An Isolated Structural System Using Localized Vibration Control

This paper describes an approach to actively isolate vibration of a complex structural system by controlling six degrees of freedom in its support areas. The controller attempts to stabilize only localized areas near where the structure is supported rather than attempting to stabilize the entire structure. Actuator/sensor placement and model reduction are discussed, and the specific controller design and performance measure are described. The relative performance levels of different control strategies are evaluated by examining a frequency-dependent disturbance rejection property. Concepts are illustrated by numerically simulating a complex structural system comprising a flat plate supported by two box girders; plant dynamics are obtained from a finite-element model. Conclusions are drawn regarding the mechanisms by which localized vibration control is exerted.