Controller design for dual-stage actuator-driven load devices considering suppression of vibration due to input saturation

This paper presents a controller design approach considering vibration suppression due to input saturation for load devices. In the target load device, a pneumatic actuator and a voice coil motor are combined as a dual-stage actuator to expand the control servo bandwidth. However, vibrations due to the input saturation of the voice coil motor deteriorate the force tracking performance for the desired load reference. In this research, therefore, a loop-shaping approach is adopted to suppress the vibration, where a compensator is designed to improve the disturbance suppression at the plant resonant frequency. The proposed approach has been verified by experiments using a prototype of load device.