Granted Patent B2

US 10,082,520 · App. 15/074,126 · Granted Sep 25, 2018

Abstract

Claims (82)

1. An apparatus for estimating, using a frequency spectrum weighing function, a rotational frequency of a rotating member, the apparatus comprising:

an accelerometer;

one or more processors; and

one or more storage devices encoded with instructions that, when executed by the one or more processors, cause the apparatus to perform the steps of:

a) calculating, using the one or more processors, a frequency spectrum weighting function;

b) storing, in one or more storage devices, the frequency spectrum weighting function;

c) retrieving, from one or more storage devices, the frequency spectrum weighting function;

d) receiving, from the accelerometer, temporal signals indicative of vibrations, the vibrations sensed by the accelerometer remotely located from the rotating member;

e) transforming, by the one or more processors, the temporal signals indicative of the vibrations to a vibrational frequency spectrum;

f) calculating, by the one or more processors, a weighted vibrational frequency spectrum by taking a product of the vibrational frequency spectrum and the frequency spectrum weighting function;

g) selecting, by the one or more processors, a frequency corresponding to a maximum amplitude of the weighted vibrational frequency spectrum; and

h) identifying, by the one or more processors, the frequency corresponding to the maximum amplitude of the weighted frequency spectrum as the rotational frequency of the rotating member.

2. The apparatus of claim 1 , wherein the one or more storage devices are encoded with instructions that, when executed by the processor, cause the apparatus to perform the steps a-h two or more times so as to estimate two or more rotational frequencies of two or more rotating members, respectively.

3. The apparatus of claim 1 , wherein the accelerometer is coupled to a stationary member of a mechanical system to which the rotating member is coupled.

4. A method of estimating, from vibrations sensed by an accelerometer remotely located from a rotating member, by using a frequency spectrum weighting function, a rotational frequency of the rotating member, the method comprising the steps of:

a) calculating, using the one or more processors, a frequency spectrum weighting function;

b) storing, in one or more storage devices, the frequency spectrum weighting function;

c) retrieving, from the one or more storage devices, the frequency spectrum weighting function;

d) receiving, from the accelerometer, temporal signals indicative of vibrations from the rotating member rotating at the rotational frequency;

e) transforming, by a processor, the temporal signals indicative of the vibrations to a vibrational frequency spectrum;

f) calculating, by the processor, a weighted vibrational frequency spectrum by taking a vector product of vibrational frequency spectrum and the frequency spectrum weighting function;

g) selecting, by a processor, a frequency corresponding to a maximum amplitude of the weighted vibrational frequency spectrum;

h) associating the frequency corresponding to the maximum amplitude of the weighted frequency spectrum with the rotational frequency of the rotating member; and

i) identifying, by the one or more processors, the frequency corresponding to the maximum amplitude of the weighted frequency spectrum as the rotational frequency of the rotating member.

5. The method of claim 4 , wherein the steps a-i are repeated two or more times using two or more different frequency spectrum weighting functions so as to estimate two or more rotational frequencies of two or more rotating members, respectively.

6. An apparatus for generating a frequency spectrum weighting function for use in estimating, using vibrations sensed by an accelerometer remotely located from a rotating member, a rotational frequency of the rotating member, the apparatus comprising:

an accelerometer remotely located from the rotating member, the accelerometer configured to sense vibrations from the rotating member and to estimate:

a rotational frequency value indicative of a rotational frequency of the rotating member; and

a vibrational frequency spectrum corresponding to vibrations propagated to the accelerometer remotely located from the rotating member, the vibrations including vibrations caused by the rotating member rotating at the rotational frequency;

one or more processors; and

one or more storage devices encoded with instructions that, when executed by the one or more processors, cause the apparatus to perform the steps of:

a) receiving, from the one or more storage devices, a set of test vectors, each test vector including:

the rotational frequency value; and

the vibrational frequency spectrum;

b) calculating, using the set of test vectors, a test weighting function;

c) calculating, using the one or more processors, a set of weighted test vectors, each weighted test vector including:

a weighted vibrational frequency spectrum calculated by taking a product of a vibrational frequency spectrum of a corresponding one of the test vectors and the test weighting function; and

a vector score relating an amplitude of the weighted vibrational frequency spectrum corresponding to the rotational frequency of the rotating member to a maximum amplitude of the weighted vibrational frequency spectrum corresponding to frequencies not including the rotational frequency of the rotating member;

d) calculating, using the one or more processors, a set score by summing the vector scores of the set of weighted test vectors; and

e) evaluating, using the one or more processors, an end condition,

wherein, if the end condition is met, then the frequency spectrum weighting function is assigned to the test weighting function that was last calculated;

wherein if the end condition is not met, then the one or more processors performs steps b-e again.

7. The apparatus of claim 6 , wherein calculating the test weighting function comprises:

calculating a gradient of the set score with respect to the test weighting function; and

calculating, based on the calculated gradient, a gradient descent direction.

8. The apparatus of claim 6 , wherein the accelerometer is coupled to a stationary member of a mechanical system to which the rotating member is coupled.

9. The apparatus of claim 6 , wherein the one or more storage devices are further encoded with instructions that, when executed by the one or more processors, cause the device to perform the additional step of:

storing, in the one or more storage devices, the frequency spectrum weighting function corresponding to the rotating number.

10. The apparatus of claim 6 , wherein the one or more storage devices is encoded with instructions that, when executed by the one or more processors, cause the apparatus to perform steps a-e two or more times so as to generate two or more frequency spectrum weighting functions corresponding to two or more rotating members, respectively.

11. The apparatus of claim 6 , wherein the device is further encoded with instructions that, when executed by the one or more processors, cause the device to perform the additional step of:

calculating the set of test vectors.

12. The apparatus of claim 11 , wherein calculating the set of test vectors comprises:

receiving, from the accelerometer, temporal signals indicative of the vibrations, the vibrations sensed by the accelerometer remotely located from the rotating member; and

transforming the temporal signals indicative of the vibrations to the vibrational frequency spectrum.

13. The apparatus of claim 12 , wherein calculating the set of test vectors further comprises:

associating the vibrational frequency spectrum with the rotational frequency of the rotating member.

14. A method of estimating, using vibrations sensed by an accelerometer remotely located from a rotating member, a rotational frequency of the rotating member using a frequency spectrum weighting function, the method comprising the steps of:

a) receiving a set of initial test vectors from one or more processors, each test vector including:

a rotational frequency value indicative of a rotational frequency of the rotating member; and

a vibrational frequency spectrum corresponding to vibrations propagated to the accelerometer remotely located from the rotating member, the vibrations including vibrations caused by the rotating member rotating at the rotational frequency;

b) calculating, using the one or more processors, a test weighting function;

c) calculating, using the one or more processors, a set of weighted test vectors, each weighted test vector including;

a weighted vibrational frequency spectrum calculated by taking a product of vibrational frequency spectrum of a corresponding one of the test vectors and the test weighting function; and

a vector score relating an amplitude of the weighted vibrational frequency spectrum corresponding to the rotational frequency of the rotating member to a maximum amplitude of the weighted vibrational frequency spectrum corresponding to frequencies not including the rotational frequency of the rotating member;

d) calculating, using the one or more processors, a set score by summing the vector scores of the set of weighted test vectors; and

e) evaluating, using the one or more processors, an end condition;

wherein if the end condition is met, then the frequency spectrum weighting function is assigned to the test weighting function that was last calculated,

wherein if the end condition is not met, then the microprocessor performs steps b-e again.

15. The method of claim 14 , wherein calculating a test weighting function comprises:

calculating a gradient of the set score with respect to the test weighting function; and

calculating, based on the calculated gradient, a gradient descent direction.

16. The method of claim 15 , wherein calculating a test weighting function further comprises:

calculating a gradient descent distance.

17. The method of claim 14 , further comprising:

storing, in the one or more storage devices, the frequency spectrum weighting function corresponding to the rotating member.

18. The method of claim 14 , further comprising:

calculating the set of test vectors.

19. The method of claim 18 , wherein calculating the set of test vectors comprises:

receiving, from the accelerometer, temporal signals indicative of the vibrations, the vibrations sensed by the accelerometer remotely located from the rotating member; and

transforming the temporal signals indicative of the vibrations to the vibrational frequency spectrum.

20. The method of claim 19 , wherein calculating the set of test vectors further comprises:

associating the vibrational frequency spectrum with rotational frequency of the rotating member.

Assignments (9)