JP2012145460A - Detection system of vehicle in blind area, detection device of vehicle in blind area, detection method of vehicle in blind area, and program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect a direction of a sound source of a vehicle in a blind area.SOLUTION: A detection device is arranged in the own vehicle and comprises: a sound collector 102 for collecting external sound; a sound pressure threshold processor 103 that holds a sound pressure threshold at which a sound pressure of a diffraction sound of the vehicle in the blind area becomes larger than a sound pressure of a reflection sound of the vehicle in the blind area, and determines whether the sound pressure of the external sound collected by the sound collector 102 is larger than the sound pressure threshold; and a vehicle detector 105 for detecting the direction of the sound source of the vehicle in the blind area from the external sound collected by the sound collector 102, when the sound pressure threshold processor 103 determines that the sound pressure of the external sound is larger than the sound pressure threshold.

Description

  The present invention relates to a blind spot vehicle detection system that detects the direction of another vehicle existing in a blind spot of a shield from outside sound. In particular, the present invention relates to a blind spot vehicle detection system that can detect the direction of another vehicle after removing the influence of reflected sound from a shield.

  A conventional vehicle sound detection device installs sound collection units at two locations on the left and right sides of the host vehicle, and determines the presence of another vehicle independently on the left and right. If the left sound collection unit detects other vehicle sound first, it is determined that the other vehicle is traveling from the left to the right side, and the right sound collection unit detects other vehicle sound first. Determines that another vehicle is traveling from the right side to the left side (see, for example, Patent Document 1).

  In addition, another conventional sound source direction estimation device performs peak hold processing on the output of the sound collection unit, and obtains the direction of the sound source after removing the influence of reflected sound whose sound pressure is lower than that of the direct sound. (For example, refer to Patent Document 2). FIG. 27 shows a conventional sound source direction estimating apparatus described in Patent Document 2.

  FIG. 27A schematically shows a direct sound and a reflected sound input to the microphone A and the microphone B. FIG. 27B shows a result of performing a peak hold process on the direct sound and the reflected sound input to the microphone A and the microphone B shown in FIG. Thus, the influence of the reflected sound having a sound pressure smaller than that of the direct sound can be removed by the peak hold process.

JP 2000-105274 A Japanese Patent Laid-Open No. 5-87903

  However, in the conventional vehicle sound detection device, when detecting the sound source direction of the vehicle sound of a blind spot vehicle that is another vehicle existing in the blind spot of the shielding object from the outside sound, the influence of the reflection of the vehicle sound on the shielding object is considered. Therefore, there is a problem that the direction of the reflected sound different from the direction of the blind spot vehicle is detected. For example, the diffracted sound of the vehicle sound may be attenuated due to the diffraction of the vehicle sound by the shield, and the sound pressure of the reflected sound of the vehicle sound by another shield may be higher. In such a case, the direction of the sound source of the blind spot vehicle is erroneously detected as the direction in which the reflected sound arrives.

  In addition, since the conventional sound source direction estimating apparatus does not consider the influence of the shielding object, the sound pressure of the reflected sound is larger than the diffracted sound of the blind spot vehicle, and the influence of the reflected sound is removed in the peak hold process. It has the problem that it cannot be done. That is, in such a case, since the direction of the sound source is obtained based on the sound pressure of the reflected sound, the direction of the sound source of the blind spot vehicle is erroneously detected as the direction in which the reflected sound arrives.

  That is, the conventional method has the common problem that the direction of the sound source of the blind spot vehicle cannot be accurately detected because the influence of the reflected sound cannot be removed when there is a shielding object.

  The present invention solves the above-mentioned conventional problems, and provides a blind spot vehicle detection system that can accurately detect the direction of a sound source of a blind spot vehicle by removing the influence of reflected sound when there is a shield. For the purpose.

  In order to solve the above-mentioned conventional problems, a blind spot vehicle detection system according to an aspect of the present invention is arranged in the own vehicle, and a sound collection unit that collects external sound and a sound pressure of diffraction sound of the blind spot vehicle are A sound pressure threshold that holds a sound pressure threshold that is greater than the sound pressure of the reflected sound of the blind spot vehicle and that determines whether or not the sound pressure of the outside sound collected by the sound collecting unit is greater than the sound pressure threshold When the sound pressure of the vehicle exterior sound is determined to be greater than the sound pressure threshold by the processing unit and the sound pressure threshold processing unit, the sound source of the blind spot vehicle is determined from the vehicle exterior sound collected by the sound collection unit. A vehicle detection unit that detects a direction.

  According to this configuration, the direction of the sound source of the blind spot vehicle is detected when the outside sound collected by the sound collecting unit is larger than the sound pressure threshold (when the diffracted sound is larger than the sound pressure of the reflected sound). That is, since the reflected sound is masked with the diffracted sound, the direction of the sound source can be detected without being affected by the reflected sound. Therefore, it is possible to prevent the wrong direction from being detected by the reflected sound when there is a shielding object, and it is possible to accurately detect the direction of the sound source of the blind spot vehicle. By presenting the direction of the sound source of such a blind spot vehicle to the driver, the driver can drive the vehicle safely.

  Preferably, the sound pressure threshold value processing unit holds a plurality of sound pressure threshold values each corresponding to the condition of the running sound of the blind spot vehicle, and the blind spot vehicle detection system further includes the running sound of the blind spot vehicle. And a sound pressure threshold value switching unit that selects a sound pressure threshold value corresponding to the acquired traveling sound condition from among the plurality of sound pressure threshold values held by the sound pressure threshold value processing unit. The sound pressure threshold processing unit determines whether or not the sound pressure of the outside sound collected by the sound collecting unit is larger than the sound pressure threshold selected by the sound pressure threshold switching unit.

  With this configuration, it is possible to detect the direction of the sound source using different sound pressure threshold values for each condition of the driving sound of the blind spot vehicle. For this reason, it is possible to detect the direction of the sound source of the blind spot vehicle by using the outside sound in which the sound pressure of the diffracted sound is always larger than the sound pressure of the reflected sound without being affected by the condition of the running sound of the blind spot vehicle. Therefore, the direction of the sound source of the blind spot vehicle can be accurately detected.

  Specifically, the condition of the traveling sound is a weather condition indicating rainy weather or clear weather, and the sound pressure threshold value switching unit is configured to travel the blind spot vehicle when a wiper installed in the host vehicle is operating. A weather condition indicating rainy weather is acquired as a sound condition, and a weather condition indicating clear weather is acquired as a driving sound condition of the blind spot vehicle when the wiper is not operating, and the sound pressure threshold processing unit holds A sound pressure threshold value corresponding to the acquired weather condition is selected from the plurality of sound pressure threshold values.

  The traveling sound condition is a weather condition indicating rainy or sunny weather, and the sound pressure threshold value switching unit detects the traveling sound of the blind spot vehicle when a raindrop sensor installed in the own vehicle detects a raindrop. A weather condition indicating rainy weather is acquired as a condition, and when the raindrop sensor does not detect a raindrop, a weather condition indicating clear weather is acquired as a driving sound condition of the blind spot vehicle, and the sound pressure threshold processing unit holds A sound pressure threshold value corresponding to the acquired weather condition may be selected from the plurality of sound pressure threshold values.

  With these configurations, it is possible to accurately detect the direction of the sound source of the blind spot vehicle by accurately removing the influence of the reflected sound without affecting the road surface condition due to weather such as rainy weather.

  Further, the traveling sound condition is a road surface condition indicating a gravel road or a paved road, and the sound pressure threshold value switching unit is information obtained from a car navigation installed in the host vehicle or vibration detection obtained from a vibration sensor. Using the result, the road surface condition of the road surface on which the blind spot vehicle travels is acquired as the condition of the running sound of the blind spot vehicle, and acquired from the plurality of sound pressure threshold values held by the sound pressure threshold processing unit A sound pressure threshold value corresponding to the road surface condition may be selected.

  With this configuration, it is possible to accurately detect the direction of the sound source of the blind spot vehicle by accurately removing the influence of the reflected sound without affecting the pavement state of the road surface.

  Further, the condition of the traveling sound is a traveling speed of the blind spot vehicle, and the sound pressure threshold value switching unit determines the traveling sound condition of the blind spot vehicle from the speed limit information of the road on which the blind spot vehicle travels. A travel speed may be acquired, and a sound pressure threshold corresponding to the acquired travel speed of the blind spot vehicle may be selected from the plurality of sound pressure thresholds held by the sound pressure threshold processing unit.

  By this configuration, for example, it is determined that the blind spot vehicle is traveling at the speed limit, and the sound pressure threshold corresponding to the travel speed is selected, so that the influence of the reflected sound does not affect the difference in the travel speed of the blind spot vehicle. The direction of the sound source of the blind spot vehicle can be accurately detected.

  Preferably, the sound collection unit includes a sound collection unit disposed on the right side of the host vehicle and a sound collection unit disposed on the left side of the host vehicle, and the vehicle detection unit collects the sound at the left sound collection unit. Detecting the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle using the sound outside the vehicle and using the outside sound collected by the right sound collecting unit to detect the direction of the left side of the host vehicle. The direction of the sound source of the blind spot vehicle that exists may be detected.

  With this configuration, (i) it is possible to suppress the sound pressure attenuation due to diffraction by detecting the direction of the sound source of the blind spot vehicle using the outside sound collected by the sound collecting unit far from the blind spot vehicle (sound source). it can. Further, (ii) the direction of arrival of the reflected sound by the shielding object collected by the sound collecting unit near the reflection position of the shielding object is out of the detection target. Further, (iii) the reflected sound from the shielding object collected by the sound collecting unit far from the reflection position of the shielding object is greatly attenuated by the distance. From these three characteristics (i) to (iii), the sound pressure of the diffracted sound becomes larger than that when the sound is collected by the sound collecting unit close to the sound source, and the reflected sound is close to the arrival direction of the reflected sound. Compared to the case where the sound is collected by the sound collecting unit, it becomes smaller. For this reason, the sound pressure of the diffracted sound is higher than that of the reflected sound. For this reason, the sound pressure threshold value can be set to a small value. Therefore, the direction of the sound source of the blind spot vehicle can be detected from a distance.

  The present invention can be realized not only as a blind spot vehicle detection system including such a characteristic processing unit, but also as a blind spot vehicle detection method using the characteristic processing unit included in the blind spot vehicle detection system as a step. It can also be realized as a program for causing a computer to execute characteristic steps included in the blind spot vehicle detection method. Needless to say, such a program can be distributed via a recording medium such as a CD-ROM or a communication network such as the Internet.

  Moreover, it is also realizable as a blind spot vehicle detection apparatus provided with the sound pressure threshold value process part and vehicle detection part which are contained in a blind spot vehicle detection system.

  According to the present invention, it is possible to accurately detect the direction of the sound source of the blind spot vehicle by removing the influence of the reflected sound when there is an obstacle.

The block diagram which showed the whole structure of the blind spot vehicle detection system in Embodiment 1 of this invention. Flow chart showing operation procedure of blind spot vehicle detection system A diagram showing the relationship between the sound pressure of diffracted sound and reflected sound The figure for explaining the position of the blind spot vehicle Diagram for explaining diffracted sound The figure explaining the influence of the reflected sound by the shield Diagram showing the relationship between diffracted sound and reflected sound The figure for demonstrating the detection method of the direction of a sound source by the sound collection part which is a directional microphone installed in front of the own vehicle Diagram showing the direction of diffracted sound coming (A) The figure which shows the diffracted sound before adjusting a time axis, (b) The figure which shows the diffracted sound after the time axis is adjusted Flow chart of a method for detecting the direction of a sound source by comparing the sound pressure of outside sound The block diagram which showed the whole structure of the blind spot vehicle detection system in Embodiment 2 of this invention. The flowchart which showed the operation | movement procedure of the blind spot vehicle detection system in Embodiment 2 of this invention. The figure which shows an example of the sound pressure threshold value currently hold | maintained at the sound pressure threshold value holding part The figure which shows an example of the sound pressure threshold value currently hold | maintained at the sound pressure threshold value holding part The figure which shows an example of the sound pressure threshold value currently hold | maintained at the sound pressure threshold value holding part The block diagram which showed the whole structure of the blind spot vehicle detection system in Embodiment 3 of this invention. (A) The figure which has arrange | positioned two sound collection parts to the bumper of the own vehicle, (b) The figure which has arrange | positioned two sound collection parts on the ceiling of the own vehicle, (c) Two sound collection parts in the rear part of the own vehicle Arranged figure A diagram for explaining the right side range and the left side range of the host vehicle A diagram for explaining the right side range and the left side range of the host vehicle Diagram explaining the amount of diffraction attenuation due to the influence of the shield The figure explaining the influence of the reflected sound by the shield (A) The figure which showed the relationship of the sound pressure of the diffracted sound and the reflected sound which were collected by the sound collection part near a sound source, (b) The sound of the diffracted sound and the reflected sound which were collected by the sound collection part far from the sound source Figure showing the relationship of pressure The flowchart which showed the operation | movement procedure of the blind spot vehicle detection system in Embodiment 3 of this invention. The figure which shows an example of the sound collection part comprised with two microphones, respectively The figure which shows an example of a structure of the sound-collecting part by a directional microphone The figure explaining the conventional sound source direction estimation apparatus

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the overall configuration of the blind spot vehicle detection system according to the first embodiment of the present invention.

  In FIG. 1, the blind spot vehicle detection system 108 is a system that detects the direction of the sound source of the blind spot vehicle and presents the detection result to the driver, and includes a sound collection unit 102, a blind spot vehicle detection device 100, and a presentation unit 107. It comprises. The blind spot vehicle detection device 100 is a device that detects the direction of the sound source of the blind spot vehicle from the outside sound 101 collected by the sound collection unit 102, and includes a sound pressure threshold processing unit 103 and a vehicle detection unit 105. The sound pressure threshold processing unit 103 includes a sound pressure threshold holding unit 103A.

  The sound collection unit 102 is arranged in the own vehicle and collects the sound 101 outside the vehicle. “Outside vehicle sound” refers to sound generated outside the host vehicle including the traveling sound of other vehicles. The sound collection unit 102 is disposed on a front bumper, a door mirror, a ceiling, a rear bumper, or the like of the host vehicle. The sound collection unit 102 is specifically a microphone.

  The sound pressure threshold holding unit 103A holds a sound pressure threshold 104 at which the sound pressure of the diffracted sound is larger than the sound pressure of the reflected sound from the relationship between the diffracted sound and the reflected sound of the blind spot vehicle. The sound pressure threshold holding unit 103A is, for example, a ROM or a RAM. The “dead zone vehicle” is another vehicle when there is a sound shielding object such as a wall on a line segment connecting the host vehicle and the other vehicle. That is, the vehicle sound of the blind spot vehicle does not reach the host vehicle directly, but reaches the host vehicle after being diffracted by the shield.

  The sound pressure threshold processing unit 103 determines whether or not the vehicle exterior sound 101 collected by the sound collecting unit 102 is larger than the sound pressure threshold 104. That is, when the outside sound 101 is larger than the sound pressure threshold 104, the sound pressure of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound, and when the outside sound 101 is less than or equal to the sound pressure threshold 104, the blind spot vehicle. The sound pressure of the diffracted sound is less than the sound pressure of the reflected sound.

  When the sound pressure threshold processing unit 103 determines that the sound outside the vehicle 101 is larger than the sound pressure threshold 104, the vehicle detection unit 105 determines the direction of the sound source of the blind spot vehicle from the vehicle outside sound 101 collected by the sound collecting unit 102. Detect. That is, the vehicle detection unit 105 detects the direction of the sound source of the blind spot vehicle when the sound pressure of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound. A method for detecting the direction of the sound source will be described later.

  The presentation unit 107 presents the detection result 106 detected by the vehicle detection unit 105 to the driver. For example, the presentation unit 107 informs the direction of the sound source of the blind spot vehicle by voice, or displays the direction of the sound source of the blind spot vehicle on the display of the car navigation.

  Next, the operation of the blind spot vehicle detection device 100 configured as described above will be described.

  FIG. 2 is a flowchart showing an operation procedure of the blind spot vehicle detection system 108.

  The sound collection unit 102 arranged in the own vehicle collects the sound 101 outside the vehicle (step S200).

  Next, the sound pressure threshold processing unit 103 determines whether or not the vehicle exterior sound 101 collected by the sound collecting unit 102 is larger than the sound pressure threshold 104 stored in the sound pressure threshold holding unit 103A (step) S201).

  FIG. 3 is a diagram illustrating the relationship between the sound pressures of the diffracted sound and the reflected sound. The horizontal axis indicates the distance between the blind spot vehicle and the host vehicle. The vertical axis represents the sound pressure. In the present embodiment, as shown in FIG. 4, it is assumed that there are shielding objects on the left and right of the traveling lane of the host vehicle, and that the blind spot vehicle is traveling in a lane crossing the traveling lane of the host vehicle.

  As shown in FIG. 3, the sound pressure of the diffracted sound of the blind spot vehicle increases as the distance between the blind spot vehicle and the host vehicle decreases. Also, as the distance between the blind spot vehicle and the host vehicle becomes smaller, the sound pressure of the reflected sound of the blind spot vehicle (the reflected sound of the blind spot vehicle's running sound) increases, but as the blind spot vehicle comes to the front of the host vehicle. The sound pressure decreases. These phenomena will be described below.

  The diffracted sound will be described with reference to FIG. As shown in FIG. 5, the distance from the blind spot vehicle to the shielding object is a, the distance from the shielding object to the host vehicle is b, and the length of the line segment connecting the blind spot vehicle and the host vehicle is c. At this time, it is known that the greater the value of a + b−c, the greater the attenuation of sound due to diffraction. Since the value of a + b−c increases as the blind spot vehicle is further away, the sound attenuation amount increases and the sound pressure of the diffracted sound decreases. On the other hand, as the dead angle vehicle approaches the host vehicle, the value of a + bc decreases, so that the sound attenuation amount decreases and the sound pressure of the diffracted sound increases. Therefore, a graph of the sound pressure of the diffracted sound as shown by the solid line in FIG. 3 is obtained.

  On the other hand, the reflection sound is considered. FIG. 6 is a diagram schematically showing the reflected sound. The running sound of the blind spot vehicle located on the left side of the host vehicle is reflected by the shield located on the right side of the host vehicle and collected by the sound collecting units 102a and 102b of the host vehicle. As the blind spot vehicle approaches from the distance to the vicinity, the propagation distance of the traveling sound of the blind spot vehicle becomes shorter. For this reason, the attenuation amount of the reflected sound is reduced, and the sound pressure of the reflected sound is increased. However, when the blind spot vehicle passes a certain point, the sound pressure of the reflected sound decreases as the blind spot vehicle approaches the front. This is because the incident angle and reflection angle of sound on the reflection surface of the shield approach 90 degrees. As the incident angle and the reflection angle approach 90 degrees, the reflected sound itself becomes difficult to reach the sound collection units 102a and 102b. Therefore, the sound pressure of the reflected sound gradually decreases, and a graph of the sound pressure of the reflected sound as shown by the broken line in FIG. 3 is obtained.

  That is, as shown in FIG. 3, when there is a blind spot vehicle far from the host vehicle, the attenuation of the diffracted sound increases, so the sound pressure of the reflected sound becomes larger than the diffracted sound of the blind spot vehicle. When the diffracted sound and the reflected sound are input, the direction of the sound source of the sound having a large sound pressure is detected. For this reason, in order to detect the arrival direction of the diffracted sound instead of the reflected sound, it is necessary to obtain the direction of the sound source when the diffracted sound is larger than the reflected sound. If the sound pressure of the reflected sound is higher than the diffracted sound, the direction of arrival of the reflected sound, not the direction of the sound source of the blind spot vehicle, is mistakenly detected as the direction of the sound source of the blind spot vehicle, and thus must be removed.

  The magnitude of the sound pressure of the vehicle running sound can be estimated in advance from the running sound generation mechanism that takes into account the road surface, tires, and the like. The magnitude of the sound pressure of the reflected sound from the shield can also be estimated in advance from the properties of the actual shield such as a building. Using these pieces of information, a sound pressure threshold 104 at which the sound pressure of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound can be set in advance. In the example of FIG. 3, the sound pressure threshold 104 is set to 85 dB. As a result, for a sound larger than 85 dB, the sound pressure of the diffracted sound is larger than the sound pressure of the reflected sound.

  That is, the sound pressure threshold processing unit 103 determines whether or not the sound pressure of the sound collected by the sound collecting unit 102 is larger than the sound pressure threshold 104, so that the sound pressure of the diffracted sound is the sound pressure of the reflected sound. Determine if greater than.

  Although the sound pressure threshold value is determined, the sound pressure threshold value may be set so as to obtain the direction of the sound source when the sound pressure of the diffracted sound is several tens dB or more higher than the sound pressure of the reflected sound. In this case, since the direction accuracy of the arrival direction of the diffracted sound is increased, the direction of the sound source of the blind spot vehicle can be obtained stably. On the other hand, when the sound pressure threshold is set so as to obtain the direction of the sound source when the sound pressures of the diffracted sound and the reflected sound are substantially equal (for example, the sound pressure threshold 85 dB in FIG. 3), Since the direction can be obtained, the driver can easily determine the condition of the blind spot vehicle.

  Next, when the sound pressure threshold processing unit 103 determines that the sound 101 outside the vehicle is larger than the sound pressure threshold 104, the vehicle detection unit 105 detects the direction of the sound source of the blind spot vehicle from the sound 101 outside the vehicle (step S202). .

  When the vehicle exterior sound 101 is larger than the sound pressure threshold 104, the sound pressure of the diffracted sound is larger than the reflected sound, so that the direction of the sound source of the blind spot vehicle can be accurately detected. FIG. 7 is a diagram showing the relationship between diffracted sound and reflected sound, where the horizontal axis indicates time and the vertical axis indicates sound pressure. As shown in FIG. 7, the diffracted sound and the reflected sound are assumed to be continuous sounds. Since the sound pressure of the diffracted sound is higher than the sound pressure of the reflected sound, the reflected sound having a low sound pressure is masked by the diffracted sound having a large sound pressure. Therefore, the direction of the blind spot vehicle is determined by the diffracted sound without being affected by the reflected sound, and the direction of the sound source of the blind spot vehicle is accurately detected.

  As a first example of a method for detecting the direction of a sound source, as shown in FIG. 8, a sound collecting unit 102, which is a directional microphone, is installed in front of the host vehicle, and the sound collecting unit 102 is mechanically moved left and right. May detect the direction of the sound source. That is, the vehicle detection unit 105 detects the direction of the sound source of the blind spot vehicle by detecting the angle of the sound collection unit 102 when the sound pressure of the collected vehicle exterior sound 101 is maximized.

  As a second example of the method of detecting the direction of the sound source, the sound collecting unit 102 is configured by two horizontally arranged sound collecting units, and the arrival of the outside sound 101 collected by the two sound collecting units is reached. The direction of the sound source may be obtained from the time difference. For example, as shown in FIG. 4, the sound collection unit 102a and the sound collection unit 102b are arranged in the front bumper of the host vehicle. Further, as shown in FIG. 9, it is assumed that the diffracted sound of the blind spot vehicle comes from the direction Θ. Further, when the distance between the sound collection unit 102a and the sound collection unit 102b is L, the arrival time difference τ of the diffracted sound between the sound collection unit 102a and the sound collection unit 102b can be expressed by the following (Equation 1). .

  Here, C is the speed of sound.

  That is, if the arrival time difference τ can be obtained, the direction Θ of the sound source of the blind spot vehicle can be calculated from (Equation 1).

  FIG. 10 shows an example of a diffracted sound in which the time axis is adjusted so that the arrival time difference between the sound collection units becomes zero with respect to the diffracted sound arriving from a predetermined direction Θ. The horizontal axis represents the time axis, and the vertical axis represents the amplitude. FIG. 10A shows a diffracted sound before adjusting the time axis, and FIG. 10B shows a diffracted sound after adjusting the time axis. The vehicle exterior sound a and the vehicle exterior sound b indicate the vehicle exterior sound 101 collected by the sound collection unit 102a and the sound collection unit 102b. As shown in FIG. 10B, the vehicle detection unit 105 calculates a correlation value between the vehicle exterior sound a and the vehicle exterior sound b while sequentially delaying the time axis of the vehicle exterior sound a with reference to the vehicle exterior sound b. It is assumed that the correlation value becomes maximum when the time axis of the external sound a is delayed by the time τ. The vehicle detection unit 105 calculates the direction Θ of the sound source of the blind spot vehicle by substituting τ at this time into (Equation 1). The method for obtaining the arrival time difference τ is not limited to the method for obtaining the correlation value between the waveforms, and τ may be obtained from the phase difference between the two waveforms.

  As a third example of the method for detecting the direction of the sound source, the sound collecting unit 102 is composed of two horizontally arranged sound collecting units, and the sound of the vehicle exterior sound 101 collected by the two sound collecting units is used. The direction of the sound source may be obtained by comparing the pressures. For example, as shown in FIG. 4, the sound collection unit 102a and the sound collection unit 102b are arranged in the front bumper of the host vehicle.

  FIG. 11 is a flowchart of a method for detecting the direction of the sound source by comparing the sound pressure of the vehicle exterior sound 101. The vehicle detection unit 105 compares the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102a with the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102b (step S1001). When the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102b is larger than the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102a (YES in S1001), the vehicle detection unit 105 The direction of the sound source of the vehicle is determined to be the left side (S1002). When the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102b is equal to or lower than the sound pressure of the vehicle exterior sound 101 collected by the sound collection unit 102a (NO in S1001), the vehicle detection unit 105 detects the blind spot vehicle. The direction of the sound source is determined to be the right side (S1003).

  Referring to FIG. 2 again, the presenting unit 107 presents and informs the driver of information on the blind spot vehicle detected by the vehicle detecting unit 105 (step S203). As an example of the presentation method, there are a method of roughly informing the direction in which the blind spot vehicle approaches, such as “approaching from the right”, and a method of notifying the position of the blind spot vehicle by radar display. The presentation may be performed by voice as described above, or may be performed by displaying information on a display.

  According to such a configuration, the direction of the sound source of the blind spot vehicle is detected when the outside sound 101 collected by the sound collection unit 102 is larger than the sound pressure threshold 104 (when the diffracted sound is larger than the sound pressure of the reflected sound). Thus, it is possible to prevent the driver from presenting the wrong direction due to the reflected sound when there is an obstacle. Therefore, the direction of the sound source of the blind spot vehicle can be accurately detected.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment, one type of sound pressure threshold value for determining the sound pressure of the sound outside the vehicle is used. However, in the second embodiment, a plurality of types of sound pressure threshold values are prepared, from which the driving sound of the blind spot vehicle is detected. The point which selects the sound pressure threshold value corresponding to conditions differs from Embodiment 1.

  FIG. 12 is a block diagram showing the overall configuration of the blind spot vehicle detection system according to the second embodiment of the present invention. In FIG. 12, the same components as those in FIG.

  In FIG. 12, the blind spot vehicle detection system 404 is a system that detects the direction of the sound source of the blind spot vehicle and presents the detection result to the driver, and includes a sound collection unit 102, a blind spot vehicle detection device 400, and a presentation unit 107. It comprises. The blind spot vehicle detection device 400 is a device that detects the direction of the sound source of the blind spot vehicle from the outside sound 101 collected by the sound collection unit 102, and includes a sound pressure threshold processing unit 401, a sound pressure threshold switching unit 403, and a vehicle. And a detection unit 105. The sound pressure threshold processing unit 401 includes a sound pressure threshold holding unit 401A.

  The sound pressure threshold holding unit 401A holds a plurality of sound pressure thresholds 402 corresponding to the driving sound conditions.

  The sound pressure threshold value switching unit 403 acquires the driving sound condition of the blind spot vehicle, and the sound pressure corresponding to the acquired driving sound condition from the plurality of sound pressure threshold values held by the sound pressure threshold value holding unit 401A. Select a threshold.

  The sound pressure threshold processing unit 401 uses the sound pressure threshold 402 selected by the sound pressure threshold switching unit 403 and corresponding to the condition of the driving sound of the blind spot vehicle to sound the outside sound 101 collected by the sound collecting unit 102. It is determined whether the pressure threshold value switching unit 403 is greater than the selected sound pressure threshold value.

  Next, the operation of the blind spot vehicle detection device 400 configured as described above will be described.

  FIG. 13 is a flowchart showing an operation procedure of the blind spot vehicle detection system 404.

  The sound collection unit 102 arranged in the own vehicle collects the sound 101 outside the vehicle (step S200).

  The sound pressure threshold switching unit 403 obtains the condition of the driving sound of the blind spot vehicle by determining the condition of the driving sound of the blind spot vehicle, and the sound pressure threshold holding unit 401A holds a plurality of sound pressure threshold values. The sound pressure threshold value corresponding to the acquired traveling sound condition is selected from the inside (step S500).

  As an example of the traveling sound conditions, a weather situation indicating rainy weather or clear weather will be described. When the road surface gets wet in the rain, the sound pressure of the tire running sound increases by a certain value. Conversely, when the road surface is dry, the sound pressure of the tire running sound decreases by a certain value. From this relationship, the sound pressure threshold value processing unit 401 associates the sound pressure threshold value 402 at which the diffracted sound is larger than the sound pressure of the reflected sound with the traveling sound condition in advance for each of rainy weather and fine weather. Keep it. FIG. 14 is a diagram illustrating an example of the sound pressure threshold value 402 held in the sound pressure threshold value holding unit 401A. The sound pressure threshold holding unit 401A stores 85 dB as a sound pressure threshold during fine weather, and 90 dB as a sound pressure threshold during rainy weather. The sound pressure threshold value switching unit 403 determines whether the weather condition is rainy or sunny using a wiper operation or a raindrop sensor. That is, when determining the weather condition using the wiper, the sound pressure threshold value switching unit 403 acquires the weather condition indicating rainy weather as a condition of the driving sound of the blind spot vehicle when the wiper is operating, and the wiper When it is not operating, a weather condition indicating a clear sky is acquired as a condition of the driving sound of the blind spot vehicle. Further, when determining the weather condition using the raindrop sensor, the sound pressure threshold value switching unit 403 acquires the weather condition indicating rainy weather as a condition of the driving sound of the blind spot vehicle when the raindrop sensor detects the raindrop, When the raindrop sensor does not detect raindrops, a weather condition indicating fine weather is acquired as a condition of the running sound of the blind spot vehicle. Next, the sound pressure threshold value switching unit 403 selects a sound pressure threshold value corresponding to the acquired weather condition from the plurality of sound pressure threshold values held by the sound pressure threshold value holding unit 401A. In the example of FIG. 14, 90 dB is selected as the sound pressure threshold in the case of rainy weather, and 85 dB is selected as the sound pressure threshold in the case of fine weather.

  As another example of the traveling sound condition, a road surface condition indicating a gravel road or a paved road will be described. When the vehicle travels on a gravel road, the sound pressure of the tire traveling sound increases by a certain value. Conversely, when traveling on a paved road, the sound pressure of the tire traveling sound decreases by a certain value. From this relationship, for each of the gravel road and the paved road, the sound pressure threshold value processing unit is associated with the sound pressure threshold value 402 in which the diffracted sound is larger than the sound pressure of the reflected sound in advance in association with the traveling sound condition (road surface condition) 401. The sound pressure threshold value switching unit 403 acquires the road surface condition of the road surface on which the blind spot vehicle travels as a condition of the traveling sound of the blind spot vehicle using information obtained from the car navigation or a vibration sensor. In addition, the sound pressure threshold switching unit 403 selects a sound pressure threshold corresponding to the acquired road surface condition from a plurality of sound pressure thresholds held by the sound pressure threshold holding unit 401A.

  As another example of the traveling sound condition, the traveling speed of the blind spot vehicle will be described. When the vehicle travels at a high speed, the sound pressure of the tire traveling sound increases by a certain value. Conversely, when traveling at low speed, the sound pressure of the tire traveling sound decreases by a certain value. From this relationship, for each traveling speed, a sound pressure threshold value 402 at which the diffracted sound is larger than the sound pressure of the reflected sound is previously stored in the sound pressure threshold value processing unit 401 in association with the traveling sound condition (traveling speed). . The sound pressure threshold switching unit 403 uses the speed limit information of the road on which the blind spot vehicle travels, and acquires the travel speed of the blind spot vehicle as the condition of the travel sound of the blind spot vehicle. For example, the car navigation system acquires speed limit information of a road on which a blind spot vehicle travels from VICS (Vehicle Information and Communication System), and the sound pressure threshold value switching unit 403 is indicated by the speed limit information as the travel speed of the blind spot vehicle. The speed limit may be acquired. Further, when the road on which the blind spot vehicle is traveling is congested, a speed (for example, a constant speed of 15 km) corresponding to the traffic condition may be acquired as the traveling speed of the blind spot vehicle. Next, the sound pressure threshold value switching unit 403 selects a sound pressure threshold value corresponding to the acquired traveling speed of the blind spot vehicle from a plurality of sound pressure threshold values held by the sound pressure threshold value holding unit 401A.

  Referring to FIG. 13 again, the sound pressure threshold processing unit 401 determines whether or not the vehicle exterior sound 101 collected by the sound collecting unit 102 is larger than the sound pressure threshold 402 selected by the sound pressure threshold switching unit 403. (Step S201).

  Subsequent processing (steps S202 and S203) is the same as that in the first embodiment, and a description thereof will be omitted.

  According to such a configuration, rain or sunny weather is determined using the operation of the wiper or the raindrop sensor. The sound pressure threshold value is changed depending on the difference in road surface condition in the weather condition indicating rainy weather or fine weather, which is one of the driving sound conditions. Thereby, the influence of the reflected sound can be accurately removed without being affected by the road surface condition due to weather such as rainy weather. Therefore, the direction of the sound source of the blind spot vehicle can be accurately detected, and the accurate direction of the sound source of the blind spot vehicle can be presented to the driver.

  Also, the difference in road surface condition between gravel road and paved road is determined using information obtained from car navigation or a vibration sensor. The sound pressure threshold value is changed according to the difference in road surface conditions of a gravel road or a paved road, which is one of the conditions of running sound. Thereby, the influence of the reflected sound can be accurately removed without being affected by the pavement state of the road surface. Therefore, the direction of the sound source of the blind spot vehicle can be accurately detected, and the accurate direction of the sound source of the blind spot vehicle can be presented to the driver.

  Further, the difference in the traveling speed of the blind spot vehicle is determined using the speed limit information. The sound pressure threshold is changed according to the difference in the traveling speed of the blind spot vehicle, which is one of the traveling sound conditions. Thereby, the influence of the reflected sound can be accurately removed without being affected by the difference in the traveling speed of the blind spot vehicle. Therefore, the direction of the sound source of the blind spot vehicle can be accurately detected, and the accurate direction of the sound source of the blind spot vehicle can be presented to the driver.

  In the second embodiment, the weather condition, the road surface condition, or the traveling speed is used as the condition of the driving sound of the blind spot vehicle. However, a combination of these may be used as the condition of the driving sound of the blind spot vehicle. FIG. 15 is a diagram illustrating an example of the sound pressure threshold value 402 held in the sound pressure threshold value holding unit 401A. The sound pressure threshold holding unit 401A shows the relationship between the sound pressure threshold and the condition of the running sound, which is a combination of the weather situation (road surface wetness), the road surface situation (road surface), and the running speed (dead angle vehicle speed). Has been. For example, when the weather condition is clear, the road surface condition is a paved road, and the traveling speed is less than 30 km, the sound pressure threshold value switching unit 403 selects 80 dB as the sound pressure threshold value.

  The sound pressure threshold holding unit 401A stores the reference sound pressure threshold as shown in FIG. 16 instead of storing the running sound condition and the sound pressure threshold in association with each other as shown in FIG. The difference between the running sound condition and the reference sound pressure threshold value may be stored. For example, when the weather condition is clear, the road surface condition is a paved road, and the traveling speed is 30 km or more, the difference in the sound pressure threshold is +5 dB. For this reason, the sound pressure threshold value switching unit 403 selects 85 dB obtained by adding the difference +5 dB of the sound pressure threshold value to the reference sound pressure threshold value 80 dB as the sound pressure threshold value in the traveling sound condition.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. In the first and second embodiments, the direction of all the sound sources of the blind spot vehicle is detected using the outside sound 101 collected by the sound collecting unit 102. However, in the third embodiment, a plurality of collection points are collected on the own vehicle. The difference from Embodiments 1 and 2 is that a sound section is installed and the detection range of the direction of the sound source is changed for each sound collection section.

  FIG. 17 is a block diagram showing the overall configuration of the blind spot vehicle detection system according to the third embodiment of the present invention. In FIG. 17, the same components as those in FIG.

  In FIG. 17, a blind spot vehicle detection system 602 is a system that detects the direction of the sound source of the blind spot vehicle and presents the detection result to the driver, and includes a sound collecting unit 102a, a sound collecting unit 102b, and a blind spot vehicle detection device. 600 and a presentation unit 107. The blind spot vehicle detection device 600 is a device that detects the direction of the sound source of the blind spot vehicle from the outside sound 101a collected by the sound collection unit 102a or the sound collection unit 102b collected by the sound collection unit 102b. A processing unit 103 and a vehicle detection unit 601 are provided. The sound collection unit 102a and the sound collection unit 102b are spaced apart from each other and disposed on the host vehicle. The sound pressure threshold processing unit 103 includes a sound pressure threshold holding unit 103A.

  FIG. 18 shows an example of a method for arranging the sound collection unit 102a and the sound collection unit 102b. As shown in FIG. 18 (a), the front bumper of the host vehicle is disposed on the right side and the left side of the front bumper. As shown in FIG. 18 (b), the vehicle is disposed on the right side and the left side of the ceiling. As shown in FIG. 18 (c), there is a method in which the vehicle is separated from the right and left sides of the rear part of the host vehicle.

  The sound collection unit 102a is disposed on the right side of the host vehicle and collects the vehicle exterior sound 101a. The sound collection unit 102b is disposed on the left side of the host vehicle and collects the outside sound 101b.

  The sound pressure threshold processing unit 103 performs threshold processing on each of the vehicle exterior sound 101a collected by the sound collection unit 102a and the vehicle exterior sound 101b collected by the sound collection unit 102b as in the first embodiment.

  The vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle using the outside sound 101b collected by the left sound collection unit 102b, and detects the blind spot vehicle existing in the left range. The direction of the sound source is not detected. Further, the vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle existing in the left range of the host vehicle using the outside sound 101a collected by the right sound collection unit 102a, and the blind spot vehicle existing in the right range. The direction of the sound source is not detected. That is, the vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle using only the right side range of the host vehicle as the detection target using the outside sound 101b collected by the left sound collection unit 102b. In addition, the vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle using only the left side range of the host vehicle as a detection target using the outside sound 101a collected by the right sound collection unit 102a. Note that not detecting the direction of the sound source includes the case where the direction of the sound source is detected but not output.

  FIG. 19 is a diagram for explaining the right side range and the left side range of the host vehicle. A straight line is assumed that is parallel to the longitudinal direction of the host vehicle (the straight direction of the host vehicle) and is indicated by a broken line that is equidistant from the sound collection unit 102a and the sound collection unit 102b. Let the right side and the left side of the straight line shown with a broken line toward the advancing direction of the own vehicle be the right side range and the left side range of the own vehicle, respectively. The sound collecting unit 102a and the sound collecting unit 102b are preferably separated by at least 50 cm, preferably 1 m or more.

  FIG. 20 is another diagram for explaining the right side range and the left side range of the host vehicle. It is assumed that the sound collection unit 102a and the sound collection unit 102b are directional microphones whose directivity ranges are ranges 301a and 301b, respectively. Assume a straight line indicated by a broken line that is equidistant from the ranges 301a and 301b (the radiation intensity (sound pressure sensitivity) of the directivity of the sound collection unit 102a and the sound collection unit 102b is equal). When the sound source is on this straight line, the sound pressure of the sound collected by the sound collection unit 102a is equal to the sound pressure of the sound collected by the sound collection unit 102b. Let the right side and the left side of the straight line shown with a broken line toward the advancing direction of the own vehicle be the right side range and the left side range of the own vehicle, respectively. The sound collecting unit 102a and the sound collecting unit 102b are preferably separated by at least 50 cm, preferably 1 m or more.

  FIG. 21 is a diagram for explaining the magnitude of diffraction attenuation due to the influence of the shield.

  FIG. 21 shows an example in which a blind spot vehicle is present in the blind spot of the shield in the left range of the host vehicle. The magnitude of the diffraction attenuation amount is determined by the angle formed by the sound source position (dead angle vehicle), the angle of the shielding object, and the sound collection unit, and the diffraction attenuation amount increases rapidly when the angle becomes steep (decreases). The sound pressure attenuation due to this diffraction is extremely large compared to the distance attenuation. For this reason, the sound pressure attenuation amount due to diffraction can be reduced to a small extent by collecting the dead-angle vehicle in the left range by the right-side sound collecting unit 102a far from the dead-angle vehicle (sound source) as in this configuration. As a result, the blind spot vehicle sound can be collected with high sensitivity (sound pressure is increased). In addition, when collecting a blind spot vehicle in the right range with the sound collecting unit 102b on the left side, the blind spot vehicle sound can be collected with high sensitivity by the same principle.

  FIG. 22 is a diagram for explaining the influence of the reflected sound by the shield.

  FIG. 22 shows an example in which a blind spot vehicle exists in the blind spot of the shield in the right range of the host vehicle. In this example, the sound emitted from the blind spot vehicle is reflected by the left-side shield of the host vehicle, and the reflected sound arrives from the left side. Since the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle is detected using the outside sound 101b collected by the left sound collecting unit 102b, the reflected sound arriving from the left side is not detected and the direction Will not be detected. On the other hand, when the vehicle exterior sound 101a collected by the right sound collecting unit 102a is used, the reflected sound that arrives from the left side is within the detection target, but the reflection position from the shielding object and the sound collecting unit 102a are a distance from each other. Therefore, the reflected sound is greatly attenuated depending on the distance.

  FIG. 23 is a diagram showing the relationship between the sound pressures of the diffracted sound and the reflected sound.

  FIG. 23 (a) shows the relationship between the sound pressures of the diffracted sound and the reflected sound similar to those shown in FIG. 3 of the first embodiment collected by the sound collecting unit near the diffracted sound source. ing. The horizontal axis indicates the distance between the blind spot vehicle and the host vehicle. The vertical axis represents the sound pressure.

  FIG. 23B shows the relationship between the sound pressures of the diffracted sound and the reflected sound according to the configuration of the third embodiment. That is, the relationship between the sound pressure of the diffracted sound and the reflected sound collected by the sound collection unit far from the diffracted sound source is shown. The horizontal axis indicates the distance between the blind spot vehicle and the sound collection unit. The vertical axis represents the sound pressure. According to the third embodiment, (i) by collecting the diffracted sound at the sound collecting unit far from the blind spot vehicle (sound source), it is possible to suppress the sound pressure attenuation amount due to diffraction. Further, (ii) the direction of the reflected sound collected by the sound collecting unit close to the reflection position of the shield is outside the detection target. Furthermore, (iii) the reflected sound collected by the sound collection unit far from the reflection position of the shielding object is greatly attenuated by the distance. From these three characteristics (i) to (iii), the sound pressure of the diffracted sound is larger than that collected by the sound collecting unit near the diffracted sound source, and the reflected sound is in the direction of arrival of the reflected sound. Compared to the case where the sound is collected by a nearby sound collecting unit, it becomes smaller. For this reason, the sound pressure of the diffracted sound is higher than that of the reflected sound. For this reason, the sound pressure threshold 104 can be set to a small value, and a blind spot vehicle can be detected from a distance.

  Next, the operation of the blind spot vehicle detection device 600 configured as described above will be described.

  FIG. 24 is a flowchart showing an operation procedure of the blind spot vehicle detection system 602.

  The sound collection unit 102a is disposed on the right side of the host vehicle and collects the vehicle exterior sound 101a. The sound collection unit 102b is disposed on the left side of the host vehicle and collects the vehicle exterior sound 101b (step S1100).

  The sound pressure threshold processing unit 103 performs threshold processing on each of the vehicle exterior sound 101a collected by the sound collection unit 102a and the vehicle exterior sound 101b collected by the sound collection unit 102b in the same manner as in the first embodiment (step). S1101). That is, the sound pressure threshold processing unit 103 determines whether each of the outside sound 101a and the outside sound 101b is larger than the sound pressure threshold 104 held in the sound pressure threshold holding unit 103A.

  The vehicle detection unit 601 uses a vehicle exterior sound 101b having a sound pressure higher than the sound pressure threshold 104 among the vehicle exterior sound 101b collected by the left sound collection unit 102b, and detects the sound source of the blind spot vehicle existing in the right range of the host vehicle. Detect direction. In addition, the vehicle detection unit 601 uses a vehicle exterior sound 101a having a sound pressure higher than the sound pressure threshold 104 among the vehicle exterior sound 101a collected by the right sound collection unit 102a, and detects a blind spot vehicle existing in the left range of the host vehicle. The direction of the sound source is detected (step S1102).

  As an example, as shown in FIG. 25, the sound collecting unit 102a is configured by two horizontally arranged microphones 102aL and 102aR, and the sound collecting unit 102b is configured by two horizontally arranged microphones 102bL and 102bR. Shall be. The vehicle detection unit 601 obtains the direction of the sound source of the blind spot vehicle based on the arrival time difference between the vehicle exterior sound 101a collected by the microphone 102aL and the vehicle exterior sound 101a collected by the microphone 102aR. At this time, the range for searching the direction of the sound source is limited to the left range of the host vehicle. The method for obtaining the direction of the sound source is as described in the first embodiment.

  Regarding the method in which the vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle, the vehicle detection unit 601 detects the direction of the sound source of the blind spot vehicle present in the left range of the host vehicle. It can be performed in the same manner as the method.

  Further, the sound pressures of the microphones 102aL and 102aR may be compared to determine the direction of the sound source. This method can be obtained by the same method as in the first embodiment described with reference to FIG.

  Furthermore, as shown in FIG. 26, the sound collecting unit 102a may be a directional microphone having directivity on the left side of the own vehicle, and the sound collecting unit 102b may be a directional microphone having directivity on the right side of the own vehicle. Good. In this case, the vehicle detection unit 601 determines that the direction of the sound source of the blind spot vehicle is the left side when the sound collection unit 102a collects the vehicle exterior sound 101a whose sound pressure is higher than the sound pressure threshold. In addition, the vehicle detection unit 601 determines that the direction of the sound source of the blind spot vehicle is the right side when the sound collection unit 102b collects the outside sound 101b having a sound pressure higher than the sound pressure threshold.

  Referring to FIG. 24 again, the presenting unit 107 presents and informs the driver of information on the blind spot vehicle detected by the vehicle detecting unit 105 (step S203). The information presentation method is the same as that in the first embodiment.

  According to such a configuration, the vehicle exterior sound collected by the left sound collecting unit is detected by detecting the direction of the sound source of the blind spot vehicle existing in the left range of the host vehicle from the vehicle outside sound collected by the right sound collecting unit. To the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle. For this reason, (i) the sound pressure attenuation amount by diffraction can be suppressed small by collecting a diffracted sound in the sound collection part far from a blind spot vehicle (sound source). Further, (ii) the direction of the reflected sound collected by the sound collecting unit close to the reflection position of the shield is outside the detection target. Furthermore, (iii) the reflected sound collected by the sound collection unit far from the reflection position of the shielding object is greatly attenuated by the distance. From these three characteristics (i) to (iii), the sound pressure of the diffracted sound is larger than that collected by the sound collecting unit near the sound source, and the reflected sound is a collection that is close to the arrival direction of the reflected sound. It becomes smaller than the case where the sound is collected by the sound part. For this reason, the sound pressure of the diffracted sound is higher than that of the reflected sound. For this reason, the sound pressure threshold 104 can be set to a small value, and a blind spot vehicle can be detected from a distance.

  As mentioned above, although the blind spot vehicle detection system which concerns on embodiment of this invention was demonstrated, this invention is not limited to Embodiment 1-3.

  Among the blind spot vehicle detection systems described above, the essential components for the present invention are the sound collection unit, the sound pressure threshold processing unit, and the vehicle detection unit, and the presentation unit may not be included. Among the blind spot vehicle detection devices described above, the essential components for the present invention are the sound pressure threshold value processing unit and the vehicle detection unit, and the sound pressure threshold value switching unit may not be included.

  Further, according to the blind spot vehicle detection system, it is possible to detect the direction of the sound source of both vehicles other than the own vehicle without distinguishing between the blind spot vehicle and other vehicles that are not dead from the host vehicle.

  Each of the above systems or devices may be specifically configured as a computer system including a microprocessor, ROM, RAM, hard disk drive, display unit, keyboard, mouse, and the like. A computer program is stored in the RAM or hard disk drive. Each system or each device achieves its functions by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

  Furthermore, a part or all of the constituent elements constituting each of the above systems or apparatuses may be constituted by one system LSI (Large Scale Integration). The system LSI is an ultra-multifunctional LSI manufactured by integrating a plurality of components on a single chip, and specifically, a computer system including a microprocessor, ROM, RAM, and the like. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program.

  Furthermore, a part or all of the components constituting each of the above systems or devices may be configured from an IC card or a single module that can be attached to and detached from each system or each device. The IC card or module is a computer system that includes a microprocessor, ROM, RAM, and the like. The IC card or the module may include the super multifunctional LSI described above. The IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

  Further, the present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.

  Furthermore, the present invention provides a non-transitory recording medium that can read the computer program or the digital signal, for example, a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD ( It may be recorded on a Blu-ray Disc (registered trademark), a semiconductor memory, or the like. The digital signal may be recorded on these non-temporary recording media.

  In the present invention, the computer program or the digital signal may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, a data broadcast, or the like.

  The present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program, and the microprocessor operates according to the computer program.

  Further, by recording the program or the digital signal on the non-temporary recording medium and transferring it, or transferring the program or the digital signal via the network or the like, another independent computer It may be implemented by the system.

  Furthermore, the above embodiment and the above modification examples may be combined.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the blind spot vehicle detection system of the present invention, it is possible to detect the direction of the sound source of the blind spot vehicle existing in the blind spot of the shield by removing the influence of the reflected sound. For this reason, the blind spot vehicle detection system according to the present invention can be applied to a blind spot vehicle detection system for safe driving support that detects in advance a blind spot vehicle hidden behind an obstacle such as an encounter and notifies the driver.

100, 400, 600 Blind spot vehicle detection device 101, 101a, 101b Outside vehicle sound 102, 102a, 102b Sound collecting unit 102aL, 102aR, 102bL, 102bR Microphone 103, 401 Sound pressure threshold processing unit 103A, 401A Sound pressure threshold holding unit 104, 402 Sound pressure threshold 105, 601 Vehicle detection unit 106 Detection result 107 Presentation unit 108, 404, 602 Blind spot vehicle detection system 403 Sound pressure threshold switching unit

Claims (10)

A sound collection unit that is arranged in the host vehicle and collects outside sound;
The sound pressure threshold of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound of the blind spot vehicle, and the sound pressure of the outside sound collected by the sound collecting unit is greater than the sound pressure threshold. A sound pressure threshold processing unit for determining whether or not it is large;
When the sound pressure threshold processing unit determines that the sound pressure of the outside sound is larger than the sound pressure threshold, the direction of the sound source of the blind spot vehicle is detected from the outside sound collected by the sound collecting unit. A vehicle detection unit;
A blind spot vehicle detection system comprising: The sound pressure threshold processing unit holds a plurality of sound pressure thresholds each corresponding to the condition of the running sound of the blind spot vehicle,
The blind spot vehicle detection system further acquires a condition of the traveling sound of the blind spot vehicle, and sets the acquired traveling sound condition from the plurality of sound pressure threshold values held by the sound pressure threshold processing unit. A sound pressure threshold value switching unit for selecting a corresponding sound pressure threshold value;
The sound pressure threshold processing unit determines whether or not the sound pressure of the outside sound collected by the sound collecting unit is larger than the sound pressure threshold selected by the sound pressure threshold switching unit. Blind spot vehicle detection system. The traveling sound condition is a weather condition indicating rainy weather or sunny weather,
The sound pressure threshold switching unit obtains a weather condition indicating rain as a condition of the driving sound of the blind spot vehicle when a wiper installed in the own vehicle is operating, and when the wiper is not operating A weather condition indicating a clear sky is acquired as a condition of the driving sound of the blind spot vehicle, and a sound pressure threshold value corresponding to the acquired weather condition is selected from the plurality of sound pressure threshold values held by the sound pressure threshold value processing unit. The blind spot vehicle detection system according to claim 2 to be selected. The traveling sound condition is a weather condition indicating rainy weather or sunny weather,
When the raindrop sensor installed in the host vehicle detects a raindrop, the sound pressure threshold value switching unit acquires a weather condition indicating rain as a driving sound condition of the blind spot vehicle, and the raindrop sensor does not detect a raindrop. A weather condition indicating clear weather as a condition of the driving sound of the blind spot vehicle, and a sound pressure corresponding to the acquired weather condition from the plurality of sound pressure threshold values held by the sound pressure threshold processing unit The blind spot vehicle detection system according to claim 2, wherein a threshold value is selected. The traveling sound condition is a road surface condition indicating a gravel road or a paved road,
The sound pressure threshold value switching unit uses the information obtained from the car navigation installed in the host vehicle or the vibration detection result obtained from the vibration sensor, and the road surface on which the blind spot vehicle travels as the condition of the traveling sound of the blind spot vehicle. 3. The blind spot vehicle detection according to claim 2, wherein a sound pressure threshold corresponding to the acquired road surface condition is selected from the plurality of sound pressure thresholds held by the sound pressure threshold processing unit. system. The condition of the traveling sound is the traveling speed of the blind spot vehicle,
The sound pressure threshold value switching unit obtains the traveling speed of the blind spot vehicle as a condition of the traveling sound of the blind spot vehicle from the speed limit information of the road on which the blind spot vehicle travels, and the sound pressure threshold processing unit holds The blind spot vehicle detection system according to claim 2, wherein a sound pressure threshold value corresponding to the acquired traveling speed of the blind spot vehicle is selected from the plurality of sound pressure threshold values. The sound collection units are separated from each other, and include a sound collection unit disposed on the right side of the host vehicle and a sound collection unit disposed on the left side,
The vehicle detection unit detects the direction of the sound source of the blind spot vehicle existing in the right range of the host vehicle using the outside sound collected by the left sound collection unit, and is collected by the right sound collection unit. The blind spot vehicle detection system according to claim 1, wherein a direction of a sound source of the blind spot vehicle existing in a left range of the host vehicle is detected using a sound outside the vehicle. The sound pressure of the diffracted sound of the blind spot vehicle has a sound pressure threshold value that is greater than the sound pressure of the reflected sound of the blind spot vehicle, and the sound pressure of the outside sound collected by the sound collecting unit arranged in the own vehicle is A sound pressure threshold value processing unit for determining whether or not the sound pressure threshold value is greater than the sound pressure threshold value;
When the sound pressure threshold processing unit determines that the sound pressure of the outside sound is larger than the sound pressure threshold, the direction of the sound source of the blind spot vehicle is detected from the outside sound collected by the sound collecting unit. A vehicle detection unit;
A blind spot vehicle detection device comprising: A sound collection step for collecting the sound outside the vehicle,
A sound for determining whether or not the sound pressure of the outside sound collected in the sound collecting step is larger than a sound pressure threshold at which the sound pressure of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound of the blind spot vehicle A pressure threshold processing step;
When the sound pressure threshold processing step determines that the sound pressure of the outside sound is greater than the sound pressure threshold, the direction of the sound source of the blind spot vehicle is detected from the outside sound collected in the sound collecting step. Vehicle detection step,
A blind spot vehicle detection method including: A sound collection step for collecting the sound outside the vehicle,
A sound for determining whether or not the sound pressure of the outside sound collected in the sound collecting step is larger than a sound pressure threshold at which the sound pressure of the diffracted sound of the blind spot vehicle is larger than the sound pressure of the reflected sound of the blind spot vehicle A pressure threshold processing step;
When the sound pressure threshold processing step determines that the sound pressure of the outside sound is greater than the sound pressure threshold, the direction of the sound source of the blind spot vehicle is detected from the outside sound collected in the sound collecting step. Vehicle detection step,
Blind spot vehicle detection program for causing a computer to execute.

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