Discrete Variable Structure Control

Dean of the Graduate College ii PREFACE The methodology of variable structure with sliding mode is proven to be very successful in controlling uncertain continuous-time dynamical systems. When the system is sampled or purely discrete, the invariance property of sliding mode, which is originally a continuous-time concept, no longer hold and the reaching condition has to be modiied to allow a pseudo-sliding mode. Moreover, the state dependency of parametric uncertainties makes the satisfaction of reaching condition considerably more diicult especially in multivariable systems. These diiculties have ooered challenges that attracted a great deal of research interests. This thesis presents theoretical results on the discrete variable structure control of uncertain linear multivariable systems using the concepts of sliding mode and switching sector. It considers both the state and output feedback cases for systems with additive uncertainties and the state feedback case for systems with parametric uncertainties. The thesis also presents a sliding surface design procedure for single-input systems based on the version of discrete variable structure control developed by Dr. Eduardo Misawa. Here, I would like to express my gratitude to Dr. Eduardo Misawa, my thesis adviser, who has always been encouraging me and supporting me throughout the course of this research. I am also grateful to my committee members, Dr. Gary Young and Dr. Prabhakar Pagilla, for their help and guidance. To my parents Chooi Leng Tang and Chai Kim Ng, my sincere thanks for their love and support during all these years of my education. Also, my thanks to Ms. Yeun Fun Yau for her patience during my study in the United States. Finally, I wish to thanks my lab-mates, Brian, May-Win, and Hanz for proofreading the thesis.