JP4432821B2 - VEHICLE LOAD INTEGRATED VALUE OPERATION DEVICE AND VEHICLE Pedestrian Collision Judgment System - Google Patents

Description

  The present invention relates to a vehicle load integral value calculation device and a vehicle pedestrian collision determination system, and more particularly to a system suitable for appropriately calculating a time integral value obtained by time-integrating a load applied to a vehicle. .

Conventionally, the load applied to the front part of the vehicle body is detected by using a load sensor disposed on the front bumper or the like at the front part of the vehicle body, and the object on which the vehicle collides is a pedestrian or a person other than the pedestrian based on the detected load. There is known a vehicle pedestrian collision determination device that determines whether there is a vehicle (for example, see Patent Document 1). In this determination apparatus, the pedestrian collision determination is performed based on the duration of the state in which the load applied to the front part of the vehicle body 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 object on which the vehicle collided is something other than a pedestrian, while if the duration is within a certain range, the collision target is a pedestrian. It is determined that there is. And when it determines with the collision object being a pedestrian, the actuator for protecting the pedestrian will be started.
Japanese Patent Laid-Open No. 11-28994

  However, when a vehicle collides with a light obstacle such as a pylon or post cone, which is relatively lighter than a pedestrian, at a high speed, the load applied to the front of the vehicle is constant, as with a low-speed collision with a pedestrian. A value within the range may be indicated, and 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 on the front part of the vehicle body and the duration thereof as in the above-described conventional device, the result of the collision with the light obstacle at a high speed is a low speed with the pedestrian. May approximate the result of the collision. For this reason, in the said conventional apparatus, there exists a possibility of misjudging that it is a pedestrian although the object which the vehicle collided is not a pedestrian, and it is difficult to perform a highly accurate pedestrian collision determination.

  Therefore, in order to avoid the above inconvenience, it is conceivable to perform the pedestrian collision determination using a time integral value (impact) of a load obtained by time-integrating the load applied to the front part of the vehicle body. In general, when a vehicle collides with a light obstacle such as a pylon that is lighter than a pedestrian at high speed, the light obstacle is bounced off the vehicle without riding on the hood of the vehicle. A large load does not continue over a long period of time, and immediately after the collision, a peak load appears as soon as the vehicle collides with a pedestrian at a low speed, while a relatively low load appears thereafter. On the other hand, when the vehicle collides with the pedestrian at a low speed, the pedestrian rides on the hood of the vehicle, so a large load continues for a relatively long time on the front of the vehicle body, and the load gradually rises from the beginning of the collision, The state where the load shows a relatively large value continues. That is, the time change between the load applied to the front portion of the vehicle body and the integrated value thereof differs between a high-speed collision with a light obstacle and a low-speed collision with a pedestrian. Therefore, if the pedestrian collision determination is performed using the time integral value of the load, it is possible to accurately determine whether or not the target on which the vehicle collides is a pedestrian.

  Here, in calculating the time integral value of the load as described above, not only the load detected every predetermined time is added, but also when the load is small near zero, the time at that time It is appropriate that the integral value is gradually maintained with time and converged to zero without maintaining the integral value thereafter. In addition, in the stage where the collision with the collision target is still ongoing, the calculation process in a form close to the complete integration that does not attenuate the time integral value of the load is necessary to accurately calculate the parameters related to the load by the collision target. On the other hand, after the collision with the collision target is completed, converging the time integration value to zero as soon as possible misrecognizes the load of multiple collision targets as the load of a single collision target. This is effective in preventing the occurrence of the problem. Accordingly, the attenuation rate for attenuating the time integral value of the load with the passage of time is switched depending on whether or not the detected load is equal to or greater than a predetermined value. Specifically, the detected load is less than the predetermined value and greater than or equal to the predetermined value. After that, the attenuation rate is set to a low value, while when the detected load shifts from a predetermined value to less than a predetermined value, the attenuation rate can be set to a high value as usual. Is appropriate.

  In addition, when the detected load is shifted from a predetermined value to a value lower than the predetermined value, if the attenuation rate is switched from low to high immediately, the two peaks appear, for example, when the vehicle collides with the pedestrian's right foot and left foot in order. In a situation where a load waveform appears, the load integral value may have already greatly attenuated after the first peak load and at the second peak load, so the vehicle has collided with a single collision target. Nevertheless, the time integral value of the load due to the collision target cannot be accurately calculated. Therefore, in order to solve such a problem, when the detected load shifts from a predetermined value or more to a value less than the predetermined value, the attenuation rate is kept low until the predetermined hold time thereafter, and the hold time is It is appropriate to switch the attenuation rate to a higher one when the time has elapsed.

  However, assuming that the hold time is fixed at a constant value, when the vehicle collides with a light obstacle such as a post cone lined up on the road at a predetermined interval continuously at high speed, As in the case of collision with both feet in order at low speed, a situation occurs in which multiple peak loads corresponding to each light obstacle are added to the integrated value without the time integrated value being greatly attenuated, resulting in a pedestrian collision. The determination is not performed with high accuracy, and there may be a problem that the pedestrian protection actuator malfunctions.

  The present invention has been made in view of the above-described points, and is a vehicle load integrated value calculation device and a vehicle pedestrian collision capable of appropriately calculating a time integral value of a load caused by a collision object with which the vehicle collides. An object is to provide a judgment system.

  The object is to detect the load applied to the vehicle, and the load integration means for integrating the load detected by the load detection means with time and attenuating the time integral value with a predetermined attenuation rate over time. Means for calculating an integral value of load when the load detected by the load detecting means changes from less than a predetermined value to more than the predetermined value. Attenuation rate control for returning the predetermined attenuation rate to the normal one after a predetermined hold time when the load changes from the predetermined value or more to less than the predetermined value. A vehicle load comprising: means; vehicle speed detection means for detecting the vehicle speed; and hold time changing means for changing the predetermined hold time according to the vehicle speed detected by the vehicle speed detection means. It is achieved by the integration value calculation device.

  In the invention of this aspect, when the load changes from a predetermined value or more to less than a predetermined value, the predetermined hold time that should be maintained at a predetermined attenuation rate lower than that at the normal time is changed according to the vehicle speed. The At this time, if the hold time is lengthened when the host vehicle speed is low and the hold time is shortened when the host vehicle speed is high, the right foot, the left foot and two peaks in a situation where the vehicle collides with a pedestrian at a low vehicle speed. Even if a load appears, the time integral value of the load by the pedestrian can be calculated appropriately without significant attenuation, and the vehicle has continuously collided with a light obstacle such as a post cone at high speed. When two or more peak loads appear, the time integral value of the load can be greatly attenuated quickly for each collision with the light obstacle. Therefore, according to the present invention, when a vehicle continuously collides with a light obstacle such as a post cone at a high speed, it is possible to prevent a situation in which individual loads are added to the integrated value without the time integrated value being greatly attenuated. Therefore, it is possible to appropriately calculate the time integral value of the load caused by the collision target of the vehicle.

  In this case, in the vehicle load integral value calculation device described above, the hold time changing means may shorten the predetermined hold time as the host vehicle speed increases.

  Further, in the above-described vehicle load integral value calculation device, the load detection means is based on an output signal of a load sensor disposed on a front end surface of a front side member on the front side member on the front side member on the front or left side of the front part of the vehicle body. What is necessary is just to detect the total value of the load applied to the front part of the vehicle body.

  Whether the collision target of the own vehicle is a pedestrian using the time integrated value of the load calculated by the attenuation integration means or the effective mass obtained by dividing the time integrated value of the load by the own vehicle speed. According to the vehicle pedestrian collision determination system equipped with the above-described vehicle load integral value calculation device including a pedestrian collision determination means for determining whether or not the accuracy of whether or not the object on which the vehicle collides is a pedestrian Can be judged well.

  In this case, in the vehicle pedestrian collision determination system described above, a device that activates a device for protecting a pedestrian when the collision target of the host vehicle is determined to be a pedestrian by the pedestrian collision determination unit. If the activation means is provided, it is possible to prevent the pedestrian protection device from malfunctioning when the vehicle continuously collides with a light obstacle.

  According to the present invention, it is possible to appropriately calculate a time integral value of a load due to a collision object with which a vehicle collides.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration diagram of a vehicle pedestrian collision determination system 10 including a vehicle load integral value calculation device mounted on a vehicle according to an 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 10 of this embodiment is a system that determines whether or not the collision target is a pedestrian when a vehicle collides. The vehicle pedestrian collision determination system 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.

  A load sensor 24 is connected to the input / output circuit 14 of the ECU 12. One or a plurality of load sensors 24 are arranged on the bumper reinforcement at the front of the vehicle body or the front end surfaces and the radiators of the left and right front side members. The 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 load sensor 24 is supplied to the input / output circuit 14 and stored in the RAM 20 as appropriate according to instructions from the CPU 16. The CPU 16 of the ECU 12 detects the magnitude 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 load sensor 24.

  In addition, the magnitude | size of the load which acts on a vehicle body front part becomes the total value of the load based on the output of each load sensor 24, when the some load sensor 24 is mounted in the vehicle. When the CPU 16 detects the load applied to the vehicle as described above, according to the processing program stored in the ROM 18, whether the vehicle and the pedestrian collide based on the detected load on the front of the vehicle body, as will be described in detail later. No, that is, whether or not the collision target when the vehicle collides is a pedestrian is determined.

  A vehicle speed sensor 26 is also connected to the input / output circuit 14. The vehicle speed sensor 26 is disposed on each wheel and outputs a signal corresponding to the vehicle speed of the host vehicle. The output signal of the vehicle speed 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. The CPU 16 of the ECU 12 detects the vehicle speed of the host vehicle based on the output signal of the vehicle speed sensor 26.

  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 system 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. FIG. 3 shows an example of a determination map based on determination parameters used when performing a pedestrian collision determination in this embodiment.

  When a vehicle collides with a light obstacle such as a post cone or pylon at high speed, the light obstacle will not enter the hood of the vehicle, but will enter under the vehicle body or jump off the vehicle body. 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 addition, when the vehicle collides with a heavy obstacle such as a wall, a very large load continuously acts on the front portion of the vehicle body for an extremely long time. 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 determining whether the object on which the vehicle collided is a pedestrian, the time integrated value (impact) from the start of the collision of the load acting on the front of the vehicle body or the time integrated value is divided by the own vehicle speed. It is appropriate to use a parameter that uses the time integral value of the load, such as the effective mass (effective mass) of the collision target obtained by doing so.

  Therefore, in this embodiment, as a determination map for performing pedestrian collision determination, there are two types of collision target effective masses obtained by dividing the load and the time integral value of the load by the own vehicle speed as shown in FIG. Dimension maps are used, and a threshold change pattern is used in which the threshold value for the load is maintained at a certain large value when the effective mass is small, and the pattern changes so that the effective mass decreases from the predetermined value. The The ECU 12 stores in advance in the ROM 18 a determination map as shown in FIG. 3 set at the boundary so that a collision with a pedestrian, a collision with a light obstacle, and a collision with a heavy obstacle are distinguished. . This determination map is defined in advance corresponding to the load characteristics at the time of collision at the position where the load sensor 24 is disposed.

  In this embodiment, the CPU 16 detects the magnitude of the load acting on the front part of the vehicle body from the front of the vehicle using the load sensor 24 every predetermined time (for example, 10 ms), and uses the vehicle speed sensor 26 to detect the vehicle's own vehicle. Detect the vehicle speed. Further, the load is time-integrated, and the time-integrated value (impulse) is divided by the vehicle speed to calculate the effective mass of the collision target. And the two-dimensional parameter consisting of load and effective mass is the lower threshold change pattern that distinguishes the collision with the pedestrian and the collision with the light obstacle as the judgment map, the collision with the pedestrian and the serious obstacle It is determined whether or not it belongs to an area between the upper threshold change pattern for distinguishing the collision with an object.

  As a result, if the two-dimensional parameter consisting of the load and the effective mass belongs to the region between the lower threshold change pattern and the upper threshold change pattern, it is determined that the object on which the vehicle collided is a pedestrian. Then, the pedestrian protection device 30 for protecting the pedestrian is activated. Thereby, even when the vehicle collides with a pedestrian, the pedestrian can be protected by the activation of the pedestrian protection device 30. On the other hand, if the above two-dimensional parameter does not belong to the above region, it is not determined that the vehicle collision target is a pedestrian, and the pedestrian protection device 30 is not activated.

  By the way, as for the time integral value of the load, not only the load detected every predetermined time is integrated by time integration, but also when the load becomes close to zero, the time integral value at that time is thereafter It is appropriate to gradually decrease and converge to zero over time without maintaining. Also, at the stage where the collision with the collision target is still continuing after the start of the collision, the calculation of the time integral value is performed in a form close to complete integration that does not attenuate the time integral value of the load. This is appropriate for accurately calculating the parameters. On the other hand, after the collision with the collision target is completed, converging the time integration value to zero as quickly as possible prevents the load from multiple collision targets from being mistaken as a single collision target. This is effective.

  Therefore, depending on whether or not the load detected using the load sensor 24 is greater than or equal to a predetermined value, the attenuation rate for attenuating the time integral value of the load with the passage of time is switched. When the value changes from less than the specified value to more than the specified value, the decay rate is set lower than the normal value (low decay rate) so that the time integral value of the load is less likely to decay over time. When the load changes from the predetermined value or more to less than the predetermined value, it is appropriate to return the attenuation rate to a normal one (high attenuation rate) so that the time integral value of the load is easily attenuated over time. .

  4A shows the situation when the vehicle collides with a pedestrian, and FIG. 4B shows the situation when the vehicle collides with a plurality of post cones installed on the road at predetermined intervals. The figure which each represented is shown. FIG. 5 is a diagram illustrating an example of a temporal change in the collision load when the vehicle collides with both feet of the pedestrian at low speed in order and when the vehicle collides with a plurality of post cones continuously at high speed. FIG. 6 is a diagram for explaining a method of performing attenuation integration in which the load is attenuated with time while the load is integrated in this embodiment. 7 shows (A) the time waveform of the effective mass calculated when the time integration of the load is performed by complete integration, and (B) high attenuation when the load waveform as shown in FIG. 5 is obtained. The figure which represented each the time waveform of the effective mass calculated when performing the time integration of a load, switching a damping rate with a rate and a low damping rate is shown.

  When the vehicle collides with a pedestrian, the collision occurs sequentially with a time difference with respect to both feet of the pedestrian, so that the time waveform of the load applied to the front of the vehicle body is two as shown by the solid line in FIG. May indicate peak load. Therefore, when the detected load changes from the predetermined value or more to less than the predetermined value, the above-described switching of the attenuation rate from the low attenuation rate to the high attenuation rate is performed, and the time integral value of the load is easily attenuated in time. Even if the vehicle is colliding with a pedestrian, the peak load due to one foot appears, and when the peak load due to the other foot appears, the time integral value of the load may already be greatly attenuated. Therefore, it becomes impossible to calculate the time integral value and effective mass of the load by the pedestrian with high accuracy. Therefore, in order to solve such a problem, as shown in FIG. 6, even if the detected load changes from a predetermined value or more to less than a predetermined value, a hold time for maintaining the attenuation rate at a low attenuation rate after that is provided. It is effective to maintain the attenuation rate at a low attenuation rate until the time has elapsed, and to switch the attenuation rate from the low attenuation rate to the high attenuation rate when the hold time has elapsed.

  However, assuming that the hold time is fixed at a certain constant value, when the vehicle collides with a plurality of post cones installed at predetermined intervals on the road at a relatively high speed. Even if the time waveform of the load applied to the front part of the vehicle body shows two peak loads that are separated in time as shown by the one-dot chain line in FIG. There may occur a situation in which a plurality of peak loads corresponding to each post cone are added to the integrated value without the time integrated value being greatly attenuated. In this case, when the vehicle collides with a pedestrian, the effective mass of the pedestrian obtained by fully integrating the time integral value of the load without attenuating the vehicle is set on the road with a predetermined interval 2 Even in the situation corresponding to the effective mass of two post cones obtained by complete integration without attenuation of the time integral value of the load when continuously colliding with two post cones (FIG. 7A), Because the hold time for suppressing the switching of the attenuation rate from the low attenuation rate to the high attenuation rate is too long, the calculated effective mass of the collision target is not much different from the effective mass of the pedestrian. (FIG. 7B). On the other hand, if the hold time is too short, when a collision with a pedestrian occurs sequentially with a time difference with respect to both feet as described above, the pedestrian may not be regarded as a single collision target. There is.

  Therefore, the system of the present embodiment is characterized in that the hold time described above is changed to a value corresponding to the own vehicle speed, so that the above-described inconvenience is avoided and the pedestrian collision determination is appropriately performed. . Hereinafter, the characteristic part of the present embodiment will be described with reference to FIGS.

  In the system according to the present embodiment, the ECU 12 stores in advance in the ROM 18 a map that defines the relationship between the vehicle speed and the hold time. As shown in FIG. 8, this map is a quadratic curve that is relatively long when the vehicle speed is low and has a short hold time as the vehicle speed is high.

  When the CPU 16 of the ECU 12 calculates the time integral value of the load based on the output of the load sensor 24, when the detected load changes from less than the predetermined value to more than the predetermined value, the attenuation rate is made lower than that at the normal time, In addition, when the detected load changes from a predetermined value or more to a value less than the predetermined value, the attenuation rate is returned to the normal value after the hold time has elapsed, and this hold time is set according to the vehicle speed. Specifically, the hold time is long when the vehicle speed detected based on the output signal of the vehicle speed sensor 26 is low, and short when the vehicle speed is high.

  According to such a configuration, even when two peak loads appear due to the vehicle sequentially colliding with both feet of the pedestrian at low speed, it is assumed that a collision with a single collision target has occurred, and a solid line in FIG. As shown in the figure, it is possible to appropriately calculate the time integral value of the load by the pedestrian without significant attenuation, and the vehicle continuously collides with a light obstacle such as a plurality of post cones to When a peak load appears, it is assumed that a collision with a plurality of collision objects has occurred, and the time integral value of the load is rapidly attenuated rapidly every collision with each light obstacle as shown by a one-dot chain line in FIG. It becomes possible.

  FIG. 10 shows a flowchart of an example of a control routine executed by the CPU 16 in the pedestrian collision determination system 10 of this embodiment in order to realize the above function. The routine shown in FIG. 10 is repeatedly started every predetermined time. When the routine shown in FIG. 10 is started, the process of step 100 is first executed.

  In step 100, a process of reading a load applied to the front of the vehicle body from the front of the vehicle based on the output signal of the load sensor 24 and reading the vehicle speed of the host vehicle based on the output signal of the vehicle speed sensor 26 is executed. In step 102, when the load sensor 24 is single, the load itself read in the above step is used, and when there are a plurality of load sensors 24, the load F is calculated by summing the loads read in the above step 100. In addition to calculating (n) and referring to the map as shown in FIG. 8 on the basis of the vehicle speed read in step 100, time integration is performed even if the load changes from a predetermined value to a predetermined value. Processing is performed to determine the hold time H (n) at which the value attenuation rate should be maintained at a lower attenuation rate than that at normal times.

  In step 104, it is determined whether or not the detected load F (n) calculated in step 102 is greater than or equal to a predetermined value. The predetermined value is a threshold value of the load applied to the position where the load sensor 24 is disposed at the front of the vehicle body, which is set to switch the attenuation rate between a high attenuation rate and a low attenuation rate. As a result, if a negative determination is made, then in step 106, the current time falls below the predetermined value from the state in which the previously detected load is equal to or higher than the predetermined value, and then the hold time H ( n) whether it is within or not is determined. As a result, if the hold time has already passed and a negative determination is made, the process of step 108 is executed next.

  In step 108, a process of setting the attenuation rate used for time attenuation of the time integral value of the load described above to the high attenuation rate β is executed. This high attenuation rate β is higher than the low attenuation rate α described later. In step 110, the time integral value I (n-1) of the load at the time of the previous processing, the damping rate β set in step 108, and the load F (n) calculated in step 102 according to the following equation (1): From this, a process for obtaining the calculated value X is executed. Δt is a sampling interval of processing by the CPU 16.

X = (1−β) I (n−1) + F (n) Δt (1)
On the other hand, if it is determined in step 104 that the detected load F (n) has become equal to or greater than a predetermined value, the process of step 112 is executed next. Also, if it is determined in step 106 that the detected load has become equal to or greater than a predetermined value but less than the predetermined value, but the hold time H (n) has not yet elapsed, the process of step 112 is executed next. In step 112, processing for setting the attenuation rate used for time attenuation of the time integral value of the load to the low attenuation rate α is executed. This low attenuation rate α is lower than the above-described high attenuation rate β. In step 114, according to the following equation (2), the time integral value I (n-1) of the load at the time of the previous processing, the attenuation rate α set in step 112, and the load F (n) calculated in step 102 above. From this, the processing for obtaining the calculated value X is executed.

X = (1−α) I (n−1) + F (n) Δt (2)
Then, in step 116, a process of setting the calculated value X calculated in step 110 or 114 as the time integral value I (n) of the current load is executed. When the processing of step 116 is executed, the effective mass to be collided is calculated using the time integral value I (n), and pedestrian collision determination is executed. When the processing of step 116 is finished, the current routine is finished.

  According to the routine shown in FIG. 10, when calculating the time integral value of the load based on the output of the load sensor 24, if the detected load changes from less than a predetermined value to more than a predetermined value, the decay rate of the time integral value When the detected load changes from the predetermined value or more to less than the predetermined value, the attenuation factor can be returned to the normal high attenuation factor after the hold time elapses. Even if the load changes from the predetermined value or more to less than the predetermined value, the hold time that should keep the attenuation rate of the time integral value at a lower attenuation rate than that at the normal time is long when the vehicle speed is low. When is high, it can be short.

  Therefore, according to this embodiment, even if the vehicle collides with both feet in order at a low speed against a pedestrian, it is assumed that a collision with a single collision target has occurred, and the time integral value of the load is greatly attenuated. It can be calculated appropriately without accompanying, and even if the vehicle collides continuously with light obstacles such as multiple post cones, it is assumed that there is a collision with multiple collision objects, The time integral value of the load can be greatly attenuated quickly for each collision, and it is possible to avoid a situation where a plurality of loads corresponding to each collision target are accumulated in the time integral value without being greatly attenuated. It is possible to appropriately calculate the time integral value of the load by distinguishing low-speed collision with a pedestrian and continuous high-speed collision with a plurality of light obstacles.

  For this reason, according to the pedestrian collision determination system 10 of the present embodiment, it is possible to accurately determine whether or not the collision target of the collision of the vehicle is a pedestrian, and as a result, the vehicle has a plurality of posts. Even when the vehicle collides with a light obstacle such as a cone continuously, the pedestrian protection device 30 is erroneously activated to ensure that the engine hood is lifted accidentally or the pedestrian protection airbag is erroneously deployed. The pedestrian protection device 30 can be activated only at an appropriate timing without being activated unnecessarily.

  In the above embodiment, the CPU 16 of the ECU 12 detects the load applied to the front of the vehicle body in step 102 in the routine shown in FIG. By executing the processing of 110 and 114, the “attenuation integration means” described in the claims is executed, and by executing the processing of steps 108 and 112, the “attenuation rate control means” described in the claims is By detecting the vehicle speed of the host vehicle based on the output of the vehicle speed sensor 26, the “own vehicle speed detecting means” described in the claims changes the hold time according to the vehicle speed with reference to a map as shown in FIG. By doing so, the “hold time changing means” described in the claims uses the time integral value of the load calculated by the processing of step 116 as the vehicle speed. By determining whether or not the collision target is a pedestrian using an effective mass obtained by division, the “pedestrian collision determination means” described in the claims determines that the collision target is a pedestrian In such a case, the “device activation means” described in the claims is realized by activating the pedestrian protection device 30.

  By the way, in the above embodiment, the effective mass obtained by dividing the time integral value of the load applied to the front part of the vehicle body by the own vehicle speed is used as a determination parameter for performing the pedestrian collision determination. The time integration value itself may be used. Strictly speaking, the two-dimensional parameter of the load and the effective mass is used as the determination parameter, but a one-dimensional parameter of only the effective mass or only the time integral value of the load may be used.

  In the above embodiment, the map that defines the relationship between the vehicle speed and the hold time is a quadratic curve in which the hold time becomes shorter as the vehicle speed becomes higher as shown in FIG. The time may be switched to a staircase, and at that time, the number of steps may be only one, or two or more.

It is a lineblock diagram of a pedestrian collision system for vehicles provided with a load integrated value calculation device for vehicles carried in vehicles which are one example of the present 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 an example of the determination map by the determination parameter used when performing a pedestrian collision determination in a present Example. (A) shows the situation when the vehicle collides with a pedestrian, and (B) shows the situation when the vehicle collides with a plurality of post cones installed at predetermined intervals on the road. FIG. It is a figure showing an example of the time change of the collision load when the vehicle collides with both feet of the pedestrian at low speed in order and when the vehicle collides with a plurality of post cones continuously at high speed. It is a figure for demonstrating the method of performing the attenuation | damping integration which attenuate | damps the time integral value according to time progress, integrating a load in this Example. When the load waveform as shown in FIG. 5 is obtained, (A) the time waveform of the effective mass calculated when the time integration of the load is performed by complete integration, and (B) the high attenuation rate and the low attenuation rate FIG. 6 is a diagram illustrating time waveforms of effective masses that are calculated when load integration is performed while switching the attenuation rate in FIG. It is a figure which shows the map which prescribed | regulated the relationship between a vehicle speed and hold time. FIG. 6 is a diagram showing a time waveform of an effective mass calculated when a load waveform as shown in FIG. 5 is obtained in the present embodiment. It is a flowchart of an example of the control routine performed in a present Example.

Explanation of symbols

10 Pedestrian collision determination system 12 ECU
16 CPU
24 Load sensor 26 Vehicle speed sensor

Claims (5)

Load detecting means for detecting a load applied to the vehicle, and attenuation integration means for attenuating the time integrated value at a predetermined attenuation rate over time while integrating the load detected by the load detecting means over time. A vehicle load integral value calculation device comprising:
When the load detected by the load detecting means changes from less than a predetermined value to the predetermined value or more, the predetermined attenuation rate is lowered from that at normal time, and the load is increased from the predetermined value or more to the An attenuation rate control means for returning the predetermined attenuation rate to a normal one after a predetermined hold time has elapsed when it has changed to less than a predetermined value;
Own vehicle speed detecting means for detecting the own vehicle speed;
Hold time changing means for changing the predetermined hold time in accordance with the own vehicle speed detected by the own vehicle speed detecting means;
A vehicle load integral value calculation device comprising:   2. The vehicle load integrated value calculation apparatus according to claim 1, wherein the hold time changing means shortens the predetermined hold time as the host vehicle speed increases.   The load detecting means detects a total value of loads applied to the front part of the vehicle body based on an output signal of a load sensor disposed on a front end surface of a front side member on the front side member of the front side member and the front bumper of the front part of the vehicle body. The vehicle load integral value calculation device according to claim 1 or 2, characterized by the above-mentioned.   Whether or not the collision target of the own vehicle is a pedestrian using the time integrated value of the load calculated by the attenuation integration means or the effective mass obtained by dividing the time integrated value of the load by the own vehicle speed A vehicle pedestrian collision determination system equipped with the vehicle load integrated value calculation device according to any one of claims 1 to 3, further comprising a pedestrian collision determination means for determining   5. The apparatus according to claim 4, further comprising device activation means for activating a device for protecting a pedestrian when the collision target of the host vehicle is determined to be a pedestrian by the pedestrian collision determination means. A pedestrian collision determination system for vehicles.

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