JP2015009774A - Collision detection device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision detection device for a vehicle capable of accurately detecting an occurrence of a collision accident of a vehicle with a simple configuration.SOLUTION: A collision detection device 1 for a vehicle includes: a floor G sensor 3 provided in a vehicle for detecting an acceleration speed of the vehicle; a chamber member arranged in a bumper of the vehicle in which a chamber space is formed inside; a pressure sensor 5 for detecting the pressure in the chamber space; and an air bag ECU 2, which is determination means for determining whether or not a collision that requires an operation of an air bag device 6 has occurred to the vehicle using the result of the detection by the floor G sensor 3 and the result of the detection by the pressure sensor 5.

Description

  The present invention relates to a vehicle collision detection device that can accurately detect the occurrence of a vehicle collision accident.

  Conventionally, in a vehicle equipped with an airbag as occupant protection means, when a vehicle accident such as a collision accident occurs, the airbag is activated to protect the occupant. In such a vehicle, an acceleration sensor or the like is provided as a collision detection means to detect a vehicle collision. With this configuration, it is determined whether the acceleration detection result by the acceleration sensor is equal to or greater than a predetermined threshold value. If the acceleration value is equal to or greater than the threshold value, it is determined that a collision has occurred in the vehicle. The bag is actuated (see, for example, Patent Document 1).

JP-A-10-86787

  However, with the above configuration, the airbag is activated because the detection result of the acceleration sensor becomes a large value even when a large impact is applied to the vehicle, for example, when the vehicle rides on a curbstone, etc., although it is not a collision accident. There is a problem that the airbag is activated even though it is not necessary to do so.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a vehicle collision detection device that can accurately detect the occurrence of a vehicle collision accident with a simple configuration.

  The vehicle collision detection device (1) according to claim 1, which is made to solve the above object, includes a first acceleration sensor (3) provided in a vehicle for detecting acceleration of the vehicle, and a vehicle bumper. (8) a chamber member (9) disposed in the chamber space (9a), a pressure sensor (5) for detecting the pressure in the chamber space, a detection result of the first acceleration sensor, and And determining means (2) for determining whether or not a collision requiring operation of occupant protection means (6) has occurred in the vehicle using the detection result of the pressure sensor.

  According to this configuration, by using the detection results of the first acceleration sensor and the pressure sensor, it is possible to accurately detect that a collision requiring the operation of the occupant protection means has occurred in the vehicle with a simple configuration. In particular, it is possible to distinguish between a collision that requires operation of the occupant protection means accompanied by bumper deformation and a collision that does not require operation of the occupant protection means without bumper deformation such as when the vehicle rides on a curb. Occupant protection measures can be activated in some circumstances. In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is a schematic diagram illustrating an overall configuration of a vehicle collision detection device according to an embodiment of the present invention. It is a block diagram which shows the electric constitution of the collision detection apparatus for vehicles. It is a figure which shows the logic circuit of the collision determination of the collision detection apparatus for vehicles. It is a flowchart which shows the flow of the collision determination by the vehicle collision detection apparatus. It is a figure which shows the change of the output by a floor G sensor. It is a figure which shows the change of the output by a pressure sensor. It is a figure which shows the change of the output by a front G sensor. It is a flowchart which shows the flow of the collision determination by the vehicle collision detection apparatus of a modification.

  Hereinafter, specific embodiments of the vehicle collision detection device of the present invention will be described with reference to the drawings. As shown in FIG. 2, the vehicle collision detection device 1 in the present embodiment includes an airbag ECU 2 (corresponding to a determination unit), a floor G sensor 3 (corresponding to a first acceleration sensor), and a front G sensor 4 (first 2), a pressure sensor 5, and an airbag device 6 (corresponding to occupant protection means).

  The airbag ECU 2 is configured mainly with a CPU, and controls the overall operation of the vehicle collision detection device 1. The floor G sensor 3, the front G sensor 4, the pressure sensor 5, the airbag device, and pedestrian protection Each of the devices 7 is electrically connected. The airbag ECU 2 receives an acceleration signal (acceleration data) from the floor G sensor 3 and the front G sensor 4 and a pressure signal (pressure data) from the pressure sensor 5. Based on these input signals, the airbag ECU 2 executes a collision determination process, which will be described later, and controls the operation of the airbag device 6.

  The floor G sensor 3 and the front G sensor 4 are G sensors (acceleration sensors) that detect the impact of the vehicle. As shown in FIG. 1, the floor G sensor 3 is provided on the floor portion at the center in the front-rear direction of the vehicle. The front G sensor 4 is provided on both the left and right sides of the front portion of the vehicle. The floor G sensor 3 and the front G sensor 4 output the value of acceleration detected in each part to the airbag ECU 2 as an acceleration signal.

  The pressure sensor 5 (front P sensor) detects the bumper pressure of the vehicle, and two, for example, are provided in the chamber member 9 which is a resin-made hollow structure disposed in the bumper 8 of the vehicle ( (See FIG. 1). A chamber space 9 a is formed inside the chamber member 9. The pressure sensor 5 detects the internal pressure of the chamber space 9a. When a vehicle collision accident involving deformation of the bumper 8 occurs, the pressure sensor 5 detects a change in the internal pressure of the chamber space 9a accompanying the deformation of the bumper 8, and uses the detected bumper pressure value as a pressure signal for air. Output to the bag ECU 2.

  The airbag device 6 is provided in the steering wheel in front of the driver's seat or in the instrument panel in front of the passenger seat. When a vehicle collision accident involving a large impact occurs, the airbag device 6 is inflated in front of the occupant, for example. It is a device that absorbs shocks. In the present embodiment, the vehicle collision detection device 1 is applied to the airbag ECU 2. However, the present invention is not limited to this, and for example, a seat belt device that restrains the driver to the vehicle seat, and a shock absorption mechanism built in the steering column. The present invention may also be applied to a steering device that is used, a brake pedal device that retracts when an impact occurs and absorbs the impact.

  The pedestrian protection device 7 is assumed to be a pop-up hood provided at the front part of the vehicle, for example. This pop-up hood instantly raises the rear end of the engine hood in the event of a collision between the vehicle and a pedestrian, supports the stroke of the increased amount with a buffer mechanism, and allows the pedestrian to hit the engine hood. It is a device that softens and protects the impact. Instead of the pop-up hood, a cowl airbag that deploys an airbag from above the engine hood outside the vehicle body to the lower part of the front window and cushions the impact of the pedestrian may be used.

  Next, the flow of the collision determination process in the vehicle collision detection apparatus 1 having the above-described configuration will be described with reference to the flowchart of FIG. 4 and FIGS. 3 and 5 to 7. However, the flowchart of FIG. 4 is an example, and the present invention is not limited to this. The graphs “frontal collision”, “ODB”, and “underride” in FIGS. 5 to 7 show changes in the outputs of the sensors 3 to 5 when the vehicle causes a frontal collision, an ODB collision, and an underride. The “curbstone” graph shows changes in the outputs of the sensors 3 to 5 when the vehicle rides on a curbstone or the like.

  The airbag ECU 2 performs a collision determination based on input signals from the floor G sensor 3, the front G sensor 4, and the pressure sensor 5. In the present embodiment, the airbag ECU 2 performs a collision determination process using an AND circuit of a logic circuit as shown in FIG. That is, when an ON signal is output from both the floor G sensor 3 and the pressure sensor 5, it is determined that a frontal collision that requires the operation of the airbag device 6 has occurred. Further, when an ON signal is output from both the floor G sensor 3 and the front G sensor 4, it is determined that a low-speed / irregular collision other than a frontal collision that requires the operation of the airbag device 6 has occurred. . Here, the frontal collision (normal collision) refers to a case where the vehicle has a full lap collision (when the entire width of the front surface of the vehicle has collided with the collision object). Collisions other than frontal collisions include low-speed / irregular collisions other than full-lap collisions, such as oblique collisions in which a vehicle obliquely collides with a collision target, ODB (Offset Deformable Barrier) collisions, underride collisions, and the like. The ODB collision refers to a collision with a deforming collision object among offset collisions in which the vehicle collides on either the left or right side with its position offset with respect to the collision object. Underride collision means that a normal vehicle collides under a bumper of a large vehicle such as a truck.

  Hereinafter, the collision determination process performed by the airbag ECU 2 will be described with reference to the flowchart of FIG. First, the airbag ECU 2 performs signal calculation processing of outputs from the sensors 3 to 5 (step S1, step is omitted hereinafter). Specifically, the acceleration values detected by the floor G sensor 3 and the front G sensor 4 are integrated in a section per unit time, and the pressure values detected by the pressure sensor 5 are integrated in a section per unit time. . Here, the section integral value of the floor G sensor 3 is ∫G1 (t) dt, the section integral value of the front G sensor 4 is ∫G2 (t) dt, and the section integral value of the pressure sensor 5 is ∫P (t) dt. To do.

  Subsequently, the airbag ECU 2 determines whether or not the section integral value ∫G1 (t) dt of the floor G sensor 3 is equal to or greater than a preset threshold value Gth1 (S2). The threshold value Gth1 is set as shown in FIG. FIG. 5 shows an example in which the floor G sensor 3 outputs an ON signal when the vehicle rides on a curb or the like.

  When the interval integral value ∫G1 (t) dt of the floor G sensor 3 is equal to or greater than the threshold value Gth1 (S2: Yes), the airbag ECU 2 is preset with the interval integral value ∫P (t) dt of the pressure sensor 5. It is determined whether or not the threshold value Pth is exceeded (S3). The threshold value Pth is set as shown in FIG. This threshold value Pth is, for example, the minimum integral value of the bumper pressure generated in a collision accident that requires the operation of the airbag device 6. FIG. 6 shows an example in which the pressure sensor 5 outputs an OFF signal when the vehicle rides on the curb. When the section integral value ∫G1 (t) dt of the floor G sensor 3 is less than the threshold value Gth1 (S2: No), the process returns to S1.

  The airbag ECU 2 determines that a frontal collision that requires the operation of the airbag device 6 has occurred in the vehicle when the interval integral value ∫P (t) dt of the pressure sensor 5 is greater than or equal to the threshold value Pth (S3: Yes). (S4), the airbag device 6 is activated (S7). When the interval integral value ∫P (t) dt of the pressure sensor 5 is less than the threshold value Pth (S3: No), it is determined that the vehicle has climbed over a curb or the like, and the process returns to S1.

  Further, when the section integral value ∫G1 (t) dt of the floor G sensor 3 is greater than or equal to the threshold value Gth1 (S2: Yes), the airbag ECU 2 proceeds to S3 and also determines the section integral value の of the front G sensor 4. It is determined whether or not G2 (t) dt is equal to or greater than a preset threshold Gth2 (S5). The threshold value Gth2 is set as shown in FIG. FIG. 7 shows an example in which the front G sensor 4 outputs an ON signal when the vehicle causes a collision such as an ODB collision other than a frontal collision or an underride.

  When the interval integral value ∫G2 (t) dt of the front G sensor 4 is greater than or equal to the threshold value Gth2 (S5: Yes), the airbag ECU 2 performs a low-speed / irregular collision other than a frontal collision that requires the operation of the airbag device 6. Is generated in the vehicle (S6), and the airbag device 6 is activated (S7). When the section integral value ∫G2 (t) dt of the front G sensor 4 is less than the threshold value Gth2 (S5: No), the process returns to S1.

  Thus, in the vehicle collision detection apparatus 1 of the present embodiment, the airbag ECU 2 uses the three types of sensors, the floor G sensor 3, the front G sensor 4, and the pressure sensor 5, to determine the type of collision. The airbag apparatus 6 can be operated more appropriately. That is, in this embodiment, for example, a frontal collision that requires the operation of the airbag device 6 and a frontal collision that does not require the operation of the airbag device 6 such as when the vehicle rides on a curb can be distinguished. Conventionally, when the floor G sensor 3 and the front G sensor 4 are equal to or higher than the respective threshold values Gth1 and Gth2, the airbag device 6 is activated although it is not necessary to operate the airbag device 6. There was a thing. On the other hand, in this embodiment, when the vehicle rides on a curbstone or the like, the bumper 8 is not deformed, so that the pressure sensor 5 is not turned ON. For this reason, the section integral value ∫P (t) dt of the pressure sensor 5 becomes less than the threshold value Pth (S3: No), and the airbag device 6 does not operate.

  As described above, the vehicle collision detection apparatus 1 according to the present embodiment is provided in the vehicle and detects the acceleration of the vehicle, the floor G sensor 3, the vehicle bumper 8, and the chamber space 9 a. Is a chamber member 9 formed inside, a pressure sensor 5 for detecting the pressure in the chamber space 9a, the detection result of the floor G sensor 3 and the detection result of the pressure sensor 5, and the air serving as occupant protection means for the vehicle The airbag ECU 2 is a determination unit that determines whether or not a collision that requires the operation of the bag device 6 has occurred.

  According to this configuration, it is possible to distinguish between a collision that requires the operation of the airbag device 6 (airbag deployment ON requirement) and a collision that does not require the operation of the airbag device 6 (airbag deployment OFF requirement). The airbag device 6 can be operated in an appropriate situation. That is, as described above, for example, when the vehicle rides on a curbstone, the detection result of the floor G sensor 3 is large (see FIG. 5), but the pressure sensor 5 is a collision that does not involve the deformation of the bumper 9. No pressure change is detected (see FIG. 6). Therefore, the airbag device 6 does not operate. On the other hand, conventionally, since the detection result of the floor G sensor 3 becomes large, the airbag device 6 sometimes operates when the airbag deployment OFF requirement is satisfied. In the present embodiment, since the collision determination is performed based on the detection result of the pressure sensor 5 in addition to the floor G sensor 3, it is possible to prevent malfunction of the airbag device 6 at the time of the airbag deployment OFF requirement. As described above, according to the vehicle collision detection device 1, by using the existing configuration in the vehicle including the pressure sensor 5, it is further determined whether or not a collision requiring the operation of the airbag device 6 has occurred in the vehicle. It is possible to detect accurately and at a reduced cost.

  Further, when the detection results of both the floor G sensor 3 and the pressure sensor 5 are equal to or higher than the threshold values Gth1 and Pth respectively set (S2: Yes, S3: Yes), the airbag ECU 2 is the airbag device 6. It is determined that a frontal collision that requires operation (S4) has occurred (S4). According to this configuration, it is possible to more accurately execute the collision determination by setting an appropriate threshold value in advance.

  Further, the airbag ECU 2 has a case where at least one of the detection results of the floor G sensor 3 and the pressure sensor 5 is smaller than the thresholds Gth1 and Pth respectively set (S2: No, S3: No). It is characterized in that it is determined that a collision requiring the operation of the airbag device 6 has not occurred. According to this configuration, for example, when the vehicle rides on a curb or the like, the bumper 8 is not deformed. Therefore, the pressure sensor 5 does not operate and the interval integral value ∫P (t) dt of the pressure sensor 5 is the threshold value Pth. (S3: No). In this way, it is possible to reliably prevent the airbag device 6 from being activated at the time of a collision that does not require the airbag device 6 to be activated (when the airbag deployment is turned off).

  Further, a front G sensor 4 that is provided at a position different from the floor G sensor 3 in the vehicle and detects the acceleration of the vehicle is provided. The airbag ECU 2 further detects the detection result of the floor G sensor 3 and the front G sensor 4. It is characterized by determining whether the collision which requires the action | operation of the airbag apparatus 6 generate | occur | produced using the detection result of this. According to this configuration, by providing the front G sensor 4 at a position different from the floor G sensor 3, it is possible to improve the detection accuracy of the impact caused by the collision.

  Furthermore, when the detection result of both the floor G sensor 3 and the front G sensor 4 is equal to or greater than the set threshold values, the airbag ECU 2 has caused a collision other than a frontal collision that requires the airbag device 6 to operate. It is characterized by determining. According to this configuration, by using the two types of acceleration sensors 3 and 4, it is possible to detect a collision other than a frontal collision with high accuracy.

  Further, the floor G sensor 3 is provided at the center in the front-rear direction of the vehicle, and the front G sensor 4 is provided on both the left and right sides of the front part of the vehicle. According to this configuration, the front G sensor 4 provided on the left and right sides of the front portion of the vehicle can reliably detect a collision at the side portion of the vehicle. Furthermore, by using the detection result of the floor G sensor 3 provided at the center in the front-rear direction of the vehicle, it is possible to accurately determine the situation in which the occupant needs to operate the airbag device 6, and to appropriately determine the airbag device 6. Can be operated.

  The present invention is not limited to the above-described embodiments, and various modifications or expansions can be made without departing from the spirit of the present invention. For example, in the present embodiment, the front G sensor 4 is provided on both the left and right sides of the front portion of the vehicle, but may be provided on both the left and right sides of the front portion and the rear portion of the vehicle. And the number may be changed as appropriate. In addition, the number of installed pressure sensors 5 and the detection range can be changed as appropriate. Further, an emergency notification device may be provided in the vehicle collision detection device 1 so that an emergency notification is made to the emergency center when a collision accident requiring the operation of the airbag device 6 occurs.

  In addition, the pressure sensor 5 is configured to detect the pressure in the chamber space 9a of the chamber member 9, but is not limited thereto, and may be configured to detect, for example, the pressure in the hollow tube member. Further, a threshold value Gth3 larger than the threshold value Gth1 is set as the threshold value of the floor G sensor 3, and the section integral value ∫G1 (t) dt of the floor G sensor 3 is equal to or greater than the threshold value Gth3. In that case, the airbag device 6 may be activated immediately. Further, as the threshold value, a predetermined detection value detected by each of the sensors 3 to 5 may be used instead of the interval integral value.

  Moreover, although the floor G sensor 3 was used as the first acceleration sensor of the present invention and the front G sensor 4 was used as the second acceleration sensor in the above embodiment, the present invention is not limited to this. The front G sensor 4 may be used as the first acceleration sensor of the present invention, and the floor G sensor 3 may be used as the second acceleration sensor. Hereinafter, a modification will be described with reference to the flowchart of FIG.

  First, the airbag ECU 2 performs signal calculation processing of outputs from the sensors 3 to 5 as in the above embodiment (S11). In other words, the acceleration values detected by the floor G sensor 3 and the front G sensor 4 are integrated over a section per unit time, and the pressure value detected by the pressure sensor 5 is integrated over a section per unit time.

  Subsequently, the airbag ECU 2 determines whether or not the interval integral value ∫G2 (t) dt of the front G sensor 4 is greater than or equal to the threshold value Gth2 (S12). When the interval integral value ∫G2 (t) dt of the front G sensor 4 is equal to or greater than the threshold value Gth2 (S12: Yes), the airbag ECU 2 determines that the interval integral value ∫P (t) dt of the pressure sensor 5 is the threshold value. It is determined whether or not Pth or more (S13). When the section integral value ∫G2 (t) dt of the front G sensor 4 is less than the threshold value Gth2 (S12: No), the process returns to S11.

  If the interval integral value ∫P (t) dt of the pressure sensor 5 is greater than or equal to the threshold value Pth (S13: Yes), the airbag ECU 2 determines that the interval integral value ∫G1 (t) dt of the floor G sensor 3 is equal to the threshold value. It is determined whether or not Gth1 or more (S14). If the interval integral value ∫P (t) dt of the pressure sensor 5 is less than the threshold value Pth (S13: No), the airbag ECU 2 determines that the vehicle has run on a curb or the like, and returns to S11.

  When the section integral value ∫G1 (t) dt of the floor G sensor 3 is greater than or equal to the threshold value Gth1 (S14: Yes), the airbag ECU 2 detects the frontal collision, ODB, and underride that require the airbag device 6 to operate. It is determined that such a collision has occurred in the vehicle, and the airbag device 6 is activated (S15). When the section integral value ∫G1 (t) dt of the floor G sensor 3 is less than the threshold value Gth1 (S14: No), the airbag ECU 2 determines that it is not necessary to operate the airbag device 6, and S11 Return to.

  Thus, in the vehicle collision detection device 1 of the above-described modification, the airbag ECU 2 uses the detection results of the floor G sensor 3, the front G sensor 4, and the pressure sensor 5 to operate the airbag device 6. It is possible to distinguish a required collision from a collision that does not require the operation of the airbag device 6 such as when the vehicle rides on a curb.

DESCRIPTION OF SYMBOLS 1 Vehicle collision detection apparatus 2 Airbag ECU (determination means)
3 Floor G Sensor (First Acceleration Sensor <Embodiment>, Second Acceleration Sensor <Modification>)
4 Front G Sensor (Second Acceleration Sensor <Embodiment>, First Acceleration Sensor <Modification>)
5 Pressure sensor 6 Airbag device (occupant protection means)
7 Pedestrian protection device 8 Bumper 9 Chamber member 9a Chamber space

Claims (9)

A first acceleration sensor (3) provided in the vehicle for detecting the acceleration of the vehicle;
A chamber member (9) disposed in the vehicle bumper (8) and having a chamber space (9a) formed therein;
A pressure sensor (5) for detecting the pressure in the chamber space;
Determination means (2) for determining whether or not a collision requiring the operation of occupant protection means (6) has occurred in the vehicle using the detection result of the first acceleration sensor and the detection result of the pressure sensor;
A vehicle collision detection device (1) comprising:   The determination means determines that a frontal collision that requires operation of the occupant protection means has occurred when detection results of both the first acceleration sensor and the pressure sensor are equal to or greater than a threshold value set for each. The vehicle collision detection device according to claim 1.   When the detection result of at least one of the detection results of the first acceleration sensor and the pressure sensor is smaller than a threshold value set for each of the determination means, a collision that requires operation of the occupant protection means occurs. The vehicle collision detection device according to claim 2, wherein it is determined that the vehicle collision has not occurred. A second acceleration sensor (4) provided in a position different from the first acceleration sensor in the vehicle for detecting the acceleration of the vehicle;
The determination means further determines whether or not a collision requiring operation of occupant protection means has occurred in the vehicle, using the detection result of the first acceleration sensor and the detection result of the second acceleration sensor. The collision detection apparatus for vehicles according to any one of claims 1 to 3 characterized by things.   When the detection results of both the first acceleration sensor and the second acceleration sensor are equal to or greater than the set threshold values, the determination means generates a collision other than the frontal collision that requires the occupant protection means to operate. The vehicle collision detection device according to claim 4, wherein the vehicle collision detection device is determined. The first acceleration sensor is provided at a central portion in the front-rear direction of the vehicle,
The collision detection apparatus for a vehicle according to any one of claims 1 to 5, wherein the second acceleration sensor is provided in a front portion of the vehicle.   The vehicle collision detection device according to claim 6, wherein the second acceleration sensor is provided on both left and right sides of a front portion of the vehicle. The first acceleration sensor is provided at a front portion of the vehicle,
6. The vehicle collision detection device according to claim 1, wherein the second acceleration sensor is provided at a central portion in the front-rear direction of the vehicle.   The vehicle collision detection device according to claim 8, wherein the first acceleration sensor is provided on both right and left sides of a front portion of the vehicle.

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