JP2016188050A - Pedestrian collision detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pedestrian collision detection device which can detect a failure of the pedestrian collision detection device which occurs while a vehicle is stopped.SOLUTION: A pedestrian collision detection device 11 comprises: a bumper support member 18; a foam member 20 arranged on the front surface of the bumper support member 18; a detection tube 22 arranged on the front surface of the foam member 20; and pressure sensor parts 26A, 26B which are connected to end parts of the detection tube 22. The pressure sensor part 26A incorporates an electrode 39A consisting of a rotating electrode 40A and a fixed electrode 42A. When an impact is applied while a vehicle 10 is stopped, the rotating electrode 40A rotates and comes into contact with the fixed electrode 42A, causing electric power 39A to be conducted. With this, a failure of the pedestrian collision device 11 is recorded and the vehicle 10 is prevented from traveling in a state in which the pedestrian collision detection device 11 is failed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pedestrian collision detection device, and more particularly to a pedestrian collision detection device that detects a collision when the vehicle is stopped.

  It is known that a secondary collision occurs when a traffic accident occurs between a pedestrian and a vehicle. This secondary collision means that when a vehicle traveling at a predetermined speed or more collides with a pedestrian, the pedestrian collides with a vehicle bumper, and then is lifted onto the front hood and collides with a windshield or the like. is there.

  Patent Document 1 discloses a pedestrian protection device that inflates and deploys an airbag on a front hood in order to protect a pedestrian from a secondary collision. Referring to FIG. 1 of this document, an airbag module 10 provided in the pedestrian protection device is installed on a front hood 4 of a vehicle. The airbag module 10 is configured to inflate and deploy the airbag 15 on the front hood 4 when a pedestrian collision occurs.

  However, when an impact is applied to the vehicle, the detection device that detects the pedestrian collision described above may fail due to the impact. In such a case, even if the vehicle collides with a pedestrian, the pedestrian collision is not properly detected, and the pedestrian may not be protected after the collision.

  With reference to Patent Literature 2, a vehicle collision detection device having a sensor for detecting a failure of the detection device is shown. Referring to FIG. 2 of this document and the explanation thereof, the vehicle collision detection device 1 includes a pressure sensor 8 in addition to the pressure sensor 72. The pressure sensor 72 detects a pressure change of the chamber member 71 in which the chamber space 71a is formed, thereby detecting a pedestrian collision during vehicle travel. On the other hand, the pressure sensor 8 is provided separately from the pressure sensor 72 and outputs a high level signal when a predetermined collision occurs in the vehicle bumper 2. Further, the pedestrian protection device ECU 10 determines a failure of the detection unit 7 based on a signal output from the pressure sensor 8. Thus, by detecting the failure of the detection unit based on the output of the pressure sensor 8, it is possible to prevent the vehicle from being used while the detection unit is broken.

Japanese Patent No. 2920284 JP 2010-100075 A

  However, in the vehicle collision detection device 1 described in Patent Document 2 described above, the pressure sensor 8 that detects a failure of the detection device is operating when the vehicle is running, but the vehicle is stopped. Sometimes no pressure-sensitive operation is performed. Therefore, even if the vehicle collision detection device 1 breaks down due to a collision when the vehicle is stopped, there is a problem that the pressure sensor 8 cannot detect this failure.

  Furthermore, if a dedicated sensor for detecting a failure of the pedestrian collision detection device is provided at the front of the vehicle and the output of this sensor is permanently monitored by an ECU (Electronic Control Unit), the power consumption of the entire detection device There has been a problem that increases. In particular, when the monitoring by the ECU is performed when the vehicle is stopped, there is a problem that the power consumption when the vehicle is stopped increases, and there is a concern that the battery may be increased.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a pedestrian collision detection device that can efficiently detect a failure of a pedestrian collision detection device while the vehicle is stopped. There is in providing.

  A pedestrian collision detection device according to the present invention is disposed between a bumper support member extending in a vehicle width direction of a vehicle, a bumper skin constituting a design portion of the vehicle, and between the bumper support member and the bumper skin. A collision detection unit that detects impact energy acting on the vehicle, and the collision detection unit is disposed in front of the bumper support member and absorbs the impact energy when the vehicle collides. An absorbing member, a cylindrical member disposed between the bumper support member and the bumper skin, and compressively deformed when the vehicle collides; a pressure sensor unit for measuring an internal pressure of the cylindrical member; and A pedestrian collision determination unit that detects a pedestrian collision of the vehicle based on an output of the pressure sensor unit when the vehicle is running, and an output of the pressure sensor unit when the vehicle is stopped. Based on And having a failure determination means for determining the presence or absence of collision, the.

  According to the present invention, when the vehicle is stopped, the failure of the collision detection unit is determined based on the output of the pressure sensor unit. Therefore, it is possible to prevent the vehicle from traveling in a state where the collision detection for detecting the collision with the pedestrian remains broken.

  Furthermore, according to the present invention, the pressure sensor unit is used for detecting a pedestrian collision during traveling, and is further used for determining a failure of the collision detection unit during stoppage. Therefore, since it is not necessary to arrange a dedicated detection tube or the like for determining the failure of the collision detection unit at the time of stopping, an increase in the number of parts can be suppressed. For the same reason, there is no need to add a special function to the ECU. Increase in cost is suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the front-end part of the vehicle provided with the pedestrian collision detection apparatus, (B) decomposes | disassembles a pedestrian collision detection apparatus. It is a perspective view shown. It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is sectional drawing, (B) is sectional drawing which shows a pressure sensor part. It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a block diagram which shows the connection structure, (B) is a block diagram which shows the connection structure of ECU and an electrode. It is a figure which shows the pedestrian collision detection apparatus of this invention, and is a flowchart which shows the method of detecting a collision at the time of a stop. It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a top view which shows the structure of a vehicle front part, (B) is a side view which shows the structure of an electrode, (C) is a pressure sensor. It is a graph which shows the output from a part. It is a figure which shows the pedestrian collision detection apparatus of this invention, and is a flowchart which shows the method of detecting a failure of a pedestrian collision detection apparatus after engine starting.

  Hereinafter, the pedestrian collision detection device of the present embodiment will be described with reference to the drawings. In the following description, description will be made using the vertical and horizontal directions as appropriate, but the horizontal direction indicates the horizontal direction when facing the traveling direction (front) of the vehicle.

  With reference to FIG. 1, the schematic structure of the pedestrian collision detection apparatus of this form is demonstrated. FIG. 1A is a perspective view showing a front end portion of the vehicle 10, and FIG. 1B is an exploded perspective view showing a pedestrian collision detection device 11 built in the front portion of the vehicle 10.

  With reference to FIG. 1 (A), the design part of the front part of the vehicle 10 is comprised from the upper part from the front hood 12, the grill 16, and the bumper skin 14. FIG. The members constituting the pedestrian collision detection device 11 of this embodiment are provided behind the grill 16 or the bumper skin 14. When the pedestrian collision detection device 11 detects that the vehicle 10 has collided with a pedestrian, the airbag disposed in the vicinity of the front hood 12 is inflated and deployed to protect the pedestrian from secondary collisions. Or a pop-up hood apparatus (not shown) operates, the rear part of the front hood 12 is lifted upward, and the impact given to a pedestrian's head is reduced.

  Referring to FIG. 1 (B), a pedestrian collision detection device 11 of this embodiment includes a bumper support member 18 attached to the vehicle body side from the rear, and a foam material 20 (impact disposed on the front surface of the bumper support member 18. An absorbent member), a detection tube 22 (cylindrical member) incorporated in the front portion of the foam material 20, and a bumper skin 14 are mainly provided.

  Further, the foam material 20 and the detection tube 22 detect impact energy together with pressure sensors 26A and 26B (FIG. 2B) and an ECU 30 (FIG. 3A), which will be described later, to detect a pedestrian collision and stop. A collision detection unit 15 that detects a time collision is configured.

  The pedestrian collision detection device 11 of this embodiment is of a so-called pressure fluctuation type, and is measured by measuring the internal pressure of the detection tube 22 with pressure detection elements 38A and 38B (FIG. 2B) described later. Based on the fluctuation of the internal pressure, the above-described pedestrian protection device such as an airbag is operated. Furthermore, as will be described later, the pedestrian collision detection device 11 according to the present embodiment also has a function of detecting a collision when the vehicle is stopped and preventing the pedestrian collision detection device 11 from traveling in a broken state.

  The bumper support member 18 is a cylindrical member that extends in the width direction of the vehicle and has a rectangular cross section made of metal. The bumper support member 18 supports the foam material 20 and the like, and absorbs energy in the event of a large collision. In a pedestrian collision or a light collision, the bumper support member 18 is not deformed in principle.

  The foam material 20 is made of a resin material, and is continuously formed from the vicinity of the left end of the bumper support member 18 to the vicinity of the right end. As the material of the foam material 20, a foamed resin made of PP foam material or polyethylene is adopted. The foam material 20 has an action of absorbing an impact by being deformed when a pedestrian collides.

  The detection tube 22 is a pipe-shaped resin member (for example, silicon resin) having a circular cross section, and the inside thereof is substantially sealed. The detection tube 22 is disposed from the vicinity of the right end of the bumper support member 18 to the vicinity of the left end. As will be described later, pressure sensor portions 26A and 26B (FIG. 2B) (not shown) are arranged in the detection tube 22, and fluctuations in pressure when the detection tube 22 is compressed by an impact at the time of collision. Is detected by the pressure sensor units 26A and 26B, thereby detecting a pedestrian collision.

  With reference to FIG. 2, the structure of the pedestrian collision detection apparatus 11 of this form is explained in full detail. 2A is a cross-sectional view showing the structure of the pedestrian collision detection device 11, and FIG. 2B shows a detection tube 22 and pressure sensor units 26A and 26B included in the pedestrian collision detection device 11. It is sectional drawing.

  Referring to FIG. 2A, a foam material 20 is fixed to the front surface of the bumper support member 18. The foam material 20 is a soft member made of foamed resin as described above, and the cross-sectional shape thereof has a substantially hat shape opened to the rear side. The detection tube 22 is housed in a recess 24 in which the front surface of the foam material 20 is recessed backward.

  When an impact caused by a pedestrian collision or the like occurs in the vehicle 10 while the vehicle 10 is traveling, the bumper skin 14 is deformed rearward by the impact, and the foam material 20 is further directed rearward by the deformed bumper skin 14. Pressed. At this time, since the bumper support member 18 is not deformed or moved during a pedestrian collision, the bumper skin 14 and the foam material 20 are supported by the bumper support member 18 from the rear. As a result, the foam material 20 is deformed so as to be compressed in the front-rear direction, so that the impact energy is absorbed and the impact energy acting on the legs of the pedestrian is reduced.

  When the foam material 20 is compressed in the front-rear direction, the detection tube 22 disposed at the front end of the foam material 20 is also compressed in the front-rear direction, and the internal pressure increases. This pressure fluctuation is measured by the pressure sensor units 26A and 26B described below, and the above-described pedestrian protection device such as an airbag is operated based on the output of the pressure sensor units 26A and 26B.

  Referring to FIG. 2B, pressure sensor units 26A and 26B for measuring the internal pressure of the detection tube 22 are arranged at both ends of the detection tube 22.

  The pressure sensor unit 26A includes a pressure detection chamber 36A, and an electrode 39A and a pressure detection element 38A built in the pressure detection chamber 36A.

  The pressure detection chamber 36A communicates with the left end of the detection tube 22 and forms a substantially sealed space.

  The pressure detection element 38A is an element that detects the internal pressure of the pressure detection chamber 36A, and is made of, for example, MEMS (Micro Electro Mechanical Systems). The pressure detection element 38A transmits an electric signal indicating the internal pressure of the pressure detection chamber 36A to the ECU 30 (FIG. 3A) when the vehicle 10 is traveling.

  The electrode 39A is composed of a rotating electrode 40A (switch blade) and a fixed electrode 42A. The electrode 39A is disposed in the vicinity of the connection portion between the pressure detection element 38A and the detection tube 22 inside the pressure detection chamber 36A. The electrode 39A has a function of detecting that an impact has been applied to the vehicle 10 when the vehicle 10 is stopped.

  The rotating electrode 40A is a metal piece having an area equal to or larger than the cross section of the detection tube 22, and the vicinity of the upper end thereof is fixed rotatably. Under a situation in which no impact is applied to the front portion of the vehicle 10, the rotating electrode 40A is maintained in a vertical state and is not in contact with the fixed electrode 42A. On the other hand, while the impact is applied to the front portion of the vehicle 10, the rotating electrode 40A rotates clockwise to contact the fixed electrode 42A, and the electrode 39A is in a conductive state. After the impact is finished, the rotating electrode 40A is separated from the fixed electrode 42A and is in a vertical state, and the electrode 39A is in a cut-off state.

  The rotating electrode 40 </ b> A is disposed at a position spaced from the end of the detection tube 22. That is, a gap that allows communication between the inside and the outside of the detection tube 22 is formed between the end of the detection tube 22 and the rotary electrode 40A. As a result, the internal pressure of the detection tube 22 and the internal pressure of the pressure detection chamber 36 </ b> A become equal, so that the rotating electrode 40 </ b> A is prevented from blocking the end portion of the detection tube 22 under use conditions. .

  The fixed electrode 42A is composed of a metal electrode fixed outside the rotating electrode 40A and in the vicinity of the rotating electrode 40A.

  The electrode 39A described above is used to detect that an impact has acted on the stopped vehicle 10. Specifically, when the vehicle 10 is stopped and another vehicle collides with the front portion of the vehicle 10 and an impact is applied, the detection tube 22 is compressed in the front-rear direction by the impact. When the detection tube 22 is compressed, the air that is about to move from the inside of the detection tube 22 toward the pressure detection chamber 36A hits the main surface of the rotating electrode 40A. As a result, the rotating electrode 40A rotates clockwise and contacts the fixed electrode 42A. Therefore, the rotating electrode 40A and the fixed electrode 42A are brought into conduction, and the fact that they are conducted is recorded by the ECU.

  Moreover, what has a permanent change is employ | adopted as electrode 39A. Specifically, the electrode 39A is required to have a property of conducting for a certain period of time as necessary, then shutting off and returning to the original state. This is because the magnitude of the impact acting on the detection tube 22 is measured, and it is determined that the pedestrian collision detection device 11 has failed only when a certain level of impact is applied.

  In the electrode 39A, when the amount of air discharged from the detection tube 22 increases, the time during which the rotating electrode 40A and the fixed electrode 42A come into contact with each other increases. Further, when the supply of air from the detection tube 22 is lost, the rotating electrode 40A is reversed counterclockwise and separated from the fixed electrode 42A to be in a cut-off state. Thus, the electrode 39A has a permanent change.

  A pressure sensor portion 26 </ b> B is also formed at the right end of the detection tube 22. The configuration of the pressure sensor unit 26B is the same as that of the pressure sensor unit 26A described above, and a pressure detection element 38B and an electrode 39B are built in the pressure detection chamber 36B. The configuration of the electrode 39B is the same as that of the above-described electrode 39A, and includes a rotating electrode 40B and a fixed electrode 42B.

  With reference to FIG. 3, operation | movement of the pedestrian collision detection apparatus 11 is demonstrated. FIG. 3 is a block diagram showing each part constituting the pedestrian collision detection device 11.

  The ECU 30 includes a CPU 31 (Central Processing Unit) and a RAM 33 (Random Access Memory). The ECU 30 performs a predetermined calculation process based on information input from various sensors when the vehicle 10 is running, and activates a pedestrian protection device such as an air bag as necessary. Is functioning as In addition, the ECU 30 performs a predetermined calculation process based on information input from various sensors when the vehicle 10 is stopped, and determines whether or not a detection unit that detects a collision has failed. It functions as a means.

  Input terminals of the ECU 30 are connected to the pressure detection elements 38A and 38B, the speed sensor 28 that measures the speed at which the vehicle 10 travels, and the electrodes 39A and 39B. The output terminal of the ECU 30 is connected to the airbag 32, the pop-up hood 34, and the notification device 44.

  When the vehicle 10 is traveling, the ECU 30 determines whether or not to activate a pedestrian protection device such as an air bag based on information obtained from these sensors. Specifically, it is determined whether or not the vehicle 10 has collided with a pedestrian by calculating information input from the pressure detection elements 38A and 38B. Further, the ECU 30 calculates information input from the speed sensor 28 and determines whether or not the speed of the vehicle 10 at the time of the collision is within a speed range in which a pedestrian protection device such as an air bag should be operated.

  If it is determined that the vehicle 10 has collided with a pedestrian under a predetermined condition, the airbag 32 is inflated and deployed on the upper surface of the front hood 12 (see FIG. 1A) based on the output of the ECU 30. When the pop-up hood 34 is provided, the rear portion of the front hood 12 shown in FIG. 1A is lifted upward based on the output from the ECU 30. These protect pedestrians.

  When the vehicle is stopped, the ECU 30 detects whether or not an impact is applied to the front portion of the vehicle 10 when the vehicle is stopped, based on information input from the electrodes 39A and 39B. When a predetermined electrical signal is input from the electrodes 39A and 39B to the ECU 30 due to an impact acting on the vehicle 10 while the vehicle is stopped, the information is stored in the RAM 33. Furthermore, when the engine is started to run the vehicle 10, the ECU 30 reads information from the RAM 33, and if the read information indicates a collision, the ECU 30 displays that fact. Let For example, an instrument panel is employed as the notification device 44.

  Thereby, since the driver who drives the vehicle 10 can know that the pedestrian collision detection device 11 has failed, the vehicle 10 is caused to travel in a state where the pedestrian collision detection device 11 has failed. It is prevented.

  Referring to FIG. 3B, ECU 30 and electrode 39A are connected via a conductive wire 46 (for example, a wire harness). Specifically, the rotating electrode 40A of the electrode 39A is connected to the ECU 30 via the conductive wire 46, and a predetermined voltage (for example, 5V) is applied. On the other hand, the fixed electrode 42A is grounded.

  When an impact acts on the vehicle 10 and the rotating electrode 40A rotates and contacts the fixed electrode 42A, a current flows in the order of the ECU 30, the conductive wire 46, the rotating electrode 40A, and the fixed electrode 42A. If the current conduction time satisfies a predetermined condition, information indicating that is recorded in the RAM 33 described above.

  On the other hand, while the vehicle 10 is stopped and no impact is applied, the rotating electrode 40A and the fixed electrode 42A are separated from each other, so that no current flows as described above.

  Therefore, while the vehicle 10 is stopped, a small amount of power is required to place the ECU 30 in the standby state (standby mode), but the power consumption of the pedestrian collision detection device 11 as a whole is extremely small.

  With reference to FIG. 4 and FIG. 5, the flow which detects a failure with the pedestrian collision detection apparatus 11 of this form when the engine of a vehicle has stopped is demonstrated. FIG. 4 is a flowchart showing this detection method, FIG. 5 (A) is a top view showing the front portion of the vehicle, and FIG. 5 (B) is a view showing an electrode 39A provided in the pressure sensor portion 26A. 5 (C) is a graph showing the value of the current flowing through the electrode 39A during the impact action.

  Referring to FIG. 4, when the driver stops vehicle 10 and stops the engine (step S10), detection of whether or not a failure has occurred in the vehicle is started. That is, the CPU shifts to the monitoring mode (step S11).

  Next, it is determined whether or not the switch logic is L (step S12). Here, when the switch logic is L, the electrode 39A shown in FIG. 5B is in a conductive state, and when the switch logic is H, the electrode 39A is in a cut-off state.

  When the switch logic is L, since the electrode 39A is in a conductive state, it is determined that a collision may have occurred in the stopped vehicle 10 (YES in step S12, step S13). On the other hand, if the switch logic is not L, it is not determined that a collision may have occurred, and the process does not proceed to the next step S13 (NO in step S12).

  As shown in FIG. 5B, the electrode 39A is composed of a rotating electrode 40A and a fixed electrode 42A. Therefore, when an impact such as a collision acts on the front portion of the vehicle 10, the rotating electrode 40A rotates clockwise. Contact the fixed electrode 42A. As a result, the electrode 39A becomes conductive and the switch logic becomes L. Specifically, as shown in FIG. 5A, when an impact is applied to the vehicle at the time of stopping at the position indicated by the arrow from the front, the detection tube 22 is compressed in the front-rear direction by the impact. As a result, the air inside the detection tube 22 flows into the pressure sensor units 26A and 26B connected to both ends thereof, and the electrodes 39A and 39B shown in FIG.

  When the electrode 39A is turned on, it is determined whether the switch logic is L continuously for a plurality of times (step S14). This step will be described with reference to FIG. FIG. 5C shows a situation where current flows through the electrodes 39A and 39B. The current value of the current flowing through the electrode 39A is indicated by a dotted line, and the current flowing through the electrode 39B is indicated by a one-dot chain line.

  In this step, it is determined that the pedestrian collision detection device 11 has failed only when the time L1 during which the current flows through the electrode 39A is longer than the predetermined time and the switch logic is L continuously several times. For example, if a current flows through the electrode 39A, it is possible to determine that a failure has occurred due to an impact on the pedestrian collision detection device 11. However, when a current flows momentarily through the electrode 39A, it is because the rotating electrode 40A shown in FIG. 5 (B) rotates and contacts the fixed electrode 42A due to a slight vibration acting on the vehicle 10. Is also possible. In this case, the pedestrian collision detection device 11 has not failed. If such a case is determined as a failure of the pedestrian collision detection device 11, the failure detection accuracy may be reduced. Therefore, in this step, it is determined that another vehicle or the like has collided with the front portion of the vehicle 10 and a failure has occurred in the pedestrian collision detection device 11 only when the switch logic is L consecutively. When another vehicle collides with the stopped vehicle 10, the amount of pressure change in the detection tube 22 increases due to a large impact, so that the rotating electrode 40 </ b> A continues to contact the fixed electrode 42 </ b> A for a long time. As a result, a current flows through the electrode 39A for a relatively long period of time, and the switch logic is read as L continuously several times. By doing in this way, the failure of the pedestrian collision detection apparatus 11 can be detected accurately.

  On the other hand, when the switch logic is not continuously L (for example, about three times) (NO in step S14), it is determined whether or not the switch logic is H (step S19). (YES in step S19), it is determined that there is no failure (YES in step S19, step S21). In this case, it is determined that the reason why the switch logic is L in step S12 is not a vehicle collision but other vibrations. Thereafter, the process returns to step S10 as the first flow (step S22).

  If the switch logic is not H in step S19 (NO in step S19), it is determined whether the loop is a predetermined number of times (for example, 5 times) (step S20). If it is a predetermined number of times (YES in step S20), it is determined that determination is impossible (step S23) because the detection device of this embodiment cannot detect a failure. Then, the fact that a failure has occurred and the position is unknown is written in the RAM, and the process is terminated (steps S28 and S29).

  If YES in step S14, it is determined that a collision has occurred, and it is estimated which part of the bumper skin 14 in the left-right direction the collision has occurred. Specifically, the output of the electrode 39A built in the pressure sensor unit 26A connected to the left end of the detection tube 22 and the output of the electrode 39B built in the pressure sensor unit 26B connected to the right end of the detection tube 22 are compared. (FIG. 5A).

  In step S15, with reference to FIG. 5A, it is determined whether or not the electrode 39A disposed on the left end side of the detection tube 22 conducts earlier than the electrode 39B disposed on the right end side of the detection tube 22. To do. Specifically, as shown by an arrow in FIG. 5A, when an impact is applied to the left side portion of the bumper skin 14, air is first applied to the pressure sensor unit 26 </ b> A connected to the left end of the detection tube 22. Flows in, and then air flows into the pressure sensor unit 26B connected to the right end of the detection tube 22. Therefore, in this case, the electrode 39A built in the pressure sensor unit 26A is first conducted, and then the electrode 39A built in the pressure sensor unit 26B is conducted. Therefore, as shown in FIG. 5C, the timing P1 at which the electrode 39A begins to conduct becomes earlier than the timing P2 at which the electrode 39B begins to conduct. Therefore, when the timing P1 is earlier than the timing P2, it is estimated that a collision has occurred in the left side portion of the bumper skin 14 (step S24). Then, information indicating that a failure has occurred and that a collision has occurred on the left side of the vehicle body is written in the RAM (step S25). Thereby, since the failure location of the pedestrian collision detection apparatus 11 can be easily specified, the pedestrian collision detection apparatus 11 can be easily repaired or replaced.

  It is also possible to estimate in more detail which part of the bumper skin 14 the impact has occurred from the time difference L3 between P1 and P2, and record the estimation result in the RAM 33.

  On the other hand, when the electrode 39B arranged in the right end type conducts earlier than the electrode 39A arranged on the left end side, the timing P2 shown in FIG. 5C is earlier than the timing P1 (NO in step S15, YES in step S16). In such a case, it is estimated that a collision has occurred on the right side of the bumper skin 14 (step S26). Then, information indicating that a failure has occurred and that a collision has occurred on the right side of the vehicle body is written in the RAM (step S27). Even in this case, the collision location can be estimated in more detail from the time difference L3 between P1 and P2.

  Referring to FIG. 5C, if timing P1 and timing P2 are substantially the same (NO in step S16), it is determined that a collision has occurred near the center of bumper skin 14 (step S17). . Then, information indicating that a failure has occurred and that a collision has occurred in the center of the vehicle body is written in the RAM (step S18).

  Through the above steps, it is possible to record that an impact has occurred in the front portion of the vehicle 10 while the vehicle is stopped, and it is possible to estimate the site where the impact has occurred (step S29).

  The operation of the pedestrian collision detection apparatus 11 after starting the engine of the vehicle 10 after stopping will be described based on the flowchart shown in FIG. The operations described below are performed after the engine is started.

  When the driver starts the engine to drive the vehicle 10 (step S50), the failure detection result in the RAM is referred to (step S51).

  And if the information which detected the failure is stored in RAM (YES of step S52), a warning lamp will be lighted. For example, a warning light arranged at a specific portion of the instrument panel of the vehicle 10 is turned on. Thereby, since the driver can recognize that the pedestrian collision detection device 11 of the vehicle 10 is out of order, the driver is prevented from driving the vehicle 10 in a state where the pedestrian collision detection device 11 is out of order. The

  On the other hand, if the failure detection information is not stored in the RAM (NO in step S52), normal startup is performed and the warning lamp is not lit.

  As described above, in this embodiment, when the engine is started, the presence or absence of a failure of the pedestrian collision detection device 11 is confirmed. When there is a risk of failure or when it is not possible to determine that there is no failure, the warning light is turned on. Yes. This prevents the vehicle 10 from running in a state where the pedestrian collision detection device 11 is out of order.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, In the range which does not deviate from the summary of this invention, a change is possible.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Pedestrian collision detection apparatus 12 Front hood 14 Bumper skin 16 Grill 15 Collision detection part 18 Bumper support member 20 Foam material 22 Detection tube 24 Recess 26A, 26B Pressure sensor part 28 Speed sensor 30 ECU
31 CPU
32 airbag 33 RAM
34 Pop-up hood 36A, 36B Pressure detection chamber 38A, 38B Pressure detection element 39A, 39B electrode 40A, 40B Rotating electrode 42A, 42B Fixed electrode 44 Notification device 46 Conducting wire

Claims (7)

A bumper support member extending in the vehicle width direction of the vehicle, a bumper skin constituting the design portion of the vehicle, and an impact energy acting on the vehicle disposed between the bumper support member and the bumper skin are detected. A collision detection unit that
The collision detection unit
An impact absorbing member that is disposed in front of the bumper support member and absorbs the impact energy when the vehicle collides;
A cylindrical member disposed between the bumper support member and the bumper skin and compressively deformed when the vehicle collides,
A pressure sensor for measuring the internal pressure of the cylindrical member;
Pedestrian collision determination means for detecting a pedestrian collision of the vehicle based on the output of the pressure sensor unit when the vehicle is running;
A pedestrian collision detection device comprising: failure determination means for determining presence or absence of a collision based on an output of the pressure sensor unit when the vehicle is stopped. The pressure sensor unit includes a rotating electrode that rotates by receiving air from the cylindrical member at the time of a collision, and a fixed electrode that is disposed at a position that comes into contact when the rotating electrode rotates,
The pedestrian collision detection device according to claim 1, wherein the failure determination unit detects a failure of the collision detection unit when the rotated rotating electrode and the fixed electrode are electrically connected.   The pedestrian collision detection device according to claim 2, wherein the failure determination unit detects a failure of the collision detection unit when a time during which the rotating electrode and the fixed electrode are conducted is equal to or longer than a predetermined value. .   The pedestrian collision detection device according to claim 2 or 3, wherein the rotating electrode is separated from an end portion of the cylindrical member. The pressure sensor unit includes a first pressure sensor unit disposed on one end side of the cylindrical member, and a second pressure sensor unit disposed on the other end side of the cylindrical member,
The first pressure sensor unit includes a first rotating electrode and a first fixed electrode,
The second pressure sensor unit includes a second rotating electrode and a second fixed electrode,
The failure determination means is configured to detect the collision of the vehicle based on a time difference between a timing when the first rotating electrode and the first fixed electrode are conducted and a timing when the second rotating electrode and the second fixed electrode are conducted. The pedestrian collision detection device according to claim 1, wherein the location is estimated.   The pressure sensor unit includes a pressure detection chamber that communicates with the cylindrical member, a pressure detection element that measures a pressure inside the pressure detection chamber, and an electrode that conducts as the pressure of the cylindrical member changes. The pedestrian collision detection device according to claim 1.   The information processing apparatus according to any one of claims 1 to 6, further comprising notification means for notifying a driver who drives the vehicle when the failure determination means detects the collision. Pedestrian collision detection device.

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