Method and apparatus for monitoring and analyzing vibrations in rotary machines
First Claim
1. A method of monitoring vibration amplitude and frequency in a rotary machine, comprising:
- receiving measurements of vibration amplitude and rotation speed of the machine from at least one sensor;
recording as a data point each amplitude measurement as a function of vibration frequency and rotational speed;
storing a plurality of different amplitude thresholds each representing a noise floor for a respective one of a first set of sub-ranges of vibration frequency and rotational speed,wherein each sub-range includes a sub-range of speeds and a sub-range of frequencies,wherein the different amplitude thresholds are set in a training process using training data points comprising vibration data from a run of the rotary machine deemed to be normal, andwherein the different amplitude thresholds are set by fitting an amplitude distribution to the training data points in each sub-range of vibration frequency and rotational speed;
comparing each amplitude measurement to the amplitude threshold for a corresponding sub-range of vibration frequency and rotational speed for the data points within which the amplitude measurement falls;
determining the amplitude measurement to represent noise if it falls below the amplitude threshold and as significant spectral content if it is above the amplitude threshold;
using the amplitude measurement determined to be significant spectral content, assessing abnormalities of at least a component of the rotary machine; and
when an abnormality is assessed, generating a signal configured to indicate the abnormality of at least a component of the rotary machine.
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Accused Products
Abstract
Vibration amplitudes are recorded as a function of rotation speed and of frequency and the data is analyzed to estimate a noise floor amplitude threshold for each of a plurality of different speed and frequency sub-ranges. On the basis of training data known to be normal speed-frequency areas which contain significant spectral content in normal operation are deemed “known significant spectral content”, so that during monitoring of new data points which correspond to significant vibration energy at speeds and frequencies different from the known significant spectral content can be deemed “novel significant spectral content” and form the basis for an alert. The estimation of the noise floor is based on a probabilistic analysis of the data in each speed-frequency area and from this analysis an extreme value distribution expressing the probability that any given sample is noise is obtained.
14 Citations
14 Claims
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1. A method of monitoring vibration amplitude and frequency in a rotary machine, comprising:
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receiving measurements of vibration amplitude and rotation speed of the machine from at least one sensor; recording as a data point each amplitude measurement as a function of vibration frequency and rotational speed; storing a plurality of different amplitude thresholds each representing a noise floor for a respective one of a first set of sub-ranges of vibration frequency and rotational speed, wherein each sub-range includes a sub-range of speeds and a sub-range of frequencies, wherein the different amplitude thresholds are set in a training process using training data points comprising vibration data from a run of the rotary machine deemed to be normal, and wherein the different amplitude thresholds are set by fitting an amplitude distribution to the training data points in each sub-range of vibration frequency and rotational speed; comparing each amplitude measurement to the amplitude threshold for a corresponding sub-range of vibration frequency and rotational speed for the data points within which the amplitude measurement falls; determining the amplitude measurement to represent noise if it falls below the amplitude threshold and as significant spectral content if it is above the amplitude threshold; using the amplitude measurement determined to be significant spectral content, assessing abnormalities of at least a component of the rotary machine; and when an abnormality is assessed, generating a signal configured to indicate the abnormality of at least a component of the rotary machine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of monitoring vibration amplitude and frequency in a rotary machine, comprising the steps of:
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receiving measurements of the vibration amplitude and the rotation speed of the machine from a run of the rotary machine from at least one sensor; recording as a data point each amplitude measurement as a function of vibration frequency and rotational speed; comparing each amplitude measurement to an amplitude threshold for a sub-range of vibration frequency and rotational speed for the data points within which the amplitude measurement falls, wherein the amplitude threshold represents a noise floor for the sub-range of vibration frequency and rotational speed, wherein the sub-range includes a sub-range of speeds and a sub-range of frequencies, wherein the amplitude threshold is set in a training process using training data points comprising vibration data from a run of the rotary machine deemed to be normal, and wherein the amplitude threshold is set by fitting an amplitude distribution to the training data points in the sub-range of vibration frequency and rotational speed; determining a set of sub-ranges in which the amplitude measurement is above the amplitude threshold; defining sub-ranges from the set of sub-ranges as known significant spectral content if more than a preset number of data points have an amplitude measurement above the amplitude threshold; defining sub-ranges from the set of sub-ranges as novel significant spectral content if there is less than a preset number of data points having an amplitude measurement above the amplitude threshold; using the sub-ranges defined to be novel significant spectral content, assessing abnormalities of at least a component of the rotary machine; and when an abnormality is assessed, generating a signal configured to indicate the abnormality of at least a component of the rotary machine.
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Specification