Identification and Control of Rotating Disk Vibration

Abstract

Small amplitude, transverse vibration of a circular disk can be viewed as a superposition of travelling waves each wave corresponding to a particular vibration mode. When the plate damping is small, the transverse motion of the plate is often dominated by response in one mode [1]. The active control method discussed here used an on-line FFT analysis of the rotating disk displacement to periodically identify the dominant mode of the disk response in a changing operating environment. Active control forces were applied electromagnetically to the disk to suppress the amplitude of that particular mode. In laboratory tests, the prototype controller reduced the modal amplitude to less than 15 percent of the uncontrolled value. Analytical predictions correlated well with these laboratory observations.