Study Of Sliding Mode Control In Control System Of The Multistage Inverted Pendulum

Inverted pendulum is a serious non-linearity, underactuated naturally unstable system, the research on inverted pendulum system which is involved the key technology of handling the objects in control science. Sliding mode control(SMC) has attracted more and more attention because of its perfect features of arbitrary robustness and complete adaptation to matching uncertainties and external disturbances. It has very important effect in the experiment method and research of control theory. In this paper, some problems of SMC with inverted pendulum which are studied in this thesis based on the work of previous studies, and the main contents of it are outlined as follows:First of all, the paper introductions sliding mode control algorithms, discussing the points of designing for sliding mode are: How to choose the switching function? How to determine the control law of u? Illustration of the major problem of variable structure control is the buffeting, and introducing the applications of variable structure control.Secondly , the non-linear mathematical model of inverted pendulum is formulated with the analytically investigated of the structure of inverted pendulum. Simulation and experimental results show that the method of variable structure control is effective for inverted pendulum system.Thirdly the paper analyzes the buffeting, and the method of fuzzy sliding mode controller is designed. Than, the result of comparison with conventional variable control shows that the method of fuzzy sliding mode control has good robustness and better control performance.Finally, an new adaptive fuzzy sliding mode control scheme is proposed based on clone selection algorithm (CSA) which is aimed at the problem of controlling the second order inverted pendulum. CSA is used to optimize the membership functions of fuzzy variables to adaptively adjust the switching gain of sliding mode control by fuzzy control. The controller can reduce the maximum limit of model and disturbances, and has little chattering. Simulation study is made based on second order inverted pendulum governors. The experiment results show that the proposed control scheme robustness to the higher order nonlinear system and laid the foundation for more complexed pendulum.The last chapter summarizes the thesis and gives perspective.