The Study And Application Of Variable Structure Control Theory

In this paper a class of single-input nonlinear systems with uncertainty bounds is explored, and three effective control schemes are proposed to approximate the uncertainty bounds without knowing the parameter of the object and ensure that an expected transient and steady-state performance index for tracking error can be achieved. According to the causes of the chattering a new method of chattering reduction -"trigonometric function reaching law method" is proposed. A global sliding model variable structure control approach and a sort of hierarchical switching scheme used with equivalent equation are proposed for a class of multi-input systems. In the applications, a variable structure robust observer based on Lyapunov stability theory and the method of pole allocation is used in the control of upside-pendulum. We also take the mode of five-bar robot arm for example to discuss the way of variable structure control used in trajectory tracking adaptive control and mode reference adaptive control of robots. Simulations show that the above schemes are valid.