JPH0652852B2 - Vehicle sound field control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention detects a propagation change of a sound generated by an on-vehicle audio device when the sound is propagated. The present invention relates to a vehicle sound field control device that controls the state of sound.

"Prior Art" FIG. 5 is a block diagram showing a configuration example of a conventional vehicle sound field control device, wherein 1 is a vehicle interior of the vehicle, 2 is a voice-range microphone provided near the listener in the vehicle 1, Reference numeral 3 is a vehicle-mounted audio device, 4 is a controller that adjusts the sound level of the output signal of the vehicle-mounted audio device 3, 5 is an amplifier that amplifies the output signal of the controller 4, and 6 is an output signal of the amplifier 5. It is a speaker to be replaced.

In such a configuration, when the noise in the vehicle interior 1 increases while the vehicle is traveling, the noise is input to the microphone 2 and converted into an electric signal. As a result, the electric signal is input to the controller 4, and the vehicle-mounted acoustic device 3 is responsive to the electric signal.
For example, the sound level of the output signal of is increased and output.
Then, the amplifier 5 amplifies the output signal of the controller 4 and outputs the sound from the speaker 6. Therefore, the sound level in the vehicle interior 1 is starved more than before.
FIG. 6 shows an example in which this device is actually mounted on a vehicle.

Further, as shown in FIG. 7, an acoustic emission sensor (hereinafter referred to as an AE sensor) 7 for detecting vibration of the vehicle body is attached to the vehicle body in place of the microphone 2 shown in FIG. AE sensor 7 according to the vibration of
It is also known to control the acoustic state of the vehicle interior 1 using a signal generated in the vehicle.

[Problems to be Solved by the Invention] In the above-described conventional vehicle sound field control apparatus, first, in the case of FIG. 5, the sound level of the interior 1 of the vehicle is directly detected, so that the problem occurs in the interior of the vehicle 1. There was a feature that the sound level and the like of the vehicle-mounted sound device 3 was adjusted according to the noise level. However, when the listeners have a conversation with each other, the microphone 2 is provided in the vicinity of the listeners. Therefore, as in the case where the microphone 2 detects this conversation and the noise level increases, the sound level in the vehicle interior 1 rises. become.
As a result, in order to hear each other's conversation, they have to speak loudly.
However, there is a drawback that a vicious circle occurs in which the sound level in the vehicle interior 1 is further detected and is further detected. Moreover, depending on the content of the sound output from the speaker 6, the sound level may change regardless of the noise, an unspecified frequency may be output, or the duration of these sounds may change. There is a problem that it is difficult to control the sound level and the like only by detecting the level change of the sound signal including unspecified time, phase, level and frequency elements that are input to the. Therefore, the acoustic signal was switched from the speaker 6 to a specific signal and output, and the state of the acoustic was controlled by detecting the propagation change of the signal, but it can be controlled only intermittently and immediately follows the variation of the acoustic signal. It had the drawback of not being able to do it.

Further, in the case of FIG. 7, since the vibration of the vehicle body is detected, it means that the noise in the vehicle interior 1 is indirectly detected.
The above-mentioned adverse effects can be prevented. However, the AE is located at a position where the noise inside the vehicle 1 and the vibration of the vehicle body are sufficiently correlated.
Special techniques are required to attach the sensor 7.
Further, since this device utilizes the correlation between the noise in the vehicle interior 1 and the vibration of the vehicle body, for example, when the speaker 6 is installed in the rear of the vehicle as shown in FIG. When the cavity of the vehicle interior 1 is changed by opening or closing the vehicle, or when the sound output from the speaker 6 toward the passenger, that is, the listener is bent or attenuated by the wind entering the vehicle interior 1 through the window 8, However, there is a drawback that the sound level in the vehicle interior 1 is not controlled because the above situation cannot be detected.

In addition, when these devices are used in an open type vehicle or a two-wheeled vehicle that receives a cross wind, etc., similarly to the above case,
When the sound output from the speaker toward the passenger is bent by the wind and attenuated at the listening position, these situations cannot be detected, and there is a problem that the change in the sound field cannot be corrected.

The present invention has been made in view of the above-mentioned circumstances, and is capable of controlling the acoustic state of a vehicle to a constant level without being affected by opening and closing of windows, wind, etc., and having a simple configuration with less malfunction. An object is to provide a sound field control device for a vehicle.

"Means for Solving the Problem" The present invention provides a vehicle-mounted acoustic device that generates sound from a speaker to form a sound field, and a directivity similar to the directivity of the speaker in the vicinity of the speaker or integrally with the speaker. An ultrasonic wave radiator that is installed in the sound field and radiates ultrasonic waves to the sound field, an ultrasonic wave receiver that receives the ultrasonic waves transmitted to the sound field, and an ultrasonic wave using the output signal of the ultrasonic wave receiver. It is characterized by comprising a discriminator that discriminates a propagation change in the sound field and a controller that controls the state of the sound generated from the vehicle-mounted acoustic device using the output signal of the discriminator.

[Operation] According to the present invention, the ultrasonic wave signal is emitted from the ultrasonic wave radiator to the sound field formed by the acoustic signal output from the vehicle-mounted acoustic device. As a result, the ultrasonic signal is propagated in the sound field in the same manner as the acoustic signal and received by the ultrasonic receiver, so that the discriminator discriminates the change in the received ultrasonic signal due to the propagation. Then, the controller controls the output signal of the vehicle-mounted audio device by the output signal of the discriminator. As a result, the acoustic state is controlled in accordance with the propagation change of the ultrasonic signal in this sound field.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a vehicle sound field control apparatus according to an embodiment of the present invention. In this figure, the parts corresponding to the respective parts in FIG. Is omitted. The vehicle sound field control device shown in FIG. 1 is additionally provided with an ultrasonic oscillator 9 for oscillating ultrasonic waves of 40 KHz and the like, and an ultrasonic radiator 10 composed of a transducer such as a ceramic vibrator. . Since the ultrasonic radiator 10 radiates ultrasonic waves to the sound field formed by the sound output from the speaker 6, the ultrasonic radiator 10 has a directivity similar to that of the speaker 6 in the vicinity of the speaker 6 or integrally with the speaker 6. It is installed with a certain nature. Therefore, the ultrasonic signal and the acoustic signal are radiated toward the listener. Further, instead of the microphone 2 in FIG. 5, an ultrasonic wave receiver 11 such as a condenser microphone or a ceramic vibrator for receiving the ultrasonic wave propagated in the sound field.
And the output signal of the ultrasonic receiver 11 is used to change the propagation of ultrasonic waves in the sound field, that is, whether the ultrasonic signal is propagated and received in a windless state, or when the vehicle travels or cross winds generate noise. A discriminator 1 for discriminating whether or not the ultrasonic wave signal is being received due to the disturbance of the field.
2 is connected to the controller 4. The discriminating method of the discriminator 12 includes a method of discriminating by a change in the amplitude level of the signal received by the ultrasonic receiver 11, a method of discriminating by a frequency deviation due to the Doppler effect of the radiation signal and the received signal. Here, a method of discriminating based on a change in the amplitude level of the received signal will be described. The discriminator 12 is a band amplifier 13 that amplifies only the ultrasonic signal of 40 KHz.
And an amplitude detector 14 for detecting the amplitude level of the output signal of the band amplifier 13. 15 is a passenger,
That is, the listener. FIG. 2 shows an example in which this device is mounted on an open type vehicle.

The operation when this apparatus is used in a state in which sound is output from the speaker 6 in such a configuration will be described. First, when the vehicle is stopped and there is no wind, the ultrasonic signal of 40 KHz oscillated by the ultrasonic oscillator 9 is radiated from the ultrasonic radiator 10 to the sound field. As a result, in the sound field near the listener 15, as shown in FIG. 3 (a), there is a signal in which the ultrasonic signal is superimposed on the acoustic signal. Therefore, the ultrasonic receiver 11 receives this signal, the band amplifier 13 in the discriminator 12 amplifies it, the amplitude detector 14 detects it, and the signal shown in FIG. 3B is output. On the other hand, the listener 15 is shown in FIG. 3 (c).
Listening to the acoustic signal shown in. Then, in the controller 4, the acoustic level of the output signal of the vehicle-mounted acoustic device 3 is controlled and output by the output signal of the amplitude detector 14. Further, the output signal of the controller 4 is amplified by the amplifier 5 and the sound is output from the speaker 6.

Next, when the vehicle travels and the directivity of the acoustic signal and the ultrasonic signal are both bent by the wind, first, the ultrasonic signal of 40 KHz oscillated by the ultrasonic oscillator 9 is emitted from the ultrasonic radiator 10. Radiated to the place. As a result, the listener 15
As shown in FIG. 3 (d), a signal in which an ultrasonic signal is superposed on an acoustic signal is present in the sound field in the vicinity of the above, being attenuated by the wind. Therefore, this signal is received by the ultrasonic receiver 11, amplified by the band amplifier 13 in the discriminator 12, detected by the amplitude detector 14, and then detected in FIG.
The signal shown in (e) is output. On the other hand, the listener 15 is the third
We are listening to the acoustic signal shown in Figure (f). And the controller 4
At, the output signal of the on-vehicle audio device 3 is raised and output by the output signal of the acoustic level amplitude detector 14.
Further, the output signal of the controller 4 is amplified by the amplifier 5 and the sound is output from the speaker 6. That is, when the output signal of the amplitude detector 14 is large, the acoustic level of the output signal of the controller 4 becomes low, and conversely, when the output signal of the amplitude detector 14 is small, the acoustic level of the output signal of the controller 4 becomes large. Become.

In this way, the sound level in the sound field can be indirectly controlled by the reception level of the ultrasonic signal. Therefore, the listener 15 produces a certain level of sound regardless of whether the vehicle is stationary and in a calm state or when the vehicle is traveling and the directivity of the acoustic signal and the ultrasonic signal is both bent by the wind. I can listen.

Further, since the ultrasonic oscillator 9 outputs a continuous wave signal or a pulse wave signal of a constant level to the ultrasonic radiator 10,
The above-mentioned reception level of the ultrasonic signal can be easily detected.

By the way, if the control of the sound level and the like is performed too often using this device, the so-called "breathing" phenomenon of the sound output occurs. Therefore, the discriminator 12 averages the output signals of the amplitude detector 14, It is necessary to provide an averaging circuit that does not change the level of the output signal of the discriminator 12 when the level of the output signal of the amplitude detector 14 changes for a short time. The averaging circuit is constituted by, for example, a rectifying circuit with its time constant lengthened to about 3 seconds. As a result, the "breathing" phenomenon of the acoustic output due to the instantaneous wind speed such as cross wind can be prevented.

In addition, as for the installation location of the ultrasonic wave receiver 11, it is easy to obtain the correlation between the change in the acoustic signal and the change in the ultrasonic wave signal in a place near the listener's ear, and therefore, for example, as shown in FIG. In the case of installing the vehicle 15 as a target, the vicinity of the headrest of the driver's seat or the overhead ceiling of the try bar 15 is desirable.

Next, an example in which this device is mounted on a two-wheeled vehicle will be described. FIGS. 4 (a) and 4 (b) are a schematic left side view and a plan view when a vehicle sound field control device according to an embodiment of the present invention is mounted on a two-wheeled vehicle, and in FIG. The parts corresponding to the parts in the figure are denoted by the same reference numerals, and the description thereof will be omitted. In the vehicle sound field controller shown in FIG. 4, the speaker 6 is located at a lower position apart from the driver 15.
For example, it is provided below the handle. Therefore, the ultrasonic radiator 10 is installed in the center of the speaker 6 in order to have the same directivity as that of the speaker 6. Further, although the ultrasonic receiver 11 is installed near the saddle near the driver 15 in this figure, it may be installed above the handle. Regarding the installation of the ultrasonic radiator 10 and the ultrasonic receiver 11, particularly in the case of a two-wheeled vehicle, ultrasonic noise mechanically generated in addition to the ultrasonic waves radiated from the ultrasonic radiator 10 is relatively large. Therefore, the distance between the ultrasonic radiator 10 and the ultrasonic receiver 11 should be as short as possible, or the directivity range of the ultrasonic receiver 11 should be narrowed.
It is necessary to consider raising the / N ratio. Further, when the sound field contains a large amount of reflected wave components of the acoustic signal from the vehicle body, if the ultrasonic receiver 11 is provided in the propagation path of the reflected wave signal, the change of the acoustic signal and the change of the ultrasonic signal are performed. It is easy to obtain correlation with. On the other hand, when the sound field contains a large amount of the direct wave component from the speaker 6, providing the ultrasonic receiver 11 in the propagation path of the direct wave signal causes a change in the acoustic signal and a change in the ultrasonic signal. Correlation is easy to obtain.

The operation when this apparatus is used in a state in which sound is output from the speaker 6 in such a configuration will be described. First, when the vehicle is stopped and there is no wind, the ultrasonic signal of 40 KHz oscillated by the ultrasonic oscillator 9 is radiated from the ultrasonic radiator 10 to the sound field. As a result, in the sound field near the driver 15, there is a signal in which the ultrasonic signal is superimposed on the acoustic signal. Therefore, this signal is received by the ultrasonic receiver 11, amplified by the band amplifier 13 in the discriminator 12, detected by the amplitude detector 14, and output. Then, in the controller 4, the acoustic level of the output signal of the vehicle-mounted acoustic device 3 is controlled and output by the output signal of the amplitude detector 14. Further, the output signal of the controller 4 is amplified by the amplifier 5 and the sound is output from the speaker 6.

Next, when the vehicle travels and the directivity of the acoustic signal and the ultrasonic signal are both bent by the wind, first, the ultrasonic signal of 40 KHz oscillated by the ultrasonic oscillator 9 is emitted from the ultrasonic radiator 10. Radiated to the place. This allows Dryer 1
In the sound field in the vicinity of 5, there exists a signal in which an ultrasonic signal is superposed on an acoustic signal attenuated by the wind. Therefore, this signal is received by the ultrasonic receiver 11 and the discriminator 1
Amplified in the band amplifier 13 in 2 and detected by the amplitude detector 1
It is detected in 4 and output. Then, in the controller 4, the acoustic level of the output signal of the vehicle-mounted acoustic device 3 is raised by the output signal of the amplitude detector 14 and output.
Further, the output signal of the controller 4 is amplified by the amplifier 5 and the sound is output from the speaker 6. That is, driver 1
5 can enjoy sound with a good S / N ratio.

In this way, the acoustic level in the sound field can be indirectly controlled by the reception level of the acoustic wave signal. Therefore, the driver 15 listens to a certain level of sound regardless of whether the vehicle is stationary and in a calm state or when the vehicle is traveling and the directivity of the acoustic signal and the ultrasonic signal is both bent by the wind. be able to.

The above explanation is an example of an open type four-wheeled vehicle and two-wheeled vehicle. However, when a normal four-wheeled vehicle is running with the window closed, recent vehicles tend to keep the noise level inside the vehicle low. , It is no longer necessary to control the volume according to the running. However, when the outside air flows into the vehicle by opening and closing the window, or when the cavity inside the vehicle changes by keeping the window open, it is necessary to control the sound level etc. by the vehicle sound field control device described above. There is. In addition, when the outside airflow inlet is opened to let the outside air into the vehicle, or when the air inside the vehicle is caused by the car cooler and the heating fan, it is necessary to similarly control the sound level. In addition, since this device constantly detects the propagation change when sound is transmitted to the sound field, even if there are multiple passengers and the sound field changes as a result, the volume inside the vehicle decreases. Since this can be detected, the decrease in volume can be corrected immediately.

In the above-mentioned embodiment, the open loop control in which the output level of the ultrasonic oscillator 9 is constant is used, but the ultrasonic oscillator 9 is constituted by the output variable oscillator whose output level is controlled by the control output of the controller 4. For example, by controlling the output level of the ultrasonic oscillator 9 so that the level of the ultrasonic wave signal also increases when the sound level of the sound field is controlled to increase, the output signal of the discriminator 12 is always constant. You may perform the closed loop control which controls as follows.

Further, in the above-described embodiment, the change in the amplitude level of the ultrasonic signal is used, but a similar device can be configured by using the frequency deviation due to the Doppler effect between the radiated wave signal and the reflected signal of the ultrasonic wave. . Further, in the above-mentioned embodiment, the level of the output signal of the vehicle-mounted audio device 3 is simply controlled by the output signal of the discriminator 12, but the output signal of the vehicle-mounted audio device 3 is controlled by the output signal of the discriminator 12 for each frequency band. It can also be applied to sound quality adjustment (tone control) that changes the amount of change. In addition, the above-mentioned device may be combined with various sensors such as the microphone 2 and the AE sensor 7 or the speed sensor used in the conventional examples shown in FIGS.

By the way, although one speaker has been described in the above embodiments, a pair of left and right rear speakers, a center speaker and the like are provided as an in-vehicle warm-thickness device for generating a sound to form a sound field to provide a rich sound field. There is a surround method to make. In the case of this surround-type on-vehicle audio device, first, the ultrasonic radiator 10 is installed in the vicinity of each speaker or integrally with each speaker so as to have the same directivity as the directivity of each speaker. Next, ultrasonic waves are radiated from each ultrasonic radiator 10 in a time division manner, or ultrasonic waves of different frequencies are radiated from each ultrasonic wave radiator 10. Then, each ultrasonic wave propagated in the sound field formed by the sound output from each speaker is received by the ultrasonic receiver 11, and the ultrasonic wave signal is separated and processed by the discriminator 12. Thereby, it is possible to control the acoustic state of the sound field described above.

The above examples are all about the control of the acoustic state of the sound field formed by the sound output from the on-vehicle audio device, but control other in-vehicle devices by hands-free telephone or voice recognition and voice synthesis. The acoustic state of the sound field formed by the above-described device can be easily detected by the vehicle sound field control device according to the present invention. Therefore, this device can easily control the volume of the voice transmitting side of the hands-free telephone or voice synthesizer, and the sensitivity of the microphone amplifier of the voice receiving side of the hands-free telephone or voice recognition device is simple. Controlled by.

Although all of the above description is for the vehicle, this device may be applied to the detection of acoustic changes in the sound field in the room other than the vehicle.

[Advantages of the Invention] As described above, according to the present invention, the sound is generated from the speaker and installed in the vicinity of the speaker or integrally with the speaker with a directivity substantially similar to that of the speaker. An on-vehicle acoustic device that forms a field and an ultrasonic radiator that emits ultrasonic waves in the sound field, installed near or in the vicinity of the speaker with almost the same directivity as the speaker. Using the ultrasonic receiver that receives the ultrasonic waves transmitted to the field, the discriminator that discriminates the propagation change in the sound field of the ultrasonic wave using the output signal of the ultrasonic receiver, and the output signal of the discriminator Since a controller for controlling the state of the sound generated from the vehicle-mounted audio device is provided, it is possible to control the sound level of the vehicle to a constant level without being affected by the opening and closing of windows and wind. is there. In addition, since the propagation change of the acoustic signal including unspecified time, phase, level and frequency elements is not used, the device can be realized with a simple configuration and there is also an effect that there are few malfunctions. Moreover, since ultrasonic waves that are relatively similar in nature to sound are used, there is an effect that correlation with sound can be obtained more easily than in a device that detects vibration of the vehicle body.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle sound field control device according to an embodiment of the present invention, and FIG. 2 is an example in which the vehicle sound field control device according to the embodiment of the present invention is mounted on an open type vehicle. 3 (a) and 3 (d) are waveform diagrams of a signal in which an ultrasonic signal is superimposed on an acoustic signal existing in the sound field near the listener 15 in FIG. 2, and FIG. ) And (e) are waveform diagrams of the output signal of the amplitude detector 14 in FIG. 1, and FIGS. 3 (c) and (f) are waveform diagrams of the acoustic signal opened by the listener 15 in FIG. 4 (a) and 4 (b) are a schematic left side view and a plan view of a vehicle sound field control device according to an embodiment of the present invention mounted on a motorcycle, and FIG. FIG. 6 is a block diagram showing a configuration example of a sound field control device, and FIGS. 6 and 7 are schematic diagrams in which a conventional vehicle sound field control device is mounted on a vehicle. 1 ... In-vehicle acoustic device, 4 ... Controller, 10 ... Ultrasonic radiator, 11 ... Ultrasonic receiver, 12 ... Discriminator.

Claims (1)

[Claims] 1. An in-vehicle acoustic device for generating a sound field by generating sound from a speaker, and installed in the vicinity of the speaker or integrally with the speaker with a directivity substantially similar to that of the speaker. An ultrasonic wave radiator for radiating ultrasonic waves to the sound field, an ultrasonic wave receiver for receiving the ultrasonic waves propagated in the sound field, and the ultrasonic wave using the output signal of the ultrasonic wave receiver. A discriminator that discriminates a propagation change in the sound field, and a controller that controls a state of the sound generated from the vehicle-mounted audio device by using an output signal of the discriminator. Vehicle sound field control device.