Design of disturbance observer for air ball movement system

For the rapid positioning air ball movement system, the simplified model was built and the influences to the servo performance were analyzed, including changes of the system, external disturbance and uncertain factors. A robust control strategy based on combining the disturbance observer(DOB)and PD controller was proposed. It can ensure the robust performance of the system. The theory analysis and simulation experiment results show that the robust feedback controller based on DOB can overcome the influences of the uncertainties, such as external disturbance, un-modeled dynamics and the parameters perturbation and so on, and the robust performance is improved greatly.