Waveform acquisition optimization

Patent metadata

Field	Value
Publication number	US-11898994-B2
Application number	US-202217964077-A
Country	US
Kind code	B2
Filing date	Oct 12, 2022
Priority date	Mar 15, 2019
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (F max ) and the number of lines of resolution (N lines ) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.

First claim

What is claimed is:

1. A method implemented by a computer processor for configuring a vibration data collection device to acquire machine vibration data from a machine for use in generating a vibration spectrum having amplitude peaks at a plurality of fault frequencies that are indicative of faults in the machine, wherein the machine includes components that rotate at a turning speed, the method comprising the following steps performed prior to acquiring the machine vibration data using the vibration data collection device:
(a) specifying a number N of harmonics of the turning speed and a number M of harmonics of the plurality of fault frequencies to be included in the vibration spectrum;
(b) calculating N number of turning speed frequencies associated with the N number of harmonics of the turning speed;
(c) calculating M number of fault frequencies associated with the M number of harmonics of the plurality of fault frequencies;
(d) determining a maximum frequency of data collection based at least in part on a highest frequency of the N number of turning speed frequencies and the M number of fault frequencies;
(e) determining a minimum frequency spacing within the N number of turning speed frequencies and the M number of fault frequencies;
(f) based on the maximum frequency and the minimum frequency spacing, determining a number of lines of resolution that will allow identification of all of the amplitude peaks associated with each of the plurality of fault frequencies that are resolvable given limitations of the vibration data collection device; and
(g) configuring the vibration data collection device using the maximum frequency and the number of lines of resolution.

2. The method of claim 1 wherein step (d) further comprises:
(d1) accessing from a memory device a list of discrete maximum frequency values at which the vibration data collection device is operable;
(d2) comparing one or more of the discrete maximum frequency values to the highest frequency of the N number of turning speed frequencies and the M number of fault frequencies;
(d3) based on the comparing of step (d2), determining a largest one of the discrete maximum frequency values that is less than or equal to the highest frequency of the N number of turning speed frequencies and the M number of fault frequencies; and
(d4) setting the maximum frequency to be equal to the largest one of the discrete maximum frequency values determined in step (d3).

3. The method of claim 2 wherein step (d) further comprises:
(d5) accessing the memory device to determine a device maximum frequency value at which the vibration data collection device is operable;
(d6) comparing the device maximum frequency value to the maximum frequency set in step (d4); and
(d7) if the maximum frequency set in step (d4) is greater than the device maximum frequency value, setting the maximum frequency to be equal to the device maximum frequency value.

4. The method of claim 3 wherein, if the maximum frequency is set to be equal to the device maximum frequency value, the method includes:
determining a number of amplitude peaks associated with unresolved fault frequencies based on the maximum frequency and the number of lines of resolution; and
generating a listing of the amplitude peaks associated with unresolved fault frequencies.

5. The method of claim 1 wherein step (f) comprises calculating

N
lines

=

2
×

F

m
⁢
a
⁢
x

Δ
⁢
f

,

where N lines is a calculated number of lines of resolution, F max is the maximum frequency, and Δf is the minimum frequency spacing.

6. The method of claim 5 wherein step (f) further comprises:
(f1) accessing from a memory device a list of discrete number of lines of resolution values at which the vibration data collection device is operable;
(f2) comparing one or more of the discrete number of lines of resolution values to the calculated number of lines of resolution;
(f3) based on the comparing of step (f2), determining a largest one of the discrete number of lines of resolution values that is less than or equal to the calculated number of lines of resolution; and
(f4) setting the number of lines of resolution to be equal to the largest one of the discrete number of lines of resolution values determined in step (f3).

7. The method of claim 6 wherein step (f) further comprises:
(f5) accessing the memory device to determine a device maximum number of lines of resolution value at which the vibration data collection device is operable;
(f6) comparing the device maximum number of lines of resolution value to the number of lines of resolution set in step (f4); and
(f7) if the number of lines of resolution set in step (f4) is greater than the device maximum number of lines of resolution value, setting the number of lines of resolution to be equal to the device maximum number of lines of resolution value.

8. The method of claim 7 wherein, if the number of lines of resolution is set to be equal to the device maximum number of lines of resolution value, the method includes:
determining a number of amplitude peaks associated with unresolved fault frequencies based on the maximum frequency and the number of lines of resolution; and
generating a listing of the amplitude peaks associated with unresolved fault frequencies.

9. The method of claim 1 further comprising determining a minimum waveform data acquisition time, which is a smallest amount of time during which the vibration data collection device can acquire vibration data without increasing a number of amplitude peaks associated with unresolved fault frequencies.

10. The method of claim 9 wherein the minimum waveform data acquisition time is calculated according to

T
acq

=

N
lines

F

m
⁢
a
⁢
x

,

where, T acq is the minimum waveform data acquisition time, N lines the number of lines of resolution, and F max is the maximum frequency.

11. The method of claim 9 wherein the minimum waveform data acquisition time is determined by:
(h) determining a value M lines according to

M
lines

=

N
lines

2

,

where N lines is the

Assignees

• Computational Systems Inc

Inventors

• Hayzen Anthony J
• Walker Jim W

Classifications

• G01N29/46 Primary

  by spectral analysis, e.g. Fourier analysis {or wavelet analysis (spectral signal processing per se G06F17/14)} · CPC title

• G01N29/14 Primary

  using acoustic emission techniques {(echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00)} · CPC title

• G01N2291/014

  Resonance or resonant frequency · CPC title

• G01N2291/0289

  Internal structure, e.g. defects, grain size, texture · CPC title

• G01M13/045 Primary

  Acoustic or vibration analysis · CPC title