Active vibration or noise suppression system

Patent metadata

Field	Value
Publication number	US-9390701-B2
Application number	US-201313857560-A
Country	US
Kind code	B2
Filing date	Apr 5, 2013
Priority date	Jun 28, 2011
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

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.

First claim

What is claimed is:

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 Δa (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 Δφ (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 Δa (n+1) and the phase update term Δφ (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 Δa (n+1) and the phase update term Δφ (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 Δa (n+1) is a term in Expression (2); and
the sine wave or cosine wave term of the phase update term Δφ (n+1) is a term in Expression (3);

[

Expression
⁢

⁢
2

]

a
⁢

⁢

1
·

e

(
n
)

·

sin
⁡

(

ω
·

t

(
n
)

+

ϕ

(
n
)

m

+

ϕ
⁢

⁢
1

)

(
2
)

wherein:
e (n) : residual error signal
a 1 : amplitude coefficient
φ 1 : phase coefficient
m: stability coefficient (m ≧1)

[

Expression
⁢

⁢
3

]

a
⁢

⁢

2
·

e

(
n
)

·

cos
⁡

(

ω
·

t

(
n
)

+

ϕ

(
n
)

m

+

ϕ
⁢

Assignees

• Tokai Rubber Ind Ltd
• Sumitomo Riko Co Ltd

Inventors

• Yasuda Takayoshi
• Ichikawa Hiroyuki
• Goto Katsuhiro

Classifications

• F16F15/002

  characterised by the control method or circuitry (control of mechanical oscillations per se G05D19/00) · CPC title

• G10K11/178

  by electro-acoustically regenerating the original acoustic waves in anti-phase · CPC title

• G10K11/1784

  Physics · mapped topic

• G10K2210/3053

  Speeding up computation or convergence, or decreasing the computational load · CPC title

• G10K11/16 Primary

  Methods or devices for protecting against, or for damping, noise or other acoustic waves in general (G10K11/36 takes precedence) · CPC title