Vibration suppression with frequency adaptation

Abstract

T h e aim o f this paper is to present an adaptive solution to suppression o f vibrations. Adaptation is appropriate whenever the fundamental frequency is unknown or drifting, e.g. when the vibration is caused by a rotational machine with unknown rotational speed. T h e approach presented here has its roots in repetitive control based on models o f isolated frequencies rather than the commonly used delay model. T h e relationship between different modeled frequencies is fixed by the model structure, and the fundamental frequency is obtained by a Newton method. To show the feasibility o f this approach, it was used to reduce vibrations on a lever that were caused by a motor with imbalance in its rotation. A s actuator, a standard loudspeaker was used, and the vibration was sensed by an accelerometer.