Research on the mechanism of acoustic signal detection based on EMI and ANN Technology

摘要

Black boxes from aircraft which had crashed into the sea are highly difficult to locate. To solve this problem, an identification and location method based on piezoelectric impedance technology was presented in this paper. An experimental device for detecting aircraft black boxes based on impedance analysis was first designed, after which the beacon simulation emitter and piezoelectric impedance acceptor were produced. An experimental platform for detecting and simulating black boxes' ultrasound beacon was set up. For the underwater detection experiment, the signal frequency sent from the simulation generator was set to 37.5kHz, which is the frequency of the ultrasound beacon of the underwater generator on the black box. Combined with the use of back-propagation (BP) neural networks, the ultrasonic beacon was recognized and located. The results show that the largest wave crest always appeared at the frequency of 37.5kHz, and the piezoelectric impedance acceptor's impedance real value curve generally increased as the acceptor got closer to the beacon simulation emitter. This proved that using piezoelectric impedance technology to detect ultrasonic signals sent from the beacon simulation emitter is viable.