Method and system for unobtrusive spatial localization and detection of impact induced soundwaves

A system for spatial localization of impact induced sound waves, further comprising:

• a memory storing instructions;
• one or more communication interfaces;
• and
• one or more hardware processors coupled to the memory via the one or more communication interfaces, wherein the one or more hardware processors are configured by the instructions to:
• preconfigure an industrial machinery by placing a microphone array at different locations within the machinery to record a sound signal s(t), and simultaneously obtaining geometrical structure parameters of the machinery;
• obtain (i) the sound signal s(t) from the microphone array occurred surface of target of interest of the machinery, (ii) an impact duration which is an occurrence duration of the sound signal s(t), and (iii) a target FPS;
• slice the sound signal s(t) by adjusting a sliding time window T and a step size ΔT to obtain a time windowed sound signal s(t)win;
• applying filter to filter the time windowed sound signal s(t)win to obtain a filtered sound signal s(t)filt based on (i) a sliding narrow band pass filter of central frequency f, (ii) a frequency range between [FL, FH] a spectral response of impact type, and (iii) a band distance ΔF;
• perform an eigenvalue decomposition over a covariance matrix R of the filtered sound signal s(t)FILT to determine a noise subspace Qn;
• obtain a steering vector A(θσ, φσ) from the geometrical structure parameters of the machinery and the noise subspace Qn to evaluate a spatial power matrix P_SPATIAL(θσ, φσ)T,f for each time window of the sound signal s(t)filt;
• obtain a spatial localization map on a microphone array plane for each time window (P_TOTAL(θσ, φσ)T) using the spatial power matrix P_SPATIAL(θσ, φσ)T,F;
• project the spatial localization map on target surface of the microphone array plane with a cartesian coordinates σ′(x, y, z);
• identify one or more impact hotspots on the target surface of the machinery by searching one or more peaks in the spatial localization map projected into the target surface and accumulating the one or more impact hotspots over a long temporal range;
• and
• localize exact location of occurred impact sound from the one or more impact hotspots and is projected on the machinery.

One or more non-transitory machine-readable information storage mediums comprising one or more instructions which when executed by one or more hardware processors cause:

• preconfiguring an industrial machinery by placing a microphone array at different locations within the machinery to record a sound signal s(t), and simultaneously obtaining geometrical structure parameters of the machinery;
• obtaining (i) the sound signal s(t) from the microphone array occurred surface of target of interest of the machinery, (ii) an impact duration which is an occurrence duration of the sound signal s(t), and (iii) a target FPS;
• slicing the sound signal s(t) by adjusting a sliding time window T and a step size ΔT to obtain a time windowed sound signal s(t)win;
• applying filtering to filter the time windowed sound signal s(t)win to obtain a filtered sound signal s(t)filt based on (i) a sliding narrow band pass filter of central frequency f, (ii) a frequency range between [FL, FH] a spectral response of impact type, and (iii) a band distance ΔF;
• performing an eigen value decomposition over a covariance matrix R of the filtered sound signal s(t)FILT to determine a noise subspace Qn;
• obtaining a steering vector A(θσ, φσ) from the geometrical structure parameters of the machinery and the noise subspace Qn to evaluate a spatial power matrix P_SPATIAL(θσ, φσ)T,f for each time window of the sound signal s(t)filt;
• obtaining a spatial localization map on a microphone array plane for each time window (P_TOTAL(θσ, φσ)T) using the evaluated spatial power matrix P_SPATIAL(θσ, φσ)T,F;
• projecting the spatial localization map on target surface of the microphone array plane with a cartesian coordinates σ′(x, y, z);
• identifying a one or more impact hotspots on the target surface of the machinery by searching one or more peaks in the spatial localization map projected into the target surface and accumulating the one or more impact hotspots over a long temporal range;
• and
• localizing exact location of occurred impact sound from the one or more impact hotspots and is projected on the machinery.