Discrete-time variable structure control using modified recursive switching function

This paper proposes anew second-order recursive switching function for discrete-time variable structure control (DVSC). The proposed switching function consists of the current state vector and the two previous switching function values, and has two design parameters. Using the proposed switching function, a DVSC controller is designed and combined with a decoupled disturbance compensator (DDC). For the combined DVSC structure, constraints of the two design parameters are derived to achieve robustness property against disturbances. Using numerical example, the performance of the proposed DVSC is shown.