Active/Passive Hybrid Approach for Noise and Vibration Control

In Phase I, the feasibility of adaptive-passive devices to control noise and vibration is studied. In many applications, adaptive- passive devices may be as effective as fully active control but without the attendant drawbacks. Compared to fully active systems, the adaptive-passive system consumes less power, is more reliable and is less costly. The feasibility is determined through two parallel efforts: An analytic study and the construction and testing of a prototype device. The analytic study compares the adaptive-passive approach to both passive systems and fully active systems. The devices are compared on the basis of acoustic/vibration performance, reliability, cost and power consumption. Also included in the analytic study is the development of simple, effective feedback control strategies for resonant tuning of the adaptive passive device. The feedback control and acoustic/vibration performance is verified through experimental testing of the prototype device.