JP5454926B2 - Vehicle collision detection device - Google Patents

Description

  According to the present invention, an object such as a pedestrian or other object collides with the vehicle bumper by detecting a chamber member mounted in the vehicle bumper and a pressure sensor to detect a pressure change in the chamber space of the chamber member. The present invention relates to a vehicle collision detection device that detects

  Conventionally, as a collision detection apparatus for vehicles, there is a thing of patent documents 1, for example. As shown in FIGS. 1 (a) and 1 (b), this is configured to determine whether or not an object collides with the vehicle bumper 1 in order to operate, for example, a pedestrian protection device 21 mounted on the vehicle. This is a vehicle collision determination device. This apparatus includes a chamber member 7 disposed in the vehicle bumper 1 and having a chamber space 7a formed therein, a main sensor 9A for detecting pressure in the chamber space 7a, and a chamber space separately from the main sensor 9A. 7A includes a safing sensor 9B that detects the pressure in 7a, a vehicle speed sensor 11 that detects the vehicle speed of the vehicle, and a controller 13.

  Here, the main sensor 9A is a pressure sensor that mainly detects a collision by detecting a pressure change in the chamber space 7a, and the safing sensor 9B is separate from the main sensor 9A in order to secure a redundant system. And a sensor for detecting a pressure change in the chamber space 7a. The controller 13 is a collision determination unit that determines the presence or absence of a collision that requires the operation of the pedestrian protection device 21 based on the pressure detection result by the main sensor 9A and the safing sensor 9B and the vehicle speed detection result by the vehicle speed sensor 11. Function as. In this way, the controller 13 that functions as a collision determination unit also functions as a controller for the protection device 21. The pedestrian protection device 21 is a device that protects personnel such as pedestrians that have collided with the vehicle bumper 1. For example, the pedestrian protection device 21 includes an active hood or a cowl airbag mounted on the vehicle, and is output from the controller 13. The pedestrian protection operation is performed according to the control signal.

  Further, a bumper reinforcement 3, a chamber member 7 and an absorber 4 are provided in the vehicle bumper 1 (the vehicle rear side of the bumper cover 2). The chamber member 7 and the absorber 4 are disposed on the vehicle front side of the bumper reinforcement 3, and the absorber 4 is disposed adjacent to the lower side of the chamber member 7. As shown in FIG. 2, a front side member 5 of the vehicle is adjacent to the bumper reinforcement 3 on the vehicle rear side. The main sensor 9A and the safing sensor 9B each have a body having a sensor element fixed to both left and right ends of the bumper reinforcement 3, and pressure introduction pipes for the sensors 9A and 9B are formed in the chamber member 7. The sensor mounting ports (holes) 7Ah and 7Bh are inserted into the chamber space 7a.

  In such a configuration, the controller 13 calculates the logical product of the outputs of the main sensor 9A and the safing sensor 9B, and when the result is determined to be a collision, the vehicle speed at the time of the collision by the vehicle speed sensor 11 is further set to a predetermined value. If it is in the range of a threshold value, for example, the range of 25-55 [km / h], the pedestrian protection apparatus 21 will be operated. This ensures the reliability of collision detection.

JP 2009-298265 A

  By the way, in the apparatus of the above-mentioned Patent Document 1, the chamber member 7 has a long cylindrical shape with both left and right ends closed. For this reason, when the vehicle bumper 1 collides during traveling or the like, a pressure amplitude is generated in the chamber space 7a due to the resonance frequency due to the pressure fluctuation of the collision. The resonance frequency is mainly the primary resonance frequency amplitude waveform R1 shown in FIG. 3A, and the secondary resonance frequency amplitude waveform R2 shown in FIG. 3B is slightly generated. The next and subsequent frequencies are also slightly generated. That is, when the length of the chamber member 7 in the longitudinal direction is L, an n-th order resonance frequency amplitude waveform having a wavelength of 2L / n (n is a natural number) that swings up and down in the chamber space 7a is generated. Accordingly, the primary resonance frequency amplitude waveform R1 has a wavelength of 2L, and the secondary resonance frequency amplitude waveform R2 has a wavelength of L. In addition, when the primary resonance frequency amplitude waveform R1 is represented by an electric signal, as shown in FIG. 4A, the first resonance frequency amplitude waveform R1 is a small waveform that swings up and down along the envelope of the collision waveform CW. As shown in FIG. 4B, the secondary resonance frequency amplitude waveform R2 is a fine waveform that swings up and down along the envelope of the primary resonance frequency amplitude waveform R1.

  When the primary resonance frequency amplitude waveform R1 and the secondary resonance frequency amplitude waveform R2 are generated, for example, when the vehicle bumper 1 slightly collides with an object, the collision waveform CW is as shown in FIG. Assume that the threshold value th for determining the collision by the controller 13 is not exceeded. At this time, if the collision waveform CW is slightly below the threshold th, the primary resonance frequency amplitude waveform R1 generated in response to the occurrence of the collision waveform CW exceeds the threshold th. There is a problem of misjudging as a collision.

  In the case of this erroneous determination, there is a problem that the pedestrian protection device 21 is activated when the vehicle speed at the time of collision by the vehicle speed sensor 11 is within a predetermined threshold range. Further, in a vehicle collision detection device of a type that does not take into account the determination by the vehicle speed sensor 11, the pedestrian protection device 21 is activated due to the erroneous determination.

  The present invention has been made in view of such circumstances, and provides a vehicle collision detection device capable of preventing erroneous detection of a collision due to an nth-order resonance frequency amplitude waveform generated in a chamber member at the time of a vehicle bumper collision. The purpose is to do.

In order to achieve the above object, an invention according to claim 1 is provided for a vehicle having a chamber member having a hollow tubular shape whose both ends are closed, and a pressure sensor for detecting a pressure change in the internal space of the chamber member. in the collision detection apparatus, the pressure sensor is disposed at a position of the chamber member that corresponds to the node of pressure distribution wherein the chamber member is produced in accordance with the pressure change of the internal space when subjected to shock, the chamber In order to avoid detection by the pressure sensor of an nth-order resonance frequency amplitude waveform having a wavelength of 2 L / n (n is an even natural number), where L is the length between the closed ends of the member, sensor the one closed end from (2k-1) of the chamber member L / 2n (k = 1,2, ..., n) are disposed at the position of, characterized in Rukoto.

According to this configuration, since the pressure sensor is arranged at the node of the pressure distribution in the internal space of the chamber member, the resonance frequency amplitude waveform is not detected. Thereby, it is possible to prevent an error in the collision control of the controller by detecting the resonance frequency amplitude waveform. Specifically, since the pressure sensor is arranged at a position where the n-th order resonance frequency amplitude waveform (n is an even natural number) generated in the internal space of the chamber member is not detected, the even-order resonance frequency amplitude waveform is not detected. Can be.

The invention according to claim 2, among the n-th order resonant frequency amplitude waveform, in order to avoid detection of the secondary resonant frequency amplitude waveform having a wavelength of L, the pressure sensor is either one of blockage of the chamber member It is arranged at a position of L / 4 from the end.

  According to this configuration, since the pressure sensor is arranged at a position where the secondary resonance frequency amplitude waveform generated in the internal space of the chamber member is not detected, the secondary resonance frequency amplitude waveform can be prevented from being detected. The effect of preventing the erroneous determination of collision can be obtained.

The invention according to claim 3, characterized in that it comprises a filter you block the primary resonance frequency amplitude waveform sensed by the pressure sensor.

  According to this configuration, in the configuration in which the secondary resonance frequency amplitude waveform is not detected, the detection result of the primary resonance frequency amplitude waveform is not used for the collision determination. can get.

According to a fourth aspect of the invention, prior Symbol filter frequency f = nc / 2L (n = 1, C = 340m / s: speed of sound) and removing the.

The invention according to claim 5 is characterized in that either one of the pressure sensors is a first pressure sensor and a second pressure sensor for ensuring redundancy.

  According to this configuration, when the first pressure sensor is, for example, a main sensor and the second pressure sensor is a safing sensor for ensuring redundancy, the main sensor and the safing sensor are L / L of the above-described chamber member. It is arranged at the position 2 or at the position L / 4. In either case, either or both of the main sensor and the safing sensor do not detect the primary resonance frequency amplitude waveform or the secondary resonance frequency amplitude waveform. It is possible to eliminate the misjudgment of the collision related to.

(A) The figure which shows the structure of the conventional vehicle collision detection apparatus, (b) It is a block diagram of the vehicle collision detection mechanism. It is a top view which shows the structure of the conventional vehicle collision detection apparatus. (A) It is a figure which shows the primary resonance frequency amplitude waveform which generate | occur | produces in the chamber space of a chamber member, (b) It is a figure which shows a secondary resonance frequency amplitude waveform. (A) The figure which represented the collision waveform and the primary resonance frequency amplitude waveform with the electrical signal, (b) Furthermore, the figure which represented the secondary resonance frequency amplitude waveform with the electrical signal. BRIEF DESCRIPTION OF THE DRAWINGS (a) Top view which shows the structure of the collision detection apparatus for vehicles which concerns on 1st Embodiment of this invention, (b) The block diagram which shows a collision detection protection control mechanism. It is A1-A2 sectional drawing shown to Fig.5 (a). It is a figure which shows the pressure sensor arrangement | positioning position to the chamber member in the collision detection apparatus for vehicles of 1st Embodiment. (A) The figure which represented the collision waveform and the primary resonance frequency amplitude waveform with the electric signal, (b) The figure which represented the collision waveform when the primary resonance frequency amplitude waveform was not detected with the electric signal. It is a figure which shows the pressure sensor arrangement | positioning position to the chamber member in the collision detection apparatus for vehicles which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the collision detection protection control mechanism in the collision detection apparatus for vehicles of 2nd Embodiment. It is a figure which shows the arrangement | positioning position to the chamber member of both sensors when the collision detection apparatus for vehicles is provided with a main sensor and a safing sensor.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.

(First embodiment)
FIG. 5A is a plan view showing the configuration of the vehicle collision detection apparatus according to the first embodiment of the present invention, FIG. 5B is a block diagram showing a collision detection protection control mechanism, and FIG. It is A1-A2 sectional drawing shown to).

  The vehicle collision detection apparatus 10 shown in these drawings includes a chamber member 17 disposed in the vehicle bumper 12, and a pressure sensor 18 attached to the chamber member 17 by a bracket 19. The controller 20 is configured to include an electrically connected controller 20 and a pedestrian protection device 21 such as an active hood or a cowl airbag controlled by the controller 20. The vehicle bumper 12 is mainly composed of a bumper cover 13, a bumper reinforcement 14, a side member 15, an absorber 16, and a chamber member 17.

  The bumper cover 13 has a longitudinal shape extending substantially in an arc shape in the vehicle width direction (vehicle left-right direction) at the front end of the vehicle, and is attached to the vehicle body so as to cover the bumper reinforcement 14, the absorber 16, and the chamber member 17. A cover member made of resin (for example, polypropylene). The bumper reinforcement 14 is a metal beam-like member that is disposed in the bumper cover 13 and extends in the vehicle width direction.

  The side members 15 are a pair of metal members that are located in the vicinity of both the left and right side surfaces of the vehicle and extend in the longitudinal direction of the vehicle, and the bumper reinforcement 14 described above is attached to the front end thereof. The absorber 16 is a foamed resin member that is attached to the front lower side of the bumper reinforcement 14 in the bumper cover 13 and extends longitudinally in the vehicle width direction, and exhibits an impact absorbing action in the vehicle bumper 12.

  The chamber member 17 is attached to the upper front side of the bumper reinforcement 14 in the bumper cover 13, extends in the vehicle width direction (vehicle left-right direction), and has a long cylindrical shape (hollow tubular shape) closed at both left and right ends. A sealed chamber space 17a which is a resin member and is surrounded by a wall having a thickness of several millimeters is formed. The chamber member 17 has two actions of shock absorption and pressure transmission in the vehicle bumper 12.

  The pressure sensor 18 is a sensor device capable of detecting a gas pressure, and is configured to be mounted on the chamber member 17 with a bracket 19 so as to detect a pressure change in the chamber space 17a. The pressure sensor 18 detects the pressure change. Is output to the controller 20. The controller 20 is an electronic control device for controlling the operation of the pedestrian protection device 21 and determines whether or not a pedestrian or the like has collided with the vehicle bumper 12 according to a detected pressure signal output from the pressure sensor 18. Perform the process. In addition to the detected pressure result from the detected pressure signal from the pressure sensor 18, the controller 20 receives a vehicle speed detection result from a vehicle speed sensor (not shown), and the pedestrian collision based on the pressure detection result and the vehicle speed detection result. It is preferable to make the determination.

  The reason for discriminating the pedestrian in this way is that when the obstacle colliding with the vehicle bumper 12 is not a pedestrian, various adverse effects occur when the pedestrian protection device 21 (for example, an active hood) is operated. For example, if it cannot be distinguished from a pedestrian when it collides with a lightweight fallen object such as a triangular cone or a signboard during construction, the pedestrian protection device 21 is activated wastefully and extra repair costs are generated. In addition, if it is indistinguishable from a pedestrian when it collides with a fixed wall such as a concrete wall or a vehicle, the hood will move backward with the hood lifted up. is there.

  As shown in FIG. 7, when the length of the long cylindrical chamber member 17 closed at both ends is set to L, as shown in FIG. The member 17 is located at a position L / 2 from one end (closed end) of both ends of the long cylindrical shape of the member 17. In the chamber space 17a of the chamber member 17, when the vehicle bumper 12 collides during traveling or the like, a pressure amplitude due to the resonance frequency is generated due to the pressure fluctuation of the collision. Here, assuming that the chamber space 17a has a rectangular parallelepiped shape, an n-th order resonance frequency amplitude waveform having a wavelength of 2 L / n (n is a natural number) that swings up and down is generated. Of these, the primary resonance frequency amplitude waveform R1 is generated as most of the wavelength components in the nth order, the secondary resonance frequency amplitude waveform is slightly generated, and the third and subsequent components are generated only slightly.

  When the primary resonance frequency amplitude waveform R1 is represented by an electric signal, as shown in FIG. 4A, the primary resonance frequency amplitude waveform R1 becomes a small waveform that swings up and down along the envelope of the collision waveform CW. As shown in FIG. 4B, the resonance frequency amplitude waveform R2 is a fine waveform that amplifies the envelope up and down along the envelope of the primary resonance frequency amplitude waveform R1.

Here, the primary resonance frequency amplitude waveform R1 has a wavelength of 2L as shown in FIG . The position of L / 2 of the chamber member 17 is the antinode position of the primary resonance frequency amplitude waveform R1, and the vibration amplitude is maximum in this portion, so the pressure amplitude is zero. This position is a section of the pressure distribution that put to the chamber space 17a. Therefore, if the pressure sensor 18 is arranged at a position of L / 2 which is a node of the pressure distribution , the primary resonance frequency amplitude waveform R1 is not detected.

  For example, when the vehicle bumper 12 slightly collides with an object (collision that does not affect the object), as shown by an electric signal in FIG. 8A, the collision waveform CW and the primary resonance frequency amplitude waveform. Suppose that R1 occurs and the collision waveform CW is slightly below the threshold th for determining the collision by the controller 20. In this case, since the primary resonance frequency amplitude waveform R1 is conventionally detected by the pressure sensor 18, the controller 20 erroneously determines that the collision has occurred.

  However, in the case of this embodiment, as shown in FIG. 8B, the primary resonance frequency amplitude waveform R1 is not detected by the pressure sensor 18, so that the controller 20 does not erroneously determine a collision. Therefore, the operation control of the pedestrian protection device 21 is not performed.

  As described above, according to the vehicle collision detection device 10 of the first embodiment, a pressure change is detected in the chamber member 17 having a hollow tubular shape whose both ends are closed, and the chamber space 17a which is an internal space of the chamber member 17. In the configuration having the pressure sensor 18, the primary resonance frequency amplitude having a wavelength of 2L among the n-th order resonance frequency amplitude waveforms generated according to the pressure change of the chamber space 17 a when the chamber member 17 receives an impact. In order to avoid detection of the waveform R1, the pressure sensor 18 was disposed at a position L / 2 from one closed end of the chamber member 17.

  Accordingly, since the pressure sensor 18 is disposed at a position where the primary resonance frequency amplitude waveform R1 generated in the chamber space 17a of the chamber member 17 is not detected, the primary resonance frequency amplitude waveform R1 can be prevented from being detected. . Since the primary resonance frequency amplitude waveform is generated as most of the wavelength components in the nth order resonance frequency amplitude waveform, by making the primary resonance frequency amplitude waveform R1 undetected by the pressure sensor 18, an erroneous detection of a collision is performed. Can be prevented. That is, since the pressure sensor 18 does not detect the unnecessary primary resonance frequency amplitude waveform R1, the controller 20 does not erroneously determine a collision, and the pedestrian protection device 21 is not controlled to malfunction.

Further , in order to avoid detection by the pressure sensor 18 of the n-th order resonance frequency amplitude waveform having a wavelength of 2 L / n (n is an even natural number), the pressure sensor 18 is moved from one closed end of the chamber member 17 to (2k− 1) It may be arranged at a position of L / 2n (k = 1, 2,..., N). With this configuration, the pressure sensor 18 is disposed at a position where the n-th order resonance frequency amplitude waveform (n is an even natural number) generated in the chamber space 17a is not detected, so that the even-order resonance frequency amplitude waveform is not detected. can do.

Configuration of This, in other words, the pressure sensor 18 is to be disposed in the position of the chamber member 17 corresponding to the node of pressure distribution generated in response to pressure changes in the chamber space 17a.

  Further, in the case where the pressure sensor 18 includes the main sensor and the safing sensor described with reference to FIG. 1 in the above-mentioned “Background Art”, the main sensor and the safing sensor are connected to L / 2 of the chamber member 17 described above. You may arrange | position in the position of back and forth or up and down. Furthermore, the main sensor and the safing sensor may be arranged so as to be line-symmetric with respect to a center line extending in the vehicle front-rear direction at the position L / 2.

  Also in this configuration, since either or both of the main sensor and the safing sensor do not detect the primary resonance frequency amplitude waveform R1, the logical product result of the outputs of the main sensor and the safing sensor is in an erroneous detection state. This eliminates the erroneous determination of collision. Other n-th order resonance frequency amplitude waveforms can also have the same configuration as described above.

(Second Embodiment)
FIG. 9 is a view showing a position where the pressure sensor is disposed on the chamber member in the vehicle collision detection apparatus according to the second embodiment of the present invention, and FIG. 10 is a block diagram showing a collision detection protection control mechanism of the second embodiment. .

  The vehicle collision detection device of the second embodiment is different from the first embodiment in that the pressure sensor 18 is moved from one end (closed end) of the chamber member 17 having a length L as shown in FIG. As shown in FIG. 10, the filter 23 is provided on the signal output side of the pressure sensor 18 to cut off the primary resonance frequency amplitude waveform R1. However, the filter 23 may be provided on the signal input side of the controller 20.

The secondary resonance frequency amplitude waveform R2 has a wavelength of length L as shown in FIG . The position of L / 4 of the chamber member 17 is the antinode position of the secondary resonance frequency amplitude waveform R2, and the vibration amplitude is maximum in this portion, so the pressure amplitude becomes zero. This position is a section of the pressure distribution that put to the chamber space 17a. Therefore, if the pressure sensor 18 is arranged at a position of L / 4 which is a node of the pressure distribution , the secondary resonance frequency amplitude waveform R2 shown in FIG. 4B is not detected. Further, in the arrangement of the pressure sensor 18, the primary resonance frequency amplitude waveform R 1 is detected, but the component of the primary resonance frequency amplitude waveform R 1 is blocked by the filter 23 and is not output to the controller 20.

  Therefore, since the signals of both the primary resonance frequency amplitude waveform R1 and the secondary resonance frequency amplitude waveform R2 are not transmitted / received by the controller 20, the controller 20 will not erroneously determine that there is a collision. Therefore, the operation control of the pedestrian protection device 21 is not performed.

  As described above, the vehicle collision detection apparatus according to the second embodiment includes an n-order resonance frequency amplitude waveform generated in response to a pressure change in the chamber space 17a when the length L chamber member 17 receives an impact. In order to avoid detection of the secondary resonance frequency amplitude waveform R2 having a wavelength of L, the pressure sensor 18 was disposed at a position L / 4 from either closed end of the chamber member 17. Accordingly, since the pressure sensor 18 is disposed at a position where the secondary resonance frequency amplitude waveform R2 generated in the chamber space 17a of the chamber member 17 is not detected, the secondary resonance frequency amplitude waveform R2 can be prevented from being detected. . Accordingly, it is possible to prevent erroneous detection of a collision in the controller 20 due to detection of the secondary resonance frequency amplitude waveform R2.

Further, in addition to the configuration in which the pressure sensor 18 is disposed at the position L / 4 of the chamber member 17, a filter 23 for blocking the primary resonance frequency amplitude waveform R1 detected by the pressure sensor 18 is provided. However, the filter 23 may remove the frequency f = nc / 2L (n = 1 , C = 340 m / s: sound velocity). With this configuration, since the component of the primary resonance frequency amplitude waveform R1 is blocked by the filter 23, the controller 20 does not receive or transmit the signals of both the primary resonance frequency amplitude waveform R1 and the secondary resonance frequency amplitude waveform R2. This eliminates the possibility of misjudgment as a collision.

  In addition, as shown in FIG. 11, as the pressure sensor 18, when the main sensor 18 a and the safing sensor 18 b are provided, the main sensor 18 a and the safing sensor 18 b are placed at an L / 4 position from one end of the chamber member 17. Alternatively, it may be disposed at a position L / 4 from the other end. Also in this configuration, both or one of the main sensor 18a and the safing sensor 18b does not detect the secondary resonance frequency amplitude waveform R2, so that the logical product result of the outputs of the main sensor 18a and the safing sensor 18b is obtained. An erroneous state relating to the detection of the secondary resonance frequency amplitude waveform R2 is not shown, thereby eliminating erroneous determination of collision.

DESCRIPTION OF SYMBOLS 10 Vehicle collision detection apparatus 12 Vehicle bumper 13 Bumper cover 14 Bumper reinforcement 15 Side member 16 Absorber 17 Chamber member 17a Chamber space 18 Pressure sensor 18a Main sensor 18b Safe sensor 19 Bracket 20 Controller 21 Pedestrian protection device 23 Filter R1 Primary resonance frequency amplitude waveform R2 Secondary resonance frequency amplitude waveform CW Collision waveform

Claims (5)

In a vehicle collision detection device having a chamber member having a hollow tube closed at both ends, and a pressure sensor for detecting a pressure change in the internal space of the chamber member,
The pressure sensor is disposed at a position of the chamber member corresponding to a node of a pressure distribution generated according to a pressure change in the internal space when the chamber member receives an impact ,
In order to avoid detection by the pressure sensor of an nth-order resonance frequency amplitude waveform having a wavelength of 2 L / n (n is an even natural number) when the length between the closed ends of the chamber member is L, the pressure sensor from said one closed end of the chamber member (2k-1) L / 2n (k = 1,2, ..., n) is disposed at a position of a vehicle collision detection apparatus according to claim Rukoto. Distribution of the n-th order resonant frequency amplitude waveform, in order to avoid detection of the secondary resonant frequency amplitude waveform having a wavelength of L, the pressure sensor is in a position of L / 4 from one of the closed end of the chamber member The vehicle collision detection device according to claim 1 , wherein the vehicle collision detection device is provided. The vehicle collision detecting apparatus according to claim 2, characterized in that it comprises a filter you block the primary resonance frequency amplitude waveform sensed by the pressure sensor. Before SL filter, the frequency f = nc / 2L (n = 1, C = 340m / s: sound velocity) for a vehicle collision detection apparatus according to claim 3, characterized in that the removal of. The pressure sensor is either one vehicle collision detecting apparatus according to any one of claims 1-4, characterized in that the first and second pressure sensors for redundancy.

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