JP2015105069A - Vehicular pedestrian collision sensing unit and vehicular pedestrian collision sensing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To upgrade pedestrian collision sensing performance using a single configuration.SOLUTION: Thresholds for use in sensing a collision with a pedestrian are predesignated by utilizing the fact that in case a vehicle collides, a deformation quantity of an upper part of a vehicular bumper and a deformation quantity of a lower part thereof vary depending on a type of collided object. A control unit performs second-order integration on each of results of detection, which are provided by a bumper upper part acceleration sensor and bumper lower part acceleration sensor respectively, in terms of time so as to detect the deformation quantities, and discriminates a collision with a pedestrian on the basis of the detected deformation quantities and thresholds. More particularly, if the deformation quantity of the upper part of a vehicular bumper and the deformation quantity of the lower part thereof fall within a left upper area of the drawing (an area predefined by classifying values using a larger threshold for the deformation quantity of the upper part than for the deformation quantity of the lower part), the control unit discriminates the collision with a pedestrian.

Description

  The present invention relates to a vehicle pedestrian collision detection device and a vehicle pedestrian collision detection program for detecting a pedestrian collision with a vehicle.

  Conventionally, an apparatus for determining whether or not a collision target that collided with a vehicle bumper is a pedestrian has been proposed.

  For example, in Patent Document 1, a first sensor that detects contact with a collision target and a second sensor that detects impact acceleration at a position below the first sensor are provided, and the collision target is determined based on each detection result. It has been proposed to discriminate.

  Specifically, the first sensor is disposed at substantially the same height as the bumper beam of the bumper face that covers the bumper beam at the front of the vehicle, and the contact of the output to the collision target at the front of the vehicle is monitored. Further, the second sensor is disposed below the bumper beam in the front part of the vehicle, and the impact acceleration accompanying the collision of the output to the collision target in the front part of the vehicle is monitored. Furthermore, a vehicle speed sensor is arranged on the vehicle, and the vehicle speed of the vehicle is monitored from the output. The first sensor detects a collision target contact, and the impact acceleration signal waveform output from the second sensor has a plurality of peak values satisfying a preset magnitude relationship, and the collision target by the first sensor The time from the point of contact detection to the point of occurrence of the predetermined peak value is less than or equal to the threshold for estimating the pedestrian type that is preset according to the number of peak values and the vehicle speed at the point of contact detection of the collision target by the first sensor In this case, the collision target is estimated as a short stature pedestrian. On the other hand, it is described that when the pedestrian physique type estimation threshold is exceeded, the collision target is estimated as a tall pedestrian.

  Further, in Patent Document 1, when the acceleration is detected by the second sensor and the first sensor is not turned on, it is estimated that the obstacle has a low center of gravity and the acceleration is detected by the second sensor, and the first sensor is turned on. It is described that when the initial impact acceleration by the second sensor is equal to or higher than the pedestrian estimation threshold, the obstacle is estimated as a high center of gravity small obstacle.

JP 2008-007059 A

  However, in the technique of Patent Document 1, since it is necessary to count the number of peak values of the acceleration signal in order to determine whether the collision target is a short stature pedestrian or a high stature pedestrian, the configuration is complicated. In addition, the judgment performance is affected by the peak.

  Moreover, in patent document 1, although it determines with having collided with the pedestrian when the 1st sensor is on and the initial impact acceleration detected by the 2nd sensor is below the threshold for pedestrian estimation, There is a possibility that the vehicle is determined to be a pedestrian when there is a collision, and there is room for improvement in order to improve the pedestrian collision detection performance.

  The present invention has been made in consideration of the above facts, and an object thereof is to improve the pedestrian collision detection performance with a simple configuration.

  In order to achieve the above object, the invention described in claim 1 includes a first detection unit that detects a deformation amount of the vehicle bumper or a physical quantity corresponding to the deformation amount when a collision target collides with the vehicle bumper. A second detection unit that detects a deformation amount of the vehicle bumper on the vehicle lower side from a detection position of the first detection unit when a collision target collides with the vehicle bumper or a physical amount corresponding to the deformation amount; A threshold value for determining a predetermined pedestrian collision from a difference of the deformation amount or the physical quantity depending on the type of collision target at each detection position of the first detection unit and the second detection unit; and the first detection unit And a determination unit that determines a collision with a pedestrian based on each detection result of the second detection unit.

  According to the first aspect of the present invention, in the first detection unit, the deformation amount of the vehicle bumper when a collision target (for example, a pedestrian, a small animal, an obstacle on the road, a road surface, etc.) collides with the vehicle bumper. Alternatively, a physical quantity corresponding to the deformation amount is detected.

  In the second detection unit, the deformation amount of the vehicle bumper on the lower side of the vehicle from the detection position by the first detection unit of the vehicle bumper when the collision target collides with the vehicle bumper or a physical amount corresponding to the deformation amount is obtained. Detected.

  By the way, when the collision target collides with the vehicle bumper, the deformation amount of the upper part (detection position of the first detection unit) and the deformation amount of the lower part (detection position of the second detection unit) of the vehicle bumper are the types of the collision target. It depends on. For example, when the vehicle collides with a small animal, the amount of deformation at the upper part and the amount of deformation at the lower part of the vehicular bumper are both about the same size, which is relatively smaller than when the vehicle collides with another collision target. In addition, when the vehicle bumper interferes with the road surface, the deformation amount of the upper portion of the vehicle bumper is smaller than that of the lower portion, and the deformation amount of the lower portion becomes large. In addition, when the vehicle collides with an obstacle on the road, the upper and lower deformation amounts of the vehicle bumper are both the same size and larger than when the vehicle collides with another collision target. When the vehicle collides with a pedestrian, the pedestrian falls over the hood due to the collision, so that the deformation amount of the lower part of the vehicle bumper is smaller than that of the upper part, and the deformation amount of the upper part is increased.

  Therefore, a threshold value for detecting a collision with a pedestrian is set in advance by using the fact that the deformation amount at the upper part and the deformation amount at the lower part of the vehicle bumper are different depending on the type of the collision object, and the determination unit And a pedestrian collision is determined based on each detection result of a 1st detection part and a 2nd detection part. For example, as in the invention described in claim 4, the threshold value of the detection result of the first detection unit and the detection unit of the second detection unit is larger than the detection result of the second detection unit. The determination unit determines that the vehicle has collided with the pedestrian in the case of a predetermined area separated by. Thus, the collision with a pedestrian can be reliably determined by determining the collision with a pedestrian.

  In other words, the pedestrian collision detection performance is improved by determining the collision with the pedestrian using a threshold value that uses the fact that the deformation amount of the upper part of the vehicle bumper and the deformation amount of the lower part differ depending on the type of the colliding object. Can be improved. Furthermore, since it is possible to determine a collision with a pedestrian based on only two detection results and a threshold value, it can be realized with a simple configuration.

  As in the second aspect of the invention, when at least one of the first detection unit and the second detection unit detects the deformation amount of the vehicle bumper, the collision occurs when the collision target collides with the vehicle bumper. The amount of deformation of the vehicular bumper may be detected by integrating the acceleration second-order with time, and at least one of the first detection unit and the second detection unit as in the invention according to claim 3. When detecting the physical quantity corresponding to the deformation amount, the effective mass calculated from the pressure and the vehicle speed generated when the collision target collides with the vehicle bumper may be detected as the physical quantity.

  As described above, according to the present invention, there is an effect that the pedestrian collision detection performance can be improved with a simple configuration.

It is a figure which shows schematic structure of the pedestrian collision detection apparatus for vehicles which concerns on embodiment of this invention. It is a disassembled perspective view which shows schematic structure around the bumper for vehicles. It is a figure which shows an example of the threshold value for detecting the collision with a pedestrian used with the pedestrian collision detection apparatus for vehicles which concerns on embodiment of this invention. It is a flowchart which shows an example of the flow of the process performed with the control apparatus of the pedestrian collision detection apparatus for vehicles which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the pedestrian collision detection apparatus for vehicles of a modification. It is a figure which shows an example of the threshold value for detecting the collision to a pedestrian used with the pedestrian collision detection apparatus for vehicles which concerns on a modification. It is a flowchart which shows an example of the flow of the process performed with the control apparatus of the pedestrian collision detection apparatus for vehicles which concerns on a modification. It is a figure which shows the example of a combination of an acceleration sensor and a pressure sensor.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a vehicle pedestrian collision detection apparatus according to an embodiment of the present invention.

  The vehicle pedestrian collision detection device 10 includes a control device 12 that performs various controls for detecting a collision with a pedestrian.

  The control device 12 includes a microcomputer including a CPU 12A, a RAM 12B, a ROM 12C, and an I / O 12D.

  The ROM 12C stores a program for detecting a collision with a pedestrian, a threshold value for detecting a collision with a pedestrian, and the like, and the CPU 12A executes the program stored in the ROM 12C so that the program to the pedestrian is performed. Control is performed to detect a collision. The RAM 12B is used as a cache memory or the like when executing a program.

  A bumper upper acceleration sensor 14, a bumper lower acceleration sensor 16, and an active device 18 are connected to the I / O 12D.

  The bumper upper acceleration sensor 14 is provided at a predetermined position (details will be described later) of the vehicle bumper, and detects acceleration generated by a collision of a collision target.

  The bumper lower acceleration sensor 16 is provided at a predetermined position (details will be described later) on the vehicle lower side than the bumper upper acceleration sensor 14, and detects acceleration generated by a collision of a collision target.

  The active device 18 is a device for operating a pedestrian protection device for protecting a pedestrian when a pedestrian collides. As the active device 18, for example, a device such as a gas generator that operates a pop-up hood that raises the hood to absorb a shock to a pedestrian, an inflator that operates an airbag device that is deployed on the hood, and the like can be applied. it can.

  That is, the control device 12 detects a collision with a pedestrian based on the detection results of the bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16, and sets the active device 18 when a collision with the pedestrian is detected. Control to operate.

  In the present embodiment, the bumper upper acceleration sensor 14 and the control device 12 correspond to a first detection unit of the present invention, and the bumper lower acceleration sensor 16 and the control device 12 correspond to a second detection unit of the present invention. The control device 12 corresponds to the determination unit of the present invention.

  Here, a schematic configuration around the vehicle bumper 30 will be described with reference to FIG. FIG. 2 is an exploded perspective view showing a schematic configuration around the vehicle bumper 30. Note that an arrow UP, an arrow FR, and an arrow OUT shown in FIG. 2 respectively indicate the vehicle vertical direction upper side, the vehicle front-rear direction front side, and the vehicle width direction outer side (left side).

  The vehicle bumper 30 shown in FIG. 2 is provided at the front of a vehicle such as a passenger car, for example. The vehicle bumper 30 includes a front bumper cover 32, a bumper reinforcement 34, a lower reinforcement 36, an upper absorber 38, and a lower absorber 40.

  The front bumper cover 32 covers the bumper reinforcement 34 from the front side of the vehicle, and is attached to a vehicle body such as the bumper reinforcement 34. In the lower part of the front bumper cover 32, an opening 32A for introducing wind into the radiator 42 disposed on the rear side of the bumper reinforcement 34 and the lower reinforcement 36 is formed.

  The bumper reinforcement 34 and the lower reinforcement 36 are each formed in an elongated shape extending in the vehicle width direction, and the lower reinforcement 36 is disposed on the vehicle lower side than the bumper reinforcement 34.

  Each of the upper absorber 38 and the lower absorber 40 is disposed with the vehicle width direction as a longitudinal direction. As shown in FIG. 2, the upper absorber 38 is disposed on the vehicle rear side of the front bumper cover 32. The upper absorber 38 has a cross-sectional hat shape that has a cross-sectional shape viewed from the side of the vehicle and opens to the rear side of the vehicle.

  The lower absorber 40 is disposed between the front bumper cover 32 and the lower reinforcement 36.

  In the present embodiment, as shown in FIG. 2, the bumper upper acceleration sensor 14 is provided in the upper absorber 38, and the bumper lower acceleration sensor 16 is provided in the lower absorber 40. FIG. 2 shows an example in which each of the bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16 is provided in a total of three, two on the side and one on the center of the vehicle. This is not a limitation. For example, one may be provided at the center position of the vehicle, may be provided only at two lateral locations, or may be provided at four or more locations along the vehicle width direction. When a plurality are provided, they may be provided at equal intervals or not at equal intervals.

  Next, the threshold value for detecting a collision with a pedestrian will be described in detail. FIG. 3 is a diagram illustrating an example of a threshold for detecting a collision with a pedestrian, which is used in the vehicle pedestrian collision detection apparatus 10 according to the embodiment of the present invention. Note that a threshold value for detecting a collision with a pedestrian is stored in advance in the ROM 12C.

  When the vehicle collides, the deformation amount at the upper part and the deformation amount at the lower part of the vehicle bumper 30 differ depending on the type of the collision target. For example, when the vehicle collides with a small animal, the deformation amount at the upper part and the deformation amount at the lower part of the vehicle bumper 30 are approximately the same, and are relatively smaller than when colliding with another collision target. In addition, when the vehicle bumper 30 interferes with the road surface, the deformation amount of the upper portion of the vehicle bumper 30 is smaller than that of the lower portion, and the deformation amount of the lower portion is increased. Further, when the vehicle collides with an obstacle on the road, the deformation amount of the upper part and the lower part of the bumper 30 for the vehicle are both the same size, and larger than when colliding with another collision target. . When the vehicle collides with a pedestrian, the pedestrian falls on the hood due to the collision, so that the deformation amount of the lower portion of the vehicle bumper 30 is smaller than the upper portion, and the deformation amount of the upper portion is increased.

  Therefore, in the present embodiment, a threshold value for detecting a collision with a pedestrian is set in advance by using the fact that the deformation amount at the upper part and the deformation amount at the lower part of the vehicle bumper 30 are different depending on the type of the collision object. ing.

  Specifically, as shown in FIG. 3, when the horizontal axis is the amount of deformation at the bottom of the vehicle bumper and the vertical axis is the amount of deformation at the top, the value on the vertical axis increases with respect to the increase in the value on the horizontal axis. The threshold value is set so that the value gradually increases and the horizontal axis is a predetermined value and becomes a constant value with respect to the increase of the vertical axis. As a result, the upper deformation amount and the lower deformation amount of the vehicle bumper 30 are separated in advance from the upper left region (the upper deformation amount is larger than the lower deformation amount with respect to the threshold value in FIG. 3. If the vehicle falls within a defined area), it is determined that the vehicle is a collision with a pedestrian. Thereby, the collision with the pedestrian of a vehicle is detectable.

  In the present embodiment, as described above, the bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16 are provided in order to detect the upper deformation amount and the lower deformation amount of the vehicle bumper 30.

  The bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16 detect acceleration applied to each of the upper and lower parts of the vehicle bumper 30. Therefore, by integrating the acceleration second-order by time, the upper and lower parts of the vehicle bumper are respectively integrated. The amount of deformation can be detected. That is, the control device 12 acquires the detection result of the bumper upper acceleration sensor 14 and detects the deformation amount of the upper portion of the vehicle bumper 30 by integrating the acceleration of the detection result by the second floor with time. Similarly, the amount of deformation of the lower portion of the vehicle bumper 30 is detected by acquiring the detection result of the bumper lower acceleration sensor 16 and integrating the acceleration of the detection result by the second order with respect to time. And the control apparatus 12 reads the above-mentioned threshold value, and detects the collision with the pedestrian of a vehicle by comparing with the detection result of a deformation | transformation amount.

  Next, a specific processing example performed by the control device 12 of the vehicle pedestrian collision detection device 10 according to the embodiment of the present invention configured as described above will be described. FIG. 4 is a flowchart illustrating an example of a flow of processing performed by the control device 12 of the vehicle pedestrian collision detection device 10 according to the embodiment of the present invention. In the present embodiment, the processing of FIG. 4 is described as processing performed by executing a program stored in advance in the ROM 12C, but may be processing performed by hardware. Also, the process of FIG. 4 starts when an ignition switch (not shown) is turned on.

  First, when the ignition switch is turned on, in step 100, the detection result of each acceleration sensor is acquired, and the process proceeds to step 102. That is, the control device 12 acquires the detection results of the bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16.

  In step 102, the amount of deformation of the lower part of the vehicle bumper is detected, and the routine proceeds to step 104. The deformation amount of the lower part of the vehicle bumper 30 is detected based on the detection result of the bumper lower acceleration sensor 16 acquired in step 100. Specifically, the control device 12 detects the amount of deformation of the lower portion of the vehicle bumper 30 by integrating the acceleration detected by the bumper lower acceleration sensor 16 by the second order with respect to time.

  In step 104, the amount of deformation of the upper portion of the vehicle bumper is detected, and the routine proceeds to step 106. The amount of deformation of the upper portion of the vehicle bumper 30 is detected based on the detection result of the bumper upper acceleration sensor 14 acquired in step 100. Specifically, the control device 12 detects the amount of deformation of the upper portion of the vehicle bumper 30 by integrating the acceleration detected by the bumper upper acceleration sensor 14 with the second order of time.

  In step 106, the pedestrian collision detection threshold value is read and the routine proceeds to step 108. The control device 12 reads the threshold value shown in FIG. 3 described above from a storage unit such as the ROM 12C.

  Note that the processing order of steps 102 to 106 is not limited to this, and any of them may be performed first.

  In step 108, it is determined whether a pedestrian collides with the vehicle. The determination is made based on the deformation amounts detected by the control device 12 at step 102 and step 104 and the threshold value read at step 106. Specifically, in the upper left area of FIG. 3 (within a predetermined area where the upper deformation amount is larger than the lower deformation amount with respect to the threshold value shown in FIG. ), If the determination is affirmative, the process proceeds to step 110. If the determination is negative, the process returns to step 100 and the above-described processing is repeated.

  In step 110, an operation instruction for the active device 18 is issued, and the series of processing ends. That is, the control device 12 outputs an instruction to operate to the active device 18. This activates the active device 18 to protect the pedestrian. In the present embodiment, a collision with a pedestrian can be reliably detected by the deformation amount of the upper portion of the vehicle bumper 30, the deformation amount of the lower portion, and the threshold shown in FIG. 3, and unnecessary operation of the active device 18 can be detected. Can be prevented.

  Then, the modification of the pedestrian collision detection apparatus for vehicles which concerns on embodiment of this invention is demonstrated. FIG. 5 is a block diagram illustrating a schematic configuration of a vehicle pedestrian collision detection device according to a modification. In addition, about the same structure as said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the above embodiment, the deformation amount of the vehicle bumper 30 is detected from the acceleration applied to the vehicle bumper 30. However, in the vehicle pedestrian collision detection device 11 according to the modification, the deformation of the vehicle bumper 30 is detected. The effective mass of the collision object is detected as a physical quantity corresponding to the quantity.

  That is, instead of the bumper upper acceleration sensor 14 and the bumper lower acceleration sensor 16 in the above embodiment, a bumper upper pressure sensor 15, a bumper lower pressure sensor 17, and a vehicle speed sensor 20 are provided as shown in FIG. Is different. The bumper upper pressure sensor 15, the bumper lower pressure sensor 17, and the vehicle speed sensor 20 are each connected to the I / O 12D.

  Although the illustration of the bumper upper pressure sensor 15 and the bumper lower pressure sensor 17 is omitted, for example, a pressure chamber or a pressure tube is provided in the vehicle bumper 30 to detect the pressure in the pressure chamber or the pressure tube.

  In the modification, for example, the control device 12 calculates the impulse by time-integrating the pressure detected by each pressure sensor, and calculates the effective mass of the collision target based on the calculated impulse and the vehicle speed detected by the vehicle speed sensor. To detect. The effective mass calculated here is a physical quantity corresponding to the modification in the above embodiment.

  Specifically, the effective mass is calculated by effective mass [kg] = impact [N / s] / vehicle speed [km / h] × 3.6. 3.6 is a value obtained by unit conversion.

  In the modification, the bumper upper pressure sensor 15, the vehicle speed sensor 20, and the control device 12 correspond to the first detection unit of the present invention, and the bumper lower pressure sensor 17, the vehicle speed sensor 20, and the control device 12 of the present invention. It corresponds to the second detection unit, and the control device 12 corresponds to the determination unit of the present invention.

  Next, the threshold value for detecting the collision with the pedestrian in the modification will be described in detail. FIG. 6 is a diagram illustrating an example of a threshold for detecting a collision with a pedestrian, which is used in the vehicle pedestrian collision detection device 11 according to the modification.

  As shown in FIG. 6, basically, the form is the same as the threshold shown in the above embodiment, and each parameter on the vertical and horizontal axes is the effective mass.

  That is, when the vehicle collides, the effective mass of the collision target detected from the pressure at the upper part of the vehicle bumper 30 and the effective mass of the collision target detected from the lower pressure differ depending on the type of the collision target. For example, when the vehicle collides with a small animal, the effective mass detected from the pressure at the upper portion of the bumper 30 for the vehicle and the effective mass detected from the pressure at the lower portion are both about the same size and collide with other collision targets. It is relatively smaller than the case. Further, when the vehicle bumper 30 interferes with the road surface, the effective mass detected from the pressure at the upper portion of the vehicle bumper 30 is smaller than that at the lower portion, and the effective mass detected from the lower pressure is increased. In addition, when the vehicle collides with an obstacle on the road, the effective mass detected from the pressure at the upper part of the bumper 30 for the vehicle and the effective mass detected from the pressure at the lower part are both the same size, It becomes larger than the case where it collides. When the vehicle collides with a pedestrian, the pedestrian falls over the hood due to the collision, so the effective mass detected from the pressure at the lower part of the vehicle bumper 30 is smaller than that at the upper part, and is detected from the upper pressure. Increased effective mass.

  Therefore, in the present embodiment, the effective mass detected from the pressure at the upper part of the bumper 30 for the vehicle and the effective mass detected from the pressure at the lower part are different depending on the type of the collision object. A threshold value for detecting is preset.

  Specifically, as shown in FIG. 6, when the effective mass detected from the pressure at the lower part of the vehicle bumper is on the horizontal axis and the effective mass detected from the upper pressure is on the vertical axis, the value on the horizontal axis increases. The threshold is set so that the value on the vertical axis gradually increases, and the horizontal axis is a predetermined value and becomes a constant value with respect to the increase in the vertical axis. As a result, the effective mass detected from the pressure at the top of the vehicle bumper 30 and the effective mass detected from the pressure at the bottom are the upper left region (the effective mass above the lower effective mass is higher than the effective mass below the threshold in FIG. When the vehicle falls within a predetermined area separated by a large threshold value, it is determined that the vehicle is a collision with a pedestrian. Thereby, the collision with the pedestrian of a vehicle is detectable.

  Next, a specific processing example performed by the control device 12 of the vehicle pedestrian collision detection device 11 according to the modified example configured as described above will be described. FIG. 7 is a flowchart illustrating an example of a flow of processing performed by the control device 12 of the vehicle pedestrian collision detection device 11 according to the modification. 7 is described as a process performed by executing a program stored in the ROM 12C in advance, but may be a process performed by hardware. Further, the process of FIG. 7 starts when an ignition switch (not shown) is turned on.

  First, when the ignition switch is turned on, in step 200, the detection results of the pressure sensors and the vehicle speed sensor 20 are acquired, and the process proceeds to step 102. That is, the control device 12 acquires the detection results of the bumper upper pressure sensor 15 and the bumper lower pressure sensor 17 and the detection result of the vehicle speed sensor 20.

  In step 202, the effective mass of the collision target on the lower side of the vehicle bumper is detected, and the routine proceeds to step 204. The effective mass of the collision target on the lower side of the vehicle bumper 30 is detected based on the detection result of the bumper lower pressure sensor 17 and the detection result of the vehicle speed sensor 20 acquired in step 200. Specifically, the controller 12 calculates an impulse by time-integrating the pressure detected by the bumper lower pressure sensor 17, and divides the calculated impulse [N / s] by the vehicle speed [km / h]. The effective mass is detected by integrating the value 3.6 for unit conversion.

  In step 204, the effective mass of the collision target on the upper side of the vehicle bumper is detected, and the routine proceeds to step 206. The effective mass of the collision target on the upper side of the vehicle bumper 30 is detected based on the detection result of the bumper upper pressure sensor 15 and the detection result of the vehicle speed sensor 20 acquired in step 200. Specifically, the control device 12 calculates the impulse by time-integrating the pressure detected by the bumper upper pressure sensor 15, and divides the calculated impulse [N / s] by the vehicle speed [km / h]. The effective mass is detected by integrating the value 3.6 for unit conversion.

  In step 206, the pedestrian collision detection threshold value is read and the routine proceeds to step 208. The control device 12 reads the threshold value shown in FIG. 6 described above from a storage unit such as the ROM 12C.

  Note that the processing order of steps 202 to 206 is not limited to this, and any of them may be performed first.

  In step 208, it is determined whether a pedestrian collides with the vehicle. The determination is made based on each effective mass detected in step 202 and step 204 by the control device 12 and the threshold value read in step 206. Specifically, the detected effective mass value is in the upper left area of FIG. 6 with respect to the threshold value shown in FIG. 6 (in a predetermined area divided by a threshold value where the effective mass in the upper part is larger than the effective mass in the lower part). If the determination is affirmative, the process proceeds to step 210. If the determination is negative, the process returns to step 200 and the above-described processing is repeated.

  In step 210, an operation instruction for the active device 18 is issued, and the series of processing ends. That is, the control device 12 outputs an instruction to operate to the active device 18. This activates the active device 18 to protect the pedestrian. In the present embodiment, it is possible to reliably detect a collision with a pedestrian using the effective mass detected from the pressure on the upper side of the bumper 30 for the vehicle, the effective mass detected from the pressure on the lower side, and the threshold shown in FIG. And unnecessary operation of the active device 18 can be prevented.

  In the above-described embodiment, an example in which two acceleration sensors are used has been described. In the modification, an example in which two pressure sensors are used has been described. However, the present invention is not limited to this, and the acceleration sensor and the pressure sensor are combined. You may do it. For example, as shown in FIG. 8A, a bumper upper acceleration sensor 14 and a bumper lower pressure sensor 17 may be used. As shown in FIG. 8B, a bumper upper pressure sensor 15 and a bumper lower pressure sensor 17 are used. The acceleration sensor 16 may be used. When combining the acceleration sensor and the pressure sensor, a predetermined threshold value is set based on the relationship between the deformation amount of the vehicle bumper 30 on the upper side or the lower side and the effective mass of the other collision target on the upper side or the lower side. By using it, a pedestrian's collision with the vehicle can be detected in the same manner as in the above-described embodiments and modifications.

  In the above-described embodiment, the deformation amount of the vehicle bumper 30 is detected using an acceleration sensor, and in the modification, a physical amount corresponding to the deformation amount of the vehicle bumper 30 is detected using a pressure sensor and a vehicle speed sensor. Although the example has been described, the amount of deformation of the vehicle bumper 30 and the detection of the physical quantity corresponding to the amount of deformation are not limited to this, and the amount of deformation of the vehicle bumper 30 and the amount of deformation are detected using the detection results of other sensors. A physical quantity corresponding to the quantity may be detected.

  In the above-described embodiment, the front side of the vehicle has been described as an example, but may be applied to the rear side of the vehicle.

  Further, the processing performed by the control device 12 in the above-described embodiments and modifications may be stored and distributed as a program in a storage medium or the like.

10, 11 Vehicle pedestrian collision detection device 12 Control device (first detection unit, second detection unit, determination unit)
14 Bumper upper acceleration sensor (first detector)
15 Bumper upper pressure sensor (first detector)
16 Bumper lower acceleration sensor (second detector)
17 Bumper lower pressure sensor (second detector)
20 vehicle speed sensors (first detection unit, second detection unit)
30 Vehicle bumper

Claims (4)

A first detector that detects a deformation amount of the vehicle bumper or a physical quantity corresponding to the deformation amount when the collision target collides with the vehicle bumper;
A second detection unit that detects a deformation amount of the vehicle bumper on the vehicle lower side from a detection position of the first detection unit when a collision target collides with the vehicle bumper or a physical amount corresponding to the deformation amount;
A threshold value for determining a predetermined pedestrian collision from a difference of the deformation amount or the physical quantity depending on the type of collision target at each detection position of the first detection unit and the second detection unit; and the first detection unit And a determination unit that determines a collision with a pedestrian based on each detection result of the second detection unit;
A pedestrian collision detection device for a vehicle comprising:   When at least one of the first detection unit and the second detection unit detects the deformation amount of the vehicle bumper, the acceleration generated when the collision target collides with the vehicle bumper is second-order integrated over time. The vehicle pedestrian collision detection device according to claim 1, wherein the amount of deformation of the vehicle bumper is detected.   When at least one of the first detection unit and the second detection unit detects a physical quantity corresponding to the deformation amount, an effective mass calculated from the pressure generated when the collision target collides with the vehicle bumper and the vehicle speed. The pedestrian collision detection device for a vehicle according to claim 1, wherein the pedestrian collision detection device for a vehicle is detected as the physical quantity.   In the determination unit, each detection result of the first detection unit and the second detection unit is divided by the threshold value that is larger in the detection result of the first detection unit than the detection result of the second detection unit. The pedestrian collision detection device for a vehicle according to any one of claims 1 to 3, wherein it is determined that the vehicle has collided with a pedestrian in a predetermined region.

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