JPH06167984A - Noise controller - Google Patents

Abstract

PURPOSE:To prevent effect dispersion from being generated by disabling the installation of a speaker for cancellation at an optimum position by outputting the compensating tone of an opposite phase and equal sound pressure in comparison with noise from the speaker. CONSTITUTION:The noise controller equipped with an opposite phase signal generation part 33 for feedback to the formation of the compensating tone is provided with direction change type speakers 1 and 2 in plural directions for outputting the compensating tones and revolving the fixed shafts, microphone 3 for measuring intensity provided with a couple of three sensor microphones installed at both of terminals of bar-shaped parts with fixed lengths respectively perpendicular to three directions so as to catch residual tones, analysis circuit 4 for analyzing the sound pressure distribution of residual tones and the flow of tones, and angle control circuit 5 for controlling the revolutions of fixed shafts by calculating the angles of turning the direction change type speakers 1 and 2 corresponding to the positions or the flow of tones according to the maximum value of the sound pressure distribution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise control device for canceling noise by outputting a compensating sound of noise and anti-phase equal sound pressure from a speaker, and in particular, in the present invention, a canceling speaker cannot be installed at an optimum position. It relates to preventing the occurrence of effect variations.

[0002]

2. Description of the Related Art Conventionally, there have been techniques described below as techniques in such a field. FIG. 4 is a diagram showing a conventional noise control device. The noise control device shown in this figure is provided in the front door for canceling noise in the vehicle interior of the vehicle 200, and canceling speakers 10 and 11 provided in the rear part of the rear seat, and near the ceiling in the vehicle interior. Sensor microphones 12 and 13 that capture residual sound resulting from noise cancellation, power amplifiers 14 and 15 that drive the speakers 10 and 11, respectively, and high-frequency components connected to the power amplifiers 14 and 15 to remove high-frequency components. Low-pass filters 16 and 17, and D / A converters 18 and 19 (Dig connected to the low-pass filters 16 and 17 respectively) for converting a digital signal into an analog signal.
Ital to Analog Converter) and a reference signal corresponding to a noise signal are input, an antiphase signal generation unit 20 that forms a compensation signal of noise and an antiphase / equal pressure and outputs the compensation signal to the D / A converters 18 and 19 is output. And the sensor microphones 12 and 1
Low-pass filters 21 and 22 connected to 3 to prevent generation of a folding signal, and low-pass filters 21 and 2
A / D converters 23 and 24 (Analog to Digital) which are connected to 2 and convert an analog signal into a digital signal and output it as a feedback signal to the anti-phase signal generator 20.
Converter).

Thus, according to the conventional noise control device, the cancel sound is formed in accordance with the change of the noise signal which is the reference signal input to the anti-phase signal generator 20.

[0004]

However, according to the conventional noise control device, the speaker 10 installed in the vehicle is used.
Whether or not 11 and 11 are dedicated to noise or shared audio, the location and direction are fixed by the layout, and the optimum position for the nature of noise, for example, sound pressure distribution and change in sound flow. Even when set to, there is a problem in that the noise effect is sensitive to changes in the noise frequency in a narrow space, so that the canceling effect varies and the effect amount cannot be followed.

Therefore, in view of the above problems, it is an object of the present invention to provide a noise control device capable of following the effect amount even if the property of noise changes and reducing the variation in the effect.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention sets the propagation direction of a cancel sound in order to fully bring out the capability of a vehicle interior speaker (cancellation speaker) whose installation location cannot be changed. Focusing on changing the noise, a noise control device having an anti-phase signal generation unit for forming a compensation sound having an anti-phase / equal pressure with noise, detecting a residual sound with noise canceled, and feeding back to the formation of the compensation sound. In addition, a plurality of direction changing type speakers, an intensity measuring microphone, an analysis circuit and an angle control circuit are provided.

The plurality of direction changing type speakers output the compensation sound and the fixed shaft thereof is rotatable. The intensity measuring microphone has three pairs of sensor microphones provided at both ends of a rod-shaped portion having a constant length that is perpendicular to the three directions.

The analysis circuit analyzes the sound pressure distribution and the sound flow of the residual sound based on the output signal from the intensity measuring microphone. The angle control circuit obtains an angle at which the direction-changing speaker faces the position with respect to the maximum value of the sound pressure distribution, or obtains an angle at which the direction-changing speaker faces in the maximum direction of the sound flow, respectively. It controls the rotation of the fixed shaft.

In the angle control circuit, an angle at which the directional speaker is oriented with respect to a position with respect to a maximum value of the sound pressure distribution and an angle at which the directional speaker is oriented in a maximum direction of the sound flow. The angle at which the direction-changing speaker faces is determined with a certain weight.

[0010]

According to the noise control device of the present invention, the plurality of direction-changing speakers output the compensation sound, and the fixed shaft thereof is rotatable, so that it changes with the change of the noise frequency in a narrow vehicle compartment. Follow the sound pressure distribution. The intensity measuring microphone has three pairs of sensor microphones provided at both ends of a rod-shaped portion having a fixed length that is perpendicular to each other in three directions, and information in the vehicle interior that is made to follow the plurality of direction changing speakers. To collect. The analysis circuit analyzes the sound pressure distribution of the residual sound and the flow of the sound based on the output signal from the intensity measuring microphone, and the angle control circuit analyzes the direction with respect to the position with respect to the maximum value of the sound pressure distribution. By determining the angle that the changeable speaker faces, or by determining the angle that the direction changing speaker faces with respect to the sound flow, and controlling the rotation of the fixed shaft depending on this angle,
It has become possible to reduce the variation in the effect amount that has conventionally been caused by the change in frequency. In the angle control circuit,
The direction-changing speaker faces with a certain weight on the angle at which the direction-changing speaker faces the position with respect to the maximum value of the sound pressure distribution and the angle at which the direction-changing speaker faces the sound flow. By obtaining the angle, it is possible to further suppress the variation in the effect amount.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a noise control device according to an embodiment of the present invention. The noise control device shown in this figure outputs the cancel sound of the opposite phase and equal sound pressure to the noise of the vehicle 200.
Direction changeable speakers 1 and 2 provided on the front door inside and near the rear part of the rear seat and capable of changing the direction around the fixed shaft, and a vehicle interior for capturing the residual sound of noise and cancellation sound Intensity, that is, sound pressure distribution and sound flow in the passenger compartment near the ceiling of the vehicle, and a high-frequency component of an electric signal detected by the intensity-measuring microphone 3 is removed and folded back. A low-pass filter 31 for preventing signal generation, an A / D converter 32 connected to the low-pass filter 31 for converting an analog signal into a digital signal, and a reference signal which is a noise signal is input to the A / D converter. Inversion for forming a compensating sound having an opposite phase and equal sound pressure with noise by using the signal relating to the residual sound from the D converter 32 as a feedback signal The signal generator 33, the D / A converters 35 and 36 for converting the digital signal of the compensation sound by the anti-phase signal generator 33 into an analog signal, and the high frequency components connected to the D / A converters 35 and 36, respectively. And low-pass filters 36 and 37 for removing the noise, and power amplifiers 38 and 3 respectively connected to the low-pass filters 36 and 37 and driving the direction changeable speakers 1 and 2, respectively.
9 and 9 are included.

The anti-phase signal generator 33 includes a DSP (Digi
tal signal processor), and signal processing is performed by an adaptive filter. FIG. 2 is an enlarged view showing a schematic configuration of the intensity measuring microphone 3 of FIG. As shown in the figure, the intensity measuring microphone 3 includes three rod-shaped end portions of a fixed length, which are, for example, the front-rear direction, the up-down direction, and the left-right direction of the vehicle and which face each other in three directions at right angles. Are provided with sensor microphones 3-1 and 3-2, 3-3 and 3-4. The intensity measuring microphone 3 makes it possible to detect the magnitude, direction, and frequency of noise in the passenger compartment.

FIG. 3 is a schematic diagram showing the direction change type loudspeakers 1 and 2 of FIG.
It is a figure explaining the drive of. As shown in the figure, the direction-changing speakers 1 and 2 are provided with a fixed shaft 7 at the rear part thereof so as to match the axes of the speakers, and a fulcrum portion 8 rotatably fixed to the end of the fixed shaft 7. Is provided. In the direction-changing type loudspeakers 1 and 2, the direction of the fixed shaft 7 is changed around the fulcrum portion 8 by the motor described later in the xx and yy directions.

Further, the noise control device is an SI (Sound Inten
sity) method or a similar method to include an analysis circuit 4 for analyzing sound pressure distribution and sound flow. The AI analysis circuit 4 inputs the digital signal from the A / D converter 32, and on the basis of the signal from the intensity measuring microphone 3, the sound pressure distribution regarding the residual sound of the noise in which the cancel sound is superimposed in the vehicle interior, Analyze the sound flow. In the analysis of the sound pressure distribution, the intensity measuring microphone 3 is used.
, The sound pressure distribution is estimated and calculated from the sound pressure difference between the facing microphones 3-1 and 3-2, and the sound flow (vector) is calculated from the time difference detected by the facing microphones 3-1 and 3-2. Estimated to be calculated.

It should be noted that various physical quantities are calculated based on the measured values A
Since the I analysis circuit 4 itself is a well-known technique, its explanation is omitted. An angle control circuit 5 is provided downstream of the SI analysis circuit 4. The angle control circuit 5 determines the direction changeable speakers 1 and 2 at the position where the sound pressure distribution is highest from the positions of the direction changeable speakers 1 and 2 in the vehicle compartment and the sound pressure distribution data obtained by the SI analysis circuit 4. Calculate the angle to orient
The angle at which the directional speakers 1 and 2 are oriented in the maximum direction of sound flow is calculated. Further, the angle obtained from the sound pressure distribution and the angle obtained from the sound flow may be given a certain weight to obtain the angle.

A motor 6 is provided downstream of the angle control circuit, and the motor 6 mechanically drives the fixed shafts of the direction changeable speakers 1 and 2 by a control signal of the angle control circuit 5. Therefore, according to the present embodiment, the control frequency can be expanded in space in response to the change in the frequency of noise in the vehicle interior and the change in the flow of sound, so that optimum canceling sound control can be performed and the amount of silencing effect can be improved. .

[0017]

As described above, according to the present invention, the sound pressure distribution of the residual sound and the sound flow are analyzed based on the output signal from the sensor microphone, and the direction with respect to the position with respect to the maximum value of the sound pressure distribution is analyzed. The angle that the changeable speaker faces is determined, or the angle that the direction changeable speaker faces in the maximum direction of the sound flow is determined and the rotation of the fixed shaft is controlled. It has become possible to reduce the variation in.

[Brief description of drawings]

FIG. 1 is a diagram showing a noise control device according to an embodiment of the present invention.

FIG. 2 is a microphone 3 for measuring intensity shown in FIG.
It is a figure which shows schematic structure of.

FIG. 3 is a diagram illustrating driving of direction changeable speakers 1 and 2 in FIG.

FIG. 4 is a diagram showing a conventional noise control device.

[Explanation of symbols]

 1, 2 ... Direction change type speaker 3 ... Intensity measurement microphone 4 ... AI analysis circuit 5 ... Angle control circuit 6 ... Motor 7 ... Speaker fixed shaft 33 ... Anti-phase signal generation unit 200 ... Vehicle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshitaka Yamato 1-2-2 Gosho-dori, Hyogo-ku, Kobe-shi, Hyogo Within Fujitsu Ten Limited (72) Inventor Masahiro Babasaki 1 Gosho-dori, Hyogo-ku, Hyogo Prefecture 2-28, Fujitsu Ten Limited (72) Inventor Osamu Ishikawa 1-2-2, Gosho-dori, Hyogo-ku, Kobe, Hyogo Prefecture (2-72) Inside Fujitsu Ten Limited (72) Hideki Kitao Gosho, Kobe-shi, Hyogo Prefecture Fujitsu 1-22 FUJITSU TEN CORPORATION

Claims (2)

[Claims] 1. An anti-phase signal generator (33) for forming a compensating sound having an anti-phase / equal sound pressure with respect to noise, detecting a residual sound in which the noise is canceled, and feeding back to the formation of the compensating sound.
A plurality of direction changeable loudspeakers (1, 2) each of which outputs the compensation sound and which can change the direction of generation of a sound wave, and a rod-shaped speaker having a fixed length each of which is perpendicular to three directions. An intensity measuring microphone (3) for capturing the residual sound, and a residual signal by the output signal from the intensity measuring microphone (3). And an analysis circuit (4) for analyzing the sound pressure distribution and sound flow of the sound pressure distribution, and determining the angle at which the direction-changing speaker (1, 2) faces the position with respect to the maximum value of the sound pressure distribution, or The direction change type speaker (1, 2) in the maximum flow direction
A noise control device comprising: an angle control circuit (5) for obtaining an angle to which the fixed shaft faces and controlling the rotation of each fixed shaft. 2. In the angle control circuit (5), the angle at which the direction-changing speaker (1, 2) faces the position with respect to the maximum value of the sound pressure distribution and the maximum direction of the sound flow. The direction changing type speaker (1, 2) is weighted with a certain degree to the angle of the direction changing type speaker (1, 2).
2. The noise control device according to claim 1, wherein the angle at which 2) faces is obtained.