Smoother sliding mode controller for SCSM-based position servo system

A smooth sliding mode controller is designed for a position servo system based on a self-controlled synchronous motor. Using this controller, it is possible for the phase plane trajectory to move smoothly along the sliding line, even with a lower switching frequency. To ensure that the controller is used effectively in a disturbed environment, a simple parameter estimation method is also proposed. The effectiveness of both the sliding mode controller and the parameter estimation method is demonstrated by computer simulations. As the demanded control activity (the DC link current) is decreased, a large amount of energy can be saved; and as the switching frequency can be reduced without surpassing the accepted overshoot of the system, the switching devices will last long. The sliding mode controller proposed is not only effective, but also simple in controller structures and intuitive in controller parameter design