Disturbance Compensation Based Discrete-time Sliding Mode Control with a Reference Trajectory Generator

A novel disturbance compensation based sliding mode reaching law with a reference trajectory generator is presented in this work. Unlike existing similar researches, a reference trajectory generator is added to the reaching law to obtain the target evolution of the switching function. Meanwhile, a high order disturbance estimator is utilized to achieve accurate disturbance rejection. Additionally, by using the nonlinear functions, the controller parameters can be adaptively adjusted in a wise manner. The main merit of the presented method is that it is capable of ensuring a much smaller ultimate bound of the switching function, i.e., O(Tⁿ⁺¹) order accuracy and n is a positive integer, better system robustness, and improved control accuracy. Moreover, system dynamics, including the system states, are theoretically analyzed. The performance improvement of the presented method is verified through a real simulation study.