Compressor Noise Measurement And Control Based On Array Beamforming Technology

In the field of non-contact mechanical fault diagnosis and interior noise control, theacoustic source imaging of Mechanical equipment is of great significance.And the digitalbeamforming of the microphone array is a key technology to reconstruct sound pressureand position in addition to some special compensation, based on the time lapse ofmicrophone in different locations.And the Color map is applied into the analysis of systemcharacteristic.The theory and principle of beamforming are leaded by the measurement technologyof distributed signal source.the theory of plane wave and sphere wave is modeled withmathematics method and the simulation results of both algorithms were compared todiscuss the sampling rate, bandwidth, space, angle and resolution ratio. Anumerical planararrays are designed, in which of that, ghost images appear in the results of cross style arrayand the rotated homocentric array with smaller main lobe width, lower side lobe degreewithout increasing the microphone number has much better performance. Besides, someissues are recorded that should be paid attention to when operating the beamforming inpractice.An3D geometry array with stable and reliable performance is designed on basisof traditional beamforming, which improves the precision without increasing the numberof microphones.To simulate actual noise, a new improved version of cross-spectralbeamforming used in Beamforming is introduced and its filtering operations are verified.Inthe more complicated condition, frequency domain method can abstract noise sign withdifferent frequency and amplitude to satisfy the needs of the noise fault diagnosis.In theproject of Jilin Petrochemical Company, the beamforming is applied in power unit torecognize acoustic source and installing acoustic enclosure, acoustic barrier and soundabsorber are effective measure of controlling noise.