Vibration damping device and method for canceling out a vibration at a damping position based on a phase difference

• US 9,075,418 B2
• Filed: 05/17/2012
• Issued: 07/07/2015
• Est. Priority Date: 11/25/2009
• Status: Expired due to Fees

• Current Assignee: Sinfonia Technology Company Limited
• Original Assignee: Sinfonia Technology Company Limited
• Inventors: Tomizaki, Takeshi, Moriya, Hideaki, Ito, Takeo, Muragishi, Yasushi
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Kong, Sze-Hon
• Application Number:
  US13/473,876
• Publication Number:
  US 20120226414A1
• Time in Patent Office: 1,146 Days
• Field of Search: 700/279, 700/280, 381/71.4, 381/71.7, 381/71.12, 701/36, 702/56, 702/191
• 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: F16F 15/005 using electro- or magnetostrictive actuation means generating of mechanical vibrations operating with electrostriction B06B1/06, with magnetostriction B06B1/08; vehicle suspension arrangements characterised by use of piezoelectric elements B60G17/01941; piezoelectric, electrostrictive and magnetostrictive devices per se H10N30/00
• CPC Class Codes: G05D 19/02 characterised by the use of electric means
• CPC Class Codes: G10K 11/17823 Reference signals, e.g. ambient acoustic environment
• 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 11/17855 for improving speed or power requirements
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17879 using both a reference signal and an error signal

Abstract

A damping device includes a calculator calculating a pseudo vibration to cancel a source vibration transmitted from a vibration source to a position to be damped, using an adaptive control algorithm. The canceling vibration is generated according to the pseudo vibration. A vibration detector detects an error vibration remaining at the position. The adaptive control algorithm is adapted by learning to reduce the error vibration. A frequency recognizer recognizes a frequency of the source vibration from a signal related to the vibration source. The frequency of the vibration is used to determine a frequency of the pseudo vibration. A phase difference identifier identifies a phase difference between the error vibration and the canceling vibration according to the pseudo vibration, and a frequency corrector corrects, according to the phase difference, the frequency of the vibration to eliminate the phase difference.

Claims

1. A vibration damping device for canceling out a vibration to be cancelled at a position to be damped, to which a source vibration is transmitted from a vibration generating source, the vibration to be cancelled being cancelled with a canceling vibration, the vibration damping device comprising:

a calculator including an adaptive control algorithm, which has first multipliers and an adder, the first multipliers multiplying a reference wave by an adaptive filter to calculate a pseudo vibration simulating the vibration to be cancelled at the position;

a vibration applying actuator that generates a vibration based on the pseudo vibration, which is transmitted to the position to generate the cancelling vibration at the position;

a vibration detector that detects a remaining vibration remaining as a cancellation error at the position, wherein the adaptive control algorithm is adapted by learning to reduce the remaining vibration;

a frequency recognizer that recognizes a frequency of the vibration to be cancelled at the position based on a signal related to the source vibration generated by the vibration generating source;

a reference wave generator that generates the reference wave of a frequency equal to the frequency recognized by the frequency recognizer, wherein the reference wave comprises a reference sine wave and a reference cosine wave;

a phase difference identifier that detects the remaining vibration, extracts a vibration having a frequency component near the frequency recognized by the frequency recognizer from the remaining vibration with a band-pass filter, identifies a phase of the vibration extracted from the remaining vibration, and identifies a phase difference between the phase of the extracted vibration and a phase of the pseudo vibration;

a frequency corrector that corrects, based on the phase difference, the frequency of the vibration recognized by the frequency recognizer in a direction of eliminating the phase difference, which corrects a frequency of the reference wave generated by the reference wave generator;

an inverse transfer function phase setting section which stores the phase component of an inverse transfer function corresponding to the frequency in advance;

an inverse transfer function amplitude setting section which stores the amplitude component of the inverse transfer function corresponding to the frequency in advance; and

second multipliers that respectively multiply the reference sine and cosine waves incorporating the phase component of the inverse transfer function by the amplitude component of the inverse transfer function, thereby generating reference sine and cosine waves incorporating the inverse transfer function of the phase and the amplitude, wherein the reference sine and cosine waves generated by the second multipliers are multiplied by the adaptive filter by the first multipliers, and the result of the multiplication are added together by the adder, thereby generating the pseudo vibration.

2. The vibration damping device according to claim 1, wherein

when the phase difference identifier identifies the phase difference, the frequency corrector corrects the frequency of the vibration recognized by the frequency recognizer by a correction amount not exceeding an upper limit correction amount.

3. The vibration damping device according to claim 1, wherein

the frequency corrector corrects the frequency of the vibration recognized by the frequency recognizer with an amount of correction corresponding to an amount of shift of the phase difference identified by the phase difference identifier.

4. The vibration damping device according to claim 3, wherein

the frequency corrector corrects the frequency of the vibration recognized by the frequency recognizer when an amount of shift of the phase difference identified by the phase difference identifier is larger than a threshold value, and does not correct the frequency of the vibration recognized by the frequency recognizer when the amount of shift of the phase difference is equal to or smaller than the threshold value.

5. The vibration damping device according to claim 1, wherein

the frequency corrector corrects the frequency of the vibration recognized by the frequency recognizer when an amount of shift of the phase difference identified by the phase difference identifier is larger than a threshold value, and does not correct the frequency of the vibration recognized by the frequency recognizer when the amount of shift of the phase difference is equal to or smaller than the threshold value.

6. A vibration damping method for a vibration damping device for canceling out a vibration to be cancelled, at a position to be damped, to which a source vibration is transmitted from a vibration generating source, the vibration to be cancelled being cancelled with a cancelling vibration, the vibration damping method comprising:

calculating a pseudo vibration simulating the vibration to be canceled at the position based on a reference wave, by using an adaptive control algorithm;

generating a vibration based on the pseudo vibration, which is transmitted to the position to generate the canceling vibration at the position;

detecting a remaining vibration remaining as a cancellation error at the position, wherein the adaptive control algorithm is adapted by learning to reduce the remaining vibration;

recognizing a frequency of the vibration to be canceled at the position based on a signal related to the source vibration generated by the vibration generating source;

generating the reference wave of a frequency equal to the recognized frequency, wherein the reference wave comprises a reference sine wave and a reference cosine wave;

detecting the remaining vibration and extracting a vibration having a frequency component near the frequency recognized by the frequency recognizer from the remaining vibration with a band-pass filter;

identifying a phase of the vibration extracted from the remaining vibration and identifying a phase difference between the phase of the extracted vibration and a phase of the pseudo vibration;

correcting, based on the phase difference, the frequency of the vibration recognized in the recognizing in a direction of eliminating the phase difference, which corrects a frequency of the reference wave generated by the reference wave generator;

storing the phase component of an inverse transfer function corresponding to the frequency in advance; and

storing the amplitude component of the inverse transfer function corresponding to the frequency in advance;

wherein the calculating step includes;

respectively multiplying reference sine and cosine waves incorporating the phase component of the inverse transfer function by the amplitude component of the inverse transfer function, to generate reference sine and cosine waves incorporating the inverse transfer function of the amplitude and the phase;

respectively multiplying the reference sine and cosine waves incorporating the inverse transfer function of the amplitude and the phase, by an adaptive filter; and

adding together the respectively multiplied reference sine and cosine waves incorporating the inverse transfer function of the amplitude and the phase.