Fifth International Congress on Sound and Vibration Strategies for Active Control of Sound Transmitted through a Double-panel Partition Using Distributed Actuators and Sensors

The paper considers the active control of harmonic and random sound transmitted through a double-leaf partition using a single distributed actuator and a single distributed sensor. The double-leaf partition consists of a pair of small plates (300x380 mm, separated by a 100 mm air-gap,). An actuator made up of shaped, distributed PVDF offers the possibility of cent rolling the volume velocity of a plate witbout giving rise to cent rol spillover. The sensor consists of a matched PVDF sensor to detect volume velocity. For harmonic excitation with the actuator attached to either panel, substantial reductions in the transmitted sound power are possible up to around 350 Hz. A radiation mode analysis of the panels shows that the double-leaf construction provides good passive attenuation of the first radiation mode at high frequencies, so that inefficiently radiating even modes of the radiating panel make a dominant contribution to the radiated sound power. For the random excitation, an internal model control scheme is outlined for the double-panel system in which the transmission of random sound is controlled without the need for a reference signal. Cancellation of volume velocity with the distributed actuator provides reduction in random sound transmission up to 100 Hz.