JP2015110390A - Vehicle collision/crash position discrimination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve collision/crash position discrimination performance at a time of discriminating a collision/crash position using a plurality of acceleration detectors.SOLUTION: If a collision/crash object such as a pedestrian collides/crashes against a vehicle bumper, then a bumper cover 32 starts greatly deforming at a direct hit position, an absorber 38 presses a pressure member 34, a pressure of a pressure chamber 40 changes, and pressure sensors 14A and 14B, therefore, detect the pressure. Furthermore, if a lower limit determination unit determines that the pressure exceeds a pressure threshold, a collision/crash position discrimination unit discriminates an arrangement position of an acceleration sensor corresponding to a maximum displacement of displacements detected by respective acceleration sensors 16A, 16B, and 16C as a collision/crash position.

Description

  The present invention relates to a vehicle collision position discriminating apparatus that discriminates a collision position of a pedestrian or the like to a vehicle.

  Conventionally, a technique for detecting a vehicle collision by providing a plurality of sensors on a vehicle bumper is known.

  For example, Patent Document 1 discloses a bumper reinforcement disposed at the front of a vehicle so as to extend in the vehicle width direction, an impact absorber provided on the front side of the bumper reinforcement, and so as to cover them. A vehicle front body structure including a bumper cover that extends in the vehicle width direction at the vehicle front end and first to fourth G sensors that detect a vehicle collision has been proposed.

  Specifically, in the entire vehicle body structure of Patent Document 1, a bracket is provided in the vicinity of the rear of the bumper cover and extends in the vehicle width direction, and both ends of the bracket are connected to the bumper cover. And the 1st-4th G sensor is arranged in the bracket at intervals in the vehicle width direction.

JP 2013-001227 A

  By the way, when a plurality of acceleration sensors are provided as in the technique described in Patent Document 1, the displacement at the time of collision is detected from the detection result of the acceleration sensor, and the position of the maximum displacement can be determined as the collision position. Conceivable.

  However, since the displacement of the bumper cover is transmitted in the vehicle width direction in order from the direct hit position (collision position), a large displacement may be recorded regardless of the non-collision position. For example, as shown in FIG. 7A, when five acceleration sensors G1 to G5 are provided and collide with the position of the acceleration sensor G2, the displacement of the bumper cover 32 is changed as shown in FIG. As a result, as shown in FIG. 7B, the displacement of the G3 acceleration sensor may be larger than the displacement of the G2 acceleration sensor. Therefore, it is difficult to accurately determine the collision position only with the maximum displacement at the time of the collision, and there is room for improvement in order to improve the collision position determination performance.

  The present invention has been made in consideration of the above-described facts, and an object of the present invention is to improve the performance of determining a collision position when determining a collision position using a plurality of acceleration detection units.

  In order to achieve the above object, an invention according to claim 1 is provided along a vehicle width direction of a vehicle bumper, and a pressure detection unit that detects a pressure generated when a collision target collides with a vehicle bumper. A plurality of acceleration detectors that are provided at different positions in the vehicle width direction of the vehicle bumper and detect an acceleration that occurs when the collision target collides with the vehicle bumper, and a detection result of the pressure detection unit from the time of occurrence of the collision A determination unit configured to determine a collision position based on a detection result of the plurality of acceleration detection units up to a point in time when the pressure exceeds a predetermined pressure threshold and an arrangement position of each of the plurality of acceleration detection units. ing.

  According to the first aspect of the present invention, the pressure detection unit is provided along the vehicle width direction of the vehicle bumper, and detects the pressure generated when the collision target collides with the vehicle bumper. For example, as in the invention described in claim 5, the pressure detection unit includes a pressure chamber or a pressure tube provided along the vehicle width direction on the vehicle front side of the bumper reinforcement, and an internal pressure of the pressure chamber or the pressure tube. You may make it comprise with the pressure sensor which detects a change.

  The plurality of acceleration detection units are provided at different positions in the vehicle width direction of the vehicle bumper, and detect acceleration generated when the collision target collides with the vehicle bumper.

  The determination unit is based on the detection results of the plurality of acceleration detection units from the time when the collision occurs until the detection result of the pressure detection unit exceeds a predetermined pressure, and the arrangement positions of the plurality of acceleration detection units. To determine the collision position. In other words, the detection result of the acceleration detection unit used to determine the collision position is used from the time of the collision to the time when the predetermined pressure threshold is exceeded, and the detection result of the subsequent acceleration detection unit is collided. Not used for position discrimination. Thereby, the discrimination | determination performance at the time of discriminating a collision position using a some acceleration sensor can be improved.

  For example, as in the invention according to claim 2, each of the detection results of the plurality of acceleration detection units from the time of occurrence of the collision until the time when the detection result of the pressure detection unit exceeds a predetermined pressure threshold value. Of the displacements calculated from the above, the position where the acceleration detection unit where the displacement becomes the maximum value may be determined as the collision position. By determining the collision position in this way, it is possible to easily determine the collision position.

  In addition, as in the invention described in claim 3, the determination unit is configured to detect a point in time when a predetermined time has passed after the detection result of the pressure detection unit exceeds a predetermined pressure threshold value as a detection result of the plurality of pressure detection units. Any one of them may be detected as a time point exceeding a predetermined pressure threshold.

  In addition, as in the invention described in claim 4, the determination unit determines a point in time when a collision has occurred when any one of the displacements obtained from the detection results of the plurality of acceleration detection units exceeds a predetermined threshold value. May be detected.

  As described above, according to the present invention, there is an effect that it is possible to improve the collision position determination performance when determining the collision position using a plurality of acceleration detection units.

1 is a block diagram illustrating a schematic configuration of a vehicle collision position determination device according to an embodiment of the present invention. (A) is sectional drawing which shows schematic structure around the bumper for vehicles, (B) is the schematic diagram which looked at schematic structure around the bumper for vehicles from the upper surface. It is a functional block diagram showing the function of the control apparatus in the vehicle collision position determination apparatus which concerns on embodiment of this invention. (A) is a schematic diagram showing an example in which a collision target such as a pedestrian collides with a vehicle bumper, (B) is a graph showing transition of detection values of each pressure sensor, and (C) is each acceleration sensor. It is a graph which shows transition of the displacement calculated | required from this detection result. (A) is a graph which shows an example of the transition of the determination of a lower limit determination part, (B) is a graph which shows an example of the transition of the count of a waiting variable, (C) is calculated | required from the detection result of each acceleration sensor. It is a graph which shows transition of the displacement. It is a flowchart which shows an example of the flow of the process performed with the control apparatus of the collision position determination apparatus for vehicles which concerns on embodiment of this invention. (A) is a schematic diagram showing an example in which a collision target such as a pedestrian collides with a vehicle bumper when a plurality of acceleration sensors are provided as a comparative example, and (B) is a detection of a plurality of acceleration sensors in the comparative example. It is a graph which shows an example of the transition of the displacement calculated | required from the result, (C) is a schematic diagram which shows the transition example to the vehicle width direction of the displacement of the bumper for vehicles in a comparative example.

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

  The vehicle collision position determination device 10 includes a control device 12 that performs various types of control for determining a collision position of a pedestrian or the like to a vehicle bumper that is a collision target.

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

  The ROM 12C stores programs, threshold values, and the like for determining the collision position of the collision target vehicle bumper such as a pedestrian, and the CPU 12A executes the program stored in the ROM 12C. The collision position to the target vehicle bumper is determined. The RAM 12B is used as a cache memory or the like when executing a program.

  The I / O 12D includes a plurality of pressure sensors (first pressure sensor 14A and second pressure sensor 14B in the present embodiment) 14, a plurality of acceleration sensors (first to third acceleration sensors 16A in the present embodiment). -16C) 16 and the active device 18 are connected. Note that the first pressure sensor 14A and the second pressure sensor 14B may be simply referred to as the pressure sensor 14 unless otherwise distinguished. Similarly, the first to third acceleration sensors 16A to 16C may be simply referred to as the acceleration sensor 16 unless particularly distinguished.

  The pressure sensor 14 is provided at a predetermined position (details will be described later) of the vehicle bumper, and detects the pressure generated by the collision with the vehicle bumper to be collided.

  The acceleration sensor 16 is provided at a predetermined position (details will be described later) of the vehicle bumper, and detects acceleration generated by a collision with the vehicle bumper to be collided.

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

  In the present embodiment, the control device 12 determines the collision position of the collision target vehicle bumper such as a pedestrian based on the detection results of the plurality of pressure sensors 14 and the plurality of acceleration sensors 16 and the arrangement of the sensors. The operation of the active device 18 is controlled based on the determination result.

  Specific control of the active device 18 of the control device 12 includes, for example, a collision position that includes a plurality of threshold values related to the pressure at the time of the collision for operating the active device 18 for each collision position, and determines the collision position. The operation of the active device 18 is controlled using a threshold corresponding to.

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

  The front bumper 30 includes a bumper reinforcement 36. The bumper reinforcement 36 is made of, for example, a metal material (such as iron or aluminum), a resin material, or the like, and is formed as a skeleton member that is long in the vehicle width direction. The bumper reinforcement 36 is supported by the vehicle body across the front ends of a pair of left and right skeleton members (front side members) on the vehicle body side (not shown).

  The front bumper 30 includes a bumper cover 32 that covers the bumper reinforcement 36 from the outside in the vehicle longitudinal direction, that is, from the front side. The bumper cover 32 is made of a resin material or the like, and is supported by the vehicle body at a portion (not shown) so that a space S is formed between the bumper cover 32 and the bumper reinforcement 36.

  A chamber member 34 and an absorber (impact absorber) 38 are arranged in a space S between the bumper reinforcement 36 and the bumper cover 32 in the front bumper 30. The chamber member 34 is provided on the upper front side of the bumper reinforcement 36, and the absorber 38 is provided on the lower front side of the bumper reinforcement 36.

  The absorber 38 is provided along the vehicle front surface side of the bumper reinforcement 36 in the vehicle width direction, and is provided along the vehicle front surface and lower surface side of the chamber member 34. The absorber 38 is comprised by the foaming member (polypropylene foam etc.), for example. The shape of the absorber 38 is not limited to the cross-sectional shape shown in FIG.

  The chamber member 34 constitutes a pressure chamber 40 having a hollow structure elongated in the vehicle width direction, and is fixed to the upper portion of the front surface of the bumper reinforcement 36.

  The chamber member 34 has a rigidity capable of maintaining its hollow shape (the shape of the pressure chamber 40) in a state where the chamber member 34 is fixed to the front surface of the bumper reinforcement 36 at the rear end portion.

  Further, the pressure chamber 22 is provided with a pressure sensor (first pressure sensor 14A and second pressure sensor 14B) 14 that outputs a signal corresponding to the pressure. In the present embodiment, the pressure sensor 14 is provided on two pressure chambers 40 on the left and right as shown in FIG. For example, the pressure sensor 14 is provided at a position on the pressure chamber 40 corresponding to the vicinity of a side member (not shown).

  An acceleration sensor (first to third acceleration sensors 16A to 16C) 16 is provided on the rear surface of the bumper cover 32. In the present embodiment, as an example, as shown in FIG. 2B, two bumpers are provided on the rear surface of the left and right sides and one bumper cover 32 in the central portion.

  2B, P1 is the first pressure sensor 14A, P2 is the second pressure sensor 14B, G1 is the first acceleration sensor 16A, G2 is the second acceleration sensor 16B, and G3 is the third acceleration sensor 16C. Show.

  Next, the function of the control device 12 of the vehicle collision position determination device according to the embodiment of the present invention will be described. FIG. 3 is a functional block diagram showing functions of the control device 12 in the vehicle collision position determination device 10 according to the embodiment of the present invention.

  As shown in FIG. 3, the control device 12 includes a displacement calculation unit 44, a lower limit determination unit 46, a collision position determination unit 50, and an ignition determination unit 48.

  In the present embodiment, the detection result of each sensor is input to the control device 12 through a low pass filter (LPF) 42 that removes noise in a high frequency region. That is, the LPF 42 is provided corresponding to each of the first pressure sensor 14A, the second pressure sensor 14B, and the first to third acceleration sensors 16A to 16C, and noise in a high frequency region of a signal obtained from each sensor. Remove.

  The pressure signals detected by each of the first pressure sensor 14A and the second pressure sensor 14B are output to the lower limit determination unit 46 and the ignition determination unit 48 via the LPF 42.

  The acceleration signals detected by each of the first to third acceleration sensors 16A to 16C are output to the displacement calculation unit 44 via the LPF 42.

  The lower limit determination unit 46 determines whether or not the pressure signal detected by each of the first pressure sensor 14A and the second pressure sensor 14B exceeds a predetermined pressure threshold value (lower limit value), and the determination result is used as the collision position. The data is output to the determination unit 50.

  The displacement calculation unit 44 is provided corresponding to each of the first to third acceleration sensors 16A to 16C. The displacement calculation unit 44 calculates the displacement by performing second-order integration of the acceleration signal detected by the acceleration sensor 16 and from which noise in the high frequency region is removed, and outputs the calculation result to the collision position determination unit 50. .

  The collision position determination unit 50 detects the collision of a pedestrian or the like based on the determination result of the lower limit determination unit 46 and the displacement calculated by the displacement calculation unit 44 corresponding to each of the first to third acceleration sensors 16A to 16C. The collision position to the target vehicle bumper is determined.

  For example, as shown in FIG. 4A, when a collision target such as a pedestrian collides with the bumper 30 for the vehicle, the bumper cover 32 moves to the direct hit position (the position of the second acceleration sensor 16B (G2) in FIG. 4A). ) Begins to deform greatly. When the bumper cover 32 is deformed, the absorber 38 presses the chamber member 34, and the pressure in the pressure chamber 40 changes, so that each pressure sensor 14 detects the pressure. Here, as shown in FIG. 4B, when the lower limit determination unit 46 determines that the pressure threshold is exceeded (in FIG. 4B, the detection result of the first pressure sensor 14A (P1) exceeds the threshold). The collision position determination unit 50 determines the arrangement position of the acceleration sensor 16 corresponding to the maximum value of the displacement from this time (when the pressure threshold is exceeded after the collision occurs) as the collision position. Thereby, in the example of FIG. 4, as shown in FIG. 4C, the displacement calculated from the third acceleration sensor 16C (G3) becomes maximum after the pressure threshold is exceeded, but the pressure threshold is changed from the time of the occurrence of the collision. By determining the position of the acceleration sensor 16 corresponding to the displacement of the maximum value up to the point in time (the position of the second acceleration sensor 16B in the example of FIG. 4) as the collision position, the accurate collision position is determined. Can do.

  In the present embodiment, the collision position determination unit 50 detects a time when the displacement calculated from the detection result of the acceleration sensor 16 exceeds a predetermined threshold (hereinafter referred to as a displacement lower limit value) as a collision occurrence time. However, the collision occurrence time may be detected by a touch sensor or the like, or the collision occurrence time may be detected using the detection result of another sensor such as the pressure sensor 14.

  Further, in the present embodiment, the collision position determination unit 50 detects a time when a predetermined time has passed since the pressure threshold is exceeded from the time of the collision as a time when the pressure threshold is exceeded from the time of the collision. Here, as the predetermined time after the pressure threshold is exceeded, the time required for the displacement of the vehicle bumper generated by the collision to be transmitted between the acceleration sensors 16 is sufficiently short (for example, about 5 ms to 10 ms). ) Shall be set.

  Specifically, in the present embodiment, the collision position determination unit 50 determines the collision position after elapse of a predetermined time after the pressure threshold is exceeded from the time of occurrence of the collision. More specifically, as shown in FIGS. 5A and 5B, the standby variable counter is counted when the lower limit determination unit 46 determines that the pressure threshold is exceeded, and a predetermined count value ( When the hold time is reached, the collision position determination unit 50 determines the collision position. At this time, as shown in FIG. 5C, the time from when the predetermined displacement lower limit value is exceeded until the count value reaches the hold time is used as the check time for searching for the maximum displacement value. Make a decision.

  On the other hand, the ignition determination unit 48 controls the operation of the active device 18 based on the detection results of the first pressure sensor 14A and the second pressure sensor 14B and the collision position determined by the collision position determination unit 50. For example, the ignition determination unit 48 sets a threshold value (ignition determination threshold value) for operating the active device 18 to be different for each collision position, and based on the threshold value corresponding to the collision position and the detection result of each pressure sensor 14. When the detection result of any one of the pressure sensors 14 exceeds a threshold value, an ignition signal for operating the active device 18 is output.

  In the present embodiment, the pressure chamber 40 and the pressure sensor 14 correspond to the pressure detection unit of the present invention, the acceleration sensor 16 corresponds to the acceleration detection unit of the present invention, the displacement calculation unit 44 in the control device 12, the lower limit The value determination unit 46 and the collision position determination unit 50 correspond to the determination unit of the present invention.

  Next, specific processing performed by the control device 12 of the vehicle collision position determination device 10 according to the embodiment of the present invention configured as described above will be described. FIG. 6 is a flowchart illustrating an example of a flow of processing performed by the control device 12 of the vehicle collision position determination device 10 according to the embodiment of the present invention. In the present embodiment, the processing of FIG. 6 is described as processing performed by executing a program stored in advance in the ROM 12C, but may be processing performed by hardware. Further, the process of FIG. 6 starts when an ignition switch (not shown) is turned on.

  First, when the ignition switch is turned on, parameters such as various variables are initialized, and the processing from step 100 is started. In step 100, the lower limit determination unit 46 detects each pressure signal detected by each of the first pressure sensor 14A (P1) and the second pressure sensor 14B (P2), and noise in the high frequency region is removed by the LPF 42. It is determined whether any of the above has exceeded a threshold value. If the determination is negative, the process proceeds to step 102, and if the determination is affirmative, the process proceeds to step 104.

  In step 102, the collision position determination unit 50 returns to step 100 with the collision position undefined, and the above-described processing is repeated.

  In step 104, the collision position determination unit 50 starts counting of the standby variable counter and proceeds to step 106.

  In step 106, the collision position determination unit 50 compares the count value of the standby variable counter with a predetermined hold time to determine whether or not the count value is greater than the hold time. If the determination is negative, the process proceeds to step 102 described above. If the determination is positive, the process proceeds to step 108. Note that the standby variable counter is reset when the determination in step 106 is affirmed.

  In step 108, the collision position determination unit 50 selects the position where the displacement is the maximum value in the check time (the time from when the displacement lower limit value is exceeded until the displacement variable count value exceeds the hold time) as the collision position. 110. That is, it is determined that a collision target such as a pedestrian collides with a position corresponding to the acceleration sensor that recorded the maximum displacement during the check time among the positions of the first to third acceleration sensors 16A to 16C. Thereby, the displacement of the bumper cover 32 is transmitted in the vehicle width direction in order from the collision position, so that the collision position can be accurately determined even when the collision position does not reach the maximum displacement.

  In step 110, the collision position determination unit 50 determines whether or not the displacement of the selected position is greater than or equal to a threshold value. If the determination is negative, the process proceeds to step 102 described above. If the determination is positive, the process proceeds to step 112.

  In step 112, the collision position determination unit 50 outputs the position selected in step 108 as the collision position to the ignition determination unit 48 and ends the series of processes. The ignition determination unit 48 selects a threshold value for operating the active device 18 based on the collision position determined by the collision position determination unit 50, and based on the detection result of each pressure sensor 14 and the selected threshold value, Whether the active device 18 is activated is determined. That is, since an accurate collision position can be determined, malfunction of the active device 18 can be suppressed.

  In the above-described embodiment, an example in which three acceleration sensors 16 are provided has been described. However, two acceleration sensors 16 (for example, two locations near the left and right sides) may be provided, or four or more. The acceleration sensor 16 (for example, five acceleration sensors 16 as shown in FIG. 7A) may be used. Similarly, in the above-described embodiment, an example in which two pressure sensors 14 are used has been described. However, three or more pressure sensors 14 may be used. Furthermore, the position of each of the pressure sensor 14 and the acceleration sensor 16 is not limited to the above embodiment.

  In the above embodiment, the pressure sensor 14 detects the pressure in the pressure chamber 40. However, instead of the pressure chamber 40, a pressure tube is provided to detect the pressure in the pressure tube. Also good.

  In the above-described embodiment, the position where the acceleration sensor 16 that records the maximum displacement at the time when the pressure threshold is exceeded from the time when the collision occurs (when a predetermined time has passed since the pressure threshold is exceeded) is disposed. However, the present invention is not limited to this. For example, when the difference between the maximum displacement and the next largest displacement is small, it is considered that each acceleration sensor 16 is a collision position. The position between each acceleration sensor 16 corresponding to the ratio of the displacement and the next largest displacement may be determined as the collision position.

  In the above embodiment, the plurality of pressure sensors 14 are provided in the single pressure chamber 40. However, the pressure sensors 14 are provided in the plurality of pressure chambers 40 and the plurality of pressure tubes, respectively. Also good.

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

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

10 vehicle collision position discriminating device 12 control device (discriminating unit)
14 Pressure sensor (pressure detector)
14A 1st pressure sensor (pressure detection part)
14B 2nd pressure sensor (pressure detection part)
16 Acceleration sensor (acceleration detector)
16A 1st acceleration sensor (acceleration detection part)
16B 2nd acceleration sensor (acceleration detection part)
16C third acceleration sensor (acceleration detector)
30 Bumper for vehicle 36 Bumper reinforcement 40 Pressure chamber (pressure detector)
44 Displacement calculator (discriminator)
46 Lower limit judgment part (discrimination part)
50 Collision position discriminator (discriminator)

Claims (5)

A pressure detection unit that is provided along the vehicle width direction of the vehicle bumper and detects a pressure generated when the collision target collides with the vehicle bumper;
A plurality of acceleration detectors provided at different positions of the vehicle bumper and detecting acceleration generated when the collision target collides with the vehicle bumper;
Based on the detection results of the plurality of acceleration detection units from the collision occurrence time to the time when the detection result of the pressure detection unit exceeds a predetermined pressure threshold, and the arrangement positions of the plurality of acceleration detection units, A discriminator for discriminating the collision position;
A vehicle collision position determination device.   The discriminating unit has a displacement of each displacement calculated from each of the detection results of the plurality of acceleration detection units from a collision occurrence time to a time when the detection result of the pressure detection unit exceeds a predetermined pressure threshold value. The vehicle collision position determination device according to claim 1, wherein an arrangement position of the acceleration detection unit having a maximum value is determined as a collision position.   The determination unit detects a time when a predetermined time has elapsed since the detection result of the pressure detection unit exceeds a predetermined pressure threshold as a time when the detection result of the pressure detection unit exceeds a predetermined pressure threshold. The vehicle collision determination device according to claim 1 or 2.   The said discrimination | determination part detects any time from which the displacement calculated | required from each detection result of these acceleration detection part exceeded the predetermined threshold value as said collision occurrence time. The vehicle collision position determination device according to item 1.   The pressure detection unit includes a pressure chamber or a pressure tube provided along a vehicle width direction on a vehicle front side of a bumper reinforcement, and a pressure sensor that detects a change in internal pressure of the pressure chamber or the pressure tube. The vehicle collision position determination device according to any one of 1 to 4.

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