Patent ID: 8880364

Claim:
A method for sensing and analyzing the stress waves and other similar short term vibration events, comprising the steps of: sensing motion comprising of a stress wave or short term vibration event and macro scale vibration component, and converting the motion into some kind of measurable signal; separating the stress wave or short term vibration event from macro scale vibration component with a high or band pass filter applied to the measurable signal, wherein the resulting filtered signal is proportional to the stress wave or other short term vibration event; acquiring and digitizing the filtered signal; processing the digitized filtered signal for each predetermined interval of time (macro-sample time interval) using a short term energy measure or average signal power calculated over a short time window being a fraction of said predetermined interval of time, wherein calculations are performed using sliding time window and are done for every distinct time window position within the predetermined interval of time; creating multiple output signals by selecting a maximum short term energy value calculated for said predetermined interval of time from all other short term energy values calculated for said predetermined interval using sliding short time window, wherein the multiple signals are created by changing the duration of the sliding window; and performing multiple Fast Fourier Transforms (FFT) to determine a presence of stress wave and characterize its duration.