Load controller design for dual-stage actuator considering compensation for interference and disturbance

This paper presents a controller design approach to provide the precise force control considering compensation for interference and disturbance in load devices. In the control system, a pneumatic actuator and a voice coil motor are combined as a dual-stage actuator to expand the servo bandwidth of the load control. The interference between the actuators, however, deteriorates the servo performance, especially at around the cross-over frequency. In addition, the disturbance generated by an abrasive motor deteriorates the tracking performance for the target value. In this research, therefore, a PQ method is adopted to achieve the high precision load control by expanding the servo bandwidth. Here, the compensators are designed to compensate for the interference, while a resonant filter is designed to suppress the disturbance with the specific frequency, paying attention to a vector locus of the open-loop characteristic. The proposed approach has been verified by experiments using an actual load device.