DISCRETE-TIME QUASI-SLIDING MODE TRACKING CONTROL OF UNCERTAIN SYSTEMS WITH LONG SAMPLING INTERVAL

This paper presents a discrete-time quasi-sliding mode controller of S IMO systems with parameter uncertainty and long sampling interval. The discrete quasi-sliding mode control system is designed to track the d esired path on the basis of a Lyapunov function, and sufficient condit ions of the switching gain are given to make the discrete system stabl e. Each component of the switching gain can be determined separately. The switching region is variable according to the product of the bound s of uncertainty and the amplitude of the trajectory. The controller i s robust to the uncertainties, and the reaching condition of the contr ol system is satisfied for any initial condition. This control law is a generalized form of the discrete quasi-sliding mode control and redu ces the chattering problem considerably. Simulation results for motion control of an autonomous underwater vehicle which acquires position i nformation with a discrete interval show the effectiveness of the prop osed technique.