Modelling and feedback control of sound radiation from a vibrating panel

This paper considers the feedback control of sound radiation from a panel. Modelling is first used to design the sensors and actuators which are most effective in terms of both their acoustic and control performance. Controlling the volume velocity of a panel to reduce its sound radiation has previously been shown to be an effective strategy when the disturbance is tonal and, in this paper, the technique is extended to broadband disturbances. The use of various structural actuators and sensors is compared for their performance and practicality in active structural acoustic control (ASAC) applications. The best combination of transducers is then used to design an experimental rig. Measured frequency response functions are found to compare well with those obtained in simulations. Feedback control of the volume velocity of the panel is then investigated. It is shown that, to increase the performance of a feedback control system, the plant frequency response should be as close to minimum phase as possible, which can be achieved by changing the positions of secondary actuators on the plate, Internal model control (IMC) is then reviewed and an IMC feedback controller implemented in real time on the plate. The attenuation obtained is compared with the attenuation obtained from simulations. Limitations in the current experimental system are also discussed.