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US 6,275,781 B1Granted
Vibration data processor and processing method
AssigneeSKF Condition Monitoring, Inc.
InventorsPhillip L. Maness, Johannes I. Boerhout
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Abstract
A vibration data processor and processing method uses a frequency domain filter having low pipeline delay and accurate time domain signal reconstruction. The filter may be user configurable, and the filter may receive input data from a variable number of decimation stages. Sequences of extracted vibrational features are routed to a variable length output buffer for event detection.
Claims11
A method of monitoring the condition of a machine, comprising:
- periodically sampling an analog vibration signal for a selected duration of time so as to produce a portion of a time domain digital input signal comprising a block of time domain digital samples representative of the analog vibration signal during the selected duration of time;
- Fourier transforming one or more of the blocks of time domain digital samples to produce blocks of frequency domain digital data;
- multiplying the frequency domain digital data by a selected filter mask to produce filtered frequency domain digital data;
- inverse Fourier transforming the filtered frequency domain digital data to produce blocks of filtered time domain digital samples;
- constructing a portion of a filtered time domain digital output signal by selecting a subset of the filtered time domain digital samples, said subset of the filtered time domain digital samples being located in a central region of said blocks of filtered time domain digital samples;
- and
- extracting a vibrational feature from the certain ones of the time domain digital samples so as to monitor a condition of the machine.
4 more elements
A method of digitally processing vibration data, comprising:
- sequentially performing a Fourier transform on a set of overlapping time domain vibration data blocks, thereby producing frequency domain data;
- filtering said frequency domain data with a mask;
- inverse Fourier transforming said frequency domain data thereby producing a set of filtered overlapping blocks of time domain data;
- selecting, from a series of said overlapping blocks of time domain data, a centrally located subset of time domain data from each block of said series to produce a series of smaller blocks of time domain data;
- reconstructing a filtered time domain signal from said smaller blocks of time domain data.
2 more elements
A method of monitoring the condition of a machine, comprising:
- periodically sampling an analog vibration signal for a selected duration of time so as to produce a portion of a time domain digital input signal comprising a block of time domain digital samples representative of the analog vibration signal during the selected duration of time;
- Fourier transforming one or more of the blocks of time domain digital samples to produce frequency domain digital data;
- multiplying the frequency domain digital data by a selected filter mask to produce filtered frequency domain digital data;
- inverse Fourier transforming the filtered frequency domain digital data to produce filtered time domain digital samples;
- constructing a portion of a filtered time domain digital output signal by selecting certain ones of the filtered time domain digital samples;
- and
- extracting a vibrational feature from the certain ones of the time domain digital samples so as to monitor a condition of the machine;
- storing said extracted vibrational feature into a variable length accumulator which holds q extracted vibrational features prior to routing q extracted vibrational features into an output buffer.
5 more elements
Dependencies are inferred from the claim text.