Design of Sliding Mode Controller Based on SMDO and Its Application to Missile Control

Abstract

A sliding mode controller(SMC) design approach based on the sliding mode disturbance observer(SMDO) is proposed.A class of cascade multiple-input multiple-output(MIMO) nonlinear system is separated into outer and inner loops based on the singular perturbation principle,and the controllers are designed in the two loops respectively.The robustness of the traditional saturation-function-based sliding mode controller is analyzed in the outer loop,and it is found to be weak in the presence of disturbances.To overcome this problem,together with the nominal sliding mode control law,SMDOs based on the super-twisting algorithm are designed to estimate and compensate for disturbances.Finally,the approach is applied to a missile control system design.The simulation results demonstrate that SMDO-based sliding mode controller(SMDO-SMC) effectively improves both the robustness and control performance of the control system.