Anti-resonance Vibration Suppression Control in Full-closed Control System

Abstract

External position sensors such as linear scales are frequently used in motion control systems of industrial machines, and they form a full-closed position feedback loop for accurate positioning. When the velocity signal calculated with the position signal from the motor encoder is used for the velocity control loop, resonance is less likely to occur than when using the velocity signal calculated with the position signal from the external encoder. If the position loop gain is increased, vibration is generated at the anti-resonant frequency, even if the velocity loop is stably controlled with respect to the resonance frequency. Since there is no control method for suppressing the vibration, such as the vibration control method in semi-closed control, the proportional gain of the position feedback loop cannot be made sufficiently high. In this paper, we propose a full-closed control method that suppresses the vibration at anti-resonance frequency and confirm its effectiveness through simulation and experiment.