JP5825530B2 - Vehicle collision detection device - Google Patents

Description

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

  In recent years, regarding vehicle safety, not only ensuring the safety of a vehicle occupant during an accident, but also reducing the damage to the pedestrian when the pedestrian collides with the vehicle is required. Therefore, by detecting a collision of a pedestrian with a vehicle and operating a pedestrian protection device such as an active hood or a cowl airbag, the injury value (walking) that a pedestrian who collides with the vehicle and falls into the hood Have been proposed to reduce the impact received by a person. As a collision detection device in such a system, a chamber member is disposed in front of a bumper force in a bumper of a vehicle, and a pedestrian to the bumper of the vehicle is detected by detecting a pressure change in the chamber space with a pressure sensor. Some have been proposed that detect such collisions. In such a chamber type collision detection device, a chamber member is deformed by the collision, and a collision of a pedestrian or the like is detected based on a pressure change in the chamber space.

  Here, the output value of the pressure sensor attached to the chamber member differs depending on the position in the vehicle width direction due to the influence of the vehicle design and the absorber. For this reason, in order to enable collision detection over the entire vehicle width, tuning work of the vehicle members constituting the bumper is required, such as processing a part of the shape of the absorber to increase the deformation amount.

  On the other hand, in Patent Document 1, a collision position detection sensor using a pressure-sensitive switching sensor or the like for detecting a position in the vehicle width direction where an object collides is attached to the entire front surface of the absorber in the bumper. There has been proposed a technique for changing the threshold for collision object discrimination based on the detection result.

JP 2009-40393 A

  However, in the technique described in Patent Document 1, it is necessary to provide a dedicated sensor for detecting the collision position in the vehicle width direction, which causes a problem that the structure inside the bumper is complicated and the cost is increased. is there.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle collision detection device that can detect a collision position in the vehicle width direction without using a dedicated collision position sensor. And

The invention according to claim 1, which has been made to achieve the above object, is disposed in the front surface of the bumper force (10) in the bumper (2) of the vehicle and has a chamber space (4) formed therein. A chamber member (5) having a chamber main body (11) extending in a long axis shape in the vehicle width direction, and a pressure sensor for detecting the pressure in the chamber space (4), the pressure by the pressure sensor In the vehicular collision detection device (1) configured to detect a collision with the bumper based on a detection result, the pressure sensor is arranged on the left side with respect to the center in the vehicle width direction of the chamber member. A pressure sensor (6L) and a right pressure sensor (6R) disposed on the right side, wherein a left pressure value detected by the left pressure sensor and a right pressure value detected by the right pressure sensor; Difference left Left and right pressure difference calculating means for calculating a pressure difference (73),
Collision position estimation means (74) for estimating the collision position in the vehicle width direction based on the left / right pressure difference calculated by the left / right pressure difference calculation means, and the output accompanying the collision in the left pressure sensor and the right pressure sensor Peak arrival time detection means (76) for detecting the time from the start of the rise to the peak value, wherein the collision position estimation means uses the time detection result by the peak arrival time detection means to determine the collision position. It is characterized by determining whether the vehicle is in the left or right side with respect to the center in the vehicle width direction .

According to this configuration, when the chamber member is deformed due to a collision with the bumper and the pressure in the chamber space changes, the left pressure sensor detects the left pressure value, the right pressure sensor detects the right pressure value, The pressure difference calculation means calculates a difference between the left pressure value and the right pressure value as a left-right pressure difference. The collision position estimation means estimates the collision position in the vehicle width direction based on the left-right pressure difference calculated by the left-right pressure difference calculation means. Therefore, by using the outputs of the existing left and right pressure sensors in the chamber type collision detection device, it is possible to detect the collision position in the vehicle width direction without using a dedicated collision position sensor. Then, by performing the collision determination using the collision position detection result, there is an effect that the collision detection can be performed with higher accuracy.
In particular, the left pressure sensor and the right pressure sensor are provided with a peak arrival time detecting means for detecting a time from the start of the output increase due to the collision to the arrival at the peak value, and the collision position estimating means includes a time by the peak arrival time detecting means. Since it is determined whether the collision position is the left side or the right side with respect to the center in the vehicle width direction using the detection result, the collision position including the left / right determination can be estimated. Therefore, even when the bumper's collision characteristics are not symmetrical, the collision detection can be performed with high accuracy.

It is a schematic diagram which shows the structure of the collision detection apparatus for vehicles in embodiment of this invention by planar view. It is a schematic diagram which shows the structure in the bumper of a vehicle by a side view. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 showing the configuration of the main part of the vehicle collision detection device. It is a block diagram which shows the structure of pedestrian protection apparatus ECU in embodiment. It is a table | surface which shows an example of the map in embodiment. It is a schematic diagram which shows the sound pressure distribution in the primary resonance of a chamber member. It is explanatory drawing which shows a mode that a shock wave and a primary resonant wave are superimposed. FIG. 3 is a schematic plan view of a chamber member showing a region division of a collision position in the first embodiment. 6 is a graph showing output waveforms at respective collision positions by left and right pressure sensors in Example 1. It is a table | surface which shows the pressure peak value of each collision position by the left and right pressure sensor in Example 1, an absolute value of a right-and-left pressure difference, and a collision position estimation division. In Example 1, it is the graph which plotted the measured value by making the vertical axis | shaft absolute value of a left-right pressure difference and a horizontal axis | shaft into a collision position. 10 is a table showing an example of a map in Modification 1; It is a table | surface which shows the pressure peak value of each collision position by the left and right pressure sensor in the modification 1, the left-right pressure average value, the left-right pressure difference absolute value / left-right pressure average value, and the collision position estimation classification. 9 is a graph in which measured values are plotted with the vertical axis representing the absolute value of the left / right pressure difference / the left / right pressure average value and the horizontal axis representing the collision position in Modification 1. It is a block diagram which shows the structure of pedestrian protection apparatus ECU in the modification 2. It is typical explanatory drawing which shows the peak arrival time of a shock wave. It is a table | surface which shows a response | compatibility with the code | symbol of "right pressure-left pressure" at the time of a peak arrival time and the right side collision. FIG. 10 is a schematic plan view of a chamber member showing an area division of a collision position in Modification 2. 10 is a table showing an example of a map in Modification 2. It is a table | surface which shows the pressure peak value of each collision position by the left and right pressure sensor in the modification 2, the left-right pressure difference, and the collision position estimation division. 9 is a graph in which measured values are plotted with the vertical axis representing the left-right pressure difference and the horizontal axis representing the collision position in Modification 2. 10 is a table showing an example of a map in Modification 3. It is a table | surface which shows the pressure peak value of each collision position by the left and right pressure sensor in the modification 3, the left-right pressure average value, and the left-right pressure difference / left-right pressure average value. 10 is a graph in which measured values are plotted with the vertical axis representing the left / right pressure difference / left / right pressure average value and the horizontal axis representing the collision position in Modification 3. 10 is a graph for explaining an approximate expression of Modification 4. 10 is a graph for explaining an approximate expression of Modification 5.

  Hereinafter, specific embodiments of the vehicle collision detection device of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the vehicle collision detection apparatus 1 according to the present embodiment is an apparatus configured to detect a collision of an object with a bumper 2 in front of the vehicle and activate a pedestrian protection apparatus 3. It is.

  As shown in FIG. 1 and the like, the vehicle collision detection apparatus 1 includes a bumper 2, a chamber member 5 disposed in the bumper 2 and having a chamber space 4 formed therein, and a pressure change in the chamber space 4. A left pressure sensor 6L and a right pressure sensor 6R to be detected, and a pedestrian protection device electronic control unit (hereinafter, the electronic control unit is abbreviated as ECU) 7 are provided.

  As shown in FIG. 3, the bumper 2 is mainly composed of a bumper cover 8, a chamber member 5, a bumper absorber 9, and a bumper force 10.

  The bumper cover 8 is a cover member made of a resin such as polypropylene provided so as to cover the components of the bumper 2, and configures the appearance of the bumper 2.

  The chamber member 5 is a hollow member made of low density polyethylene (LDPE) that is disposed in the bumper 2 above the front surface of the bumper force 10 and extends in a long axis shape in the vehicle width direction. The chamber member 5 has a chamber body 11 extending in the vehicle width direction and having a chamber space 4 formed therein, and is fixed to the bumper force 10 by screws or the like. The chamber member 5 has a shape that extends linearly from the center in the vehicle width direction to the left and right sides, and is curved rearward on the side side of the side members 15 described later on the left and right sides in the vehicle width direction. The chamber member 5 includes a left extending portion 12L and a right extending portion 12R that communicate with the chamber space 4 inside. The chamber member 5 is preferably symmetrical.

  The left extending portion 12L and the right extending portion 12R are portions formed for attaching the left pressure sensor 6L and the right pressure sensor 6R, respectively. As shown in FIGS. 1 and 3, the left extending portion 12 </ b> L is on the left side of the center of the chamber member 5 in the vehicle width direction, and the right extending portion 12 </ b> R is on the right side of the center of the vehicle width direction from the upper surface of the chamber body 11. The palinforce 10 extends upward. The left extending portion 12L and the right extending portion 12R are integrally formed with the chamber body 11 by blow molding. The left extending portion 12L and the right extending portion 12R each have an opening 12a on the upper surface, and the left pressure sensor 6L and the right pressure sensor 6R are attached with the pressure introducing pipe 6a inserted into the opening 12a. Note that the two pressure sensors, the left pressure sensor 6L and the right pressure sensor 6R, are provided in order to ensure redundancy in collision detection.

  The bumper absorber 9 is disposed below the front surface of the bumper force 10 and below the chamber member 5, and is a member responsible for shock absorption in the bumper 2. As the bumper absorber 9, for example, foamed polypropylene or the like can be suitably used.

  The bumper force 10 is a metal beam-like member such as aluminum that is disposed in the bumper 2 and extends in the vehicle width direction, and is formed at the front end of the side member 15 that is a pair of metal members that extend in the vehicle front-rear direction. It is attached.

  The left pressure sensor 6L and the right pressure sensor 6R are sensor devices that can detect a change in gas pressure, and output a signal proportional to the pressure, and are electrically connected to the pedestrian protection device ECU7 via a signal line 7a. ing. As described above, the left pressure sensor 6L and the right pressure sensor 6R are attached to the chamber member 5 at the left extending portion 12L and the right extending portion 12R, respectively, and are configured to be able to detect a pressure change of the air in the chamber space 4. Has been. The left pressure sensor 6L and the right pressure sensor 6R are preferably arranged at equal left and right positions with respect to the center of the chamber member 5 in the vehicle width direction.

  The vehicle speed sensor 16 is an existing speed sensor that detects the traveling speed of the vehicle, and is electrically connected to the pedestrian protection device ECU 7 via the signal line 7a.

  The pedestrian protection device ECU 7 is an electronic control device that is connected to the left pressure sensor 6L and the right pressure sensor 6R, and performs activation control of the pedestrian protection device 3 arranged in the vehicle body. A signal output from the right pressure sensor 6R is configured to be input via the signal line 7a. The pedestrian protection device ECU 7 determines whether or not a pedestrian (that is, a human body) has collided with the bumper 2 of the vehicle based on the pressure detection result of the left pressure sensor 6L and the right pressure sensor 6R, the vehicle speed detection result of the vehicle speed sensor 16, and the like. The process which discriminates is performed. When the pedestrian protection device ECU 7 determines that a pedestrian collision has occurred, the pedestrian protection device ECU 7 outputs a signal to the pedestrian protection device 3 to activate the pedestrian protection device 3.

  The pedestrian protection device 3 may employ a known device called by a name such as a pop-up hood, a pop-up engine hood, an active bonnet, an active hood, a cowl airbag, or a hood airbag. The pedestrian protection device 3 raises the rear end of the engine hood instantaneously after collision detection and increases the clearance to increase the absorption stroke of the hood itself, so that the pedestrian (particularly the head) can be a hard member such as an engine. The possibility of collision can be reduced.

  Specifically, the pedestrian protection device ECU 7 includes a low-pass filter 71 and a microcomputer 72.

  The low-pass filter 71 is a filter circuit that removes a high-frequency signal from an input signal and passes a low-frequency signal. The reason why the low-pass filter is provided is as follows. That is, when a collision occurs in the bumper 2, a shock wave is generated due to a pressure fluctuation in the chamber space accompanying the deformation of the chamber member 5, and at the same time, a resonance wave is generated by a phenomenon called air column resonance. For example, as shown in FIG. 6, when the length in the major axis direction of the chamber member 5 is L, an n-order resonance wave having a wavelength represented by 2L / n (n is a natural number) is generated by air column resonance. . In addition, in FIG. 6, the elongate cylindrical chamber member with which both ends were obstruct | occluded is shown typically for description. Most of the n-th order resonance wave is a primary resonance wave component, a slight secondary resonance wave component is included, and a very slight third-order or higher resonance wave component is further included. For this reason, the output of the left pressure sensor 6L and the right pressure sensor 6R has a waveform in which the nth-order resonance wave is superimposed on the shock wave. In addition, as shown in FIG. 6, when the chamber member 5 has a left-right symmetrical shape, the resonance phenomenon also occurs left-right symmetrically.

  The low-pass filter 71 serves to remove the second-order or higher-order resonance wave component from the n-th order resonance wave and pass the first-order resonance wave component. For example, when the primary resonance frequency is 100 Hz, a filter circuit capable of removing frequency components of 300 Hz or more can be used as the low-pass filter. The outputs of the left pressure sensor 6L and the right pressure sensor 6R are input to the microcomputer 72 after the second-order and higher-order resonance wave components are removed by the low-pass filter 71.

  The microcomputer 72 includes a CPU (Central Processing Unit), a ROM (Read Only Nonvolatile Memory) for storing control programs and data, a RAM (Writable Volatile Memory) used as a work area by the CPU, and the like. It comprises, and the right-and-left pressure difference calculation part 73, the collision position estimation part 74, the map 75, and the collision determination part 77 are implement | achieved. Each part such as the left-right pressure difference calculation part 73 included in the microcomputer 72 will be described later.

  Next, the principle of detection of the collision position in the present embodiment will be described with reference to FIGS. As described above, when a collision occurs in the bumper 2 and the chamber member 5 is deformed, the outputs of the left pressure sensor 6L and the right pressure sensor 6R are waveforms in which the nth-order resonance wave is superimposed on the shock wave, but the low-pass Since the second and higher order resonance wave components are removed by the filter 71, the microcomputer 72 has a waveform in which the primary resonance wave is superimposed on the shock wave (see FIG. 7). Here, the amplitude of the primary resonance wave depends on the collision position, and theoretically becomes zero when the collision position is the center in the left-right direction of the chamber member 5, and increases as the collision position approaches the left and right ends. It becomes maximum at both left and right ends (see FIG. 6). That is, when the chamber member 5 collides at the center in the vehicle width direction, the traveling wave and the reflected wave cancel each other, so that resonance does not occur. On the other hand, at the time of a collision at the end of the chamber member 5, the traveling wave and the reflected wave completely overlap each other, so that the resonance amplitude is maximized. Further, when the left pressure sensor 6L and the right pressure sensor 6R are arranged at equal left and right positions with respect to the center of the chamber member 5 in the vehicle width direction, a theoretically complete primary phase of the opposite phase and the same amplitude amount. Can be detected (see FIG. 7). Therefore, the difference between the output of the left pressure sensor 6L and the output of the right pressure sensor 6R after passing through the low-pass filter 71 increases as the collision position is closer to the left and right ends, and decreases as it is closer to the center (theoretically zero). The present invention pays attention to such a phenomenon, and calculates a left-right pressure difference absolute value that is an absolute value of a difference between the left pressure value detected by the left pressure sensor 6L and the right pressure value detected by the right pressure sensor 6R. The collision position in the vehicle width direction is estimated based on the obtained absolute value of the left-right pressure difference.

  Next, the flow of processing from collision position detection to collision detection will be described with reference to the block diagram of FIG. 4 and a table showing an example of a map 75 in FIG.

  When a pedestrian collides with the bumper 2 of the vehicle, the body (mainly the leg) of the pedestrian presses the bumper 2, presses the chamber member 5 through the bumper cover 8, and the chamber member 5 is pressed. The part is deformed and crushed. The gas pressure in the chamber space 4 increases due to the deformation of the chamber member 5. This increase in pressure is detected by the left extension sensor 12L and the right pressure sensor 6R attached to the left extension part 12L and the right extension part 12R, and the output signal is sent to the pedestrian protection device ECU7 via the signal line 7a. Sent.

  The pressure signals output from the left pressure sensor 6L and the right pressure sensor 6R pass through the low-pass filter 71, and second-order and higher-order resonance wave components are removed.

  Next, when the pressure signal after the low-pass filter 71 of the output of the left pressure sensor 6L and the right pressure sensor 6R is input, the left-right pressure difference calculation unit 73 receives the absolute value of the left-right pressure difference that is the absolute value of these differences Is calculated.

  Subsequently, the collision position estimation unit 74 refers to the map 75 based on the absolute value of the left-right pressure difference and determines whether the collision position belongs to the area sections A, B, or C.

  As shown in the figure, the map 75 stores the left and right pressure difference absolute values D and the collision position area sections (three sections A, B, and C) in association with each other. Specifically, in the map 75, when the left-right pressure difference absolute value D is less than 1 [kPa], the collision position is in the area section A (distance from the left-right center is 0 [mm] or more and less than 200 [mm]). When the absolute value D of the left-right pressure difference is 1 [kPa] or more and less than 1.5 [kPa], the absolute value of the left-right pressure difference is indicated in the region classification B (distance from the left and right center is 200 [mm] or more and less than 600 [mm]) D is equal to or greater than 1.5 [kPa], and is associated with a region section C (distance from the left and right center is equal to or greater than 600 [mm]).

  Next, the collision determination unit 77 performs a collision detection process based on the pressure signals output from the left pressure sensor 6L and the right pressure sensor 6R. That is, based on a pressure detection result, the process which discriminate | determines whether the pedestrian (namely, human body) collided with the bumper 2 is performed. Here, the determination as to whether or not the person is a pedestrian is performed by comparing the data obtained based on the pressure detection result and the signal from the vehicle speed sensor 16 with a predetermined threshold value. In the present embodiment, the threshold value is determined. Is changed according to the collision position estimation result in the collision position estimation unit 74. For example, if the threshold value when the collision position estimation result is the region segment A is TH1, TH2 (<TH1) may be set for the region segment B, and TH3 (<TH2) may be set for the region segment C. Alternatively, instead of correcting the threshold value, the pressure detection result may be corrected based on the collision position estimation result, and the pedestrian collision may be determined based on the corrected pressure detection result. Good.

  As is clear from the above detailed description, the vehicle collision detection device 1 of the present embodiment is a chamber that is disposed in front of the bumper force 10 in the bumper 2 of the vehicle and has a chamber space 4 formed therein. A chamber member 5 having a main body 11 extending in a long axis shape in the vehicle width direction and a pressure sensor for detecting the pressure in the chamber space 4 are provided, and the bumper 2 is applied to the bumper 2 based on the pressure detection result by the pressure sensor. The pressure sensor is configured to detect a collision, and the pressure sensor includes a left pressure sensor 6L disposed on the left side with respect to the center in the vehicle width direction of the chamber member 5 and a right pressure sensor 6R disposed on the right side. The left-right pressure difference calculating unit 7 as a left-right pressure difference calculating means for calculating the difference between the left pressure value detected by the left pressure sensor 6L and the right pressure value detected by the right pressure sensor 6R as the left-right pressure difference. If, on the basis of the right and left pressure difference calculated by the right and left pressure difference calculating unit 73, and a collision position estimating unit 74 as the collision position estimating means for estimating a collision position in the vehicle width direction.

  According to this configuration, when the chamber member 5 is deformed by the collision with the bumper 2 and the pressure in the chamber space 4 changes, the left pressure sensor 6L detects the left pressure value and the right pressure sensor 6R detects the right pressure value. The right / left pressure difference calculation unit 73 calculates the difference (absolute value) between the left pressure value and the right pressure value as the left / right pressure difference (absolute value). The collision position estimation unit 74 estimates the collision position in the vehicle width direction based on the left-right pressure difference (absolute value) calculated by the left-right pressure difference calculation unit 73. That is, the primary resonance wave generated by the pressure fluctuation in the chamber space has an opposite phase between the left and right pressure sensors, and the amplitude varies depending on the collision position in the vehicle width direction. This is because the position can be estimated.

  Therefore, by using the outputs of the existing left pressure sensor 6L and right pressure sensor 6R in the chamber type collision detection device, the collision position in the vehicle width direction can be detected without using a dedicated collision position sensor. There is an effect. Then, the collision determination unit 77 performs the collision determination using the detection result of the collision position, so that it is possible to detect the collision with higher accuracy.

  The collision position estimation unit 74 estimates the collision position using a map 75 that stores the left-right pressure difference (absolute value) and the collision position in association with each other. Therefore, it is possible to estimate the collision position based on the left-right pressure difference at high speed with a simple configuration. In the present embodiment, it is estimated which of the area sections A, B, and C the collision position belongs to.

  Further, a low-pass filter 71 is provided as filter means for removing a frequency component (for example, 300 Hz or higher) higher than the primary resonance frequency (for example, 100 Hz) of the chamber member 5 from the outputs of the left pressure sensor 6L and the right pressure sensor 6R. . Therefore, the collision position can be estimated more accurately by using the pressure value from which the secondary and higher-order resonance wave components are removed.

  Further, since the left pressure sensor 6L and the right pressure sensor 6R are arranged at equal left and right positions with respect to the center of the chamber member 5 in the vehicle width direction, the left resonance sensor 6L and the right pressure sensor 6R detect the primary resonance wave component in the left and right phases and in the same amplitude amount. Therefore, it is possible to estimate the collision position with high accuracy. In particular, when the chamber member 5 has a bilaterally symmetric shape with respect to the center in the vehicle width direction, a symmetrical primary vibration wave is generated, so that the collision position can be estimated with higher accuracy.

[Example 1]
Next, in the present embodiment, an experimental result in which the collision position on the chamber member 5 is changed and the pressure is detected by the left pressure sensor 6L and the right pressure sensor 6R to estimate the collision position will be described.

  As shown in FIG. 8, the chamber member 5 used in the experiment is straight up to the left and right 426 mm positions with respect to the center in the left and right direction, bent to the rear side at the 426 [mm] positions, and straight to the left and right ends. Is formed. The left pressure sensor 6L is mounted in the vicinity of −400 [mm] from the center, and the right pressure sensor 6R is mounted in the vicinity of 400 [mm] from the center. The distance from the center is indicated by a positive value on the right side and a negative value on the left side.

  In the experiment, an object was caused to collide at each position of −600 [mm], −426 [mm], −200 [mm], 0 [mm], 200 [mm], 426 [mm], and 600 [mm]. The outputs of the left pressure sensor 6L and the right pressure sensor 6R were measured. FIG. 9 is a graph showing the outputs of the left pressure sensor 6L and the right pressure sensor 6R at each collision position. In each graph, “pressure R” indicated by a solid line indicates an output waveform of the right pressure sensor 6R, and “pressure L” indicated by a broken line indicates an output waveform of the left pressure sensor 6L.

  FIG. 10 is a table showing left and right pressure detection values and right and left pressure difference absolute values for each collision position. FIG. 11 shows the horizontal axis as the collision position and the vertical axis as the absolute value of the left and right pressure difference. Each measured value is plotted on a graph. According to FIGS. 10 and 11, the absolute value of the left-right pressure difference is closer to 0 as the collision position is closer to the center, and the value increases toward the left and right ends.

  The result of estimating the collision position using the map 75 shown in FIG. 5 based on these data is shown at the bottom of the table of FIG. It can be seen that at each collision position of −600 [mm] to 426 [mm], the region segment is accurately estimated. The reason why the region classification is erroneously estimated at 600 [mm] is considered to be due to variations in the magnitude of the impact. From the above, it can be seen that the collision position can be estimated based on the left-right pressure difference (absolute value).

[Modification 1]
In the above-described embodiment, an example in which the collision position estimation unit 74 estimates the collision position using the left and right pressure difference absolute values as they are is shown. The position may be estimated. In addition, the same code | symbol is attached | subjected to the member same as embodiment mentioned above, and detailed description about them is abbreviate | omitted (the same also in the following modifications).

  An example of the map 75 in the first modification is shown in FIG. 12, and the experimental results are shown in FIGS. FIG. 13 is a table showing left and right pressure detection values, left and right pressure average values, values obtained by dividing right and left pressure difference absolute values by left and right pressure average values, and collision position estimation categories for each collision position. FIG. 14 is a graph in which each measurement value is plotted with the horizontal axis as the collision position and the vertical axis as the absolute value of the left / right pressure difference / left / right pressure average value.

  According to FIGS. 13 and 14, the left / right pressure difference absolute value / left / right pressure average value is closer to 0 as the collision position is closer to the center, and increases toward the left and right ends.

  The result of estimating the collision position using the map 75 shown in FIG. 12 based on these data is shown at the bottom of the table in FIG. It can be seen that the region segment is accurately estimated at each collision position of −600 [mm] to 600 [mm].

  According to this modification, the collision position estimation unit 74 corrects the value of the left-right pressure difference (absolute value) according to the output magnitudes of the left pressure sensor 6L and the right pressure sensor 6R, and uses the correction result. Since the collision position is estimated, the collision position can be estimated with high accuracy regardless of the magnitude of the impact.

[Modification 2]
In the above embodiment, the example in which the distance from the center is estimated using the right and left pressure difference absolute value without distinguishing whether the collision position is on the left or right side of the vehicle is shown. You may comprise so that the collision position estimation including a left-right distinction may be performed using a difference. That is, when the collision characteristics of the bumper 2 of the vehicle are bilaterally symmetric, it is not necessary to distinguish whether the collision position is left or right in collision detection (that is, determination of a collision object). On the other hand, in the case of left-right asymmetry, collision detection can be performed with higher accuracy by performing collision position detection that distinguishes left and right.

  Here, which of the primary resonance waves detected by the left pressure sensor 6L and the right pressure sensor 6R has a larger phase when a collision occurs on the left or right side is a peak value from the start of the shock wave rise. It is known that it depends on the time to reach.

  Therefore, in the second modification, as shown in FIG. 15, the microcomputer 72 further includes a peak arrival time detection unit 76 as a peak arrival time detection means. The peak arrival time detector 76 detects the time from the rising start time of the shock wave to the peak value arrival time. The collision position estimation unit 74 estimates the collision position based on the detection result of the peak value arrival time and the left-right pressure difference (including positive and negative).

FIG. 16 schematically shows the peak arrival time of the shock wave detected by the peak arrival time detection unit 76. FIG. 17 is a table showing the correspondence between the value of the peak arrival time T and the sign (+ or −) indicating the sign of “right pressure−left pressure” at the time of the right collision, and a map representing this content is a microcomputer 72. Stored in the ROM. In the example of the graph illustrated in FIG. 9, the sign is “−” because the pressure R is smaller than the pressure L at the time of a right collision (collision positions 200 mm, 426 mm, and 600 mm). Note that T _n−1 , T _n , T _{n + 1} ... Indicate, for example, a time represented simply by [ms]. FIG. 18 shows the area divisions of the collision position in the modified example 2, and six area divisions CL, BL, AL, AR, BR, and CR are set from the left to the right of the vehicle.

  FIG. 19 is a table showing an example of the map 75 in the second modification. The sign of “right pressure—left pressure” at the time of the right collision is determined based on the peak arrival time from the map representing the table of FIG. Based on this sign and the value of the left-right pressure difference, it is estimated which of the six sections the area section of the collision position belongs to.

  FIG. 20 is a table showing left and right pressure detection values, right and left pressure differences (value of “right pressure−left pressure” in the present modification), and collision position estimation classification for each collision position. FIG. 21 is a graph in which measured values are plotted with the horizontal axis as the collision position and the vertical axis as the left-right pressure difference. It should be noted that, based on the detection result of the peak arrival time, it is experimental that the collision position is on the left side of the center when the right-left pressure difference obtained from the right pressure-left pressure is positive, and is on the right side of the center when negative. Shall be known.

  20 and 21, the closer the collision position is to the center, the closer the left-right pressure difference is to zero. Further, the value increases toward the left end, and the value decreases toward the right end.

  The result of estimating the collision position using the map 75 shown in FIG. 19 based on these data is shown in the lowermost part of the table of FIG. It can be seen that at each collision position of −600 [mm] to 426 [mm], the region segment is accurately estimated. The reason why the region classification is erroneously estimated at 600 [mm] is considered to be due to variations in the magnitude of the impact. From the above, it can be seen that the collision position can be estimated based on the left-right pressure difference, which is a relative value including positive and negative.

  According to this modification, the peak arrival time detection unit 76 that detects the time from the start of the output increase due to the collision in the left pressure sensor 6L and the right pressure sensor 6R to the arrival at the peak value is provided, and the collision position estimation unit 74 is provided. Uses the time detection result by the peak arrival time detection unit 76 to determine whether the collision position is on the left side or the right side of the center in the vehicle width direction based on the positive / negative of the left / right pressure difference. be able to. Accordingly, even when the collision characteristics of the bumper 2 are not symmetrical, collision detection can be performed with high accuracy.

[Modification 3]
In the third modified example, a left-right pressure difference including a negative value is used as in the second modified example, and the collision position is estimated using the result corrected with the left-right pressure average value as in the first modified example.

  An example of the map 75 in Modification 3 is shown in FIG. 22, and the experimental results are shown in FIGS. FIG. 23 is a table showing left and right pressure detection values, left and right pressure average values, values obtained by dividing left and right pressure differences by left and right pressure average values, and collision position estimation categories, respectively. FIG. 24 is a graph in which each measurement value is plotted with the horizontal axis as the collision position and the vertical axis as the left / right pressure difference / left / right pressure average value.

  23 and 24, the closer the collision position is to the center, the closer the left / right pressure difference / left / right pressure average value is to zero. Further, the value increases toward the left end, and the value decreases toward the right end.

  The result of estimating the collision position using the map 75 shown in FIG. 22 based on these data is shown at the bottom of the table in FIG. It can be seen that the region segment is accurately estimated at each collision position of −600 [mm] to 600 [mm]. From the above, it can be seen that the collision position including left / right discrimination can be estimated based on the left / right pressure difference / left / right pressure average value.

[Modification 4]
In the above-described embodiment, the collision position estimation unit 74 is configured to estimate the collision position using the map 75. However, instead of using the map 75, the collision position estimation unit 74 is an approximation using the left-right pressure difference as a parameter. It is good also as a structure which estimates a collision position using a type | formula.

  FIG. 25 shows an example in which a linear approximation line representing the relationship between the left-right pressure difference y [kPa] and the collision position x [mm] is obtained using the experimental data of Modification 2 shown in FIG. An approximate line y = −0.0029x is drawn so as to pass on or near the plot. In the fourth modification, the collision position x is estimated using the left-right pressure difference y as a parameter by using an approximate expression x = -345y obtained by modifying the expression representing this approximate straight line. For example, in the table of FIG. 20, when the left-right pressure difference y = 1.725 [kPa], it is estimated that the collision position x = −345 × 1.725 = −595 [mm], and the actual collision position “−600 [mm]. It can be seen that a value very close to “]” is estimated. Hereinafter, when the left-right pressure difference y = 1.416, 1.025, −0.336, −1.053, −1.203, and −1.379, the collision position x = −489 [mm] and −354, respectively. [Mm], 116 [mm], 363 [mm], 415 [mm], and 476 [mm] are estimated.

  According to this modification, the collision position estimation unit 74 can accurately estimate the collision position by using an approximate expression that represents the relationship between the left-right pressure difference based on the experimental value and the collision position.

[Modification 5]
In the fifth modification, the collision position estimation unit 74 estimates the collision position using an approximate expression using the left / right pressure difference / left / right pressure average value as a parameter.

  FIG. 26 shows an example in which a linear approximation line representing the relationship between the left / right pressure difference / left / right pressure average value y and the collision position x is obtained from the experimental data of Modification 3 shown in FIG. A straight line y = −0.0006x is drawn so as to pass therethrough. In the fifth modification, the collision position x is estimated using the left / right pressure difference / left / right pressure average value y as a parameter by using an approximate expression x = −1667y obtained by modifying the expression representing this approximate straight line. For example, in the table of FIG. 23, when the left-right pressure difference / left-right pressure average value y = 0.356, it is estimated that the collision position x = −1667 × 0.356 = −593 [mm], and the actual collision position “−600 It can be seen that a value very close to [mm] is estimated. Hereinafter, when the left-right pressure difference / left-right pressure average value y = 0.276, 0.223, −0.116, −0.222, −0.243, and −0.283, the collision position x = −460 [ mm], -372 [mm], 193 [mm], 370 [mm], 405 [mm], and 472 [mm].

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  For example, in the first embodiment and the first modification, the example in which the collision position area section is set to three and in the second and third modifications is set to six, but the number of sections other than these may be set. .

  Moreover, in the said embodiment and the modifications 1-5, although the left-right pressure difference was defined as "right pressure-left pressure", you may define as "left pressure-right pressure". In that case, in FIGS. 17, 19 and 22, the signs “+” and “−” are reversed.

  Moreover, in the said embodiment etc., the chamber member 5 has a shape which linearly extends from the center in the vehicle width direction to both sides and is curved toward the rear side of the side members 15 on both the left and right sides in the vehicle width direction. However, the whole chamber member 5 may be configured to be curved in a convex arc shape toward the vehicle front side.

  Moreover, it is not necessary to set it as the structure which always implements the said embodiment and the modifications 1-5 independently, and it is good also as a structure implemented combining these suitably.

DESCRIPTION OF SYMBOLS 1 Vehicle collision detection apparatus 2 Bumper 4 Chamber space 5 Chamber member 6L Left pressure sensor 6R Right pressure sensor 10 Bumper force 11 Chamber main body 73 Left-right pressure difference calculation part 74 Collision position estimation part

Claims (6)

It has a chamber body (11) which is disposed in front of the bumper force (10) in the bumper (2) of the vehicle and has a chamber space (4) formed therein, and extends in the longitudinal direction in the vehicle width direction. An existing chamber member (5) and a pressure sensor for detecting the pressure in the chamber space (4), and configured to detect a collision with the bumper based on a pressure detection result by the pressure sensor. In the vehicle collision detection device (1),
The pressure sensor includes a left pressure sensor (6L) disposed on the left side with respect to the vehicle width direction center of the chamber member, and a right pressure sensor (6R) disposed on the right side,
Left and right pressure difference calculating means (73) for calculating a difference between a left pressure value detected by the left pressure sensor and a right pressure value detected by the right pressure sensor as a left and right pressure difference;
A collision position estimating means (74) for estimating a collision position in the vehicle width direction based on the left / right pressure difference calculated by the left / right pressure difference calculating means ;
Peak arrival time detection means (76) for detecting the time from the start of the output increase due to the collision in the left pressure sensor and the right pressure sensor to the arrival of the peak value;
With
The collision detection apparatus for a vehicle according to claim 1, wherein the collision position estimation means determines whether the collision position is on the left side or the right side with respect to the center in the vehicle width direction, using the time detection result by the peak arrival time detection means .   The vehicle collision detection device according to claim 1, wherein the collision position estimation means estimates the collision position using a map (75) that stores the left-right pressure difference and the collision position in association with each other.   The vehicular collision detection device according to claim 1, wherein the collision position estimation means estimates the collision position using an approximate expression representing a relationship between a left-right pressure difference and a collision position.   The filter means (71) which removes the frequency component higher than the primary resonance frequency of the chamber member from the outputs of the left pressure sensor and the right pressure sensor is provided. The vehicle collision detection device according to the item. The left pressure sensor and the right pressure sensor, a collision for a vehicle according to any one of claims 1 to 4, characterized in that disposed laterally equalized position with respect to the vehicle width direction center of the chamber member Detection device. It said chamber member, for a vehicle collision detection device according to any one of claims 1 to 5, characterized in that it has a symmetrical shape with respect to the vehicle width direction center.

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