Adaptive feedforward compensation for reaction force with nonlinear specimen in shaking tables

This paper presents an adaptive control methodology of shaking table systems for earthquake simulators. In the system, reaction force generated by a specimen on the shaking table generally deteriorates the table motion performance, resulting in the lower control accuracy of seismic tests. In order to compensate for the reaction force and to provide the precise table motion, therefore, an adaptive identifier is introduced, where dynamic characteristics of a nonlinear specimen are adaptively identified and can compensate for the deterioration in the motion performance. The proposed control approach has been verified by numerical simulations and experiments using a prototype of shaking table system.