ASA 124th Meeting New Orleans 1992 October

4aSA7. Advanced time domain sensing techniques for active structural acoustic control.

J. P. Maillard

C. R. Fuller

Vib. and Acoust. Labs., Dept. of Mech. Eng., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061

This paper discusses new work concerned with developing structural sensors and associated signal processing that provide time domain estimates of far-field pressure or structural wave-number information. The sensor arrangement consists of multiple accelerometers whose outputs are passed through an array of linear filters. The impulse response of the filters is constructed from the appropriate Green's function for the elemental source area associated with each sensor. The outputs of the filter array are then summed in order to provide far-field pressure or wave-number information somewhat analogous to the well-known boundary element technique. A major significance of the approach is that it provides time domain information. The use of the sensing procedure is illustrated through simulations on radiation control from a baffled simply supported beam excited by both narrow-band and broadband disturbances. The control approach used is the time domain adaptive LMS algorithm. [Work supported by Office of Naval Research.]