Research on the Steady Precision of Sliding Mode Control of a Class of Nonlinear Systems

Steady tracking precision of linear sliding mode control system and terminal sliding mode control system of a class of nonlinear systems was researched. Steady errors of linear sliding mode control system and terminal sliding mode control system with the saturation function instead of sign function in the sliding control laws were analyzed and a mathematical relationship between the steady error and the width of the saturation function which was used to weaken the chattering of sliding mode control system was formulated, which provided theoretical basis for the choice of the width of the saturation function used for weakening chattering of sliding mode control system and guaranteeing the tracking precision simultaneously. Steady precision was compared quantitatively between linear sliding mode control and terminal sliding mode control which showed that terminal sliding mode control performed better than linear sliding mode control in tracking precision. Simulation results proved the validity of the theoretical analysis in the end