Active vibration or noise suppression system

• US 9,390,701 B2
• Filed: 04/05/2013
• Issued: 07/12/2016
• Est. Priority Date: 06/28/2011
• Status: Active Grant

• Current Assignee: Sumitomo Riko Company Limited.
• Original Assignee: Sumitomo Riko Company Limited.
• Inventors: Yasuda, Takayoshi, Ichikawa, Hiroyuki, Goto, Katsuhiro
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Zhu, Qin
• Application Number:
  US13/857,560
• Publication Number:
  US 20130259252A1
• Time in Patent Office: 1,194 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: F16F 15/002 characterised by the control method or circuitry control of mechanical oscillations per se G05D19/00
• CPC Class Codes: G10K 11/16 Methods or devices for protecting against, or for damping, noise or other acoustic waves in general G10K11/36 takes precedence
• CPC Class Codes: G10K 11/17823 Reference signals, e.g. ambient acoustic environment
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17855 for improving speed or power requirements
• 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 2210/3053 Speeding up computation or convergence, or decreasing the computational load
• CPC Class Codes: G10K 2210/3056 Variable gain

Abstract

An active vibration or noise suppression system is provided that achieves fast convergence of vibration or noise. A sine wave control signal y_(n) is constituted by frequency of a vibration or noise source, and an amplitude filter coefficient a_(n) and a phase filter coefficient φ_(n) as an adaptive filter coefficient. The sine wave control signal y_(n) is expressed by a sine wave having an amplitude component and a phase component, and each of an amplitude update term Δa_(n+1) and a phase update term Δφ_(n+1) includes a sine wave or cosine wave term having an amplitude component and a phase component. The phase component of the sine wave control signal y_(n) is multiplied by a coefficient other than 1, or the phase component of the sine wave or cosine wave term of each of the amplitude update term Δa_(n+1) and the phase update term Δφ_(n+1) is multiplied by a coefficient other than 1.

Claims

1. An active vibration or noise suppression system is applied to a vehicle for actively suppressing vibration or noise at an evaluation point by outputting control vibration or control sound, comprising:

an active vibration or noise suppression circuit that generates a sine wave control signal y_(n) constituted by frequency of a vibration or noise source, and an amplitude filter coefficient a_(n) and a phase filter coefficient φ

_(n) as an adaptive filter coefficient;

outputs the control vibration or control sound corresponding to the sine wave control signal y_(n);

detects, at the evaluation point, a residual error signal e_(n) generated by interference between vibration or noise caused by the vibration or noise source and the control vibration or control sound;

calculates an amplitude update term Δ

a_(n+1) to be added to or subtracted from a last updated value of the amplitude filter coefficient a_(n) for update, so as to reduce the residual error signal e_(n); and

calculates a phase update term Δ

φ

_(n+1) to be added to or subtracted from a last updated value of the phase filter coefficient φ

_(n) for update, so as to reduce the residual error signal e_(n),

the sine wave control signal y_(n) is expressed by a sine wave having an amplitude component and a phase component,

each of the amplitude update term Δ

a_(n+1) and the phase update term Δ

φ

_(n+1) contains a sine wave or cosine wave term having an amplitude component and a phase component, and

the phase component of the sine wave control signal y_(n) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ

_(n), or the phase component of the sine wave or cosine wave term of each of the amplitude update term Δ

a_(n+1) and the phase update term Δ

φ

_(n+1) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ

_(n),

wherein the active vibration or noise suppression circuit improves convergence,

wherein the phase component of the sine wave control signal y_(n) is expressed by multiplying a value greater than 1 by the phase filter coefficient φ

_(n), and

wherein the sine wave control signal y_(n) is expressed by Equation (1);

[Equation 1]

y_(n)=a_(n)·

sin(ω

·

t_(n)+q·

φ

_(n)) 

 

(1)

wherein;

y_(n);

sine wave control signal

a_(n);

amplitude filter coefficient

φ

_(n);

phase filter coefficient

ω

;

angular frequency

q;

phase multiplier coefficient (q >

1)

t_(n);

sampling time

(n);

the number of samples (time step).

2. The active vibration or noise suppression system according to claim 1, wherein:

the sine wave or cosine wave term of the amplitude update term Δ

a_(n+1) is a term in Expression (2); and

the sine wave or cosine wave term of the phase update term Δ

φ

_(n+1) is a term in Expression (3);

3. The active vibration or noise suppression system according to claim 2,

wherein the amplitude coefficient a1 and the phase coefficient φ

1 in Expression (2) and the amplitude coefficient a2 and the phase coefficient φ

2 in Expression (3) are coefficients which are independent of a transfer function between the control signal generator and the evaluation point.

4. The active noise vibration or noise suppression system according to claim 3, wherein:

Expression (2) is replaced by Expression (4); and

Expression (3) is replaced by Expression (5);

5. The active vibration or noise suppression system according to claim 2, wherein:

the active vibration or noise suppression system further comprises an estimated transfer function storage for storing an estimate value of a transfer function between the control signal generator and the evaluation point beforehand; and

at least one of the amplitude coefficient a1 and the phase coefficient φ

1 in Expression (2), and at least one of the amplitude coefficient a2 and the phase coefficient φ

2 in Expression (3) are coefficients obtained based on the estimate value of the transfer function.

6. The active vibration or noise suppression system according to claim 5, wherein:

Expression (2) is replaced by Expression (6); and

Expression (3) is replaced by Expression (7);

7. The active vibration or noise suppression system according to claim 2, wherein:

the stability coefficient m is set to a value greater than 1; and

the phase multiplier coefficient q is set to a value greater than the stability coefficient m.

13. The active vibration or noise suppression system according to claim 1,

wherein an initial value φ

₍₀₎ of the phase filter coefficient is set based on a value φ

_(last) of the phase filter coefficient at a time of last convergence.

14. The active vibration or noise suppression system according to claim 13,

wherein the initial value φ

₍₀₎ of the phase filter coefficient is the value φ

_(last) of the phase filter coefficient at the time of last convergence.

15. The active vibration or noise suppression system according to claim 13,

wherein the initial value φ

₍₀₎ of the phase filter coefficient is set based on the value φ

_(last) of the phase filter coefficient at the time of last convergence, frequency f at the time of last convergence, and frequency f at a present time.

16. The active vibration or noise suppression system according to claim 13,

wherein an initial value a₍₀₎ of the amplitude filter coefficient is set based on frequency f at a present time.

17. The active vibration or noise suppression system according to claim 13,

wherein a step size parameter of the amplitude update term ω

a_(n+1) is set based on a value a_(last) of the amplitude filter coefficient at the time of last convergence.

18. The active vibration or noise suppression system according to claim 17, wherein:

the active vibration or noise suppression system is applied to a vehicle having an engine; and

the step size parameter of the amplitude update term ω

a_(n+1) is set to a value which is proportional to a value obtained by dividing the value a_(last) of the amplitude filter coefficient at the time of last convergence by a value trq_(last) of a driving torque variation amount of the engine at the time of last convergence.

19. The active vibration or noise suppression system according to claim 1,

wherein an initial value φ

₍₀₎ of the phase filter coefficient is set within a range which satisfies Inequality (15);

20. The active vibration or noise suppression system according to claim 1, wherein the amplitude filter coefficient is a positive number.

8. An active vibration or noise suppression system is applied to a vehicle for actively suppressing vibration or noise at an evaluation point by outputting control vibration or control sound, comprising:

an active vibration or noise suppression circuit that

generates a sine wave control signal y_(n) constituted by frequency of a vibration or noise source, and an amplitude filter coefficient a_(n) and a phase filter coefficient 100 _(n) as an adaptive filter coefficient;

outputs the control vibration or control sound corresponding to the sine wave control signal y_(n);

detects, at the evaluation point, a residual error signal e_(n) generated by interference between vibration or noise caused by the vibration or noise source and the control vibration or control sound;

calculates an amplitude update term Δ

a_(n) to be added to or subtracted from a last updated value of the amplitude filter coefficient a_(n) for update, so as to reduce the residual error signal e_(n); and

calculates a phase update term Δ

φ

_(n) to be added to or subtracted from a last updated value of the phase filter coefficient φ

_(n) for update, so as to reduce the residual error signal e_(n),

the sine wave control signal y_(n) is expressed by a sine wave having an amplitude component and a phase component,

each of the amplitude update term Δ

a_(n+1) and the phase update term Δ

φ

_(n+1) contains a sine wave or cosine wave term having an amplitude component and a phase component, and

the phase component of the sine wave control signal y_(n) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ

_(n) , or the phase component of the sine wave or cosine wave term of each of the amplitude update term φ

a_(n+1) and the phase update term φ

Δ

_(n+1) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ

_(n),

wherein the active vibration or noise suppression circuit improves convergence,

wherein when the sine wave control signal y_(n) is expressed by Equation (8),

the sine wave or cosine wave term of the amplitude update term Δ

a_(n+1) contains a sine wave term in Expression (9); and

the sine wave or cosine wave term of the phase update term Δ

a_(n+1) contains a cosine wave term in Expression (10);

[Equation 8]

y_(n)=a_(n)·

sin(ω

·

t_(n)=φ

_(n)) 

 

(8)

wherein;

y_(n)sine wave control signal

a_(n));

amplitude filter coefficient

φ

_(n);

phase filter coefficient

ω

;

angular frequency

t_(n);

sampling time

(n);

the number of samples (time step)

9. The active vibration or noise suppression system according to claim 8,

wherein the amplitude coefficient a1 and the phase coefficient φ

1 in Expression (9) and the amplitude coefficient a2 and the phase coefficient φ

2 in Expression (10) are coefficients which are independent of a transfer function between the control signal generator and the evaluation point.

10. The active vibration or noise suppression system according to claim 9, wherein:

Expression (9) is replaced by Expression (11); and

Expression (10) is replaced by Expression (12);

11. The active vibration or noise suppression system according to claim 8, wherein:

the active vibration or noise suppression system further comprises an estimated transfer function storage for storing an estimate value of a transfer function between the control signal generator and the evaluation point beforehand, and

at least one of the amplitude coefficient a1 and the phase coefficient φ

1 in Expression (9), and at least one of the amplitude coefficient a2 and the phase coefficient φ

2 in Expression (10) are coefficients obtained based on the estimate value of the transfer function.

12. The active vibration or noise suppression system according to claim 11, wherein:

Expression (9) is replaced by Expression (13), and

Expression (10) is replaced by Expression (14);

21. An active vibration or noise suppression system for actively suppressing vibration or noise at an evaluation point by outputting control vibration or control sound, comprising:

an active vibration or noise suppression circuit that generates a sine wave control signal y_(n) constituted by frequency of a vibration or noise source, and an amplitude filter coefficient a_(n) and a phase filter coefficient φ

_(n) as an adaptive filter coefficient;

outputs the control signal or control sound corresponding to the sine wave control signal y_(n);

detects a residual error signal e_(n) generated by interference between vibration or noise caused by the vibration or noise source and the control vibration or control sound at the evaluation point;

calculates an amplitude update term Δ

a_(n+1) to be added to or subtracted from a last updated value of the amplitude filter coefficient a_(n) for update, so as to reduce the residual error signal e_(n); and

calculates a phase update term Δ

φ

_(n+1) to be added to or subtracted from a last updated value of the phase filter coefficient φ

_(n) for update, so as to reduce the residual error signal e_(n); and

an initial value φ

₍₀₎ of the phase filter coefficient is set based on a value φ

_(last) of the phase filter coefficient at a time of last convergence,

wherein the active vibration or noise suppression system is applied to a vehicle having an engine,

wherein the active vibration or noise suppression circuit improves convergence, and

wherein a step size parameter of the amplitude update term Δ

a_(n+1) is set to a value which is proportional to a value obtained by dividing the value a_(last) of the amplitude filter coefficient at the time of last convergence by a value trq_(last) of a driving torque variation amount of the engine at the time of last convergence.