A Novel Digital Filter Control Technique of Servo System

Tracking Differentiator is applied to deal with digital alternating servo system´s position signal. Using tracking differentiator to track command signal and feedback signal, transferring them to smooth signal and separating the differentiator signal from them, which are used to build the element of feed forward and error control. The principle of nonlinear tracking differentiator is discussed. The proposed control system has been successfully tested by means of experiment. The results of measurements taken from a laboratory setup are presented which shown that the design is easy to achieve. The experiments prove that it ensures smoothness of feed forward velocity signal and command signal and resolves the issue of feed forward signal carrying disturbance signal smoothing to adopt tracking differentiator for signal pre-processing. It ensures the controller´s fine control quality, resolves the issue that the parameters are hard to match with each other due to the strict requirements placed on the servo system precision, stability and quick response. Dramatically promotes the servo system´s closed-loop response quality, dramatically improves the system comprehensive performances to adopt non-linear PID control for signal combination and control. The system shows an excellent transient response and stability, a good quick response and following characteristic.