| 摘要 |
PCT No. PCT/US95/12951 Sec. 371 Date May 6, 1997 Sec. 102(e) Date May 6, 1997 PCT Filed Oct. 6, 1995 PCT Pub. No. WO96/11466 PCT Pub. Date Apr. 18, 1996An acoustic energy dissipating device (100) comprises an acoustic driver (112) coupled to an acoustic medium and an acoustic sensor (110) for detecting a pressure of the acoustic medium near the acoustic driver. An inverting amplifier (115) and a compensator (114) are placed in a feedback system including the acoustic driver and the acoustic sensor. The compensator modifies the open loop phase response of the feedback system. Specifically, the compensator compensates for transduction device dynamics associated with the acoustic driver and the acoustic sensor to increase a gain margin of the feedback system. More specifically, the phase response of the open-loop system is constrained to alternate between +90 degrees and -90 degrees for each alternating complex conjugate pair of poles and zeros for an operational bandwidth of the device. In situations in which the acoustic characteristics of an enclosure in which the device is placed is dynamic, an adaptive gain feedback amplifier (120 not shown) can also be placed in the system for adaptively changing a feedback gain from the sensor to the driver according to a least-mean-squares or time-averaged gradient decent algorithm. Further a matched array of sensors-detectors can be used for applications with high modal densities or large enclosures.
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