JP2819957B2 - Three-dimensional sound field alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects an object around a vehicle, informs the driver of the position and direction of the object using a sound image from a speaker, and prompts the driver to pay attention to the object. The present invention relates to a three-dimensional sound field alarm device that contributes to improving safety during traveling.

[0002]

2. Description of the Related Art As a conventional alarm device using a sound field, there is, for example, one disclosed in Japanese Utility Model Laid-Open No. 63-16392. This means that an obstacle behind the vehicle is detected by a sensor, and when an obstacle is detected, driving is performed by indicating the direction of the obstacle by changing the left and right sound signal outputs of the speakers according to the position of the obstacle. It gives an alarm to the person. As described above, not only changing the left and right output levels of the speaker but also controlling the phases of the left and right outputs in order to more accurately localize the sound image is being studied.

[0003]

Here, since there is a problem that the localization in the front-rear direction is ambiguous for the driver with the sound in the low frequency band, in order to accurately localize the sound image with respect to the distance in the front-rear direction, It is said that a sound signal in a relatively high frequency band is required. However, when using a sound in such a high frequency band, its wavelength is short,
A slight change in the position of the driver's ear will cause a large change in the phase, and not only will the sound image not be localized at the correct position,
There is a problem that the high frequency may make the driver feel uncomfortable. Accordingly, the present invention has been made in view of the above-described conventional problems, and provides a three-dimensional sound field alarm device which can easily suppress a change in a sound image even if the driver's position fluctuates, can be easily localized accurately, and does not give any discomfort. The purpose is to provide.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, when a sound of about 4 kHz is added to a sound in a low frequency band, a sound image is localized forward, or when a sound of 1 kHz is heard, the sound image is easily localized backward. As shown in FIG. 1, based on the knowledge about the auditory characteristics of a person that it is easy to localize in a specific direction when a specific frequency is heard, an object around the vehicle is detected as shown in FIG. An object detecting means for outputting position information, a plurality of speakers arranged at predetermined positions in a vehicle cabin;
Based on the output, the stereoscopic sound field warning device consisting of a control unit 20 for controlling the sound field level of the speaker to localize a sound image at a predetermined position with respect to the driver, the control means 20, the sound image Left / right position to be localized
In correspondence with the amplitude and phase control means 22 to output a first sound signal in a low frequency band in which the amplitude and phase is controlled from the speaker 30, the second high frequency band corresponding to longitudinal position of the sound image And an adding means 24 for adding the first sound signal to the first sound signal and outputting the first sound signal from a speaker.

[0005]

The amplitude / phase control means 22 controls the amplitude and phase based on the angle and distance in the left-right direction for determining the sound image position.
Is performed for low frequency band sound,
The wavelength is long, and the amount of change according to the direction mediated by the pinna is smaller than that of the sound in the high frequency band, so that the localization in the left and right direction due to the phase difference between both ears is easy. Since a specific high-frequency sound is added to this in accordance with the position of the sound image in the front-rear direction , it is ensured that the sound is localized forward or backward in accordance with the auditory characteristics. Done.

[0006]

FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a layout diagram thereof. The object detection device 110 using a radar (110a, 110b, 110c, 1)
10d) are provided on the front and rear and sides of the vehicle 200,
Detects objects around the vehicle. The position information of the object detected from the object detection device 110 is sent to the control device 120, and the control device 120 controls the sound image to be presented based on the position information, and is disposed at a predetermined position in the passenger compartment 190. The sound image signal is output to the speakers 130 and 131. Control device 12
0 has a built-in memory for recording data for presenting a sound image. In addition, 160 and 161 are side mirrors for checking the left and right rear of the vehicle, and 162 is an indoor rearview mirror for checking the rear of the vehicle.

As shown in FIG. 4, each of the object detecting devices 110a to 110d includes a light emitting unit 111 for transmitting a pulse laser beam and a light receiving unit 112 for receiving a laser beam. Can be changed arbitrarily. At the same time as the light emitting unit 111 emits the pulse laser light at the angle θ as shown in FIG. 5, the light receiving unit 112 starts counting the elapsed time. When the object 113 exists within the range irradiated with the pulsed laser light, the irradiated pulsed laser light is reflected and input to the light receiving unit 112. The light receiving unit 112 emits the pulsed laser light from the counted number and then outputs the pulsed laser light to the light receiving unit. Time T until reflected light returns
[Sec] is required. The distance L [m] to the object is obtained by the following equation. L = T · C / 2 where C = 3.0 × 10 ⁸ [m / sec].

When the reflected light is not detected by the light receiving unit 112 for more than T1 seconds after the irradiation of the pulse laser light, it is determined that there is no object, and the light emitting unit 111 irradiates the pulse laser light in the next angle direction. . Here, the above time T1
Is set to change in proportion to the vehicle speed V [Km / h] of the vehicle 200. For example, the braking distance R of the own vehicle
Braking distance R = V
[M], and R = 4 when the vehicle speed is 40 [Km / h] or less.
0 [m], and is determined by T1 = 2 · R [m] / C.

When an object is detected in the irradiation range, pulse laser light irradiation and measurement are performed again in the same direction at least again, and the vehicle 200 and the object 11 are detected based on a change in the measured distance.
A relative speed between 3 and 3 is determined. If no object is detected during the second measurement, the data is cut as an erroneous detection. Next, the irradiation angle θ of the pulsed laser light
Are sequentially changed, an object within a predetermined angle range is detected.

In order to change the irradiation direction of the pulsed laser beam, a system in which the emitting unit is rotated by a motor or the like, a system in which a rotatable mirror surface is provided in front of the laser beam irradiation unit, and the laser beam is reflected and output therefrom Alternatively, an appropriate one is selected, such as a method of providing a plurality of emission parts directed in different directions, sequentially irradiating a pulsed laser beam, and rotating this. In this way, objects in an arbitrary range around the vehicle necessary for traveling of the own vehicle are detected by the sharing of the object detection devices 110a to 110d provided in the front, rear, and side portions of the vehicle 200.

The flow of the processing operation in the embodiment system configured as described above is shown in the flowchart of FIG. When the engine is started, the system is turned on and the process starts. First, in step 201, an object is detected by the object detection devices 110a to 110d. When an object is detected, position information of the object is obtained and sent to the control device 120. The position information includes the distance L to the object and the angle θ, and which of the plurality of object detection devices has been detected.
Here, the distance L is positive in the forward and left directions, the angle is 0 ° in front of the driver, and the angle is positive in the left direction from the front.

In step 202, the control device 120
Receives the position information from the object detection device and calculates the angle φ of the detected object as viewed from the driver 180. For example, when the object is in front of the vehicle 200, as shown in FIG.
Assuming that the distance to 0 is x, y, an angle φ in the left-right direction from the driver to the object is obtained by the following equation. φ = tan ⁻¹ {(x + L · sin θ) / (y + L · cos θ)}

In the next step 203, the filter data stored in advance in the memory built in the control device 120 is read out according to the angle φ obtained above, and is calculated by the calculation with the alarm sound S to be controlled. , Left and right speakers 13
Output levels SLL and SLR of 0 and 131 are calculated. Here, the alarm sound S to be controlled is a sound in a low frequency band of, for example, 800 Hz or less. The filter data includes filter data CLL, CLR, and CR for correcting the sound field in the cabin.
L and CRR, and filter data T (φ) L and T (φ) R for localizing the sound image in the angle φ direction.

In particular, the filter data for localizing the sound image simulates the transfer characteristic from the sound source to the driver's both ears when the sound source is actually present in that direction. The driver 180
To give to both ears. The filter data for correcting the sound field in the vehicle cabin includes data for correcting asymmetry of the speaker. Thus, using the filter data, each output level is expressed as follows. SLL = (CLL * S * T (φ) L + CRL * S * T (φ) R) SRR = (CLR * S * T (φ) L + CRR * S * T (φ) R) where * is convolution Represents an operation.

Thereafter, at step 204, a sound signal to be added to the sound signal whose amplitude and phase are controlled is determined. Here, a sound having a frequency corresponding to whether the sound image is forward or backward as a result of the angle φ is selected, and the driver 18
In accordance with the distance from 0 to the left and right speakers 130 and 131, the output level of the left and right speakers of the sound to be added is determined so that no amplitude difference occurs between the two ears of the driver. Here, since the frequency of the alarm sound is a low-frequency band sound of 800 Hz or less for controlling the amplitude and the phase, the sounds S1 and S2 added thereto are around 4 kHz when the sound image is localized forward. When the sound is localized rearward, the sound is about 1 kHz.

The left and right output levels SHL, SHR of this additional sound
Are the sound pressure levels SLL, S of the sound in the low frequency band as follows:
The speaker is driven at a sound pressure level proportional to the average sound pressure of the LR. SHL = A · S1 · (SLL + SLR) / So SHR = A · S2 · (SLL + SLR) / So where So is a reference sound pressure and A is a proportional constant.

Here, sounds having no correlation with each other are selected as the additional sounds.

(Equation 1) S1 and S2 such that This is to prevent the sound image by the sound in the high frequency band from being localized at a specific position, so that the addition of the sound in the high frequency band does not affect the position of the sound image by the sound in the low frequency band. As described above, the outputs SL and S of the left and right speakers
R is calculated as follows. SL = SLL + SHL SR = SLR + SHR In step 205, the sound signal determined in the previous step is output from the left and right speakers 130 and 131.

This embodiment is constructed as described above. When localizing a sound image of a detected object, a sound in a low frequency band is used to indicate the angle and distance in the left-right direction, and the detected object is moved forward and backward with respect to the vehicle. 4 kHz corresponding to the positional relationship, and thus also the front and rear direction of the sound image to be localized,
Alternatively, since a sound having a frequency of around 1 kHz is added, the amount of change in the direction mediated by the pinna is smaller than that of the sound in the high frequency band because the wavelength is long in the left-right direction and the distance. And the localization in the left-right direction by the phase difference is easily performed, and the specific high-frequency sound added matches the auditory characteristics, so that the localization in the front and rear directions is reliably performed. Also, at this time, the additional sound was not particularly correlated with each other, so only the identification information of the front or the rear was accurately provided without fear of adversely affecting the localization of the sound image due to the sound in the low frequency band such as a position change. It has the effect of doing.

In this way, it is easy to determine the sound image position in the front-rear direction, and the alarm can be recognized without error. The above steps are repeated during the running of the vehicle to detect an object that may be an obstacle and its moving state, and the sound image localization operation is continued. In the embodiment, the object detection devices 110a to 110d
Is the same one using pulsed laser light,
The present invention is not limited to this. Sensors based on ultrasonic waves, electromagnetic waves, or the like can be used according to the measurement range, and object detection may be performed by a method that combines them.

[0020]

As described above, the present invention relates to a three-dimensional sound field alarm device for controlling the sound field level of a plurality of speakers disposed in a vehicle cabin to notify the detected position of an object by a sound image localized. as the output of the speaker, the localization of
The low frequency band sound that in correspondence with the lateral position of the sound image to control the amplitude and phase should be, and to output a material obtained by adding a sound of high frequency band corresponding to the longitudinal position of the sound image Therefore, the influence of the driver's movement such that the sound image swings right and left is reduced, and the auditory characteristics are effectively utilized, so that the localization in the forward or rearward direction is ensured. As a result, the presence of an obstacle or the like can be notified without error, leading to a quick discovery of the obstacle, and the effect of more reliably preventing danger during traveling of the vehicle can be obtained.
In addition, at this time, since the high frequency sound is selectively added and used, the driver does not feel uncomfortable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a layout diagram showing an arrangement of the embodiment.

FIG. 4 is a diagram showing a configuration of a radar.

FIG. 5 is an explanatory diagram of object detection by a radar.

FIG. 6 is a flowchart illustrating a process in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Object detection means 20 Control means 22 Amplitude and phase control means 24 Addition means 30 Speaker 110, 110a-110d Object detection apparatus 111 Light emitting part 112 Light receiving part 113 Object 120 Control apparatus 130, 131 Speaker 160, 161 Side mirror 180 Driver 190 car Room 200 vehicle

Continuation of front page (58) Fields investigated (Int. Cl. ⁶ , DB name) B60R 21/00 G08B 21/00 G01S 13/93 H04S 1/00

Claims (1)

(57) [Claims] 1. An object detecting means for detecting an object around a vehicle and outputting position information of the detected object, a plurality of speakers arranged at a predetermined position in a vehicle cabin, and In the three-dimensional sound field alarm device comprising control means for controlling a sound field level of the speaker so that a sound image is localized at a predetermined position with respect to a driver based on the output,
Means for positioning the sound image in the left-right direction to be localized.
Amplitude and phase control means for outputting, from the loudspeaker, a first sound signal in a low frequency band whose amplitude and phase are controlled in response thereto, and a second sound signal in a high frequency band corresponding to the position in the front-back direction of the sound image And a means for adding the first sound signal to the first sound signal and outputting the sound signal from a speaker.