Compensation for Reaction Force with Specific Frequency of Vibration Testing System Considering Frequency Variation

Abstract

This paper presents an adaptive control methodology of a vibration testing system for earthquake simulators. In the system, reaction forces generated by a specimen deteriorate the motion performance, resulting in the lower control accuracy in seismic test. Especially, in cases of excitation tests for structures (power facilities, large vehicles, etc.) including motors, the reaction force as a disturbance is excited with a specific frequency during their actual operations. In addition, the variation of the rotational frequency in the motor cause the variation of frequency in the disturbance. In order to compensate for the disturbance, therefore, an adaptive feedback compensator is designed to improve the disturbance suppression capability, by applying an adaptive notch filter to identify the frequency in real time manner. The proposed control approach has been verified by experiments using a prototype of shaking table system.