Disturbance observer-based robust perfect tracking control for servo system and its application

To meet the rising performances requirements of servo system, a novel robust perfect tracking control (PTC) strategy is proposed. On account of the PTC's dependence on accuracy of the mathematical models of the controlled plant, the disturbance observer (DOB) is introduced to eliminate the model perturbation and the external disturbance so that the input-output characteristics of the plant is always close to the nominal model within the given frequency band. The application in some flight simulator shows that the proposed strategy dramatically improves the tracking performance even though integrated with the simple phase-lead compensator.