# US 10,482,867 B2 · Active vibration noise control apparatus

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- Number: US 10,482,867 B2
- Document ID: US10482867B2
- Status: Granted
- Kind: B2
- Application number: 15/544,485
- Filed: 2015-03-24
- Published: 2017-12-21
- Granted: 2019-11-19
- Earliest claimed: 2015-03-24
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Atsuyoshi Yano
- Web page: https://patentgrep.com/patent/US10482867B2

## CPC

- G10K 11/17854: {the filter being an adaptive filter}
- G10K 11/17825: {Error signals}
- G10K 11/17883: {the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed}
- G10K 2210/121: Rotating machines, e.g. engines, turbines, motors; Periodic or quasi-periodic signals in general
- G10K 2210/1282: Automobiles
- G10K 2210/129: Vibration, e.g. instead of, or in addition to, acoustic noise
- G10K 2210/3044: Phase shift, e.g. complex envelope processing
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR

## Abstract

There are provided a control signal generation unit 120 that generates a control signal on the basis of a cosine wave signal and a sine wave signal whose frequencies are a control frequency identified according to a vibration noise source, and a correction value update unit that updates a correction value to a value for decreasing signal power of an error signal on the basis of a relationship between increase and decrease of the signal power of the error signal obtained from remaining vibration noise that remains after interference sound that is generated on the basis of the control signal and propagates through a secondary route interferes with vibration noise generated from the vibration noise source and increase and decrease of the correction value used for correction of the control frequency.

## Claims

### Claim 1

An active vibration noise control apparatus comprising:
processing circuitry configured to operate as:
a control signal generation unit that generates a control signal on a basis of a cosine wave signal and a sine wave signal, where the frequencies of the cosine wave signal and sine wave signal are a control frequency identified according to a vibration noise source; and
a correction value update unit that updates a correction value, for correcting a difference between the control frequency and a frequency of vibration noise, to a value for decreasing signal power of an error signal, on a basis of a relationship between increase and decrease of the signal power of the error signal and increase and decrease of the correction value used for correction of the control frequency, wherein
the error signal is obtained from remaining vibration noise that remains after interference sound, that is generated on a basis of the control signal and propagates through a secondary route, interferes with the vibration noise generated from the vibration noise source, and
the relationship between the increase and decrease of the signal power of the error signal and the increase and decrease of the correction value is obtained by partially differentiating the signal power of the error signal with respect to the correction value.

### Claim 2 (depends on 1)

The active vibration noise control apparatus according to claim 1, wherein the correction value update unit determines the relationship between the increase and decrease of the signal power of the error signal and the increase and decrease of the correction value, on a basis of a cosine wave amplitude which is a component of the cosine wave signal of the interference sound, the component being calculated by using a predetermined transfer characteristic of the secondary route, a sine wave amplitude which is another component of the sine wave signal of the interference sound, the another component being calculated by using the transfer characteristic of the secondary route, the cosine wave signal, and the sine wave signal.

### Claim 3 (depends on 1)

The active vibration noise control apparatus according to claim 1, wherein the correction value update unit updates the correction value according to a magnitude of a proportion of change of the signal power of the error signal to change of the correction value, so that a change amount of the correction value is made larger when the proportion of the change of the signal power of the error signal to the change of the correction value is large, and so that the change amount of the correction value is made smaller when the proportion of the change of the signal power of the error signal to the change of the correction value is small.

### Claim 4 (depends on 1)

The active vibration noise control apparatus according to claim 1, wherein the correction value update unit updates the correction value within a predetermined correction range of the control frequency.