Smart panel with multiple decentralized units for the control of sound transmission. Part I: theoretical predictions

This is the first of three companion papers that summarize the theoretical and experimental work carried out to develop a prototype smart panel with 16 decentralized vibration control units for the reduction of sound radiation/transmission. The smart panel is made of a thin aluminium plate with 16 closely spaced accelerometer sensor and piezoceramic actuator transducer pairs connected by single-channel velocity feedback controllers (i.e., active damping units). In this paper a preliminary theoretical study is carried out to assess the behaviour of the smart panel when it is mounted on the top of a rectangular cavity with rigid walls. The smart panel is excited either by the acoustic field produced in the cavity by a monopole source or by a transverse point force. The simulations carried out have shown that for both the acoustic and the force sources, good reductions of the averaged kinetic energy or total sound power radiation can be achieved within a band 0–2 kHz: The theoretical study is preceeded by a general review of the development of smart panels for the control of sound radiation/transmission. In particular, the various approaches developed for the design of sensors and actuators are analyzed with reference to the control of tonal disturbances using feed-forward controllers and the control of stationary random disturbances using feedback controllers.