An Adaptive Sliding Mode Controller with Tracking Differentiator for Servo Systems

An Adaptive Sliding Mode Controller with Tracking Differentiator for Servo Systems

  A sliding mode controller with parameter adaptation and a tracking differentiator is proposed for servo systems with unknown disturbances. The parameter adaptation is introduced both in order to enhance the disturbance rejection properties of the closed loop system, and to maintain the tracking performance despite plant parameter changes. In addition, a tracking differentiator is integrated with the sliding mode controller to get noise free differential signals to further improve the system performance. The proposed controller has been implemented and tested with an industrial Ink-jet plotter. Experimental results show that the controller achieves minimum tracking error and robust functionality.