Improvement of Control Performance in Shaking-Tables by Feedback Compensation for Reaction Force

This paper presents a practical control methodology of shaking tables for earthquake simulators. Reaction force generated by a nonlinear specimen on the shaking table generally deteriorates the motion performance of the table, resulting in the lower control accuracy of seismic tests. In order to provide the precise table motion, therefore, a compensator for the reaction force is designed by using a force sensor. The compensator can be designed under considerations of the relationship between the reaction force and the compensation signal, to achieve the desired disturbance suppression performance. The proposed approach has been verified by experiments using a laboratory shaking table system.