Modal phase compensation for application of direct velocity feedback to active control of floor vibration under impact excitation

Abstract

The modal filtering approach has been investigated as a promising efficient implementation approach for control of human-induced vibration of building floors, so that the measured response of the floor is decomposed into modal responses. It is expected to achieve a simple and cost-effective framework, taking advantage of the mode-by-mode control approach. In this study, an automatic phase compensation technique and its implementation combined with modal filtering to vibration control of an impact-excited floor are presented. It has been observed that the phase-lag of electromagnetic actuators strongly affect the efficiency of the control performance of the vibration control as a result of the combined dynamics of the structure and the control system. Phase compensation can be implemented by a simple weighted linear combination of integration with the target modal control signal itself, which is similar to the proportional-integral (PI) technique. In this study, an automatic adjustment technique of the PI parameters when the modal frequency is known is developed and implemented to the control system. Verification experiments using a steel plate with all edges fixed and the developed control system are conducted to investigate the effectiveness of this method under impact loading. The control performance achieved by the developed system show the validity of this approach.