Power efficient machine diagnostic monitoring using multiple vibration sensor wireless configuration

• US 10,551,243 B2
• Filed: 11/28/2016
• Issued: 02/04/2020
• Est. Priority Date: 11/28/2016
• Status: Active Grant

• Current Assignee: Acoem France
• Original Assignee: Acoem France
• Inventors: Wascat, Bertrand, Mazoyer, Thierry, Labeyrie, Patrick, Lavaure, Guillaume, Poizat, Philippe
• Primary Examiner(s): Gray, David M.
• Assistant Examiner(s): Evans, Geoffrey T
• Application Number:
  US15/361,980
• Publication Number:
  US 20180149516A1
• Time in Patent Office: 1,163 Days
• CPC Class Codes: G01H 1/00 Measuring characteristics of vibrations in solids by using direct conduction to the detector G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 3/005 Circuits arrangements for indicating a predetermined temperature fire detection G08B17/00
• CPC Class Codes: G01M 1/28 with special adaptations for determining imbalance of the body in situ, e.g. of vehicle wheels
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01M 15/12 by monitoring vibrations
• CPC Class Codes: G05B 23/0221 Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods
• CPC Class Codes: G08C 17/00 Arrangements for transmitting signals characterised by the use of a wireless electrical link
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: H04W 4/38 for collecting sensor information
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless monitoring unit performs condition monitoring associated with a test point location of a host machine. The unit includes a high performance vibration sensor useful for monitoring the host machine for fault conditions and the like. The unit includes a second vibration sensor that has poorer metrological performance, but draws a comparatively insignificant amount of power from the battery. The second sensor takes a vibration measure periodically, which measure is processed to evaluate whether the machine is in a state eligible to undergo a health assessment. Diagnostic monitoring using the high performance vibration sensor is enabled only when the host machine it is in the eligible state. A low power temperature sensor provides additional data for guarding against a false trigger, in effect allowing the processor to distinguish against vibration from another machine propagating to the host machine causing the host machine to vibrate while the host machine is not running.

Claims

1. A wireless monitoring unit that performs condition monitoring associated with a test point location of a host machine, comprising:

a first sensor that is a vibration sensor;

a second sensor, different from the first sensor, that is a low power, low performance vibration sensor; and

a processor configured to control activity of the first sensor and the second sensor, so that the first sensor is activated to collect vibration data only during times for which the processor has determined, using vibration data collected by the second sensor, that the host machine is in a state eligible for undergoing a health assessment; and

wherein the processor is configured to perform condition monitoring and automatic diagnosis associated with the first test point location for a health assessment of the host machine using vibration data collected by the first sensor; and

wherein the processor is configured to perform;

sampling the second sensor to obtain a second set of vibration data;

analyzing the second set of vibration data to evaluate whether the host machine is in said eligible state;

repeating said sampling and analyzing periodically;

activating the first sensor to collect vibration data only during times for which said analyzing finds the host machine to be in said eligible state;

performing said condition monitoring using a first set of vibration data collected by the first sensor; and

repeating said activating and said performing less frequently than said repeating of said sampling and analyzing.

2. The wireless monitoring unit of claim 1, wherein the processor is further configured to calibrate the second sensor using vibration data collected by the second sensor and vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor.

3. The wireless monitoring unit of claim 1, wherein the processor is further configured to perform transmitting an indication that the host machine is running to a second wireless monitoring unit installed at a second test point of the host machine.

4. The wireless monitoring unit of claim 3, wherein the second wireless monitoring unit comprises:

a vibration sensor; and

a processor configured to perform condition monitoring in response to the second wireless monitoring unit receiving the indication that the host machine is running.

5. The wireless monitoring unit of claim 3, wherein said transmitting is performed for each repetition of said analyzing for which the processor finds that the host machine is running.

6. The wireless monitoring unit of claim 3, wherein said transmitting is performed for each n-th repetition of said analyzing for which the processor finds that the host machine is running, n being an integer greater than one.

7. The wireless monitoring unit of claim 1, wherein there is no vibration data collected by the second sensor that is used by the processor to evaluate any fault condition, any alarm condition, or any other defect condition of the host machine.

8. The wireless monitoring unit of claim 1, wherein the processor is further configured to perform:

calculating a calibration factor using vibration data collected by the second sensor and vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor; and

adjusting a vibration measure derived from vibration data obtained with the second sensor using the calibration factor.

9. The wireless monitoring unit of claim 8,

wherein the calibration factor is an established calibration factor, and the processor is further configured to perform:

calculating a potential calibration factor using a current set of vibration data collected by the second sensor and a current set of vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor, and

updating the established calibration factor to be the potential calibration factor whenever the potential calibration factor deviates from the established calibration factor by at least a predetermined tolerance.

10. The wireless monitoring unit of claim 8,

wherein the calibration factor is a ratio of a first value and a second value,

in which the first value is a mean value of an overall velocity on a prescribed frequency bandwidth computed for the vibration data collected by the first sensor, and

in which the second value is a mean value of an overall velocity on a prescribed frequency bandwidth computed for the vibration data collected by the second sensor.

11. The wireless monitoring unit of claim 1, further comprising:

a first communication module configured for wireless communication;

non-volatile memory having a capacity for storing at least one set of measurement data collected for performing condition monitoring associated with the first test point location as part of the health assessment; and

a battery; and

wherein the health assessment of the host machine encompasses condition monitoring associated with one or more test points of the host machine;

wherein the first sensor detects vibration in multiple axes; and

wherein the second sensor has a power requirement of less than 0.1 .mu.Ah for a 5 second measurement sample of vibration data.

12. The wireless monitoring unit of claim 11, further comprising a near field communication module configured for wireless communication with a near field communication enabled device within a near field communication range using a near field communication protocol.

13. The wireless monitoring unit of claim 1, wherein the second vibration sensor has technical specification ratings which do not meet metrological requirements for vibration measurements used to perform condition monitoring and diagnosis of the host machine;

and

wherein the processor is configured to calibrate the second vibration sensor using vibration data collected by the second sensor and vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor.

14. The wireless monitoring unit of claim 1, further comprising a temperature sensor, and wherein the processor is further configured so that said analyzing includes evaluating data collected by the temperature sensor to attribute whether vibration sensed by the second sensor is due to the host machine running, as distinguished from being due to vibration from another machine propagating to the host machine causing the host machine to vibrate while the host machine is not running;

and

wherein said processor is configured to determine that the host machine is not running when the processor determines that a temperature deviation measure, obtained over time with the temperature sensor, does not exceed a temperature deviation threshold, even though vibration sensed by the second sensor is indicative to the processor of the machine running.

15. The wireless monitoring unit of claim 1, further comprising a temperature sensor, and wherein the processor is further configured so that said analyzing includes evaluating data collected by the temperature sensor to attribute whether vibration sensed by the second sensor is due to the host machine running, as distinguished from being due to vibration from another machine propagating to the host machine causing the host machine to vibrate while the host machine is not running;

and

wherein said processor is configured to determine that the host machine is not running when the processor determines that a temperature measure, obtained with the temperature sensor, does not trigger a temperature threshold, even though vibration sensed by the second sensor is indicative to the processor of the machine running.

16. A wireless monitoring unit that performs condition monitoring associated with a test point location of a host machine, comprising:

a first sensor that is a vibration sensor;

a second sensor, different from the first sensor, that is a low power, low performance vibration sensor; and

a processor configured to control activity of the first sensor and the second sensor, so that the first sensor is activated to collect vibration data only during times for which the processor has determined, using vibration data collected by the second sensor, that the host machine is in a state eligible for undergoing a health assessment; and

wherein the processor is configured to perform condition monitoring and automatic diagnosis associated with the first test point location for a health assessment of the host machine using vibration data collected by the first sensor; and

further comprising a temperature sensor, and wherein the processor is further configured so that said analyzing includes evaluating data collected by the temperature sensor to attribute whether vibration sensed by the second sensor is due to the host machine running, as distinguished from being due to vibration from another machine propagating to the host machine causing the host machine to vibrate while the host machine is not running.

17. The wireless monitoring unit of claim 16, wherein said processor is configured to determine that the host machine is not running when the processor determines that a temperature deviation measure, obtained over time with the temperature sensor, does not exceed a temperature deviation threshold, even though vibration sensed by the second sensor is indicative to the processor of the machine running.

18. The wireless monitoring unit of claim 16, wherein said processor is configured to determine that the host machine is not running when the processor determines that a temperature measure, obtained with the temperature sensor, does not trigger a temperature threshold, even though vibration sensed by the second sensor is indicative to the processor of the machine running.

19. A wireless monitoring unit that performs condition monitoring associated with a test point location of a host machine, comprising:

a first sensor that is a vibration sensor;

a second sensor, different from the first sensor, that is a low power, low performance vibration sensor; and

a processor configured to control activity of the first sensor and the second sensor, so that the first sensor is activated to collect vibration data only during times for which the processor has determined, using vibration data collected by the second sensor, that the host machine is in a state eligible for undergoing a health assessment;

wherein the processor is configured to perform condition monitoring and automatic diagnosis associated with the first test point location for a health assessment of the host machine using vibration data collected by the first sensor;

wherein the processor is further configured to perform;

calculating a calibration factor using vibration data collected by the second sensor and vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor; and

adjusting a vibration measure derived from vibration data obtained with the second sensor using the calibration factor; and

wherein the calibration factor is an established calibration factor, and the processor is further configured to perform;

calculating a potential calibration factor using a current set of vibration data collected by the second sensor and a current set of vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor, and

updating the established calibration factor to be the potential calibration factor whenever the potential calibration factor deviates from the established calibration factor by at least a predetermined tolerance.

20. A wireless monitoring unit that performs condition monitoring associated with a test point location of a host machine, comprising:

a first sensor that is a vibration sensor;

a second sensor, different from the first sensor, that is a low power, low performance vibration sensor; and

a processor configured to control activity of the first sensor and the second sensor, so that the first sensor is activated to collect vibration data only during times for which the processor has determined, using vibration data collected by the second sensor, that the host machine is in a state eligible for undergoing a health assessment;

wherein the processor is configured to perform condition monitoring and automatic diagnosis associated with the first test point location for a health assessment of the host machine using vibration data collected by the first sensor;

wherein the processor is further configured to perform;

calculating a calibration factor using vibration data collected by the second sensor and vibration data collected by the first sensor that corresponds in time with the vibration data collected by the second sensor; and

adjusting a vibration measure derived from vibration data obtained with the second sensor using the calibration factor; and

wherein the calibration factor is a ratio of a first value and a second value,

in which the first value is a mean value of an overall velocity on a prescribed frequency bandwidth computed for the vibration data collected by the first sensor, and

in which the second value is a mean value of an overall velocity on a prescribed frequency bandwidth computed for the vibration data collected by the second sensor.