Design of disturbance observer using composite filter in two-dimensional shaking table systems

This paper presents a design approach of disturbance observer using the composite filter in the two-dimensional shaking table systems. The target two-dimensional shaking table system has the excitation mechanism to shake the target structure on the horizontal plane, where the external disturbances act on the actuator control system during excitation. In order to perform the accurate shaking tests, the disturbance observer is designed to improve the disturbance suppression characteristic of the actuator control system. The verocity signal is used as the input signal of the disturbance observer, where high-quality velocity signal of the actuator can be generated through the composite filter based on the acceleration and displacement signals. By using the velocity signal, the performance of disturbance compensation can be improved in the feedback control system. The effectiveness of the designed control system is verified by conducting experiments using the laboratory prototype of horizontal shaking table systems.