Active/passive design for vibration control

A method has been developed for the control of panel vibration using a hybrid active/passive spatial optimization technique. The method relies on the rapid estimation of Hankel singular values (HSV’s) to predict coupling of sensor/actuator pairs to particular vibration modes of interest. The two-step process first requires the selection of the best sensor/actuator pair for active control, using a design metric which is typically used to target the control of low-frequency, long-wavelength modes, while simultaneously minimizing higher frequency, or out-of-bandwidth, system response. With the active control system in place, potentially destabilizing out-of-bandwidth modes are identified for passive control. A similar design metric is then applied which emphasizes coupling of passive damping material to the high-frequency, short-wavelength structural modes. Numerical simulations were performed to demonstrate this concept. It was then implemented on an 18-×16-in steel plate. Plate response was measured first for the uncontrolled plate, then the plate with just the active control system in place, and finally the complete hybrid active/passive system. Performance of each system was analyzed, with benefits and tradeoffs considered.