DISTURBANCE CANCELLATION CONTROL FOR VIBRATION OF MULTI-DEGREE-OF-FREEDOM SYSTEMS - CASE OF USING ACTIVE VIBRATION ABSORBER AND ACTIVE DYNAMIC VIBRATION ABSORBER

This paper describes a control system design method concerning feedback and feedforward control to cancel disturbance forces, for two kinds of active vibration control devices. One is the active vibration absorber (AVA) utilizing a fixed point for a civil structure such as a bridge, and the other is the active dynamic vibration absorber (ADVA) utilizing an auxiliary mass for a buildinglike structure. We have built two test rigs to simulate large structures with an AVA or an ADVA. In order to carry out fast computation, including the estimation of disturbances, we have used a digital signal processor (DSP). In conclusion, we found that the disturbance forces are perfectly cancelled and the output zeroing is actually realized when the disturbance frequency is exactly equivalent to the design frequency of the observer. We have confirmed that the proposed disturbance cancellation control is very useful for active vibration control.