Vibration analysis method
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorMotoshi Shitanda
Life of this patent
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Abstract
A vibration analysis method for detecting abnormalities by analyzing a vibration waveform. The method includes the steps of, in a plurality of observation time points {t.sub.j } composed of a number n of specified time points t.sub.j (j=1 to n) counted from a start time point t.sub.0, detecting displacements of a vibration wave f.sub.j (j=1 to n) at the individual time points of the plurality of observation time points, and comparing points in an n-dimensional space composed of the displacements, detected at the individual observation time points, with points in the n-dimensional space of a vibration waveform that are designated as being normal.
Claims14
A vibration analysis method for detecting abnormalities by analyzing a vibration waveform, said method comprising the steps of:
- detecting displacements of a vibration waveform f.sub.j (j=1 to n) at a set of observation time points {t.sub.j }, wherein the set of observation time points {t.sub.j } are of a specified number n wherein t.sub.j (j=1 to n) with a start time point of t.sub.0 ;
- calculating .alpha. which is a characteristic quantity of the vibration waveform by substituting .psi.(t), which is a function of time t and is descriptive of a specified phenomena, into a following equation with .xi..sub.+, .xi..sub.0, and .xi..sub.- being values such that .xi..sub.+ +.xi..sub.0 +.xi..sub.- =0:
- ##EQU10## where .psi.(t.sub.j) is a function of time t.sub.j ;
- limiting an allowable range in the n-dimensional space based upon .alpha.;
- comparing points in an n-dimensional space of the displacements detected at the set of observation time points at said detecting step with points in the n-dimensional space of a vibration waveform that is designated as being normal;
- and
- determining whether points in the n-dimensional space compared at said comparing step are abnormal, wherein a point is determined to be abnormal when the comparison falls outside the allowable range.
A vibration analysis method for detecting abnormalities by analyzing a vibration waveform, said method comprising the steps of:
- detecting displacements of a vibration waveform f.sub.j (j=1 to n) at a set of observation time points {t.sub.j }, wherein the set of observation time points {t.sub.j } are of a specified number n wherein t.sub.j (j=1 to n) with a start time point of t.sub.0 ;
- calculating .beta. which is a characteristic quantity of the vibration waveform by substituting .psi.(t), which is a function of time t and is descriptive of a specified phenomena, into a following equation with .xi..sub.+, .xi..sub.0, and .xi..sub.- being values such that .xi..sub.+ +.xi..sub.0 +.xi..sub.- =0:
- ##EQU12## where .psi.(t.sub.j) is a function of time t.sub.j ;
- limiting an allowable range in the n-dimensional space based upon .beta.;
- comparing points in an n-dimensional space of the displacements detected at the set of observation time points at said detecting step with points in the n-dimensional space of a vibration waveform that is designated as being normal;
- and
- determining whether points in the n-dimensional space compared at said comparing step are abnormal, wherein a point is determined to be abnormal when the comparison falls outside the allowable range.
Dependencies are inferred from the claim text.