JP2006292624A - Pedestrian collision decision apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which can decide whether an object with which a vehicle has collided is a pedestrian or a light obstacle in an early stage after the collision. <P>SOLUTION: A first load exerted on the front of the vehicle and its temporally integrated value are calculated using a first load sensor installed in the front of the body. When a point determined from the relationship between the first load based on the output of the first load sensor and its temporally integrated value is within an area exceeding a decision map, the object with which the vehicle has collided is decided to be a pedestrian. A second load exerted on the front of the body upper than the installation position of the first sensor is detected using a second load sensor installed in the front of the body upper than the installation position of the first load sensor. When the second load based on the output of the second load sensor exceeds a predetermined value, the decision map for pedestrian collision decision is changed to a Low map of which the threshold is lower as compared to when the second load does not exceed the predetermined value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pedestrian collision determination apparatus, and more particularly to a pedestrian collision determination apparatus suitable for determining whether or not a collision target is a pedestrian when a vehicle collides with some obstacle or the like.

Conventionally, a load applied to a vehicle is detected using a load sensor disposed on a front bumper or the like at the front of the vehicle body, and whether the object on which the vehicle collides is a pedestrian or a non-pedestrian based on the detected load There is known a pedestrian collision determination apparatus that distinguishes and determines (see, for example, Patent Document 1). In this determination apparatus, the pedestrian collision determination is specifically performed based on the duration of the state in which the load applied to the vehicle based on the output of the load sensor shows a value within a certain range. If the duration of such a state is outside a certain range, it is determined that the vehicle has collided with an object other than a pedestrian, while if the duration is within a certain range, it is determined that the vehicle has collided with a pedestrian. Is done.
Japanese Patent Laid-Open No. 11-28994

  However, in the above-mentioned conventional apparatus, it is necessary to measure the duration of the state in which the load shows a value within a certain range when performing the pedestrian collision determination. Therefore, pedestrians and particularly light obstacles such as post cones and pylons are required. And cannot be distinguished early after the collision. In addition, when a vehicle collides with a light obstacle such as a post cone, which is relatively lighter than a pedestrian, at a high speed, the load applied to the vehicle is within a certain range, similar to a collision with a pedestrian at a low speed. In addition, the duration of the state may be within a certain range. In this regard, in the configuration in which the pedestrian collision determination is performed using the load applied to the vehicle and the duration thereof as in the above-described conventional device, the result of the collision with the light obstacle at the high speed is the collision with the pedestrian at the low speed. As a result, there is a risk of erroneously determining that the object on which the vehicle collided is not a pedestrian, but a pedestrian, and a highly accurate pedestrian collision determination may be performed. It was difficult.

  The present invention has been made in view of the above points, and provides a pedestrian collision determination device capable of early determination of whether a vehicle collided object is a pedestrian or a light obstacle. The second object is to provide a pedestrian collision determination device capable of accurately determining whether or not the object on which the vehicle collides is a pedestrian. .

  The first object is detected on the basis of a first load sensor disposed at the front of the vehicle body and outputting a signal corresponding to a first load applied to the vehicle, and an output signal of the first load sensor. A pedestrian collision determination device comprising: a pedestrian collision determination unit that determines that a collision between a vehicle and a pedestrian has occurred when a parameter using the first load exceeds a predetermined threshold value. A second load sensor disposed at a front portion of the vehicle body above the position where the first load sensor is disposed and outputting a signal corresponding to a second load applied to the vehicle; and the second load This is achieved by a pedestrian collision determination device comprising: threshold changing means for changing the predetermined threshold according to a parameter using the second load detected based on an output signal of the sensor. .

  In the invention of this aspect, the pedestrian collision determination in the vehicle is based on whether or not the parameter using the load based on the output of the first load sensor disposed in the front part of the vehicle body exceeds a predetermined threshold value. However, the predetermined threshold value depends on a parameter using a load based on the output of the second load sensor disposed above the position where the first load sensor is disposed at the front of the vehicle body. Changed.

  Generally, when a vehicle collides with a pedestrian standing upright, a load tends to be applied to the front of the vehicle body in the vertical direction, but when the vehicle collides with a light obstacle such as a post cone, the front of the vehicle body There is a tendency that the load acts only on the lower part of the plate. Therefore, according to the configuration of the present invention, it is possible to determine whether the vehicle collision target is a pedestrian or a light obstacle early after the collision.

  In this case, in the above-described pedestrian collision determination device, the threshold value changing unit is configured such that the parameter using the second load detected based on the output signal of the second load sensor exceeds a predetermined value. In addition, the predetermined threshold value may be made smaller than when the parameter does not exceed the predetermined value.

  Further, in the pedestrian collision determination device described above, the threshold value changing unit increases the parameter using the second load detected based on the output signal of the second load sensor. The threshold value may be reduced.

  Further, the first object is to provide a first load sensor disposed at the front part of the vehicle body and outputting a signal corresponding to a first load applied to the vehicle, and the first load sensor at the front part of the vehicle body. A second load sensor disposed above the disposed position and outputting a signal corresponding to a second load applied to the vehicle; and the second load sensor detected based on an output signal of the second load sensor. When the parameter using the first load does not exceed a predetermined value, the parameter using the first load detected based on the output signal of the first load sensor exceeds the first threshold value. On the other hand, when the parameter using the second load detected based on the output signal of the second load sensor exceeds the predetermined value, the parameter is detected based on the output signal of the first load sensor. The parameter using the first load is the first load. When than have values greater than smaller second threshold is achieved and determining pedestrian collision determination means that the collision between the vehicle and the pedestrian has occurred, the pedestrian collision decision apparatus comprising a.

  In the invention of this aspect, the pedestrian collision determination in the vehicle is performed by using a parameter using the second load based on the output of the second load sensor disposed above the first load sensor at the front of the vehicle body. When the predetermined value is not exceeded, the determination is made based on whether the parameter using the first load based on the output of the first load sensor exceeds the first threshold value, while the second load sensor When the parameter using the second load based on the output of the first load sensor exceeds a predetermined value, the parameter using the first load based on the output of the first load sensor is smaller than the first threshold value. This is based on whether the threshold is exceeded.

  Generally, when a vehicle collides with a pedestrian standing upright, a load tends to be applied to the front of the vehicle body in the vertical direction, but when the vehicle collides with a light obstacle such as a post cone, the front of the vehicle body There is a tendency that the load acts only on the lower part of the plate. Therefore, according to the configuration of the present invention, it is possible to determine whether the vehicle collision target is a pedestrian or a light obstacle early after the collision.

  Further, the second object is to provide a first load sensor disposed at the front part of the vehicle body and outputting a signal corresponding to a first load applied to the vehicle, and the first load sensor at the front part of the vehicle body. A second load sensor disposed above the disposed position and outputting a signal corresponding to a second load applied to the vehicle; and the first load sensor detected based on an output signal of the first load sensor. The relationship between the parameter using the load and the parameter using the second load detected based on the output signal of the second load sensor is the threshold change pattern of the two-dimensional map defined in advance. When exceeding, it is achieved by a pedestrian collision determination device comprising: a pedestrian collision determination unit that determines that a collision between a vehicle and a pedestrian has occurred.

  In the invention of this aspect, the pedestrian collision determination in the vehicle is performed by using the parameter using the first load based on the output of the first load sensor disposed in the front part of the vehicle body and the first load of the vehicle body front part. The relationship with the parameter using the second load based on the output of the second load sensor arranged above the sensor arrangement position exceeds the threshold change pattern of the two-dimensional map defined in advance. This is done based on whether or not.

  Generally, when a vehicle collides with a pedestrian standing upright, a load tends to be applied to the front of the vehicle body in the vertical direction, but when the vehicle collides with a light obstacle such as a post cone, the front of the vehicle body There is a tendency that the load acts only on the lower part of the plate. Therefore, according to the configuration of the present invention, it is possible to accurately determine whether the collision target of the vehicle is a pedestrian or a light obstacle.

  In the above-described pedestrian collision determination device, the parameter is a two-dimensional parameter including a load and an integrated value of the load or a value obtained by dividing the integrated value of the load by the vehicle speed, and the predetermined threshold value, The first threshold value or the second threshold value may be a threshold change pattern of a two-dimensional map defined in advance, and the parameter may be the load itself, the integral of the load. It is good also as the value which divided the value or the integral value of the load by the own vehicle speed.

  ADVANTAGE OF THE INVENTION According to this invention, the determination whether the object which the vehicle collided is a pedestrian or a light obstacle can be performed early after a collision. Further, according to the present invention, it is possible to accurately determine whether the object on which the vehicle collides is a pedestrian or a light obstacle.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration diagram of a system mounted on a vehicle according to a first embodiment of the present invention. FIG. 2 is a diagram schematically showing the arrangement positions of the load sensors provided in the system of the present embodiment. As shown in FIG. 1, the system of this embodiment includes a pedestrian collision determination device 10 that determines whether or not a collision target is a pedestrian when a vehicle collides. The pedestrian collision determination device 10 includes an electronic control unit (hereinafter referred to as ECU) 12. The ECU 12 includes an input / output circuit (I / O) 14, a central processing unit (hereinafter referred to as a CPU) 16, a read-only memory (hereinafter referred to as a ROM) in which processing programs and tables necessary for calculation are stored in advance. ) 18, a random access memory (hereinafter referred to as RAM) 20 used as a work area, and a bidirectional bus 22 for connecting these elements.

  First and second load sensors 24 and 26 are connected to the input / output circuit 14 of the ECU 12. One or a plurality of first load sensors 24 are arranged on the front surface of the bumper reinforcement at the front of the vehicle body or on the front ends of the left and right front side members. The first load sensor 24 outputs a signal corresponding to the magnitude of the load applied to the arrangement site of the vehicle from the front of the vehicle. The output signal of the first load sensor 24 is supplied to the input / output circuit 14 and is appropriately stored in the RAM 20 in accordance with instructions from the CPU 16. The CPU 16 of the ECU 12 detects the magnitude (first load) N1 of the load applied to the front part of the vehicle body from the front of the vehicle based on the output signal of the first load sensor 24.

  One or a plurality of the second load sensors 26 are disposed at the front of the vehicle body above the position where the first load sensor 24 is disposed (for example, the front hood tip or the front grill front). Yes. The second load sensor 26 outputs a signal corresponding to the magnitude of the load applied to the arrangement site of the vehicle from the front of the vehicle. The output signal of the second load sensor 26 is supplied to the input / output circuit 14 and is appropriately stored in the RAM 20 in accordance with instructions from the CPU 16. Based on the output signal of the second load sensor 26, the CPU 16 detects the magnitude (second load) N2 of the load applied from the front of the vehicle above the position where the first load sensor 24 is disposed at the front of the vehicle body. To do.

  Note that the magnitudes N1 and N2 of the load acting on the front part of the vehicle body correspond to the outputs of the load sensors 24 and 26 when a plurality of first or second load sensors 24 and 26 are mounted on the vehicle. It is the total value of the load based on. When detecting the loads N1 and N2 applied to the vehicle as described above, the CPU 16 walks with the vehicle based on the detected loads N1 and N2 at the front of the vehicle body in accordance with a processing program stored in the ROM 18, as will be described in detail later. It is determined whether or not the vehicle has collided, that is, whether or not the collision target when the vehicle collides is a pedestrian.

  The system of this embodiment also includes a pedestrian protection device 30 that is activated to protect a collision pedestrian when the vehicle collides with a pedestrian. The pedestrian protection device 30 is, for example, a device having a mechanism that lifts only the rear end side of an engine hood that covers the engine provided at the front of the vehicle body, or a collision pedestrian from the engine hood toward the front of the external vehicle. It is a device that deploys an air bag or the like that absorbs an impact applied to the vehicle.

  The pedestrian protection device 30 has a drive circuit 32 connected to the input / output circuit 14 of the ECU 12. The CPU 16 of the ECU 12 supplies a drive signal from the input / output circuit 14 to the drive circuit 32 of the pedestrian protection device 30 based on whether or not the collision target on which the vehicle collides is a pedestrian as the pedestrian collision determination device 10. To control. Specifically, when it is determined that the collision target is a pedestrian, a command for operating the pedestrian protection device 30 is supplied to the drive circuit 32. The drive circuit 32 lifts the rear end side of the engine hood or inflates and deploys a pedestrian protection airbag in accordance with an operation command supplied from the ECU 12.

  Next, specific contents of processing for determining whether or not the collision target is a pedestrian (hereinafter referred to as pedestrian collision determination) in the CPU 16 of this embodiment will be described.

  When the vehicle collides with a heavy obstacle such as a barrier, a very large load acts on the front of the vehicle body. On the other hand, when the vehicle collides with a pedestrian at a low speed, even if the pedestrian is an adult with a large physique, the load acting on the front of the vehicle body of the vehicle can be kept smaller than the load at the time of heavy obstacle collision. Therefore, it is sufficient to use the load itself acting on the front part of the vehicle body in order to distinguish whether the collision target with which the vehicle collides is a pedestrian or a heavy obstacle. However, when the vehicle collides with a light obstacle such as a post cone or pylon at high speed, the peak load of the load acting on the front of the vehicle is about the same as the peak load when the vehicle collides with a pedestrian at low speed. May indicate a value. Therefore, it is not sufficient to use only the load acting on the front part of the vehicle body (specifically, the peak load) in order to distinguish whether the collision target of the vehicle is a pedestrian or a light obstacle. is there.

  On the other hand, when a vehicle collides with a light obstacle such as a post cone or pylon at a high speed, the light obstacle will not enter the hood of the vehicle and will sink or jump off the vehicle body. On the other hand, a large load does not continue for a long time, a peak load appears immediately after the collision, and then a relatively low load appears. In contrast, when a vehicle collides with a pedestrian at a low speed, the pedestrian rides on the hood of the vehicle, so a large load continues to the front of the vehicle for a relatively long time, and the load collides. The state where the load gradually rises from the initial stage and the load shows a relatively large value continues. Therefore, in distinguishing whether the collision target in the vehicle is a pedestrian or a light obstacle, both the load acting on the front of the vehicle body and the time integral value (impulse) from the start of the collision of the load It is effective to use.

  However, in such a configuration, the determination map for distinguishing whether the collision target is a pedestrian or a light obstacle is a two-dimensional map defined in advance from the relationship between the load applied to the front part of the vehicle body and its time integral value. If the load is used as a reference, the map changes according to the time integral value of the load. Specifically, the load integral value is kept constant until the load integral value reaches a predetermined value, and the load integral value becomes a predetermined value. When it reaches, the load integration value is set so as to become smaller, but if this judgment map has only one threshold change pattern, when the vehicle actually collides with the pedestrian In addition, it may be difficult to make the pedestrian determination early after the collision.

  Therefore, the pedestrian collision determination device 10 of the present embodiment is characterized in that it is possible to distinguish whether the vehicle collision target is a pedestrian or a light obstacle such as a post cone early after the collision. is doing. Hereafter, the characteristic part of a present Example is demonstrated with reference to FIG. 3 thru | or FIG.

  FIG. 3 is a diagram for explaining the difference in collision mode between when the vehicle collides with a pedestrian and when the vehicle collides with a post cone. FIG. 3A shows a situation at the time of a collision with a pedestrian, and FIG. 3B shows a situation at the time of a collision with a post cone. Moreover, FIG. 4 shows the figure showing the determination map for performing pedestrian collision determination in a present Example. FIG. 4 shows an example of the experimental results at the time of collision with a pedestrian at a low speed and at the time of collision with a light obstacle such as a post cone that is relatively lighter than the pedestrian. Yes.

  In the present embodiment, the determination map for performing the pedestrian collision determination is a diagram defined in advance from the relationship between the first load based on the output of the first load sensor 24 applied to the front portion of the vehicle body and its time integral value. 4 is a two-dimensional map as shown in FIG. This two-dimensional map has two threshold change patterns that change according to the time integral value of the load when the load is used as a reference, and change according to the load when the time integral value of the load is used as a reference. is doing. Both of these two threshold value change patterns are stored in the ROM 18 in advance.

  One of the two threshold change patterns is a change pattern set at the boundary so that a case where the vehicle collides with a pedestrian and a case where the vehicle collides with a light obstacle such as a post cone are distinguished. It is. The other of the two threshold change patterns is a change pattern set at the boundary so that the case where the vehicle collides with at least a pedestrian and the case where the vehicle does not collide are distinguished. Thus, it is set to a value lower than the above one threshold value change pattern. Hereinafter, of these two threshold value change patterns, a pattern having a larger threshold value is referred to as a high map, and a pattern having a smaller threshold value is referred to as a low map. In both the Low map and the High map, as shown in FIG. 4, the threshold value for the first load applied to the vehicle is maintained at a certain constant value when the load time integral value is small, and the load time integral value is predetermined. The map becomes smaller as the value increases.

  In the present embodiment, as described above, the CPU 16 uses the first load sensor 24 to detect the first load magnitude N1 acting on the relatively lower portion of the front of the vehicle body from the front of the vehicle, and the second load sensor 24. A load sensor 26 is used to detect a second load magnitude N2 acting on the relatively upper portion of the front of the vehicle body from the front of the vehicle. When it is determined that the collision has started when the detected first load N1 reaches a predetermined value slightly larger than zero, the load collision is performed by integrating the detected first load N1 over time. Calculate the time integrated value (impact) from the start.

  When a vehicle collides with an upright pedestrian, a load tends to act on the front of the vehicle body for a certain length in the vertical direction, while when the vehicle collides with a light obstacle such as a post cone. The load tends to act only on the lower part of the front part of the vehicle body. Therefore, when a certain amount of load acts on the lower part of the front part of the vehicle body but not so much on the upper part, there is a possibility that the vehicle has collided with a light obstacle such as a post cone. In order to prevent erroneous determination of collision determination, it is necessary to set the determination map relatively high. On the other hand, when a certain amount of load is applied not only to the lower part of the front part of the car body but also to the upper part, the possibility that the vehicle has collided with a light obstacle such as a post cone is very low. If the target map is set low, the misjudgment does not occur, and if the judgment map is set low, the collision target should be distinguished early whether it is a pedestrian or a light obstacle. Is possible.

  Therefore, the CPU 16 uses the second load sensor 26 disposed above the position where the first load sensor 24 at the front of the vehicle body is disposed, and the second load N2 detected using the second load sensor 26 is a predetermined value. If it is determined that there is a sufficient possibility that the collision target is a light obstacle such as a post cone, the determination map for performing the pedestrian collision determination is set in the High map. In addition, when it is determined that the possibility that the collision target is a light obstacle such as a post cone is extremely low because the detected second load N2 exceeds a predetermined value, a determination for performing a pedestrian collision determination The map is set to a Low map having a threshold larger than that of the High map.

  The CPU 16 determines a point determined from the relationship between the first load N1 itself detected using the first load sensor 24 and the time integral value of the first load N1 every predetermined time (for example, 10 ms). It is determined whether (coordinates) belong to one of the two areas divided by the determination map that is selectively set to either the high map or the low map as described above. And when it is determined that the point determined from the first load N1 and its time integral value belongs to the area below the determination map, the vehicle has collided with a relatively light light obstacle such as a post cone, It determines with the collision object which the own vehicle collided is not a pedestrian. On the other hand, if it is determined that the point determined from the first load N1 and its time integral value belongs to a region exceeding the determination map, the host vehicle has collided as if the host vehicle collided with a pedestrian such as a child or an adult. It is determined that the collision target is a pedestrian.

  FIG. 5 and FIG. 6 each show a flowchart of an example of a control routine executed by the CPU 16 in the pedestrian collision determination apparatus 10 of the present embodiment in order to realize the above function. Each of the routines shown in FIGS. 5 and 6 is repeatedly activated at predetermined time intervals. When the routine shown in FIG. 5 is started, first, the process of step 100 is executed. When the routine shown in FIG. 6 is started, the process of step 150 is first executed.

  In step 100, based on the output signal of the first load sensor 24, a first load N1 applied to the front of the vehicle body from the front of the vehicle is detected. In step 102, when the first load N1 detected in step 100 exceeds a predetermined value set to a value slightly larger than zero provided for starting the time integration of the load, the first load N1 is set. A process for calculating a time integration value is performed by performing time integration on the load N1.

  In step 104, a threshold value for the load is calculated based on the time integral value of the load calculated in step 102 with reference to a determination map set by executing the routine shown in FIG. Is executed. At this time, the threshold value for the calculated load becomes a constant value that is large to some extent when the time integral value of the load is small. On the other hand, when the time integral value of the load is larger than a predetermined value, the threshold value becomes smaller as the time integral value becomes larger. Value.

  In step 106, it is determined whether or not the first load N1 detected in step 100 has exceeded a threshold for the load corresponding to the time integral value calculated at step 104 on the determination map. Is done. As a result, if the first load N1 does not exceed the threshold value, the point determined from the first load N1 applied to the front portion of the vehicle body and its time integral value belongs to the region beyond the determination map. Since it cannot be determined, if such a determination is made, it is not determined that the collision target with which the vehicle collided is a pedestrian, and the current routine is terminated. On the other hand, when the first load N1 exceeds the above threshold value, it is determined that the point determined from the first load N1 applied to the front portion of the vehicle body and the time integral value belongs to a region exceeding the determination map. Therefore, when such a determination is made, the process of step 108 is executed next.

  In step 108, it is determined that the collision target with which the vehicle collided is a pedestrian. When the processing of step 108 is executed, an operation command is issued to the drive circuit of the pedestrian protection device 30 and the pedestrian protection device 30 is activated by lifting the engine hood or deploying the pedestrian protection airbag. It becomes. When the processing of step 108 is completed, the current routine is terminated.

  It should be noted that the determination that the collision target is a pedestrian in step 108 is appropriately performed after the determination that the collision target is a heavy obstacle such as another vehicle or a wall is excluded. For example, as a determination map for performing a pedestrian collision determination, a case where a vehicle collides with a pedestrian and a case where a vehicle collides with a heavy obstacle such as a vehicle or a wall, which has a larger threshold value than the above High map and Low map. A threshold change pattern (upper limit map) set so as to be distinguished from each other is provided, and a point determined from the first load N1 applied to the front portion of the vehicle body and its time integral value is a threshold value of the upper limit map The collision target is determined to be a pedestrian only if it does not belong to the area exceeding the change pattern, and the collision target is determined to be a heavy obstacle if it belongs to the area exceeding the threshold change pattern of the upper limit map. It is good to do. In this case, until the predetermined time has elapsed after the start of the collision, even if the above point belongs to an area exceeding the High map, the determination that the collision target is a pedestrian is not allowed. It is preferable to allow the determination that the collision target is a pedestrian after confirming that the point does not belong to the region exceeding the upper limit map.

  According to the routine shown in FIG. 5 described above, the point determined from the first load N1 applied to the front part of the vehicle body from the front of the vehicle detected using the first load sensor 24 and the time integral value of the load is a determination map. Determining whether the collision target with which the vehicle collides is a pedestrian based on whether it belongs to any of the two areas separated by the threshold value change pattern set as Can determine that the collision target is a pedestrian when the first load N1 applied to the front part of the vehicle body exceeds a threshold for the load set based on the time integral value of the load.

  Further, in this embodiment, the pedestrian collision determination is performed based on whether or not the point determined from the first load N1 applied to the front part of the vehicle body and the time integral value of the load belongs to a region exceeding the determination map. . The threshold value change pattern of this determination map is defined in advance from the relationship between the load N1 applied to the front portion of the vehicle body and its time integral value. As shown in FIG. It changes according to the time integral value of the actual load and is a constant value until the load time integral value reaches the predetermined value, but after reaching the predetermined value, it becomes smaller as the time integral value increases. Is set.

  In this respect, in the pedestrian collision determination device 10 of the present embodiment, when the vehicle actually collides with the pedestrian, the point determined from the first load N1 and the time integral value of the load exceeds the determination map. Not much time is spent on belonging. Therefore, according to the pedestrian collision determination device 10 of the present embodiment, when the vehicle collides with the pedestrian, the response time for distinguishing between the low-speed collision with the pedestrian and the high-speed collision with the light obstacle is reduced. This distinction can be made early after a collision.

  In the present embodiment, the CPU 16 of the ECU 12 executes the routine shown in FIG. 6 in parallel with the routine shown in FIG. In step 150, based on the output signal of the second load sensor 26, a second load N2 applied to the front part of the vehicle body above the position where the first load sensor 24 is disposed from the front of the vehicle is detected.

  In step 152, it is determined whether or not the second load N2 detected in step 150 exceeds a predetermined value. This predetermined value is the maximum value of the load acting on the position where the second load sensor 26 is disposed at the front of the vehicle body that can be reached when the vehicle collides with a light obstacle such as a post cone. As a result, if the second load N2 does not exceed the predetermined value, there is a sufficient possibility that the collision target is a light obstacle such as a post cone. If such a determination is made, the next step 154 is performed. The process is executed. On the other hand, if the second load N2 exceeds the predetermined value, the possibility that the collision target is a light obstacle such as a post cone is extremely low. If such a determination is made, the process of step 156 is performed next. Is executed.

  In step 154, processing for setting a determination map for determining pedestrian collision used in the processing of step 104 in the routine shown in FIG. 5 to a high map having a larger threshold value is executed. When such processing is executed, a high map is set as a determination map in step 104, a threshold value for the load is calculated, and a pedestrian collision determination is made using the high map. On the other hand, in step 156, processing for setting the determination map for determining pedestrian collision used in the processing in step 104 to a low map with a smaller threshold value is executed. When such processing is executed, the Low map is set as the determination map in Step 104, a threshold value for the load is calculated, and the pedestrian collision determination is performed using the Low map. When the processing of step 154 or 156 is completed, the current routine is terminated.

  According to the routine shown in FIG. 6, the first load disposed at the front of the vehicle body in order to calculate the parameters (first load N1 and its time integral value) necessary for determining the pedestrian collision. A determination map for performing the pedestrian collision determination according to the second load N2 based on the output of the second load sensor 26 disposed at the front of the vehicle body above the position where the sensor 24 is disposed is High. It can be selectively switched between the map and the Low map. When the second load N2 does not exceed the predetermined value and it is determined that there is a sufficient possibility that the collision target is a light obstacle such as a post cone, the High map is selected as the determination map, while the second map When it is determined that the possibility that the collision target is a light obstacle such as a post cone is extremely low because the load N2 exceeds the predetermined value, the Low map can be selected as the determination map.

  As described above, in general, when a vehicle collides with an upright pedestrian, a load tends to be applied to the front part of the vehicle for a certain length in the vertical direction, while the vehicle has a light obstacle such as a post cone. When it collides with an object, the load acts only on the lower part of the front part of the vehicle body, and the load does not tend to act much on the upper part.

  Accordingly, when the second load N2 with respect to the relatively upper part of the front part of the vehicle body is small without exceeding a predetermined value as in the configuration of the present embodiment described above, a pedestrian collision determination is made using a higher determination map (High map). When the first load N1 exceeds the threshold value for the load corresponding to the load integral value on the High map, it is determined that the collision target is a pedestrian, while the second load N2 is a predetermined value. If it is larger than the threshold, a pedestrian collision determination is performed using a lower determination map (Low map), and the collision occurs when the first load N1 exceeds the threshold value for the load corresponding to the load integral value on the Low map. If it is determined that the target is a pedestrian, it is possible to distinguish whether the target of the collision of the vehicle is a pedestrian or a light obstacle such as a post cone early after the collision without causing an erroneous determination. be able to. Thus, according to the pedestrian collision determination apparatus 10 of the present embodiment, when the vehicle actually collides with the pedestrian, it can be determined early after the collision that the collision target is a pedestrian. ing.

  In the first embodiment, the first load N1 or the second load N2 or the time integral value of the load is a “map” described in the claims, and the determination map is a two-dimensional map. The upper threshold is the “predetermined threshold” described in the claims, and the threshold on the threshold change pattern of the High map is the “first threshold” described in the claims. The threshold value on the threshold value change pattern of the Low map corresponds to the “second threshold value” described in the claims, and the CPU 16 of the ECU 12 By executing the processing of step 108 in the routine shown in FIG. 5, the “pedestrian collision determination means” described in the claims executes the processing of steps 152 to 156 in the routine shown in FIG. Described in the scope of the determined "threshold value change means" are realized respectively.

  By the way, in the first embodiment described above, as a determination map for performing the pedestrian collision determination, as shown in FIG. 4, when the threshold value for the first load is small and the load time integral value is small, a constant value that is somewhat large. However, the present invention is not limited to this, and the present invention is not limited to this. As long as the collision and the collision with the light obstacle can be distinguished, the pattern may be changed on the two-dimensional map of the load and its time integral value.

  In the first embodiment, two maps, a high map and a low map, are prepared as determination maps for performing pedestrian collision determination, as shown in FIG. The present invention is not limited to this, and three or more maps may be prepared. In such a configuration, when the second load N2 based on the output of the second load sensor 26 is small, a map having a large threshold is selected as a determination map used for pedestrian collision determination, and the second load N2 is large. It is preferable to select a map having a smaller threshold value as a determination map used for pedestrian collision determination.

  As described above, when the vehicle collides with an upright pedestrian, a load tends to be applied to the front of the vehicle body for a certain length in the vertical direction, while the vehicle is lighter such as a post cone. In the case of collision with an obstacle, in view of the fact that a load tends to act only on the lower part of the front part of the vehicle body, when the vehicle actually collides with a pedestrian, it is performed early without making a mistake, Further, in a situation where the vehicle has actually collided with a pedestrian, a large load acts on the front of the vehicle body at the position where the second load sensor 26 is disposed, while the front of the vehicle body at the position where the first load sensor 24 is disposed. In view of the fact that there may be a situation where a large load does not act on the part, even if such a situation occurs, the collision target is surely a pedestrian by lowering the threshold value of the determination map for pedestrian collision determination To judge That.

  In the first embodiment, the time integral value is used together with the first load applied to the front part of the vehicle body as the determination parameter for determining the pedestrian collision. However, the effective mass of the collision target obtained by dividing the time integral value of the load by the vehicle speed instead of the time integral value is calculated. Etc. may be used. In this case, a threshold value change pattern suitable for the determination parameter is set in advance. In a situation where the vehicle and the pedestrian collide, it cannot be assumed that the pedestrian is walking toward the vehicle. Therefore, it can be determined that the relative speed between the vehicle and the pedestrian in the vehicle traveling direction is substantially equal to the speed of the vehicle. For this reason, the effective mass of the collision target can be calculated by dividing the time integral value of the load applied to the front part of the vehicle body by the own vehicle speed. Therefore, the pedestrian collision determination may be performed using the two-dimensional map of the effective mass and the load. In this case, the effective mass of the collision target obtained by dividing the time integral value of the first load N1 by the own vehicle speed corresponds to the “parameter” described in the claims.

  Furthermore, in the first embodiment described above, the second load N2 itself is used as a parameter for switching the determination map for performing the pedestrian collision determination, but the present invention is limited to this. Instead of this, the time integral value of the second load N2 or the effective mass obtained by dividing the time integral value by the vehicle speed may be used.

  In the first embodiment described above, the pedestrian collision determination is performed based on the parameter using the first load N1 based on the output of the first load sensor 24 disposed at the front of the vehicle body, and the first load is determined. Changing the determination map for performing the pedestrian collision determination using the second load N2 based on the output of the second load sensor 24 disposed in the front part of the vehicle body below the position where the sensor 24 is disposed. It is said. On the other hand, in the second embodiment of the present invention, a parameter using the first load N1 based on the output of the first load sensor 24 and a second based on the output of the second load sensor 26 are used. The pedestrian collision determination is performed based on both of the parameters using the load N2.

  The system of the present embodiment is realized by causing the CPU 16 of the ECU 12 to execute the routine shown in FIG. 9 instead of the routines shown in FIGS. 5 and 6 in the configuration shown in FIG. Hereinafter, the specific content of the process which performs pedestrian collision determination in CPU16 of a present Example is demonstrated.

  FIG. 7A shows a situation when the vehicle collides with the shopping cart, and FIG. 7B shows a situation when the vehicle collides with the post cone. When a vehicle collides with a light obstacle such as a shopping cart that protrudes to a certain level from the ground, a large load appears only at the top of the front of the vehicle body as shown in FIG. There is a tendency that a large load does not appear in the lower part. Also, as detailed in the first embodiment described above, when the vehicle collides with a light obstacle such as a post cone, a large load appears only on the lower part of the front part of the vehicle body. There is a tendency that a large load does not appear on the upper part. On the other hand, when the vehicle collides with an upright pedestrian as described above, there is a tendency that a load acts on the front of the vehicle body over a certain length in the vertical direction.

  Therefore, when at least one of the load acting on the lower part of the front part of the vehicle body and the load acting on the upper part is small, it is not determined that the collision target is a pedestrian. If a determination map for determining a pedestrian collision that determines that is a pedestrian is prepared, the pedestrian collision determination can be accurately performed.

  FIG. 8 is a diagram showing a determination map for performing pedestrian collision determination in the present embodiment. In FIG. 8, the vehicle collides at a low speed with a pedestrian, and collides at a high speed with a shopping cart that is a lighter obstacle than a pedestrian, and relatively lighter than a pedestrian. An example of each experimental result at the time of high-speed collision with the post cone which is a light obstacle is shown.

  In this embodiment, the determination map for performing the pedestrian collision determination is based on the time integral value of the first load N1 applied to the front portion of the vehicle body based on the output of the first load sensor 24 and the first load sensor. As shown in FIG. 8, which is defined from the relationship with the time integral value of the second load N 2 applied to the front portion of the vehicle body based on the output of the second load sensor 26 disposed above the position 24. It is a dimension map. This two-dimensional map changes according to the value on the second load N2 side when the first load N1 side is used as a reference, and the first load N1 side when the second load N2 side is used as a reference. Is a threshold value change pattern that changes in accordance with the value of, and is stored in the ROM 18 in advance. This threshold value change pattern is a change pattern set at the boundary so that the case where the vehicle collides with a pedestrian and the case where the vehicle collides with a light obstacle, and is the time of the first load N1. When the integral value or the time integral value of the second load N2 is small, the threshold value is extremely large.

  In this embodiment, the CPU 16 uses the first load sensor 24 to detect the first load magnitude N1 acting on the relatively lower part of the front of the vehicle body from the front of the vehicle, and integrates the detected value over time. The time integration value from the start of load collision is calculated by Further, the second load sensor 26 is used to detect the second load magnitude N2 acting on the relatively upper part of the front of the vehicle body from the front of the vehicle, and by integrating the detected value over time, from the start of the load collision. The time integral value of is calculated.

  The CPU 16 then integrates the time integral value of the first load N1 detected using the first load sensor 24 and the second load sensor 26 detected using the second load sensor 26 every predetermined time (for example, 10 ms). Based on the time integral value of the load N2, it is determined which point (coordinates) determined from the relationship between the two belongs to one of the two regions divided by a predetermined determination map. As a result, if it is determined that the point belongs to the area below the determination map, it is assumed that the subject vehicle has collided with a relatively light obstacle such as a post cone, and the collision target of the subject vehicle is not a pedestrian. judge. On the other hand, if it is determined that the point belongs to a region exceeding the determination map, it is determined that the collision target of the collision of the own vehicle is a pedestrian, assuming that the own vehicle has collided with a pedestrian such as a child or an adult.

  FIG. 9 shows a flowchart of an example of a control routine executed by the CPU 16 in the pedestrian collision determination apparatus 10 of this embodiment in order to realize the above function. The routine shown in FIG. 9 is repeatedly activated every predetermined time. When the routine shown in FIG. 9 is started, the process of step 200 is first executed.

  In step 200, based on the output signal of the first load sensor 24, a first load N1 applied to the front of the vehicle body from the front of the vehicle is detected. Further, in step 202, based on the output signal of the second load sensor 26, a second load N2 applied to the front part of the vehicle body above the position where the first load sensor 24 is disposed from the front of the vehicle is detected. .

  In step 204, when the first load N1 detected in step 200 exceeds a predetermined value set to a value slightly larger than zero provided for starting the time integration of the load, the first load N1 is set. A process of calculating a time integral value by executing time integration with respect to the load N1 is executed, and the second load N2 detected in step 202 is set to zero provided for starting the time integration of the load. When the predetermined value set to a value slightly larger than the predetermined value is exceeded, a process for calculating a time integral value is performed by performing time integration on the second load N2. At this time, the predetermined value related to the first load N1 and the predetermined value related to the second load N2 may be different from each other.

  In step 206, whether the point determined from the relationship between the time integral value of the first load N1 calculated in step 204 and the time integral value of the second load N2 belongs to a region exceeding the two-dimensional determination map. It is determined whether or not. As a result, when a negative determination is made, it is not determined that the collision target on which the vehicle collided is a pedestrian, and the current routine is terminated. On the other hand, if a positive determination is made, the process of step 208 is then executed.

  In step 208, it is determined that the collision target with which the vehicle collided is a pedestrian. After the processing of step 208 is executed, an operation command is issued to the drive circuit of the pedestrian protection device 30 and the pedestrian protection device 30 is activated by lifting the engine hood or deploying the pedestrian protection airbag. It becomes. When the processing of step 208 is completed, the current routine is terminated.

  The determination that the collision target in step 208 is a pedestrian is appropriately performed after the determination that the collision target is a heavy obstacle such as another vehicle or a wall is excluded. For example, as a determination map for performing pedestrian collision determination, a vehicle having a threshold larger than the threshold change pattern (lower limit map) for separating the collision with the pedestrian and the collision with the light obstacle described above Is provided with a threshold change pattern (upper limit map) set so as to distinguish between a case where the vehicle collides with a pedestrian and a case where the vehicle collides with a heavy obstacle such as a vehicle or a wall, and the first load N1 The collision target is determined to be a pedestrian only when the point determined from the time integral value and the time integral value of the second load N2 does not belong to the region exceeding the upper limit map, and belongs to the region exceeding the upper limit map. In this case, it may be determined that the collision target is a heavy obstacle. In this case, until the predetermined time has elapsed after the start of the collision, even if the above point belongs to an area exceeding the lower limit map, the determination that the collision target is a pedestrian is not allowed. It is preferable to allow the determination that the collision target is a pedestrian after confirming that the point does not belong to the region exceeding the upper limit map.

  According to the routine shown in FIG. 9, the time integral value of the first load N1 applied to the vehicle based on the output of the first load sensor 24 disposed at the front of the vehicle body and the arrangement of the first load sensor 24. A point determined from the time integral value of the second load N2 applied to the vehicle based on the output of the second load sensor 26 disposed at the front of the vehicle body above the installation position is set as a determination map. It is determined whether or not the collision target of the vehicle is a pedestrian based on which one of the two areas separated by the threshold value change pattern belongs. When the point determined from the time integral value of the applied first load N1 and the time integral value of the second load N2 applied to the front part of the vehicle body above the load position belongs to a region exceeding the determination map, the collision target is Determine that you are a pedestrian Door can be.

  As described above, in general, when a vehicle collides with an upright pedestrian, a load tends to be applied to the front part of the vehicle for a certain length in the vertical direction, while the vehicle has a light obstacle such as a post cone. When it collides with an object, the load acts only on the lower part of the front part of the vehicle body, and the load does not tend to act much on the upper part. Therefore, as in the above-described configuration of the present embodiment, the relationship between the time integral value of the first load N1 for the relatively lower portion of the vehicle body front portion and the time integral value of the second load N2 for the relatively upper portion of the vehicle body front portion. If the pedestrian collision determination is performed using a two-dimensional determination map defined from the following, it is possible to prevent the erroneous determination from being caused.

  If the pedestrian collision determination is performed using the two-dimensional determination map defined from the relationship between the time integral value of the first load N1 and the time integral value of the second load N2, as described above. Even if the collision mode when the vehicle collides with a pedestrian is such that the load acts not only on the lower part of the front part of the vehicle body but also on the upper part, the two-dimensional map has an appropriate threshold value change pattern Thus, it is possible to reliably determine that the collision target is a pedestrian.

  Thus, according to the pedestrian collision determination apparatus 10 of the present embodiment, it is possible to accurately determine whether the vehicle collision target is a pedestrian or a light obstacle, and the pedestrian collision determination It is possible to improve accuracy. For this reason, according to the present embodiment, since the pedestrian protection device 30 can be appropriately operated, when the vehicle collides with the pedestrian, the pedestrian is appropriately protected, and the vehicle is not a pedestrian. When it collides with a light obstacle, it is possible to prevent the malfunction.

  In the second embodiment, the time integral value of the first load N1 or the time integral value of the second load N2 corresponds to the “parameter” described in the claims, and the ECU 12 The CPU 16 executes the processing of step 208 in the routine shown in FIG. 9 to realize the “pedestrian collision determination means” described in the claims.

  By the way, in said 2nd Example, the time integral value of the 1st load N1 applied to a vehicle body front part, and the time of the 2nd load applied to a vehicle body front as a determination parameter in performing pedestrian collision determination Although the integrated value is used, the effective mass of the collision target obtained by dividing the load itself or the time integrated value of the load by the own vehicle speed may be used. For example, the first load N1 may be used. The first load N1 such as a combination of the time integral value of the first load N2 and the second load N2 itself, a combination of the effective mass based on the first load N1 and the time integral value of the second load N2, or vice versa. Different parameters may be combined on the second side and the second load N2 side. In this case, a threshold value change pattern suitable for the determination parameter is set in advance.

It is a block diagram of the system mounted in the vehicle which is 1st Example of this invention. It is the figure which represented typically the arrangement | positioning position of the load sensor with which the system of a present Example is provided. It is a figure for demonstrating the difference in the collision form between the case where a vehicle collides with a pedestrian, and the case where it collides with a post cone. It is a figure showing the determination map for performing pedestrian collision determination in a present Example. It is a flowchart of the control routine performed in order to perform pedestrian collision determination in the pedestrian collision determination apparatus of a present Example. It is a flowchart of the control routine performed in order to perform pedestrian collision determination in the pedestrian collision determination apparatus of a present Example. FIG. 7A shows a situation when the vehicle collides with the shopping cart. FIG. 7B shows the situation when the vehicle collides with the post cone. It is a figure showing the determination map for performing pedestrian collision determination in a present Example. It is a flowchart of the control routine performed in order to perform pedestrian collision determination in the pedestrian collision determination apparatus of a present Example.

Explanation of symbols

10 Pedestrian collision determination device 12 ECU
16 CPU
24 1st load sensor 26 2nd load sensor

Claims (7)

A first load sensor disposed at a front portion of the vehicle body for outputting a signal corresponding to a first load applied to the vehicle; and the first load detected based on an output signal of the first load sensor. A pedestrian collision determination device comprising: a pedestrian collision determination unit that determines that a collision between a vehicle and a pedestrian has occurred when a used parameter exceeds a predetermined threshold,
A second load sensor disposed above the position of the first load sensor at the front of the vehicle body and outputting a signal corresponding to a second load applied to the vehicle;
Threshold changing means for changing the predetermined threshold according to a parameter using the second load detected based on an output signal of the second load sensor;
A pedestrian collision determination device comprising:   When the parameter using the second load detected based on the output signal of the second load sensor exceeds a predetermined value, the threshold changing means does not exceed the predetermined value The pedestrian collision determination device according to claim 1, wherein the predetermined threshold value is made smaller than the threshold value.   The threshold value changing means reduces the predetermined threshold value as the parameter using the second load detected based on the output signal of the second load sensor is larger. The pedestrian collision determination device according to claim 1. A first load sensor disposed at the front of the vehicle body for outputting a signal corresponding to a first load applied to the vehicle;
A second load sensor disposed above the position of the first load sensor at the front of the vehicle body and outputting a signal corresponding to a second load applied to the vehicle;
When the parameter using the second load detected based on the output signal of the second load sensor does not exceed a predetermined value, the first detected based on the output signal of the first load sensor. When the parameter using the first load exceeds the first threshold value, the parameter using the second load detected based on the output signal of the second load sensor exceeds the predetermined value. When the parameter using the first load detected based on the output signal of the first load sensor exceeds a second threshold value smaller than the first threshold value, the vehicle A pedestrian collision determination means for determining that a collision between the pedestrian and the pedestrian has occurred,
A pedestrian collision determination device comprising: A first load sensor disposed at the front of the vehicle body for outputting a signal corresponding to a first load applied to the vehicle;
A second load sensor disposed above the position of the first load sensor at the front of the vehicle body and outputting a signal corresponding to a second load applied to the vehicle;
A parameter using the first load detected based on an output signal of the first load sensor and a parameter using the second load detected based on an output signal of the second load sensor; Pedestrian collision determination means for determining that a collision between the vehicle and the pedestrian has occurred when the relationship exceeds a threshold change pattern of the two-dimensional map defined in advance,
A pedestrian collision determination device comprising: The parameter is a two-dimensional parameter composed of a load and an integrated value of the load or a value obtained by dividing the integrated value of the load by the vehicle speed,
5. The predetermined threshold value, the first threshold value, or the second threshold value is a threshold change pattern of a two-dimensional map defined in advance. The pedestrian collision determination device according to any one of the above.   The pedestrian collision determination device according to any one of claims 1 to 5, wherein the parameter is a load itself, an integrated value of the load, or a value obtained by dividing the integrated value of the load by the vehicle speed.

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