Accelerometer-Based Acoustic Control: Enabling Auscultation on a Black Hawk Helicopter

摘要: During aeromedical patient transport, acoustic noise levels in excess of 90 dB make auscultation with a stethoscope virtually impossible. Existing approaches to address this literature have relied on the use either passive shielding sensing element or active cancellation (ANC) additional reference microphone sensors. These solutions achieved inadequate performance. In paper, custom instrumented stethoscopes are used obtain structural vibration and data from UH-60 Black Hawk helicopter. The show that vibrations contribute significantly more signals than air-borne noise. Therefore, novel adaptive control system using accelerometer is pursued. By varying vibrational sources controlled laboratory environment, benefits limitations accelerometer-based investigated compared. Experimentally simulating field characteristics helicopter, ANC shown provide superior yields an average 25-dB reduction ambient over entire relevant frequency range, thereby enabling successful for first time military aircraft environment.