INTEGRATED VIBRATION MEASUREMENT AND ANALYSIS SYSTEM

• US 20140067289A1
• Filed: 11/14/2013
• Published: 03/06/2014
• Est. Priority Date: 08/16/2010
• Status: Active Grant

• Current Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Original Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Inventors: Baldwin, Joseph C.
• Granted Patent: US 9,435,684 B2
• Time in Patent Office: Days
• US Class Current: 702/56
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00
• CPC Class Codes: G01M 99/005 Testing of complete machines, e.g. washing-machines or mobile phones testing of machine parts G01M13/00; testing of electric apparatus or components G01R31/50
• CPC Class Codes: G01N 2291/011 Velocity or travel time
• CPC Class Codes: G01N 2291/0258 Structural degradation, e.g. fatigue of composites, ageing of oils
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/449 Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation

Abstract

A vibration data collection system performs an integration or differentiation process on incoming digitized vibration data in real time. The system uses a digital Infinite Impulse Response (IIR) filter running at the input data rate to provide the integration or differentiation function. With this approach, the system reduces hardware complexity and data storage requirements. Also, the system provides the ability to directly integrate or differentiate stored time waveforms without resorting to FFT processing methods.

Claims

1-25. -25. (canceled)

26. A real-time signal conversion apparatus for use in measuring machine characteristics that are indicative of a machine fault condition or a machine performance, the signal conversion apparatus comprising:

a first sensor for sensing a machine characteristic at a first position relative to the machine and generating a first analog signal based on the first position;

a second sensor for sensing a machine characteristic at a second position relative to the machine and generating a second analog signal based on the second position;

one or more analog-to-digital conversion (ADC) circuits for sampling the first and second analog signals to generate a first digital signal based on the first analog signal and a second digital signal based on the second analog signal, wherein the first and second digital signals are indicative of a performance of the machine or a fault condition of the machine;

an integrated circuit component having at least two parallel channels for simultaneously processing the first digital signal in parallel with the second digital signal, the first digital signal in parallel with the first digital signal, or the second digital signal in parallel with the second digital signal, the at least two parallel channels including at least;

a first channel for processing the first digital signal or the second digital signal; and

a second channel for processing the first digital signal or the second digital signal; and

a cross-point switching device operable in one or more settings selected from the group consisting of;

a first setting in which the first digital signal is provided to the first and second channels;

a second setting in which the second digital signal is provided to the first and second channels;

a third setting in which the first digital signal is provided to the first channel and second digital signal is provided to the second channel; and

a fourth setting in which the first digital signal is provided to the second channel and second digital signal is provided to the first channel.

27. The real-time signal conversion apparatus of claim 26 wherein the first digital signal is indicative of a performance of the machine or a fault condition of the machine selected from the group consisting of a looseness, a resonance, a shutdown protection condition, a slow-speed technology characteristic, a PeakVue characteristic, a stress wave, an impact, a bearing condition, a gear condition, an imbalance, a misalignment, a transient condition, a soft foot, an oil whirl, an oil whip, a bent shaft, a rotor bar condition, a motor current condition, a motor phase condition, and a turn-to-turn short circuit condition.

28. The real-time signal conversion apparatus of claim 26 wherein the integrated circuit component is selected from the group consisting of a field programmable gate array (FPGA) and an application specific integrated circuit (ASIC).

29. The real-time signal conversion apparatus of claim 26 wherein the integrated circuit component includes an embedded processor for controlling storage and processing of data associated with the first and second digital signals.

30. The real-time signal conversion apparatus of claim 29 wherein the embedded processor performs one or more vibration analysis functions on the first or second digital signals selected from the group consisting of statistical analysis, waveform analysis, and Fast Fourier Transform (FFT) analysis.

31. The real-time signal conversion apparatus of claim 26 wherein the integrated circuit component is field reconfigurable to switch between different machine vibration data processing techniques selected from the group consisting of slow-speed technology processing, PeakVue processing, triaxial sensor processing, and normal vibration analysis processing.

32. The real-time signal conversion apparatus of claim 26 wherein the first and second analog signals are provided to the one or more ADC circuits with no prior gain amplification, DC removal, anti-aliasing filtration, or high-pass filtration, thereby eliminating a need for calibration of analog circuit components that provide such functions.

33. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include:

a digital high-pass filter for removing direct current (DC) bias components of the first or second digital signals; and

a switch for selectively bypassing the digital high-pass filter for applications in which the DC bias components are needed.

34. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include:

a first integrator for integrating the first or second digital signals;

a first integrator bypass switch for selectively bypassing the first integrator for applications in which a first stage of integration is not needed;

a second integrator in series with the first integrator, the second integrator for integrating the first or second digital signals; and

a second integrator bypass switch for selectively bypassing the second integrator for applications in which a second stage of integration is not needed.

35. The real-time signal conversion apparatus of claim 34 wherein the first digital signal is a first acceleration signal and the second digital signal is a second acceleration signal, and wherein:

the cross-point switching device is operated in the first setting to direct the first acceleration signal to the first channel and to the second channel;

the first integrator bypass switch of the first channel is set to not bypass the first integrator of the first channel, and the second integrator bypass switch of the first channel is set to not bypass the second integrator of the first channel;

the first integrator of the first channel performs a single integration of the first acceleration signal to generate a first velocity signal, and the second integrator of the first channel performs a single integration of the first velocity signal to generate a first displacement signal, resulting in the first displacement signal being output from the first channel;

the first integrator bypass switch of the second channel is set to not bypass the first integrator of the second channel, and the second integrator bypass switch of the second channel is set to bypass the second integrator of the second channel; and

the first integrator of the second channel performs a single integration of the first acceleration signal to generate a first velocity signal, resulting in the first velocity signal being output from the second channel.

36. The real-time signal conversion apparatus of claim 34 wherein the first digital signal is a first acceleration signal and the second digital signal is a second acceleration signal, and wherein:

the cross-point switching device is operated in the first setting to direct the first acceleration signal to the first channel and to the second channel;

the first integrator bypass switch of the first channel is set to bypass the first integrator of the first channel, and the second integrator bypass switch of the first channel is set to bypass the second integrator of the first channel, resulting in the first acceleration signal being output from the first channel;

the first integrator bypass switch of the second channel is set to not bypass the first integrator of the second channel, and the second integrator bypass switch of the second channel is set to bypass the second integrator of the second channel; and

the first integrator of the second channel performs a single integration of the first acceleration signal to generate a first velocity signal, resulting in the first velocity signal being output from the second channel.

37. The real-time signal conversion apparatus of claim 34 wherein the first digital signal is a first acceleration signal and the second digital signal is a second acceleration signal, and wherein:

the cross-point switching device is operated in the first setting to direct the first acceleration signal to the first channel and to the second channel;

the first integrator bypass switch of the first channel is set to not bypass the first integrator of the first channel, and the second integrator bypass switch of the first channel is set to bypass the second integrator of the first channel;

the first integrator of the first channel performs a double integration of the first acceleration signal to generate a first displacement signal, resulting in the first displacement signal being output from the first channel;

the first integrator bypass switch of the second channel is set to not bypass the first integrator of the second channel, and the second integrator bypass switch of the second channel is set to bypass the second integrator of the second channel; and

the first integrator of the second channel performs a single integration of the first acceleration signal to generate a first velocity signal, resulting in the first velocity signal being output from the second channel.

38. The real-time signal conversion apparatus of claim 34 wherein one or both of the first and second integrators comprise a digital infinite impulse response filter running at an input sampling rate of the one or more ADC circuits, thereby reducing data storage requirements.

39. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include an arbitrary resampler for extracting a subset of data points from the first or second digital signals.

40. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include:

a peak detection module for determining peak amplitude values in the first or second digital signals during predetermined sample time periods; and

a switch for selectively bypassing the peak detection module for applications in which all data points in a sample period are needed.

41. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include:

a first integrator for integrating the first or second digital signals;

a first integrator bypass switch for selectively bypassing the first integrator for applications in which a first stage of integration is not needed;

a second integrator in series with the first integrator, the second integrator for integrating the first or second digital signals;

a second integrator bypass switch for selectively bypassing the second integrator for applications in which a second stage of integration is not needed;

a peak detection module for determining peak amplitude values in the first or second digital signals during predetermined sample time periods; and

a peak detection bypass switch for selectively bypassing the peak detection module for applications in which all data points in a sample period are needed.

42. The real-time signal conversion apparatus of claim 41 wherein the first digital signal is a first acceleration signal and the second digital signal is a second acceleration signal, and wherein:

the cross-point switching device is operated in the first setting to direct the first acceleration signal to the first channel and to the second channel;

the first integrator bypass switch of the first channel is set to not bypass the first integrator of the first channel, and the second integrator bypass switch of the first channel is set to not bypass the second integrator of the first channel;

the first integrator of the first channel performs a single integration of the first acceleration signal to generate a first velocity signal, and the second integrator of the first channel performs a single integration of the first velocity signal to generate a first displacement signal;

the first integrator bypass switch of the second channel is set to not bypass the first integrator of the second channel, and the second integrator bypass switch of the second channel is set to not bypass the second integrator of the second channel; and

the first integrator of the second channel performs a single integration of the first acceleration signal to generate a second velocity signal, and the second integrator of the second channel performs a single integration of the second velocity signal to generate a second displacement signal;

the peak detection bypass switch of the first channel is set to not bypass the peak detection module of the first channel, resulting in only peak amplitude values of the first displacement signal during predetermined sample time periods being output from the first channel; and

the peak detection bypass switch of the second channel is set to bypass the peak detection module of the second channel, resulting in all amplitude values of the second displacement signal being output from the second channel.

43. The real-time signal conversion apparatus of claim 26 wherein the first and second channels each include:

an interpolator for adding new data points between existing data points in the first or second digital signals, thereby increasing an effective sample rate of the first or second digital signals; and

a switch for selectively bypassing the interpolator for applications in which an increase in effective sample rate is not needed.

44. The real-time signal conversion apparatus of claim 26 wherein the one or more ADC circuits sample the first and second analog signals at a fixed clock frequency, and all other sample rates are synthesized by decimation and interpolation of the first and second digital signals, thereby eliminating a need for an anti-aliasing filter.

45. The real-time signal conversion apparatus of claim 26 wherein

the first sensor is a vibration sensor for sensing a vibration characteristic of the machine, the first analog signal is an analog vibration signal, and the first digital signal is a digital vibration signal;

the second sensor is a camera for sensing a visual image of the machine, the second analog signal is an analog visual image signal, and the second digital signal is a digital image signal.

46. The real-time signal conversion apparatus of claim 26 wherein the first and second analogs signal are indicative of a fault condition of the machine selected from the group consisting of mechanical imbalance, misalignment, bent shaft, soft foot, looseness, resonance, broken rotor bar, broken gear tooth, bearing defect, oil whirl, oil whip, phase imbalance, and turn-to-turn short circuit.

47. A method for measuring vibration characteristics of a machine that are indicative of a machine fault condition or a machine performance, the method comprising:

(a) sensing vibration of the machine and generating an analog vibration signal based on the sensed vibration;

(b) sampling the analog vibration signal at a fixed sampling rate to generate a first digital vibration signal;

(c) synthesizing other sampling rates based on the fixed sampling rate of the first digital vibration signal, thereby eliminating any need for an anti-aliasing filter;

(d) high-pass filtering the first digital vibration signal to remove direct current (DC) components; and

(e) performing a first mathematical operation on the first digital vibration signal to generate a second digital vibration signal that is indicative of a vibration characteristic of the machine.

48. The method of claim 47 wherein the first mathematical operation is selected from the group consisting of an integration operation and a differentiation operation.

49. The method of claim 47 further comprising:

(f) performing a second mathematical operation on the second digital vibration signal to generate a third digital vibration signal that is indicative of a vibration characteristic of the machine, wherein the second mathematical operation is selected from the group consisting of an integration operation and a differentiation operation.

50. The method of claim 49 wherein step (e) is performed in a first channel of an integrated circuit component and step (f) is performed in a second channel of the integrated circuit component that is parallel to the first channel.

51. The method of claim 50 wherein the integrated circuit component is selected from the group consisting of a field programmable gate array (FPGA) and an application specific integrated circuit (ASIC).

52. The method of claim 49 wherein steps (e) and (f) are performed sequentially in one channel of an integrated circuit component.

53. The method of claim 47 wherein at least steps (d) and (e) are performed sequentially in one channel of an integrated circuit component.

54. The method of claim 47 wherein no gain amplification, DC removal, anti-aliasing filtration, or high-pass filtration is performed between steps (a) and (b), thereby eliminating a need for calibration of analog circuit components that provide such functions.

55. The method of claim 47 wherein the first mathematical operation of step (e) is a double integration operation, the first digital vibration signal is an acceleration signal, and the second digital vibration signal is a displacement signal.

56. The method of claim 47 further comprising, after step (e), resampling the second digital vibration signal to extract a subset of data points therefrom.

57. The method of claim 47 further comprising, after step (e), performing a peak detection function on the second digital vibration signal to determine peak amplitude values during predetermined sample time periods.

58. The method of claim 47 further comprising, after step (e), adding new data points between existing data points in the second digital vibration signal, thereby increasing an effective sample rate of the second digital vibration signal.

59. The method of claim 47 wherein step (e) is performed by one or more digital infinite impulse response filters running at the fixed sampling rate of step (b), thereby reducing data storage requirements.

60. A real-time signal conversion apparatus for use in measuring machine characteristics that are indicative of a machine fault condition or a machine performance, the signal conversion apparatus comprising:

a first sensor for sensing characteristics of the machine and generating a first analog signal;

an analog-to-digital conversion (ADC) circuit for sampling the first analog signal to generate a first and second digital signals based on the first analog signal, wherein the first and second digital signals are each indicative of a different performance of the machine or a fault condition of the machine selected from the group consisting of a looseness, a resonance, a shutdown protection condition, a slow-speed technology characteristic, a PeakVue characteristic, a stress wave, an impact, a bearing condition, a gear condition, an imbalance, a misalignment, a transient condition, a soft foot, an oil whirl, an oil whip, a bent shaft, a rotor bar condition, a motor current condition, a motor phase condition, and a turn-to-turn short circuit condition; and

an integrated circuit component having at least two adaptively controlled parallel channels

for simultaneously processing the first digital signal according to a low pass filter configuration in parallel with processing the second digital signal according to a high pass filter configuration,

for processing the first digital signal according to the low pass filter configuration in parallel with processing the second digital signal according to a band pass filter configuration, or

for processing the first digital signal according to the band pass filter configuration in parallel with processing the first digital signal according to the low pass filter configuration,

the at least two parallel channels including at least;

a first channel for processing the first digital signal or the second digital signal; and

a second channel for processing the first digital signal or the second digital signal.

61. The real-time signal conversion apparatus of claim 60 further comprising the integrated circuit component for determining a peak scalar value for sequential sampling intervals, wherein each sampling interval is a measurement time interval.