JP2014052883A - Pedestrian warning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pedestrian warning device which urges a pedestrian to an action to avoid an accident and can reduce the possibility of an accident by a simple configuration without impairing quietness.SOLUTION: A pedestrian warning device 100 which is mounted on a vehicle 102 and outputs a warning to a pedestrian comprises: an infrared camera 104 for capturing an image of an area ahead of the vehicle and generating the image; a pedestrian detecting unit 134 for detecting a position of a pedestrian in the image; a self-vehicle travel area setting unit 132 which sets a self-vehicle travel area 116 to which the vehicle is predicted to travel in the future in the image; a pedestrian intrusion determination unit 138 for determining whether the pedestrian is in the self-vehicle travel area on the basis of the position of the pedestrian and the self-vehicle travel area; a relative angle measuring unit 140 which, if it is determined that the pedestrian is in the self-vehicle travel area, measures a relative angle which the direction from the vehicle to the pedestrian forms in reference to the vehicle's travel direction; and a loudspeaker 106 for outputting a narrow directional warning sound from the vehicle to the pedestrian on the basis of the relative angle.

Description

  The present invention relates to a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian.

  A traffic accident has a high proportion of pedestrian accidents, and is likely to occur at dusk or at night, for example. In particular, there are cases where elderly people do not notice the vehicle, or misunderstand the distance between the vehicle and themselves, forcing an accidental crossing and encountering an accident.

  In recent years, hybrid vehicles and electric vehicles have become widespread, but these vehicles are highly quiet and it is becoming increasingly difficult for pedestrians to recognize the vehicles. For these vehicles, it may be possible to make the pedestrian recognize the vehicle with simulated running sound or horn.

  However, if a warning is given by simulated running sound or horn, the quietness is impaired, and the influence of surrounding noise such as oncoming vehicles can be considered. For this reason, use of the above warning is limited.

  On the other hand, a technique for detecting a pedestrian and notifying a driver of the vehicle is known. However, this technique avoids accidents only on the vehicle side, and there is a limit in avoiding accidents because vehicles traveling at a certain speed have inertia.

  In addition, the above technique requires a camera with a long detection distance and high accuracy, which increases costs and is difficult to spread. Further, as an accident avoidance operation, if a sudden brake is applied, there is a possibility of a rear-end vehicle crashing. Therefore, it is preferable to prevent a situation in which a sudden brake is applied.

  Patent Document 1 describes a technique for outputting sound and light to a pedestrian and notifying the pedestrian of the vehicle. However, the technique described in Patent Document 1 merely notifies a pedestrian, does not warn a crossing person, and does not prompt an accident avoidance operation.

  Patent Document 2 describes a technique for alerting a pedestrian with a warning sound whose volume is changed according to the situation, but the silence is impaired because the volume is changed according to the situation. There is also a possibility. As an example, when considering an elderly person whose hearing ability has deteriorated and a surrounding noise environment, it is necessary to set the sound volume to a certain level or more in the above-described technique, and silence is impaired.

JP 2011-218826 A JP 2011-189916 A JP 2010-93610 A JP 2010-244474 A

  By the way, since the distance between a pedestrian and the own vehicle is usually accurately measured using the parallax between two images obtained from two cameras, a complicated configuration is required. On the other hand, Patent Documents 3 and 4 describe techniques for detecting a pedestrian using a monocular camera. According to these techniques, it is detected whether or not the object to be detected is moving, and data on the distance from the vehicle to the object becomes unnecessary.

  However, although the above technique detects the movement of the detected object, it does not determine whether the object is an object to be warned.

  The present invention has been made in view of such a problem, and an object thereof is to provide a pedestrian warning device that can prompt a pedestrian to avoid an accident with a simple configuration and can reduce the possibility of an accident without impairing silence.

  In order to solve the above problems, a typical configuration of a pedestrian warning device according to the present invention is a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian. An imaging unit, a pedestrian detection unit that detects the position of a pedestrian in the image, a host vehicle travel region setting unit that sets a host vehicle travel region in which the vehicle is predicted to travel in the future, and a pedestrian position And a pedestrian intrusion determination unit that determines whether or not a pedestrian has entered the own vehicle traveling area based on the own vehicle traveling area, and when it is determined that a pedestrian has entered the own vehicle traveling area A relative angle measurement unit that measures a relative angle formed by a direction from the vehicle toward the pedestrian with respect to the traveling direction of the vehicle, and a warning that outputs a narrow directivity warning sound from the vehicle to the pedestrian based on the relative angle And a section.

  According to the above configuration, the front of the vehicle is captured as an image by one imaging unit, and the position of the pedestrian is detected by performing image processing on the image. An example of the imaging unit is an infrared camera. By using an infrared camera, pedestrians can be detected even at night. Furthermore, when a pedestrian has entered the own vehicle traveling area, the direction toward the pedestrian is narrowly directed based on the relative angle indicating the positional relationship of the pedestrian with respect to the traveling direction of the vehicle. A sex warning sound is output.

  In the existing technology, the distance (depth) to an object such as a pedestrian is measured using left and right parallax based on images obtained from two cameras. On the other hand, in the said structure, since the relative angle of the pedestrian with respect to a vehicle is measured, it is not necessary to measure the distance to a pedestrian correctly. Also, the warning section is a narrow-directional speaker, etc., and unlike a vehicle horn or light, it can output a warning sound only to the target pedestrian and does not affect the pedestrian around by noise or light. Silence is not impaired. Therefore, according to the said structure, the possibility of an accident can be reduced without impairing quietness with a comparatively simple structure, prompting a pedestrian to avoid an accident.

  When it is determined that a plurality of pedestrians have entered the vehicle traveling area, the position of each pedestrian in the vehicle traveling area is determined according to the coordinates in the traveling direction of the vehicle, It further includes a risk determination unit that determines that a pedestrian with a smaller coordinate position is closer to the host vehicle and has a higher risk, and the relative angle measurement unit is a pedestrian whose risk is determined to be highest by the risk determination unit. It is good to measure the relative angle.

  Thereby, when a plurality of pedestrians exist in the own vehicle traveling region, the priority of the warning can be determined according to the distance from the own vehicle. That is, a warning sound is first output to a pedestrian that is present at a position where the distance from the host vehicle is smaller among a plurality of pedestrians, thereby further reducing the possibility of an accident.

The width in the left-right direction perpendicular to the traveling direction of the host vehicle in the host vehicle traveling region may be larger than the width of the host vehicle. Thereby, when a pedestrian enters the own vehicle traveling area having a width larger than the width of the own vehicle instead of the area defined by the width of the own vehicle, a warning sound is output based on the relative angle. Therefore, it is possible to prompt the pedestrian to take an accident avoidance action more quickly.

  In order to solve the above problems, a typical configuration of another pedestrian warning device according to the present invention is a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian, and images the front of the vehicle and generates an image. One imaging unit, a pedestrian detection unit that detects the position of a pedestrian in the image, a host vehicle traveling region setting unit that sets a host vehicle traveling region in which the vehicle is predicted to travel in the future, and a pedestrian And a pedestrian intrusion determination unit that determines whether or not a pedestrian has entered the own vehicle traveling area, and a pedestrian has not entered the own vehicle traveling area A risk determination unit that determines the risk level of the pedestrian in the image, and a pedestrian determined to have a high risk level by the risk level determination unit, from the vehicle to the pedestrian based on the traveling direction of the vehicle Relative angle to measure the relative angle formed by the direction of heading A measuring section, based on the relative angle, characterized in that it comprises a warning unit which toward the pedestrian from the vehicle to output a narrow directivity of the alarm sound.

  According to the above configuration, the relative angle of the pedestrian with respect to the vehicle is measured in the same manner as described above. Therefore, it is not necessary to accurately measure the distance to the pedestrian, and only one imaging unit is required. Further, the warning unit is a narrow directivity speaker or the like, and does not affect the surroundings of the pedestrian by noise or light, so that quietness is not impaired.

  Furthermore, in the above configuration, a pedestrian with a high degree of danger in the image is identified without entering the own vehicle traveling area, and the pedestrian has a narrow directivity based on the relative angle of the pedestrian to the vehicle. A warning sound can be output. Therefore, with a relatively simple configuration, an accident avoidance action can be promoted for a pedestrian who has not yet entered the own vehicle traveling area, and the possibility of an accident can be further reduced without impairing silence.

  The risk determination unit described above sets the vanishing point ahead of the own vehicle traveling area in the image, identifies the intersection where the straight line passing through the pedestrian's lowest point from the vanishing point intersects the lower edge line, It may be determined that the risk is high when the image moves toward the center of the image.

  As a result, when the intersection is directed toward the center of the image, it can be determined that the degree of danger is high because the pedestrian is approaching the own vehicle travel region. Note that when the intersection is moving away from the center of the image, the pedestrian is moving away from the traveling area of the vehicle, and therefore, it may be determined that the degree of risk is low. In this way, by paying attention to the intersection, it is also possible to determine the risk of intrusion into the own vehicle traveling area according to the moving direction of the pedestrian.

  The risk determination unit may determine that the risk is high when the intersection moves toward the center of the image and the amount of movement of the intersection per unit time exceeds a predetermined value. This makes it possible to determine the degree of risk with higher accuracy in consideration of not only the moving direction of the intersection but also the moving amount per unit time.

  The position of the pedestrian detected by the pedestrian detection unit is the coordinate of the lowest point of the pedestrian, and the determination by the pedestrian intrusion determination unit is that the coordinate of the lowest point of the pedestrian is within the own vehicle traveling region. The relative angle is determined from the center of the lower edge line, which is the lower edge of the image, to the vertical direction of the vehicle, and from the center of the lower edge line to the lowest point of the pedestrian. It may be obtained by an angle formed by a straight line connecting the two.

  Thereby, the line segment located in the image is set from the straight line corresponding to each angle, and by determining which line segment the coordinate of the lowest point of the pedestrian exists, The relative angle can be calculated.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the pedestrian warning device which can accelerate | stimulate accident avoidance action to a pedestrian with a simple structure, and can reduce the possibility of an accident, without impairing silence.

It is the figure which illustrated roughly the vehicle to which the pedestrian warning device in the embodiment of the present invention is applied. It is a functional block diagram of the pedestrian warning device of FIG. It is the flowchart which illustrated operation | movement of the pedestrian warning device of FIG. It is a figure explaining the method of measuring the relative angle of the pedestrian with respect to the own vehicle in the pedestrian warning device of FIG. It is a figure explaining determination of the risk accompanying the pedestrian's moving direction in the pedestrian warning device of FIG. It is the flowchart which illustrated operation | movement of the pedestrian warning device which is other embodiment of this invention. It is a figure explaining the judgment of the risk accompanying the position of a pedestrian's up-down direction in the pedestrian warning device of FIG. It is a figure which shows the specific example at the time of outputting a warning to a pedestrian by the pedestrian warning device of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram schematically illustrating a vehicle to which a pedestrian warning device according to an embodiment of the present invention is applied. FIG. 1A is a top view of a vehicle including a pedestrian warning device. FIG. 1B is a diagram illustrating image data obtained by an infrared camera.

  As shown in FIG. 1A, the pedestrian warning device 100 is a device that is mounted on a vehicle 102 and issues a warning to a pedestrian. One imaging unit (infrared camera 104) and a warning installed on the front side of the vehicle. (Speaker 106). The infrared camera 104 images the front of the vehicle and generates imaging data. Note that the image data 108 illustrated in FIG. 1B is processed data generated by performing later-described image processing on the captured data.

  The speaker 106 is driven at an arbitrary angle by an actuator 110 disposed on the back surface, and outputs a narrow directivity warning sound 112 as indicated by a one-dot chain line in the figure. Here, the speaker 106 outputs the warning sound 112 only toward the pedestrian A among the pedestrians A and B existing in the image data 108 as shown in FIG.

  The pedestrian A extends in the vehicle front-rear direction and is located between the opposing determination lines 114a and 114b, and is present in the own vehicle traveling region 116 where the vehicle is expected to travel in the future. The pedestrian B is located outside the determination line 114b and does not exist in the own vehicle traveling region 116. That is, the determination lines 114a and 114b are lines for determining whether or not a pedestrian is present in the own vehicle traveling area 116.

  The width Wa along the vehicle width direction of the own vehicle traveling region 116 is a value obtained by adding a margin width Wc to the vehicle width Wb of the vehicle 102 on the outside of the vehicle (that is, Wa = Wb + 2Wc). The width Wc may be appropriately set according to the speed of the vehicle 102. As an example, when the vehicle 102 is traveling at 30 to 40 km / h, the margin width 2Wc may be set to the same level as the vehicle width Wb.

  Note that an angle formed by the lines 118a and 118b indicated by dotted lines in FIG. 1A so as to extend from the infrared camera 104 may correspond to a so-called viewing angle. Further, as shown in FIG. 1B, both determination lines 114a and 114b in the image data 108 are displayed at the center of the screen from the points 122a and 122b that intersect with the lower edge line 120 that is the lower edge of the image data 108, respectively. It is shown as a line drawn toward the vanishing point 124.

  Hereinafter, the function and operation of the pedestrian warning device 100 will be described with reference to FIGS. 2 and 3. FIG. 2 is a functional block diagram of the pedestrian warning device 100 of FIG. FIG. 3 is a flowchart illustrating the operation of the pedestrian warning device 100 of FIG.

  As shown in FIG. 2, in addition to the infrared camera 104, the speaker 106, and the actuator 110, the pedestrian warning device 100 includes a vehicle information acquisition unit 126, a warning availability determination unit 128, an image information acquisition unit 130, A vehicle travel region setting unit 132, a pedestrian detection unit 134, and a control unit 136 are provided. The control unit 136 generates a drive signal for driving the actuator 110, for example, and includes a pedestrian intrusion determination unit 138, a relative angle measurement unit 140, and a risk determination unit 142.

  The vehicle information acquisition unit 126 acquires, for example, vehicle information from a vehicle ECU (Electronic Control Unit), a navigation device, or the like, that is, whether the vehicle is traveling, whether it is going straight instead of turning left or right.

  Based on the vehicle information from the vehicle information acquisition unit 126, the warning availability determination unit 128 determines whether or not a warning is possible (step S101). In step S101, when the condition that the vehicle travels and travels straight according to the vehicle information is satisfied, a warning is permitted (Yes), and the process proceeds to step S103. Is determined to be invalid (No), and the process returns to step S101 again.

  When the warning is permitted by the warning availability determination unit 128, the infrared camera 104 is activated, the front of the vehicle 102 is imaged, and imaging data is generated. Next, the image information acquisition unit 130 acquires image information based on the imaging data generated by the infrared camera 104 (step S <b> 103), and outputs the image information to the own vehicle travel region setting unit 132 and the pedestrian detection unit 134.

  Based on the image information obtained from the image information acquisition unit 130, the host vehicle travel region setting unit 132 sets the host vehicle travel region 116 shown in FIGS. 1 (a) and 1 (b) (step S105). In step S105, based on the image information obtained by measuring at one point by one infrared camera 104, the scale of the width Wa on the image data 108 is measured. Then, the line segments drawn from the intersections 122a and 122b with the lower edge line 120 toward the vanishing point 124 are set as the determination lines 114a and 114b, and an area located between the determination lines 114a and 114b is set as the own vehicle traveling area 116. Set.

  Further, the pedestrian detection unit 134 detects the position of the pedestrian in the image by detecting a face shape having a surface temperature of 28 ° C. to 39 ° C. based on the image information obtained from the image information acquisition unit 130. Is detected (step S107). In addition, the position of a pedestrian here is a coordinate of the lowest point of a pedestrian.

  Subsequently, the pedestrian intrusion determination unit 138 advances the own vehicle based on the own vehicle advance region 116 set by the own vehicle advance region setting unit 132 and the position of the pedestrian detected by the pedestrian detection unit 134. It is determined whether or not there is a pedestrian in the area 116 (step S109). If there is a pedestrian in the own vehicle traveling area 116 in step S109 (Yes), the relative angle measurement unit 140 measures the relative angle of the pedestrian with respect to the traveling direction of the own vehicle (step S111).

  In step S111, when the determination result is output from the pedestrian intrusion determination unit 138 to the relative angle measurement unit 140, the own vehicle traveling region 116 set in step S105, and the position of the pedestrian generated in step S107. Based on the above, the relative angle is measured. The signal indicating the determination result is an activation signal for the relative angle measurement unit 140.

  FIG. 4 is a diagram for explaining a method of measuring the relative angle of the pedestrian with respect to the own vehicle in the pedestrian warning device 100 of FIG. FIG. 4A is a diagram for explaining the relative angle by using simplified image data 108A. FIG. 4B is a schematic diagram showing the principle of relative angle measurement.

  First, the relative angle measurement unit 140, as shown in FIG. 4A, a straight line 144 connecting the lowest point C of the pedestrian A in the image data 108A and the center point 122C of the lower edge line 120 of the image data 108A. Is generated. Then, the relative angle measurement unit 140 may set an angle Y formed by the straight line 144 and the straight line 145 connecting the center point 122 c and the vanishing point 124 as a relative angle of the pedestrian with respect to the traveling direction of the vehicle 102. In other words, the relative angle refers to an angle formed by a direction from the vehicle 102 toward the pedestrian A based on the traveling direction of the vehicle 102.

  Here, as shown in FIG. 4B, the principle of relative angle measurement using a camera 104 </ b> A equipped with a simple flat optical lens 146 and a light receiving element 148 will be described. The camera 104A has a viewing angle X and a focal length L.

  Since the image from the point D is located at the field edge of the camera 104A, it is projected from the center line 150 of the optical lens 146 to the position E of “L · tan (X / 2)”. In addition, an image from the front of the camera, that is, a point F shifted by an angle Y from the center line 150 is projected from the center line 150 to a position G of “L · tan (Y)”.

  Here, as shown in FIG. 4A, when the horizontal width of the video (image data 108A) corresponding to the viewing angle X is the pixel Z (the number of pixels is Z), the point D is “Z / 2” pixels. (See FIG. 4B). For this reason, the position on the image data 108A of the point F corresponding to the angle Y is the position of the pixel represented by the expression “tan (Y) / tan (X / 2) · Z / 2”.

  By this formula, a plurality of line segments located in the image data 108 are set from straight lines corresponding to each angle, and by determining which line segment the lowest point C of the pedestrian A exists is The relative angle Y of the pedestrian with respect to can be calculated. Although a simple flat optical lens 146 has been described here, even a curved lens that is normally used can be converted in the same manner as described above in consideration of the refractive index.

  In this way, the relative angle measurement unit 140 shown in FIG. 2 measures the relative angle in step S111. Subsequently, the relative angle measurement unit 140 outputs a drive signal corresponding to the measured relative angle to the actuator 110. The actuator 110 receives the drive signal from the relative angle measurement unit 140, drives the speaker 106, and directs the speaker 106 toward the pedestrian A existing in the own vehicle traveling region 116 (step S113). That is, the relative angle is used as position information of a pedestrian in the own vehicle traveling area 116.

  Subsequently, as shown in FIG. 1, the speaker 106 outputs a narrow directivity warning sound 112 from the vehicle 102 toward the pedestrian A (step S115).

  When there is no pedestrian in the vehicle traveling area 116 in step S109 (No), the risk determination unit 142 determines the position of the pedestrian present in the image other than the vehicle traveling area 116 obtained in step S107. Based on the vehicle traveling area 116 set in step S105, the pedestrian risk level is determined (step S117). The signal indicating the determination result in step S109 serves as an activation signal for the risk determination unit 142.

  FIG. 5 is a diagram for explaining the determination of the degree of risk associated with the moving direction of the pedestrian in the pedestrian warning device 100 of FIG. FIG. 5A is a diagram showing a state in which a plurality of line segments 152 and 154 are set on the vehicle exterior side of the determination lines 114a and 114b that define the own vehicle traveling region 116 in the image data 108B. FIG. 5B is a diagram illustrating image data 108C obtained by enlarging a part of FIG.

  As shown in FIG. 5A, the plurality of line segments 152 and 154 extend from the portion where the lower edge line 120 of the image data 108 </ b> B is extended toward the vanishing point 124. At this time, since the line segments 152 and 154 maintain a parallel relationship with the determination lines 114a and 114b, the positional relationship between the pedestrian and the determination lines 114a and 114b is estimated depending on which line segment the pedestrian is on. it can.

  As an example, as shown in FIG. 5B, description will be made based on image data 108C that shows the right side portion of the image data 108B in FIG. Further, it is assumed that the lowest point of the pedestrian H exists on the line segment 152a included in the line segment 152 set on the image data 108C. Here, the line segment 152a is the third line segment from the outside. At this time, the line segment 152a and the lower edge line 120 intersect at an intersection 155a. It is assumed that the time when the lowest point of the pedestrian H exists on the line segment 152a is T1.

  When the lowest point of the pedestrian H moves to the position I at time T2, the position I is on the line segment 152b closest to the determination line 118a of the own vehicle traveling area 116 in the line segment 152. At this time, the line segment 152b and the lower edge line 120 intersect at an intersection 155b. That is, the intersection 155a is moving toward the own vehicle traveling region 116 between the times T1 and T2. In this case, the risk level determination unit 142 determines that the risk level of entering the host vehicle traveling area 116 is high.

  When the lowest point of the pedestrian H moves to the position J, the position J is on the outermost line segment 152 c of the line segments 152. At this time, the line segment 152c and the lower edge line 120 intersect at an intersection 155c. That is, between the times T1 and T2, the intersection 155a moves in a direction away from the own vehicle traveling region 116. In this case, the danger level determination unit 142 determines that there is no sign of entering the vehicle traveling area 116 and crossing, and the risk level is low.

  Furthermore, when the lowest point of the pedestrian H moves to the position K, the position K is on the third line segment 152d from the inside. At this time, the line segment 152d and the lower edge line 120 intersect at an intersection 155d. That is, the intersection 155a is moving toward the own vehicle traveling region 116 between the times T1 and T2. However, in this case, the risk determination unit 142 is more likely than the case where the lowest point of the pedestrian H is at the position I, although there is a sign of entering the own vehicle traveling area 116 as in the case of moving to the position I. Determines that the risk is low because it is far from the own vehicle traveling area 116.

  In this manner, the risk determination unit 142 can determine the risk according to the moving direction of the intersection 155a. The moving direction includes a direction approaching the own vehicle traveling region 116 that is the central direction in the image data 108 </ b> C, or a direction moving away from the own vehicle traveling region 116.

  In step S119, the risk determination unit 142 determines that the risk is high when the intersection 155a moves toward the center of the image data 108C and the amount of movement per unit time exceeds a predetermined value. You may judge. Alternatively, when the movement amount per unit time is equal to or less than a predetermined value, it may be determined that the degree of risk is low. In this way, it is possible to determine the degree of risk with higher accuracy in consideration of not only the moving direction of the pedestrian H but also the moving amount per unit time.

  Then, after determining the risk level in step S117, if the risk level is low (No in step S119), the risk level determination unit 142 returns to the process in step S101 again. On the other hand, if it is determined in step S119 that the degree of risk is high (Yes), the degree of risk determination unit 142 outputs the determination result to the relative angle measurement unit 140.

  Subsequently, the relative angle measurement unit 140 measures the relative angle of a pedestrian with a high degree of risk in step S111. Thereafter, the actuator 110 is driven based on the relative speed (step S113), and the speaker 106 outputs a warning sound in step S115. Then, the process of step S101 is repeated again.

  Thus, according to the pedestrian warning device 100 of the present embodiment, the presence or position of a pedestrian can be detected by capturing the front of the vehicle as an image with one infrared camera 104 and processing the image. By using the infrared camera 104, it is possible to detect a pedestrian even at night.

  In addition, when a pedestrian has entered the own vehicle traveling region 116, the pedestrian is narrowed toward the pedestrian based on a relative angle indicating the positional relationship of the pedestrian with respect to the traveling direction of the vehicle. A warning sound is output from the directional speaker 106. Thus, since the relative angle is measured, it is not necessary to accurately measure the distance to the pedestrian, and only one infrared camera 104 is required, and the configuration can be simplified.

  Further, unlike the horn or the light, the narrow-directional speaker 106 can output a warning sound only to the target pedestrian, so that noise or light is not affected around the pedestrian and the quietness is not impaired. . Therefore, with a relatively simple configuration, it is possible to promote accident avoidance behavior to pedestrians and reduce the possibility of an accident without impairing silence. The possibility of an accident can be further reduced by executing not only a pedestrian accident avoidance operation but also a driver avoidance operation.

  In addition, since the width Wa of the own vehicle traveling region 116 is larger than the width Wb of the vehicle 102, the own vehicle traveling region where the pedestrian has a width Wa larger than the width Wb, not the region defined by the width Wb of the vehicle 102. When entering 116, a warning sound can be output based on the relative angle. Therefore, it is possible to prompt the pedestrian to take an accident avoidance action more quickly.

  Furthermore, a pedestrian who has not entered the own vehicle traveling area 116 but has a high degree of danger in the image is identified, and a warning sound with a narrow directivity is given to the pedestrian based on the relative angle of the pedestrian to the vehicle. Can output. Therefore, with a relatively simple configuration, a pedestrian who has not yet entered the own vehicle traveling region 116 can be urged to avoid an accident, and the possibility of an accident can be further reduced without impairing silence.

  In the above embodiment, an example in which only one pedestrian has entered the own vehicle traveling area 116 has been described. However, the present invention is not limited to this. A warning sound may be preferentially output to a pedestrian with a high degree of danger.

  FIG. 6 is a flowchart illustrating the operation of the pedestrian warning device according to another embodiment of the present invention. The functional block itself shown in FIG. 2 is the same as the pedestrian warning device 100 described above, but the processes of the pedestrian intrusion determination unit 138 and the risk level determination unit 142 are different.

  In other words, after steps S101 to S107 described above, the pedestrian intrusion determination unit 138 returns to step S101 again if there is no pedestrian in the own vehicle travel area 116 (No in step S201). On the other hand, if a pedestrian exists in the own vehicle traveling area 116 in step S201 (Yes), the pedestrian intrusion determination unit 138 determines whether there are a plurality of pedestrians (step S203).

  If there are not a plurality of pedestrians in step S203 (No), steps S111 to S115 are executed. On the other hand, if there are a plurality of pedestrians (step S203, Yes), the risk determination unit 142 determines the distance between the plurality of pedestrians and the vehicle (step S205), and determines the pedestrian with the closest distance. (Step S207).

  FIG. 7 is a diagram for explaining determination of the degree of risk associated with the position of the pedestrian in the vertical direction in the pedestrian warning device in FIG. 6. Here, it is assumed that there are two pedestrians M and N in the own vehicle traveling area 116 as shown in the image data 108D.

  In this case, horizontal line segments 156a and l56b are set in the image data 108D. Here, since the line segment 156a is located on the nearer side than the line segment 156b, it can be understood that the distance from the own vehicle (that is, the delay until the collision) is small. The coordinates of the lowest points of the pedestrians M and N are located on the line segments 156a and 156b, respectively.

  The risk determination unit 142 determines that the pedestrian M located on the line segment 156a has a higher risk than the pedestrian N located on the line segment 156b. In other words, the risk determination unit 142 determines the perspective according to the coordinates in the vehicle traveling direction of the positions of a plurality of pedestrians in the own vehicle traveling region 116, and the pedestrian with a smaller value of the coordinates from the own vehicle. Judged that the risk level is high.

  In this way, the risk determination unit 142 performs the processes of step S205 and step S207. Then, the relative angle measurement unit 140 measures the relative angle of the pedestrian determined that the risk determination unit 142 has the highest risk, that is, the distance from the own vehicle is small (step S113). Thereafter, the above steps S113 and S115 are executed.

  Therefore, according to the processing of the pedestrian warning device in FIG. 6, when a plurality of pedestrians exist in the own vehicle traveling region 116, the priority of the warning can be determined according to the distance from the own vehicle. In other words, a warning sound is first output to a pedestrian that is located at a position where the distance from the host vehicle is smaller among a plurality of pedestrians, prompting the pedestrian to avoid an accident and further reducing the possibility of an accident. it can.

  FIG. 8 is a diagram showing a specific example when a warning is output to a pedestrian by the pedestrian warning device 100 of FIG. Here, the vehicle width Wb of the vehicle 102 on which the vehicle body warning device 100 is mounted is set to 1.8 m of 3 number size, and the speed is set to 8 m / s (about 30 km / h) assuming a residential area. The walking speed was 1.1 m / s for elderly people.

  In such a case, assuming that the pedestrian O in the position along the center of the vehicle moves to the position P or Q of the end of the vehicle, the time required for the pedestrian's avoidance action is “t1 = 0.8 sec”. Become. Further, the time until the pedestrian O notices the presence of the vehicle is “t2 = 2.2 sec”. Note that t2 is defined based on the idle running time of the brake of the vehicle 102.

  In other words, the time from when the pedestrian O notices the vehicle until it is avoided is “T = t1 + t2 = 2.8 sec”. In the meantime, the distance that the vehicle 102 approaches is “8 × 2.2 = 22.4 m”. Therefore, in the above assumption, the vehicle body warning device 100 can be realized if the detection distance of the infrared camera 104 is about 30 m.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used in a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian.

DESCRIPTION OF SYMBOLS 100 ... Pedestrian warning apparatus, 102 ... Vehicle, 104 ... Infrared camera, 106 ... Speaker, 108 ... Image data, 110 ... Actuator, 112 ... Warning sound, 114a, 114b ... Judgment line, 116 ... Own vehicle progress area, 120 ... Lower edge line, 124 ... vanishing point, 126 ... vehicle information acquisition unit, 128 ... warning availability determination unit, 130 ... image information acquisition unit, 132 ... own vehicle travel region setting unit, 134 ... pedestrian detection unit, 136 ... control unit 138 ... Pedestrian intrusion determination unit, 140 ... Relative angle measurement unit, 142 ... Risk level determination unit

Claims (7)

In a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian,
One imaging unit that images the front of the vehicle and generates an image;
A pedestrian detection unit for detecting the position of the pedestrian in the image;
A host vehicle travel region setting unit that sets a host vehicle travel region predicted to travel in the future in the image;
A pedestrian intrusion determination unit that determines whether or not a pedestrian has entered the own vehicle traveling area based on the position of the pedestrian and the own vehicle traveling area;
A relative angle measurement unit that measures a relative angle formed by a direction from the vehicle toward the pedestrian with respect to a traveling direction of the vehicle when it is determined that a pedestrian has entered the own vehicle traveling region;
A pedestrian warning device comprising: a warning unit that outputs a warning sound with narrow directivity from the vehicle toward the pedestrian based on the relative angle. When it is determined that a plurality of pedestrians have entered the own vehicle travel area, the perspective is determined according to the coordinates in the travel direction of the vehicle of the position of each pedestrian in the own vehicle travel area. , Further comprising a risk determination unit that determines that the pedestrian with a smaller value of the coordinate is closer to the own vehicle and has a higher risk,
The pedestrian warning device according to claim 1, wherein the relative angle measurement unit measures a relative angle of a pedestrian determined to have the highest degree of risk by the risk level determination unit.   3. The pedestrian warning device according to claim 1, wherein a width of the own vehicle traveling region in a left-right direction orthogonal to a traveling direction of the own vehicle is larger than a width of the own vehicle. In a pedestrian warning device that is mounted on a vehicle and issues a warning to a pedestrian,
One imaging unit that images the front of the vehicle and generates an image;
A pedestrian detection unit for detecting the position of the pedestrian in the image;
A host vehicle travel region setting unit that sets a host vehicle travel region predicted to travel in the future in the image;
A pedestrian intrusion determination unit that determines whether or not a pedestrian has entered the own vehicle traveling area based on the position of the pedestrian and the own vehicle traveling area;
When it is determined that a pedestrian has not entered the own vehicle travel area, a risk determination unit that determines the risk of the pedestrian in the image,
For a pedestrian determined to have a high degree of risk by the risk determination unit, a relative angle measurement unit that measures a relative angle formed by a direction from the vehicle toward the pedestrian with respect to the traveling direction of the vehicle;
A pedestrian warning device comprising: a warning unit that outputs a warning sound with narrow directivity from the vehicle toward the pedestrian based on the relative angle. The risk determination unit
In the image, set the vanishing point ahead of the vehicle traveling area,
A straight line passing through the lowest point of the pedestrian from the vanishing point identifies the intersection where the lower edge line intersects,
The pedestrian warning device according to claim 4, wherein it is determined that the degree of risk is high when the intersection moves toward the center of the image.   The risk determination unit determines that the risk is high when the intersection moves toward the center of the image and the amount of movement per unit time of the intersection exceeds a predetermined value. The pedestrian warning device according to claim 4, wherein the pedestrian warning device is characterized. The position of the pedestrian detected by the pedestrian detection unit is the coordinate of the lowest point of the pedestrian,
The determination by the pedestrian intrusion determination unit is performed by whether or not the coordinate of the lowest point of the pedestrian is located in the own vehicle traveling area,
The relative angle is a straight line indicating a traveling direction of the vehicle extending vertically from the center of the lower edge line which is the lower edge of the image, and a straight line connecting the center of the lower edge line to the lowest point of the pedestrian. The pedestrian warning device according to any one of claims 1 to 6, wherein the pedestrian warning device is obtained by an angle formed.

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