JP6337832B2 - Vehicle collision detection device - Google Patents

Description

  The present invention relates to a vehicle collision detection device for detecting a collision with a pedestrian or the like of a vehicle.

  Conventionally, there is a vehicle including a pedestrian protection device for reducing an impact on a pedestrian when the pedestrian collides with the vehicle. In this vehicle, a bumper unit is provided with a collision detection device, and when this sensor detects that a pedestrian or the like has collided with the vehicle, the pedestrian protection device is activated to reduce the impact on the pedestrian. It has a configuration. An example of a pedestrian protection device is a pop-up hood. This pop-up hood raises the rear end of the engine hood when a vehicle collision is detected, increases the clearance between the pedestrian and hard parts such as the engine, and uses that space to reduce the collision energy to the pedestrian's head. It absorbs and reduces the impact on the head.

  In the above-described vehicle collision detection device, a chamber member having a chamber space formed therein is disposed on the vehicle front side of a bumper reinforcement in a vehicle bumper, and the pressure in the chamber space is measured by a pressure sensor. There is something to be detected. With this configuration, when an object such as a pedestrian collides with the bumper cover, the chamber member is deformed along with the deformation of the bumper cover, and a pressure change is generated in the chamber space. The pressure sensor detects this pressure change to detect a pedestrian collision.

  In recent years, a tube-type vehicle collision detection device that detects a collision using a tube member that is smaller and more easily mounted than the chamber-type vehicle collision detection device has been proposed. This vehicle collision detection device includes a bumper absorber disposed on the front side of a bumper reinforcement in a vehicle bumper, and a hollow tube mounted in a groove formed in the bumper absorber along the vehicle width direction. It comprises a member and a pressure sensor for detecting the pressure in the tube member. When a pedestrian or the like collides in front of the vehicle, the bumper absorber is deformed while absorbing the impact, and at the same time, the tube member is also deformed. At this time, the pressure in the tube member rises, and the collision with the pedestrian of the vehicle is detected based on detecting this pressure change by the pressure sensor.

Special table 2014-505629 gazette

  However, in the vehicle collision detection device having the above-described configuration, the output of the pressure sensor may vary at the position of the bumper in the vehicle width direction. For example, the bumper cover has a structure in which the bumper cover is inclined in the vehicle front-rear direction at the corner of the bumper in the vehicle width direction end. May become smaller. Therefore, in order to ensure the accuracy of collision detection, it is a problem to estimate the position in the vehicle width direction of the bumper on which the pedestrian or the like has collided, and perform an appropriate collision determination according to the collision position.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a vehicle collision detection device capable of estimating a collision position of a bumper in a vehicle width direction.

  A vehicle collision detection device (1) according to claim 1, which is made to solve the above object, includes a bumper disposed on a front side of a bumper reinforcement (9) in a bumper (7) of the vehicle. Absorber (2), tube member for detection (3) in which hollow portion (3a) is formed in a groove (2a) formed in the bumper absorber along the vehicle width direction, and tube member for detection And a pressure sensor for detecting the pressure in the hollow portion of the hollow portion, and detects the collision of the object with the bumper based on the pressure detection result by the pressure sensors (4L, 4R). The pressure sensor includes a left pressure sensor (4L) connected to the left end of the detection tube member in the vehicle width direction and a right pressure sensor (4R) connected to the right end of the detection tube member in the vehicle width direction. It is configured. Then, a plurality of peak values (P1L, P2L) of the pressure waveform detected by the left pressure sensor and a plurality of peak values (P1R, P2R) of the pressure waveform detected by the right pressure sensor when an object collides with the bumper. ) For detecting a collision position of an object in the vehicle width direction of the bumper based on the peak value of each pressure waveform detected by the peak value detection unit. (62, S13, S15, S16, S19, S20).

  According to this configuration, the left and right pressure sensors detect the pressure in the hollow portion at the left and right ends in the vehicle width direction of the detection tube member, and the peak value of each pressure waveform detected by the left and right pressure sensors by the peak value detection unit Then, the collision position estimation unit can estimate the collision position of the object in the vehicle width direction of the bumper based on the peak value of each pressure waveform. Thereby, the collision position in the vehicle width direction of the bumper can be estimated with a simple configuration, and an appropriate collision determination according to the collision position can be performed. Therefore, it is possible to accurately determine the collision of the object with the bumper, and to improve the collision detection accuracy of the vehicle collision detection device with a simple configuration. In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is a schematic diagram illustrating an overall configuration of a vehicle collision detection device according to an embodiment of the present invention. It is an enlarged view of the bumper part of FIG. FIG. 3 is a III-III cross-sectional view of the bumper portion of FIG. It is a figure which shows the electrical constitution of the collision detection apparatus for vehicles. It is a flowchart which shows the flow of a collision determination process. It is a flowchart which shows the flow of a collision determination threshold value setting process. It is a schematic diagram which shows the collision position of an object. It is a schematic diagram which shows the propagation path of the pressure wave to the left and right pressure sensors at the time of a center collision. It is a schematic diagram which shows the propagation path of the pressure wave to the left and right pressure sensors at the time of a left corner collision. It is a figure which shows the pressure waveform detected by the left and right pressure sensors at the time of a center collision. It is a figure which shows the pressure waveform detected by the left and right pressure sensors at the time of a left corner collision.

  Hereinafter, a vehicle collision detection device according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the vehicle collision detection apparatus 1 according to this embodiment includes a bumper absorber 2, a detection tube member 3, a left pressure sensor 4L, a right pressure sensor 4R, a speed sensor 5, a collision detection ECU 6, and the like. It is configured with. The vehicle collision detection device 1 detects a collision of an object (that is, a pedestrian) with a bumper 7 provided in front of the vehicle. As shown in FIG. 3, the bumper 7 is mainly composed of a bumper cover 8, a bumper absorber 2, and a bumper reinforcement 9.

  The bumper absorber 2 is disposed at a position facing the front surface 9a of the bumper reinforcement 9 (that is, the vehicle front side). The bumper absorber 2 is a member responsible for shock absorption in the bumper 7, and is made of, for example, foamed polypropylene.

  On the rear surface 2b of the bumper absorber 2, as shown in FIG. 3, a groove portion 2a for mounting the detection tube member 3 is formed along the vehicle width direction. The groove 2a has a rectangular cross-sectional shape and extends in the vehicle width direction.

  The length of the groove portion 2a in the vehicle front-rear direction is set to be approximately the same as the length of the detection tube member 3 (that is, the length of the outer diameter). In this case, the longitudinal length of the groove 2a is about 8 mm. The length of the groove 2a in the vehicle vertical direction is set to be equal to or greater than the vertical length of the detection tube member 3 (that is, the length of the outer diameter). In this case, the vertical length of the groove 2a is about 10 mm. It is assumed that the cross-sectional shape of the groove 2a can be changed as appropriate.

  The detection tube member 3 is a tube-like member having a hollow portion 3a formed therein and extending in the vehicle width direction (that is, the vehicle left-right direction). This detection tube member 3 is mounted in the groove 2a of the bumper absorber 2 and is disposed in a bumper 7 of the vehicle at a position facing the front surface 9a of the bumper reinforcement 9 (that is, on the vehicle front side). Both left and right ends of the detection tube member 3 in the vehicle width direction are curved outside the left and right sides of the bumper reinforcement 9 in the vehicle width direction, and are respectively connected to a left pressure sensor 4L and a right pressure sensor 4R described later.

  The detection tube member 3 has a circular cross-sectional shape and is made of synthetic rubber, for example, silicone rubber. The outer diameter of the detection tube member 3 is, for example, about 8 mm. The cross-sectional shape of the detection tube member 3 is not limited to a circle, but may be a polygon such as a quadrangle. In addition, the material of the tube member 3 for detection may be ethylene propylene rubber (EPDM) or the like.

  The left pressure sensor 4L and the right pressure sensor 4R are disposed on the vehicle rear side with respect to the front surface 9a of the bumper reinforcement 9 as shown in FIGS. Specifically, the left pressure sensor 4L is installed on the rear surface 9b of the bumper reinforcement 9 on the left end side in the vehicle width direction. The right pressure sensor 4R is installed on the rear surface 9b of the bumper reinforcement 9 on the right end side in the vehicle width direction. The left pressure sensor 4L and the right pressure sensor 4R are fixedly attached to the rear surface 9b of the bumper reinforcement 9 by fastening with a bolt or the like (not shown).

  The left pressure sensor 4L and the right pressure sensor 4R are sensor devices that detect a change in gas pressure. Specifically, the left pressure sensor 4L is connected to the left end of the detection tube member 3 in the vehicle width direction, and detects the pressure in the hollow portion 3a at the left end of the detection tube member 3 in the vehicle width direction. The right pressure sensor 4R is connected to the right end of the detection tube member 3 in the vehicle width direction, and detects the pressure in the hollow portion 3a on the right side of the detection tube member 3 in the vehicle width direction.

  In the present embodiment, redundancy and detection accuracy are ensured by installing two pressure sensors, the left pressure sensor 4L and the right pressure sensor 4R. Further, the collision position of an object such as a pedestrian can be estimated based on the peak value of each pressure waveform detected by the left and right pressure sensors 4L and 4R. As shown in FIG. 1, the left pressure sensor 4L and the right pressure sensor 4R are electrically connected to the collision detection ECU 6 via a transmission line, and output a signal proportional to the pressure to the collision detection ECU 6.

  The speed sensor 5 is a sensor device that detects the speed of the vehicle, and is electrically connected to the collision detection ECU 6 via a signal line. The speed sensor 5 transmits a signal proportional to the vehicle speed to the collision detection ECU 6.

  A collision detection ECU (Electronic Control Unit) 6 is mainly composed of a CPU, and controls the overall operation of the vehicle collision detection apparatus 1. As shown in FIG. 4, the collision detection ECU 6 of the present embodiment includes a peak value detection unit 61, a collision position estimation unit 62, a collision determination unit 63, and a threshold change unit 64.

  The collision detection ECU 6 is electrically connected to each of the left pressure sensor 4L, the right pressure sensor 4R, the speed sensor 5, and the pedestrian protection device 10. The collision detection ECU 6 receives a pressure signal from the left pressure sensor 4L and the right pressure sensor 4R, a speed signal from the speed sensor 5, and the like.

  The peak value detector 61 detects the peak value of each pressure waveform detected by the left pressure sensor 4L and the right pressure sensor 4R, respectively, when a pedestrian or the like collides with the bumper cover 8. Specifically, the peak value detection unit 61 includes first peak values P1L and P1L that first peak and first peak value P1L in each pressure waveform detected by the left pressure sensor 4L and the right pressure sensor 4R, respectively. , Second peak values P2L and P2R that peak after P1L are detected. Here, the “peak value” means the maximum value of each pressure waveform detected by the pressure sensors 4L and 4R, that is, the maximum pressure value when the increasing pressure value changes to decrease.

  The collision position estimation unit 62 determines the collision position of a pedestrian or the like based on the peak values P1L, P1R, P2L, P2R of the pressure waveforms of the left pressure sensor 4L and the right pressure sensor 4R detected by the peak value detection unit 61. To be estimated. The first peak values P1L and P1R are pressure detection values that first peak in each pressure waveform detected by the left and right pressure sensors 4L and 4R, respectively. The second peak values P2L and P2R are pressure detection values that peak after the first peak values P1L and P1R in the pressure waveforms detected by the left and right pressure sensors 4L and 4R, respectively.

  Here, the first peak values P1L and P1R and the second peak values P2L and P2R of each pressure waveform detected by the left and right pressure sensors 4L and 4R will be described in detail. First, as shown in FIGS. 8 and 9, in the center collision (that is, the collision at the center portion A in the vehicle width direction) and the corner collision (that is, the collision at the corner portion C), the left and right pressure sensors 4L, The propagation path of the pressure wave reaching 4R is different. For this reason, the pressure waveforms of the pressure detection values of the left and right pressure sensors 4L and 4R in the center collision shown in FIG. 10 and the pressure detection values of the left and right pressure sensors 4L and 4R in the corner collision shown in FIG. Become.

  The “vehicle width direction center portion A” refers to a range of a predetermined length (for example, about 100 mm) from the vehicle width direction center to the left and right. Further, the “corner portion C” refers to a range extending from a vehicle width direction end portion of the bumper 7 to the center side to a predetermined length (for example, about 300 mm) (see the encircled line in FIG. 2).

  Specifically, in the center collision, the pressure waveforms detected by the left and right pressure sensors 4L and 4R have no phase shift and rise time delay. This is because there is a phase shift and a rise time delay at the timing of time t1 and time t2 in the propagation path of the pressure wave to the left pressure sensor 4L and the propagation path of the pressure wave to the right pressure sensor 4R shown in FIG. This is because the pressure wave propagates. Therefore, as shown in FIG. 10, there is no pressure waveform phase shift and rise time delay between the pressure waveform detected by the left pressure sensor 4L and the pressure waveform detected by the right pressure sensor 4R. Further, the first peak value P1L and the first peak value P1R of each pressure waveform detected by the left and right pressure sensors 4L and 4R are approximately the same value, and the second peak value P2L and the second peak value P2R are the same. It becomes a value of the degree.

  On the other hand, in a corner collision, each pressure waveform detected by the left and right pressure sensors 4L, 4R has a rise time delay and a phase shift. This is the timing of time T1 and time T1 ′, time T2 and time T2 ′ in the pressure wave propagation path to the left pressure sensor 4L and the pressure wave propagation path to the right pressure sensor 4R shown in FIG. This is because there is a delay in the rise time and a phase shift, and the pressure wave is propagated in this state.

  For example, in a corner collision where a collision occurs near the left pressure sensor 4L (see FIG. 7), as shown in FIG. 11, the rise time of the pressure waveform of the left pressure sensor 4L is earlier than that of the right pressure sensor 4R. There is a phase shift. Further, the first peak value P1L of the pressure waveform detected by the left pressure sensor 4L is larger than the second peak value P2L. Further, the first peak value P1R of the pressure waveform detected by the right pressure sensor 4R is smaller than the second peak value P2R.

  Furthermore, the second peak value P2R of the pressure waveform of the right pressure sensor 4R is larger than the second peak value P2L of the pressure waveform of the left pressure sensor 4L. This is because the pressure wave to the left pressure sensor 4L bounces toward the right pressure sensor 4R at the left end of the detection tube member 3 in the vehicle width direction at time T1, and the bounced pressure wave and right at time T1 ′. This is because the second peak value P2R of the pressure waveform of the right pressure sensor 4R becomes a large value by overlapping with the pressure wave propagated to the pressure sensor 4R (see FIG. 9).

  In the present embodiment, using the verification result described above, the collision position estimation unit 62 uses the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L and the first of the pressure waveforms detected by the right pressure sensor 4R. By determining whether or not the absolute value | ΔP2 | = | P2L−P2R | of the difference from the two peak values P2R is equal to or greater than a predetermined value ΔP2th, a pedestrian is detected at the corner C on the end side in the vehicle width direction of the bumper 7. It is possible to estimate that such a collision has occurred. The collision position estimation unit 62 compares the magnitudes of the first peak value P1L and the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L, and the pressure detected by the right pressure sensor 4R. By comparing the first peak value P1R and the second peak value P2R of the waveform, it is possible to estimate that a collision of a pedestrian or the like has occurred in the central portion A in the vehicle width direction of the bumper 7.

  The collision determination unit 63 determines whether or not an object (that is, a pedestrian) has collided with the bumper 7 based on pressure detection results by the left pressure sensor 4L and the right pressure sensor 4R. Specifically, the collision determination unit 63 performs a collision determination process, which will be described later, based on the pressure signal from the pressure sensor 4 and the speed signal from the speed sensor 5, and detects the collision of an object such as a pedestrian to the bumper 7. In such a case, the pedestrian protection device 10 is activated.

  The threshold value changing unit 64 makes a collision determination according to the collision position of the object estimated by the collision position estimation unit 62 before the collision determination unit 63 determines that an object (that is, a pedestrian) has collided with the bumper 7. Change the threshold used. Specifically, the threshold change unit 64 changes the collision determination threshold based on the collision position of the object estimated by the collision position estimation unit 62. The collision determination threshold value has a first threshold value and a second threshold value that is smaller than the first threshold value. The first threshold is used as a collision determination threshold for a center collision other than a corner collision. The second threshold value is used as a collision determination threshold value for a corner collision.

  The bumper 7 is for reducing an impact at the time of a vehicle collision, and includes a bumper cover 8, a bumper absorber 2, a bumper reinforcement 9, and the like. The bumper cover 8 is provided so as to cover the components of the bumper 7 and is a resin member such as polypropylene. The bumper cover 8 constitutes the appearance of the bumper 7 and at the same time constitutes a part of the appearance of the entire vehicle.

  The bumper reinforcement 9 is a rigid member made of metal such as aluminum which is disposed in the bumper cover 8 and extends in the vehicle width direction, and has a cross-sectional shape in which a beam is provided in the center of the interior as shown in FIG. It is a rigid member having The bumper reinforcement 9 has a front surface 9a that is a surface on the front side of the vehicle and a rear surface 9b that is a surface on the rear side of the vehicle. As shown in FIGS. 1 and 2, the bumper reinforcement 9 is attached to the front end of a side member 11 that is a pair of metal members extending in the vehicle front-rear direction.

  Usually, in a vehicle collision accident, there are many cases where the vehicle collides with a pedestrian or a vehicle existing in the traveling direction of the vehicle, that is, in front of the vehicle. For this reason, in this embodiment, the pressure sensors 4L and 4R are disposed on the rear surface 9b of the bumper reinforcement 9, and a bumper provided in front of the vehicle is subjected to an impact caused by a collision with a pedestrian or vehicle in front of the vehicle. Direct transmission from the cover 8 or the like to the pressure sensors 4L and 4R is protected by the presence of the bumper reinforcement 9.

  For example, a pop-up hood is used as the pedestrian protection device 10. This pop-up hood raises the rear end of the engine hood instantly after detecting a vehicle collision, increases the clearance between the pedestrian and hard parts such as the engine, and uses that space to collide with the pedestrian's head. It absorbs energy and reduces the impact on the pedestrian's head. Instead of the pop-up hood, a cowl airbag or the like that cushions a pedestrian's impact by deploying the airbag from the engine hood outside the vehicle body to the lower part of the front window may be used.

  Here, the operation | movement at the time of the collision of the collision detection apparatus 1 for vehicles in this embodiment is demonstrated. When an object (that is, a pedestrian or the like) collides with the front of the vehicle, the bumper cover 8 of the bumper 7 is deformed by an impact accompanying the collision with the pedestrian. Subsequently, the bumper absorber 2 is deformed while absorbing the impact, and at the same time, the detection tube member 3 is also deformed. At this time, the pressure in the hollow portion 3a of the detection tube member 3 increases rapidly, and this pressure change is transmitted to the left pressure sensor 4L and the right pressure sensor 4R.

  Next, the flow of the collision determination process by the vehicle collision detection apparatus 1 having the above configuration will be described with reference to the flowcharts of FIGS. However, these flowcharts are examples, and the present invention is not limited to these. In the collision determination process of the present embodiment, the collision position of the pedestrian is estimated based on the pressure detection results of the left pressure sensor 4L and the right pressure sensor 4R, and the pedestrian requiring the operation of the pedestrian protection device 10 is detected. It is determined whether or not a collision has occurred.

  In the “collision determination process” shown in FIG. 5, first, the collision detection ECU 6 of the vehicle collision detection device 1 acquires the vehicle speed based on the output from the speed sensor 5 (step S <b> 1, the following steps are omitted). It is determined whether or not it is within a predetermined operating range (S2). The operating range of the vehicle speed is, for example, a range of 25 km to 55 km / h. This operating range is set based on the fact that the speed at which the pedestrian protection function of the pedestrian protection device 10 effectively acts is determined by conditions such as the vehicle shape.

  When the vehicle speed is not within the operating range (S2: No), the process returns to S1, and when the vehicle speed is within the operating range (S2: Yes), the collision detection ECU 6 detects the left pressure sensor 4L and the right pressure sensor 4R. A value is acquired (S3), and an effective mass is calculated (S4).

Here, the “effective mass” refers to a mass that is calculated from the detected value of the pressure sensor 4 at the time of collision using the relationship between momentum and impulse. When a collision between a vehicle and an object occurs, the value of the detected pressure sensor 4 is different for a collision object having a mass different from that of a pedestrian. For this reason, by setting a threshold value between the effective mass of the human body and the mass of another assumed collision object, it is possible to classify the types of the collision object. This effective mass is calculated by dividing the constant integral value of the pressure value detected by the pressure sensor 4 at a predetermined time by the vehicle speed detected by the speed sensor 5 as shown in the following equation.
M = (∫P (t) dt) / V (Expression 1)

M is an effective mass, P is a value detected by the pressure sensor 4 at a predetermined time, t is a predetermined time (for example, several ms to several tens of ms), and V is a vehicle speed at the time of collision detected by the speed sensor 5. ing. As another method for calculating the effective mass, it is possible to calculate using an equation E = 1/2 · MV ² representing the kinetic energy E of the collided object. In this case, the effective mass is calculated by M = 2 · E / V ² .

  Here, the pressure detection values detected by the left pressure sensor 4L and the right pressure sensor 4R vary depending on the collision position of the bumper cover 8 of the bumper 7 in the vehicle width direction. For example, since the corner portion C on the vehicle end side is inclined in the vehicle longitudinal direction, the output of the pressure sensors 4L and 4R may be reduced when the external force applied at the time of collision escapes to the vehicle side. . In this case, it is preferable to make the collision determination threshold value of the corner portion C smaller than the collision determination threshold value in the center in the vehicle width direction. Thus, in order to ensure the collision detection accuracy, it is necessary to make the collision determination threshold different depending on the collision position in the vehicle width direction of the bumper 7 on which the pedestrian or the like collided.

  Therefore, in this embodiment, after calculating the effective mass in S4, the collision determination threshold value is changed according to the collision position of the bumper 7 in the vehicle width direction by performing the “collision determination threshold value setting process” shown in FIG. Let In this collision determination threshold value setting process, first, the peak value detection unit 61 performs first peak values P1L, P1R, second peak values P2L, P2R of the left pressure sensor 4L and the right pressure sensor 4R (FIGS. 10 and 11). Reference) is acquired (S11).

  Next, the collision position estimation unit 62 calculates the absolute value of the difference between the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L and the second peak value P2R of the pressure waveform detected by the right pressure sensor 4R. It is determined whether or not | ΔP2 | is equal to or greater than a predetermined value ΔP2th (S12). When | ΔP2 | = | P2L−P2R | ≧ ΔP2th (S12: Yes), the collision position estimation unit 62 causes a collision of a pedestrian or the like at the corner portion C on the end side in the vehicle width direction of the bumper cover 8. (S13). It is assumed that the predetermined value ΔP2th can be set as appropriate.

  Furthermore, the collision position estimation unit 62 determines whether or not P2L-P2R> 0 (S14). When P2L-P2R> 0 (S14: Yes), the collision position estimation unit 62 estimates that a collision has occurred at the right corner (S15). Further, when P2L-P2R> 0 is not satisfied, that is, P2L-P2R <0 (S14: Yes), the collision position estimation unit 62 estimates that a collision (see FIG. 11) has occurred in the left corner (S16). Then, after S15 or S16, the threshold value changing unit 64 sets the collision determination threshold value used for the collision determination process as the second threshold value (S17). Since | ΔP2 | = | P2L−P2R | ≧ ΔP2th> 0, P2L−P2R = 0 does not occur.

  On the other hand, if | ΔP2 | = | P2L−P2R | ≧ ΔP2th is not satisfied (S12: No), that is, if | ΔP2 | <ΔP2th, the collision position estimation unit 62 determines whether P1L> P2L and P1R> P2L. Perform (S18). When P1L> P2L and P1R> P2L (S18: Yes), the collision position estimation unit 62 estimates that a collision of an object such as a pedestrian has occurred in the vehicle width direction central portion A of the bumper cover 8 (S19). ). In addition, when P1L> P2L and P1R> P2L are not satisfied (S18: No), the collision position estimation unit 62 collides an object such as a pedestrian between the vehicle width direction central portion A and the corner portion C of the bumper cover 8. Is estimated to have occurred (S20). Then, after S19 or S20, the threshold value changing unit 64 sets the collision determination threshold value to the first threshold value (S21). This completes the “collision determination threshold setting process” and returns to the “collision determination process”.

  Subsequently, the collision determination unit 63 determines whether the effective mass is greater than or equal to the collision determination threshold (first threshold or second threshold) (S6). When the effective mass is the collision determination threshold value (S6: Yes), the collision determination unit 63 determines that a collision with a pedestrian or the like of the vehicle has occurred (S7), and generates a control signal for operating the pedestrian protection device 10. It outputs and the pedestrian protection apparatus 10 is operated (S8). Thereby, the impact to the pedestrian accompanying a collision is reduced. When the effective mass is less than the set collision determination threshold (S6: No), the process returns to S1.

  As described above, the vehicle collision detection device 1 of the present embodiment includes the bumper absorber 2 disposed on the front side of the bumper reinforcement 9 in the bumper 7 of the vehicle, and the bumper absorber 2 in the vehicle width direction. The detection tube member 3 in which the hollow portion 3a is formed and the pressure sensors 4L and 4R for detecting the pressure in the hollow portion 3a of the detection tube member 3 are attached to the groove portion 2a formed along And the occurrence of a collision of an object (that is, a pedestrian) with the bumper 7 is detected based on the pressure detection result by the pressure sensors 4L and 4R.

  The pressure sensors 4L and 4R are a left pressure sensor 4L connected to the left end of the detection tube member 3 in the vehicle width direction, and a right pressure sensor 4R connected to the right end of the detection tube member 3 in the vehicle width direction. It is comprised. A plurality of peak values P1L and P2L of the pressure waveform detected by the left pressure sensor 4L and a plurality of peak values P1R and P2R of the pressure waveform detected by the right pressure sensor 4R as the object collides with the bumper 7 occur. Of the bumper 7 in the vehicle width direction based on the peak values P1L, P1R, P2L, and P2R of the respective pressure waveforms detected by the peak value detector 61. A collision position estimation unit (62, S13, S15, S16, S19, S20) for estimating the position is provided.

  According to this configuration, the left and right pressure sensors 4L and 4R detect the pressure in the hollow portion 3a at the left and right ends in the vehicle width direction of the detection tube member 3, and the peak value detection unit 61 detects the left and right pressure sensors 4L and 4R. After detecting the peak values P1L, P1R, P2L, and P2R of each pressure waveform detected in step 1, the vehicle position of the bumper 7 is detected by the collision position estimation unit 62 based on the peak values P1L, P1R, P2L, and P2R of each pressure waveform. The collision position of the object in the direction can be estimated. Thereby, the collision position in the vehicle width direction of the bumper 7 can be estimated with a simple configuration, and an appropriate collision determination according to the collision position can be performed. Therefore, the collision determination of the object (that is, the pedestrian) to the bumper 7 can be accurately performed, and the collision detection accuracy of the vehicle collision detection apparatus 1 can be improved with a simple configuration.

  The peak value detection unit (61, S11) includes first peak values P1L and P1R that first peak in each pressure waveform detected by the left pressure sensor 4L and the right pressure sensor 4R, and a first peak value P1L. , Second peak values P2L and P2R that peak after P1R are detected. The collision position estimation unit 62 estimates the collision position of the object in the vehicle width direction of the bumper 7 based on the second peak values P2L and P2R. Specifically, the collision position estimation unit (62, S13, S15, S16) includes the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L and the first of the pressure waveform detected by the right pressure sensor 4R. When the absolute value | ΔP2 | of the difference from the two peak values P2R is equal to or greater than a predetermined value ΔP2th, it is estimated that a collision has occurred in the corner portion C extending from the vehicle width direction end of the bumper 7 to the center side over a predetermined length. It is characterized by that.

  According to this configuration, the peak value detector 61 detects the first peak values P1L and P1R and the second peak values P2L and P2R of the pressure waveforms detected by the left and right pressure sensors 4L and 4R, and estimates the collision position. By determining whether or not the absolute value | ΔP2 | of the difference between the second peak values P2L and P2R of the left and right pressure sensors 4L and 4R is equal to or greater than a predetermined value ΔP2th by the unit 62, the corner C It can be reliably estimated that a collision has occurred.

  The collision position estimation unit (62, S15, S16) also determines that the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L is greater than the second peak value P2R of the pressure waveform detected by the right pressure sensor 4R. If it is smaller, it is estimated that a collision has occurred at the left corner of the vehicle width direction, and the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L is the second of the pressure waveforms detected by the right pressure sensor 4R. When it is larger than the two peak values P2R, it is estimated that a collision has occurred in the corner portion C on the right side in the vehicle width direction.

  According to this configuration, the magnitude of the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L and the second peak value P2R of the pressure waveform detected by the right pressure sensor 4R is detected by the collision position estimation unit 62. Thus, it is possible to reliably estimate whether an object collision has occurred in either the left corner portion or the right corner portion.

  In addition, the collision position estimation unit (62, S19) determines that the first peak value P1L of the pressure waveform detected by the left pressure sensor 4L is larger than the second peak value P2L and the pressure detected by the right pressure sensor 4R. When the first peak value P1R of the waveform is larger than the second peak value P2R, it is estimated that an object collision has occurred in the vehicle width direction central portion A of the bumper 7.

  According to this configuration, the magnitude of the first peak value P1L and the second peak value P2L of the pressure waveform detected by the left pressure sensor 4L by the collision position estimation unit 62, the pressure waveform detected by the right pressure sensor 4R, and so on. By comparing the magnitudes of the first peak value P1R and the second peak value P2R, it is possible to reliably determine that an object collision has occurred in the central portion A of the bumper 7 in the vehicle width direction.

  In addition, when the pressure detection results by the left pressure sensor 4L and the right pressure sensor 4R are equal to or greater than a predetermined collision determination threshold, a collision determination unit (63, S7) that determines occurrence of a collision with the bumper 7, and a collision determination unit 63 And a threshold value changing unit (64, S5, S17, S21) that changes the collision determination threshold value according to the collision position estimated by the collision position estimation unit 62 before determining the occurrence of a collision. .

  According to this configuration, after the threshold change unit 64 changes the collision determination threshold according to the collision position estimated by the collision position estimation unit 62, the collision determination unit 63 determines the collision occurrence. By changing the collision determination threshold accordingly, the collision determination unit 63 can accurately determine the occurrence of the collision.

  Specifically, the threshold value changing unit (64, S17, S21) sets the first threshold value as the collision determination threshold value when it is estimated by the collision position estimation unit 62 that a collision has occurred outside the corner portion C, When the collision position estimation unit 62 estimates that a collision has occurred in the corner portion C, a second threshold value different from the first threshold value is set as the collision determination threshold value.

  According to this configuration, when a collision occurs in a portion other than the corner portion C based on the collision position of the object (that is, a pedestrian) estimated by the collision position estimating portion 62 by the threshold value changing portion 64 and in the corner portion C, By setting the collision determination threshold value to be different when a collision occurs, the collision determination threshold value of the pressure sensors 4L and 4R having different output values at the vehicle width direction position can be appropriately set according to the collision position. it can. Thereby, the collision detection accuracy of the vehicle collision detection device 1 can be effectively improved, and a pedestrian can be detected more accurately over the entire vehicle width direction of the bumper 7.

  Further, the second threshold value is smaller than the first threshold value. According to this configuration, the second threshold value that is the collision determination threshold value of the corner portion C is set to a value that is smaller than the first threshold value that is the collision determination threshold value of the center portion A in the vehicle width direction. Collision detection can be performed with high accuracy regardless of the position. That is, since the bumper cover 8 is inclined in the vehicle front-rear direction at the corner portion C, the external force applied at the time of collision escapes to the vehicle side, so that the pressure sensors 4L, 4R The pressure detection value may be small. Therefore, by setting the collision determination threshold value of the corner portion C to a value smaller than the collision determination threshold value in the center portion in the vehicle width direction, the collision caused by variations in the pressure outputs of the pressure sensors 4L and 4R at the vehicle width direction position of the bumper 7 Decrease in detection accuracy can be suppressed.

  The present invention is not limited to the above-described embodiments, and various modifications or expansions can be made without departing from the spirit of the present invention. For example, in the above embodiment, the two threshold values of the first threshold value and the second threshold value are used as the collision determination threshold value. However, the present invention is not limited to this, and three or more threshold values may be used as the collision determination threshold value. For example, it may be divided into three sections of the vehicle width direction central portion A, the vehicle width direction central portion A and the corner portion C, and the corner portion C, and different collision determination threshold values may be used. In this case, in the section between the vehicle width direction center portion A and the corner portion C, the first threshold value and the second threshold value are different values after S20 in the collision determination threshold value setting process shown in FIG. The collision determination threshold value may be set to the threshold value of 3. In addition, the size of the collision determination threshold in each section is appropriately set based on the structure of the vehicle and the collision detection performance.

  In the above embodiment, the effective mass is calculated based on the pressure detection result, and when the effective mass exceeds the collision determination threshold in the collision determination process, the collision with the pedestrian that requires the operation of the pedestrian protection device 10 is performed. However, the present invention is not limited to this. That is, the pressure detection result may be used as it is. For example, a configuration may be used in which the collision determination is performed by comparing the pressure detection result with the respective collision determination thresholds using a pressure value, a pressure change rate, or the like.

DESCRIPTION OF SYMBOLS 1 Vehicle collision detection apparatus 2 Bumper absorber 2a Groove part 3 Detection tube member 3a Hollow part 4L Left pressure sensor 4R Right pressure sensor 61 Peak value detection part 62 Collision position estimation part 63 Collision judgment part 64 Threshold change part 7 Bumper 9 Bumper rain Force P1L, P1R First peak value P2L, P2R Second peak value A Center part in the vehicle width direction C Corner part

Claims (8)

A bumper reinforcement (2) disposed on the front side of the bumper reinforcement (9) in the vehicle bumper (7) and a groove (2a) formed in the bumper absorber along the vehicle width direction are mounted. A detection tube member (3) in which a hollow portion (3a) is formed, and a pressure sensor (4L, 4R) for detecting a pressure in the hollow portion of the detection tube member. In the vehicle collision detection device (1) for detecting occurrence of collision of an object with the bumper based on a pressure detection result by a sensor,
The pressure sensor includes a left pressure sensor (4L) connected to the left end of the detection tube member in the vehicle width direction and a right pressure sensor (4R) connected to the right end of the detection tube member in the vehicle width direction. ), And
A plurality of peak values (P1L, P2L) of the pressure waveform detected by the left pressure sensor and a plurality of peak values (P1R) of the pressure waveform detected by the right pressure sensor as the object collides with the bumper. , P2R) for detecting a peak value (61, S11),
A collision position estimation unit (62, S13, S15, S16, S19, S19) that estimates the collision position of the object in the vehicle width direction of the bumper based on the peak value of each pressure waveform detected by the peak value detection unit. S20)
A collision detection apparatus for a vehicle, comprising: The peak value detection unit includes a first peak value (P1L, P1R) that first peaks in each pressure waveform detected by the left pressure sensor and the right pressure sensor, and a peak delayed from the first peak value. And the second peak value (P2L, P2R)
2. The vehicle collision detection device according to claim 1, wherein the collision position estimation unit estimates a collision position of the object in a vehicle width direction of the bumper based on the second peak value. The peak value detection unit includes a first peak value (P1L, P1R) that first peaks in each pressure waveform detected by the left pressure sensor and the right pressure sensor, and a peak delayed from the first peak value. And the second peak value (P2L, P2R)
The collision position estimation unit (62, S13, S15, S16) includes a second peak value (P2L) of the pressure waveform detected by the left pressure sensor and a second peak of the pressure waveform detected by the right pressure sensor. When the absolute value (| ΔP2 |) of the difference from the value (P2R) is equal to or greater than a predetermined value (ΔP2th), a collision occurs at the corner portion (C) extending from the end in the vehicle width direction to the center side of the bumper. The vehicle collision detection device according to claim 2, wherein the vehicle collision detection device is estimated to have occurred.   The collision position estimation unit (62, S15, S16) has a second peak value (P2R) of the pressure waveform detected by the right pressure sensor as a second peak value (P2L) of the pressure waveform detected by the left pressure sensor. Is smaller than), it is estimated that a collision has occurred at the left corner of the vehicle width direction, and the second peak value (P2L) of the pressure waveform detected by the left pressure sensor is detected by the right pressure sensor. 4. The vehicle according to claim 3, wherein when the detected pressure waveform is larger than a second peak value (P2R), it is estimated that a collision has occurred in the corner portion on the right side in the vehicle width direction. Collision detection device. The peak value detection unit includes a first peak value (P1L, P1R) that first peaks in each pressure waveform detected by the left pressure sensor and the right pressure sensor, and a peak delayed from the first peak value. And the second peak value (P2L, P2R)
The collision position estimator (62, S19) detects a first peak value (P1L) of a pressure waveform detected by the left pressure sensor larger than a second peak value (P2L) and is detected by the right pressure sensor. When the first peak value (P1R) of the measured pressure waveform is larger than the second peak value (P2R), it is estimated that the collision of the object has occurred in the vehicle width direction center portion (A) of the bumper. The collision detection apparatus for vehicles according to any one of claims 1 to 4 characterized by these. A collision determination unit (63, S7) for determining occurrence of a collision with the bumper when a pressure detection result by the left pressure sensor and the right pressure sensor is equal to or greater than a predetermined collision determination threshold;
A threshold value changing unit (64, S5, S17, S21) that changes the collision determination threshold value according to the collision position estimated by the collision position estimation unit before determining the occurrence of a collision by the collision determination unit;
The vehicle collision detection device according to claim 5, comprising:   The threshold value changing unit (64, S17, S21) is the one in which the collision of the object has occurred except for the corner portion (C) extending a predetermined length from the vehicle width direction end of the bumper to the center side by the collision position estimation unit. A first threshold value is set as the collision determination threshold value, and the first threshold value is different from the first threshold value when the collision position estimation unit estimates that a collision of the object has occurred in the corner unit. The vehicle collision detection device according to claim 6, wherein two threshold values are set as the collision determination threshold value.   The vehicle collision detection apparatus according to claim 7, wherein the second threshold value is smaller than the first threshold value.

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