The Combining Control Strategy Of Soft Variable Structure Control And Sliding-mode Variable Structure Control

Variable structure controls are normally understood to be controls that have sliding modes and robustness as their main objective. In addition to sliding mode controls, there are also variable structure controls, which were developed for the purpose of intentionally precluding sliding modes and for achieving high regulation rates and short settling times. These controls are called soft variable structure controls. The soft variable structure controls continuously varies controllers'parameters and nearly time-optimal control performance.In this paper, the author proves the process of how to construct the controller and puts forward a new combining control strategy. There are four chapters in this paper. In chapter 1, the present condition of variable structure control is analysised and some main lemmas and definitions are presented.In chapter 2, the author introduces the definition of soft variable structure control in the continuous time system and the construction of its controller. She proves the conclusion which appears in the construction of the controller.In chapter 3, the author introduces the conditions that the sliding-modes of variable structure control reach the switching surface in the continuous time system and put forward some typical approach law.In chapter 4, the author puts forward a new control strategy. Simulation results show that the performance of system using the new combining control strategy is superior to the system using sliding-mode variable structure control.