Methods and systems for measuring performance of a noise cancellation system

• US 8,340,318 B2
• Filed: 12/28/2006
• Issued: 12/25/2012
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated, Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Original Assignee: Caterpillar Incorporated, Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Inventors: Copley, David C., Faber, Benjamin Mahonri, Sommerfeldt, Scott D.
• Primary Examiner(s): Mei, Xu
• Assistant Examiner(s): Kim, Paul
• Application Number:
  US11/646,401
• Publication Number:
  US 20080162072A1
• Time in Patent Office: 2,189 Days
• Field of Search: 381/94.1, 381/71.8, 381/71.11, 381/13, 381/71.1, 381/73.1, 381/94.7, 702/124, 375/227, 375/296, 375/346, 455/296, 455/310
• US Class Current: 381/94.1
• CPC Class Codes: G10K 11/17815 between the reference signals and the error signals, i.e. primary path
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17825 Error signals
• CPC Class Codes: G10K 11/17833 by using a self-diagnostic function or a malfunction prevention function, e.g. detecting abnormal output levels
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17883 the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed
• CPC Class Codes: G10K 2210/128 Vehicles
• CPC Class Codes: G10K 2210/503 Diagnostics; Stability; Alarms; Failsafe

Abstract

A method for measuring performance of a noise cancellation system that is operable to cancel noise is provided. The method includes generating a first model of a target noise. The first model represents the target noise in a form that is received at a location remote from a noise source of the target noise and within a defined environment. The method also includes generating a second model of a cancellation noise. The cancellation noise is configured to at least partially cancel the target noise when combined with the target noise. The second model represents the cancellation noise in a form that is received at the location. The method also includes determining, using the first model and the second model, a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined. The method also includes transmitting the determined cancellation error value to a module operable to monitor a performance level of the noise cancellation system.

Claims

1. A method for measuring performance of a noise cancellation system operable to cancel noise, comprising:

generating a first model of a target noise, the first model representing the target noise received at a location remote from a noise source of the target noise and within a defined environment, wherein the environment includes an aberrant noise and the first model substantially excludes said aberrant noise;

generating a second model of a cancellation noise configured, when combined with the target noise, to at least partially cancel the target noise, the second model representing the cancellation noise in a form that is received at the location;

using the first model and the second model, determining a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined; and

transmitting the cancellation error value to a module operable to monitor a performance level of the noise cancellation system.

2. The method of claim 1, wherein generating the first model comprises:

estimating the target noise detected at the location using a simulation of a sound path traveled by the target noise between the noise source and the location.

3. The method of claim 1, and further comprising receiving a cancellation noise signal directly from a source operable to generate the cancellation noise signal, wherein the second model is generated using the directly received cancellation noise signal.

4. The method of claim 1, further comprising:

monitoring a performance measure of the noise cancellation system based on the cancellation error value; and

initiating a remedial measure if the performance measure is below a predetermined performance standard.

5. The method of claim 4, wherein initiating a remedial measure comprises deactivating the noise cancellation system.

6. The method of claim 5, wherein deactivating the noise cancellation system comprises gradually deactivating the noise cancellation system over a predetermined period of time.

7. The method of claim 1, wherein the noise cancellation system further comprises an adaptive adjustment unit operable to monitor a noise cancellation performance of the noise cancellation unit and, based on the monitoring, adjust at least one characteristic of a next cancellation noise signal generated by a source of the cancellation noise signal, and further comprising:

monitoring the noise cancellation performance of the noise cancellation unit; and

deactivating the adaptive adjustment unit without deactivating the entire noise cancellation system.

8. The method of claim 1, wherein the location is the position of a noise sensor located in a compartment for occupants of a vehicle.

9. A system for measuring performance of a noise cancellation system operable to cancel noise, comprising:

a computer having a microprocessor and a computer-readable medium coupled to the microprocessor; and

a program stored in the computer-readable medium, the program, when executed by the microprocessor, operable to;

generate a first model of a target noise, the first model representing the target noise received at a location remote from a noise source of the target noise and within a defined environment, wherein the environment includes an aberrant noise and the first model substantially excludes said aberrant noise;

generate a second model of a cancellation noise configured, when combined with the target noise, to at least partially cancel the target noise, the second model representing the cancellation noise in a form that is received at the location;

using the first model and the second model, determining a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined; and

initiate a transmission of the cancellation error value to a module operable to monitor a performance level of the noise cancellation system.

10. The system of claim 9, wherein the program is operable to generate the first model by estimating the target noise detected at the location using a simulation of a sound path traveled by the target noise between the noise source and the location.

11. The system of claim 9, wherein the program is further operable to receive the cancellation noise signal directly from a source operable to generate the cancellation noise signal.

12. The system of claim 9, wherein the program is further operable to monitor a performance measure of the noise cancellation system based on the cancellation error value, and initiate a remedial measure if the performance measure is below a predetermined performance standard.

13. The system of claim 12, wherein the remedial measure includes deactivating the noise cancellation system.

14. The system of claim 12, wherein the remedial measure includes gradually deactivating the noise cancellation system over a predetermined period of time.

15. The system of claim 12, wherein the noise cancellation system further comprises an adaptive adjustment unit operable to monitor a noise cancellation performance of the noise cancellation unit and, based on the monitoring, adjust at least one characteristic of a next cancellation noise signal generated by a source of the cancellation noise signal, and wherein the program is further operable to:

monitor the noise cancellation performance of the noise cancellation unit; and

deactivate the adaptive adjustment unit without deactivating the entire noise cancellation system.

16. The system of claim 9, wherein the location coincides with the position of a noise sensor located in a compartment for occupants of a vehicle.

17. A method for measuring performance of a noise cancellation system operable to cancel noise, comprising:

receiving a target noise signal indicative of a target noise generated by a noise source within a vehicle, the vehicle having an engine system;

receiving a cancellation noise signal indicative of a cancellation noise that is operable to at least partially cancel the target noise;

inputting the target noise signal into a vehicle system model operable to generate a first model noise signal, the first model noise signal representing the target noise as detected at a sound sensor within a compartment for occupants of the vehicle, the vehicle system model representing a sound path traveled by the target noise extending from the noise source to the sound sensor;

inputting the cancellation noise signal into a path model operable to generate a second model noise signal, the second model noise signal representing the cancellation noise as detected at the sound sensor, the path model representing a signal path between a cancellation noise source and the sound sensor;

calculating a cancellation error value by combining the first model noise signal and the second model noise signal, the cancellation error value representing a difference between the first model noise signal and the second model noise signal, the difference indicative of only the portion of the target noise that is not cancelled by the cancellation noise; and

transmitting the cancellation error value to a module operable to monitor a performance level of the noise cancellation system.

18. The method of claim 17, wherein the target noise signal is received from a sensor communicatively coupled to the engine system to detect the rotation of a flywheel of the engine system.

19. The method of claim 17, wherein the vehicle system model estimates the target noise as detected within the compartment substantially excluding aberrant noise.

20. A method for measuring performance of a noise cancellation system operable to cancel noise, comprising:

generating a first model of a target noise, the first model representing the target noise received at a location remote from a noise source of the target noise within a defined environment;

generating a second model of a cancellation noise configured, when combined with the target noise, to at least partially cancel the target noise, the second model representing the cancellation noise in a form that is received at the location;

using the first model and the second model, determining a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined;

transmitting the cancellation error value to a module operable to monitor a performance level of the noise cancellation system;

monitoring a performance measure of the noise cancellation system based on the cancellation error value; and

initiating a remedial measure if the performance measure is below a predetermined performance standard.

21. A system for measuring performance of a noise cancellation system operable to cancel noise, comprising:

a computer having a microprocessor and a computer-readable medium coupled to the microprocessor; and

a program stored in the computer-readable medium, the program, when executed by the microprocessor, operable to;

generate a first model of a target noise, the first model representing the target noise received at a location remote from a noise source of the target noise within a defined environment;

generate a second model of a cancellation noise configured, when combined with the target noise, to at least partially cancel the target noise, the second model representing the cancellation noise in a form that is received at the location;

using the first model and the second model, determine a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined;

initiate a transmission of the cancellation error value to a module operable to monitor a performance level of the noise cancellation system;

monitor a performance measure of the noise cancellation system based on the cancellation error value; and

initiate a remedial measure if the performance measure is below a predetermined performance standard.