(A) study on DC motor position control using variable structure systems with new sliding surfaces

Abstract

In the VSS control with the sliding mode, the trajectories can be robust to disturbances and parameter variations. The trajectories with the conventional sliding surfaces always have the reaching phase which is an interval from the initial states to the first touching of the sliding surfaces, because the conventional sliding surface are linear functions of the state variables. The sliding mode control can not be realized in the reaching phase, therefore the trajectories may be sensitive to disturbances and parameter variations. Simple nonlinear sliding surfaces are proposed to improve the robustness to these disturbances. Using new sliding surfaces, the position control of PM DC servo motor is carried out and is compared with the conventional surface. As a result, the trajectories with new sliding surfaces are robust to disturbances and parameter variations in all state space.