ACTIVE CONTROL OF ACOUSTIC POWER RADIATED FROM A VIBRATING PLANAR STRUCTURE USING SMART SENSORS (ACOUSTIC POWER SUPPRESSION USING ADAPTIVE FEEDFORWARD CONTROL)

This study deals with the problem of sensing structural vibration to p rovide an error signal to an adaptive feedforward control system, whic h aims to globally attenuate both structural and acoustic disturbance. This paper demonstrates the validity of a newly proposed ''smart sens or'' as a distributed parameter sensor made of PVDF film which is desi gned to measure an acoustic power mode of the total acoustic power rad iated from a vibrating plate. Firstly, with a PVDF distributed paramet er sensor attached on the entire surface of the plate, the formulas fo r sensing the j-th acoustic power mode are derived. Then, by consideri ng the practicability of implementing the smart sensors, alternative f ormulas for sensing the acoustic power mode are derived for a strip-ty pe smart sensor. The characteristics of the smart sensors optimally sh aped for measuring the acoustic power modes are also shown. Moreover, based upon an adaptive feedforward control with the filtered-xLMS algo rithm, an experiment was conducted to demonstrate the minimization of the acoustic power radiated from a vibrating plate.