Variable structure control of discrete-time systems and their quality

The design of variable structure control (VSC) of discrete-time systems and the quality control of the dynamical processes are studied. Reviewing the previously established versions of reaching conditions briefly and one of them is assured, the characteristic of the quasi-sliding mode is studied in detail. On the basis of stability and a simple form of control the conception of an adaptive discrete reaching law is proposed and the periodic convergence law is given. The reaching-convergence method is built to design VSC. It solves the steady-state chattering problem and considers the quality of all process movements.