Method and apparatus for diagnosing sound source and sound vibration source

• US 6,324,290 B1
• Filed: 10/14/1997
• Issued: 11/27/2001
• Est. Priority Date: 03/08/1994
• Status: Expired due to Fees

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: Murakami, Kazutomo, Kudoh, Hirokazu, Mizuno, Keiichiro
• Primary Examiner(s): Chang, Vivian
• Assistant Examiner(s): Pendleton, Brian T.
• Application Number:
  US08/949,759
• Time in Patent Office: 1,505 Days
• Field of Search: 381/71.1, 381/71.2, 381/71.11, 381/71.12, 381/71.14, 381/71.4, 381/71.7, 381/94.1, 381/95, 381/86, 381/73.1, 381/56, 381/92, 381/313, 704/226, 704/227, 704/234, 704/270, 704/276, 318/128, 367/119, 367/118, 367/121, 367/124, 367/125, 367/126, 367/129
• US Class Current: 381/92
• 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

Abstract

Acoustics or vibrations at a plurality of predetermined positions are respectively detected in the form of analog values, and the detected analog values are respectively converted into digital values. The digital values are subjected to digital filtering by using the digital values and filter factors, and at least one of the filter factors is changed such that the difference between the total sum of the results of digital filtering and a targeted value becomes minimum. The rate of contribution to an evaluation point is computed by using the results of digital filtering within a predetermined time when the difference becomes minimum, and the computed rate of contribution is displayed.

Claims

1. A method of diagnosing a rate of contribution of at least one sound source or at least one vibration source to an evaluation point, comprising the steps of:

detecting sounds at the at least one sound source or vibrations at the at least one vibration source and outputting a signal corresponding to the at least one sound source or the at least one vibration source in the form of a digital value;

performing a digital filtering process by using the digital value, and a filter factor, which is changed during the digital filtering process such that a result of the digital filtering process approaches a targeted value, said filtering process being performed by one of a plurality of filters; and

computing the rate of contribution of the at least one sound source of the at least one vibration source to the evaluation point as a ratio of a mean value or a square mean value of the respective output of said plurality of filters within a predetermined time, to a total sum of the output of all of said plurality of filters within the predetermined time when the difference between the total sum of results of the digital filtering process and the targeted value becomes minimum, and then displaying the computed rate of contribution.

2. The method according to claim 1, wherein the rate of contribution of the at least one sound source or the at least one vibration source to the evaluation point is computed on the basis of a result of digital filtering at a time when a total sum of the values obtained by performing the digital filtering process with respect to each of the plurality of digital values generated by delaying the digital value with respect to one of the at least one sound source or one of the at least one vibration source converges to the targeted value.

3. The method according to claim 1, wherein a digital filtering process processes a plurality of digital values from respective plurality of sound sources or vibration sources such that a total sum of the results of the digital filtering process converges to the targeted value.

12. The method according to claim 1, wherein a signal corresponding to the at least one sound source or at least one vibration source is initially output in the form of an analog value and then converted into the digital value.

4. An apparatus for diagnosing a rate of contribution of at least one sound or at least one vibration source to an evaluation point, comprising:

means including a sensor for detecting sounds or vibrations at a predetermined position in the form of an analog value;

an analog-digital converting circuit for converting the analog value into a digital value;

a plurality of filters, each adapted to perform digital filtering by using a filter factor and a plurality of digital values generated by delaying the digital value;

changing means for changing the filter factor of at least one of the plurality of filters such that a difference between a total sum of results of the digital filtering process and a targeted value becomes minimum; and

a contribution rate computing circuit for computing the rate of contribution of the at least one sound source or the at leat one vibration source to the evaluation point by using an output of each of said plurality of filters within a predetermined time when the difference becomes minimum, wherein said contribution rate computing circuit computes the rate of contribution of each of the at least one sound source or the at least one vibration source to the evaluation point as a ratio of a mean value or a square means value of the respective output of said plurality of filters within the predetermined time, to a total sum of the output of all of said plurality of filters within the predetermined time when the difference becomes minimum.

5. The apparatus according to claim 4, wherein the targeted value is an output of another analog-digital converting circuit for converting into a digital value an analog value detected by a sensor for detecting sounds or vibrations at the evaluation point and outputting a signal in the form of an analog value, or an output of another sensor for detecting sounds or vibrations at the evaluation point and outputting a signal in the form of a digital value.

6. The apparatus according to claim 5, wherein the targeted value is outputted via a band-pass filter for restricting a frequency band for analysis.

7. The apparatus according to claim 6, further comprising a plurality of delay circuits which receive and delay the digital value for compensating for delay due to passage of the targeted value to said band-pass filter.

8. An apparatus for diagnosing a rate of contribution of at least one sound source or at least one vibration source to an evaluation point, comprising:

means including a plurality of sensors each detecting sounds or vibrations at a predetermined position and outputting a signal corresponding to the at least one sound source or the at least one vibration source in the form of a digital value;

a plurality of filters, each adapted to perform digital filtering by using the digital value and a filter factor;

changing means for changing the filter factor of at least one of the plurality of filters such that a difference between a total sum of outputs of said plurality of filters and a targeted value becomes minimum; and

a contribution-rate computing circuit for computing the rate of contribution of the at least one sound source or the at least one vibration source to the evaluation point by using the outputs of said plurality of filters within a predetermined time when the difference becomes minimum, wherein said contribution rate computing circuit computes the rate of contribution of each of the at least one sound source or the at least one vibration source to the evaluation point as a ratio of a mean value or a square mean value of the respective output of said plurality of filters within the predetermined time, to a total sum of the output of all of said plurality of filters within the predetermined time when the difference becomes minimum.

9. The apparatus according to claim 8, wherein the targeted value is an output of another analog-digital converting circuit for converting into digital value an analog value detected by a sensor for detecting sounds or vibrations at the evaluation point and outputting a signal in the form of the analog value.

10. The apparatus according to claim 9, wherein the targeted value is outputted via a band-pass filter for restricting a frequency band for analysis.

11. The apparatus according to claim 10, further comprising a plurality of delay circuits which receive and delay the digital value for compensating for delay due to passage of the targeted value through said band-pass filter.

13. The apparatus according to claim 8, wherein a signal corresponding to the at least one sound source or at least one vibration source is initially output in the form of an analog value and then converted into the digital value.