust variable structure control synthesis in discrete-time uncertain systems

This paper proposes a design technique for variable structure control to achieve the robust stabilization of uncertain discrete-time systems. The ''sliding control'' depends on the determination of the matrix C of the sliding surface. The reaching control is designed with the aid of an extended region from the sliding region and the locations of the equilibrium points on the corresponding surfaces. The sliding region is also determined to avoid the occurrence of ''unstable switchback.'' It should be noted that the reaching control gain is a simple vector with the same elements. This may cause the practical controller to be easily implemented.