Discrete-time adaptive VSS control system using transfer function

This paper is concerned with the discrete-time servo control based on variable structure system (VSS) and its application to self-tuning control. The servo controller is designed by using the pulse transfer function so as to minimize the generalized minimum variance. This paper first presents a discrete-time VSS control for a known plant based on generalised minimum variance control. The control law proposed has the different feedback coefficients of the past output characterized by the sector instead of the sliding surface. Next, the VSS control system for an unknown parameter plant is considered. The simultaneous control and parameter estimation are done by using VSS control where the control law contains switching feedback coeffcients of not only past output but also past input. The latter gives the globally stable self-tuning system and its effectiveness has bees shown through simulations