Gear transmission condition monitoring method and apparatus
First Claim
1. A gear transmission condition monitoring method comprising the steps of:
- identifying gear mesh frequencies that are remote from interfering frequencies;
forming a good operating condition baseline matrix by, for each of the identified gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum;
forming a faulty operating condition baseline matrix by operating the gear transmission under a plurality of different faulty operating conditions while, for each of the identified gear mesh frequencies, obtaining a faulty operating condition signal over a segment of time and transforming the obtained faulty operating condition signal into a faulty operating condition time-frequency spectrum; and
then, obtaining a test gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions.
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Abstract
A gear transmission monitoring method includes: forming a good operating condition baseline matrix by, for each of a plurality of different gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum; and then obtaining a gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the gear mesh frequency and the good operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions.
51 Citations
29 Claims
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1. A gear transmission condition monitoring method comprising the steps of:
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identifying gear mesh frequencies that are remote from interfering frequencies;
forming a good operating condition baseline matrix by, for each of the identified gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum;
forming a faulty operating condition baseline matrix by operating the gear transmission under a plurality of different faulty operating conditions while, for each of the identified gear mesh frequencies, obtaining a faulty operating condition signal over a segment of time and transforming the obtained faulty operating condition signal into a faulty operating condition time-frequency spectrum; and
then, obtaining a test gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 13, 14, 15)
calculating a covariance matrix of the feature data set;
performing an eigenvalue decomposition of the covariance matrix; and
using multiple columns of the eigenvalue decomposition matrix to transform the feature data set to a multi-dimensional compressed vector space.
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13. The method of claim 1 wherein using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum includes forming a test feature vector from the test time-frequency spectrum.
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14. The method of claim 13 wherein using the test gear mesh frequency, the good operating condition baseline matrix, the faulty operating condition baseline matrix to examine the test time-frequency spectrum further includes obtaining a plurality of test gear mesh frequencies and a plurality of respective test signals over a plurality of respective segments of time, forming a plurality of respective test feature vectors, and tracking instances when the test feature vectors falls outside the good operating condition baseline matrix or within the faulty operating condition baseline matrix.
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15. The method of claim 14 further including declaring a fault after a predetermined number of consecutive tracked instances.
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10. A gear transmission condition monitoring method comprising the steps of:
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forming a good operating condition baseline matrix by, for each of a plurality of different identified gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum;
forming a faulty operating condition baseline matrix by operating the gear transmission under a plurality of different faulty operating conditions while, for each of the identified gear mesh frequencies, obtaining a faulty operating condition signal over a segment of time and transforming the obtained faulty operating condition signal into a faulty operating condition time-frequency spectrum, wherein forming the good and faulty operating condition baseline matrices include, for each of the identified gear mesh frequencies, selecting a window of frequency components and a sub-window around the maximum frequency component within the window to form the feature vector, forming the feature vectors into feature data sets to form distinct baselines for different operating modes, compressing the feature data sets, and characterizing a probability distribution function of each respective compressed feature data set; and
then, obtaining a test gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions. - View Dependent Claims (11, 12)
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16. A method for forming a baseline matrix for use in gear transmission condition monitoring comprising the steps of;
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identifying gear mesh frequencies that are remote from interfering frequencies; and
for each of a plurality of different ones of the identified gear mesh frequencies;
obtaining a signal indicative of gear transmission conditions over a segment of time and transforming the obtained signal into a time-frequency spectrum;
selecting a window of frequency components to form a feature vector; and
forming the feature vectors into a feature data sets to form a distinct baseline.- View Dependent Claims (17, 18, 19, 20)
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21. A gear transmission condition monitoring apparatus comprising a processor for:
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identifying gear mesh frequencies that are remote from interfering frequencies;
forming a good operating condition baseline matrix by, for each of the identified gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum;
forming a faulty operating condition baseline matrix by operating the gear transmission under a plurality of different faulty operating conditions while, for each of the identified gear mesh frequencies, obtaining a faulty operating condition signal over a segment of time and transforming the obtained faulty operating condition signal into a faulty operating condition time-frequency spectrum; and
then, obtaining a test gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A gear transmission condition monitoring apparatus comprising a processor for:
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forming a good operating condition baseline matrix by, for each of a plurality of identified gear mesh frequencies, obtaining a good operating condition signal indicative of gear transmission conditions over a segment of time and transforming the obtained good operating condition signal into a good operating condition time-frequency spectrum;
forming a faulty operating condition baseline matrix by operating the gear transmission under a plurality of different faulty operating conditions while, for each of the identified gear mesh frequencies, obtaining a faulty operating condition signal over a segment of time and transforming the obtained faulty operating condition signal into a faulty operating condition time-frequency spectrum, wherein the processor is adapted to form good and faulty operating condition baseline matrices by, for each of the identified gear mesh frequencies, selecting a window of frequency components to form a feature vector, forming the feature vectors into feature data sets to form distinct baselines for different operating modes, compressing the feature data sets, and characterizing a probability distribution function of each respective compressed feature data set; and
then, obtaining a test gear mesh frequency and a test signal over a segment of time, transforming the obtained test signal into a test time-frequency spectrum, and using the test gear mesh frequency, the good operating condition baseline matrix, and the faulty operating condition baseline matrix to examine the test time-frequency spectrum to monitor gear transmission conditions. - View Dependent Claims (28, 29)
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Specification