JP2019018642A - Collision detector and collision detection method - Google Patents

Abstract

To detect collision at an early stage at the time of a full-lap collision.SOLUTION: A collision detector comprises: an acquisition section; a first determination section; and a second determination section. The acquisition section acquires sensor values of a plurality of front sensors that are arranged on a vehicle body front part to detect impact shock applied to the vehicle. The first determination section determines whether a calculated value based on the sensor values acquired by the acquisition section exceeds a prescribed threshold value, for each front sensor. The second determination section determines whether the impact shock is caused by a full-lap collision, on the basis of a combination of determination results for each of the front sensors according to the first determination section.SELECTED DRAWING: Figure 2

Description

  Embodiments disclosed herein relate to a collision detection apparatus and a collision detection method.

  Conventionally, when a collision of a vehicle is detected by a collision detection device, for example, there is a technique for protecting an occupant by deploying an airbag or the like. The collision detection device detects a collision based on, for example, an acceleration sensor arranged near the center of the vehicle called a “floor sensor” and an acceleration sensor arranged in the front of the vehicle called a “front sensor” (for example, patents). Reference 1).

  Incidentally, in recent years, an increase in capacity of an airbag is desired for the purpose of improving the protection performance of an occupant. Therefore, with the increase in capacity of the airbag, it is necessary to make the deployment determination at the time of full lap collision earlier.

  Specifically, when the collision mode is a high-speed full lap collision, the airbag needs to be deployed first, while in the case of an offset collision, for example, the movement speed of the occupant due to the collision is slower than the full lap collision. In the case of an offset collision, it is preferable not to accelerate the deployment of the airbag.

JP 2002-178873 A

  However, the conventional technology cannot deploy the airbag unless the impact due to the collision is transmitted to the floor sensor. Therefore, in order to accelerate the airbag deployment at the time of a full lap collision, it is desired to accelerate the collision detection.

  One embodiment of the present invention has been made in view of the above, and an object thereof is to provide a collision detection device and a collision detection method that can accelerate collision detection at the time of a full-wrap collision.

  A collision detection device according to an aspect of an embodiment includes an acquisition unit, a first determination unit, and a second determination unit. The acquisition unit is provided in a plurality at the front portion of the vehicle body, and acquires a sensor value of a front sensor that detects an impact applied to the vehicle. The first determination unit determines whether or not a calculated value based on the sensor value acquired by the acquisition unit exceeds a predetermined threshold value for each front sensor. The second determination unit determines whether or not the impact is at least due to a full wrap collision based on a combination of determination results for each front sensor by the first determination unit.

  According to one aspect of the embodiment, collision detection at the time of a full lap collision can be accelerated.

FIG. 1A is a schematic explanatory diagram of a collision detection method according to a comparative example. FIG. 1B is a comparison diagram between the “conventional capacity” and the “high capacity” of the airbag. FIG. 1C is a schematic explanatory diagram (part 1) of the collision detection method according to the embodiment. FIG. 1D is a schematic explanatory diagram (part 2) of the collision detection method according to the embodiment. FIG. 1E is a schematic explanatory diagram (part 3) of the collision detection method according to the embodiment. FIG. 2 is a block diagram of the occupant protection system according to the embodiment. FIG. 3 is a diagram showing the arrangement position of each front sensor. FIG. 4 is a process explanatory diagram of the acquisition calculation unit. FIG. 5A is a process explanatory diagram (No. 1) of a determination process in the main determination unit and the safing determination unit. FIG. 5B is a process explanatory diagram (No. 2) of the determination process in the main determination unit and the safing determination unit. FIG. 5C is a process explanatory diagram (No. 3) of the determination process in the main determination unit and the safing determination unit. FIG. 5D is a process explanatory diagram (No. 4) of the determination process in the main determination unit and the safing determination unit. FIG. 5E is a process explanatory diagram (No. 5) of the determination process in the main determination unit and the safing determination unit. FIG. 5F is a process explanatory diagram (No. 6) of the determination process in the main determination unit and the safing determination unit. FIG. 5G is a process explanatory diagram (No. 7) of the determination process in the main determination unit and the safing determination unit. FIG. 5H is a process explanatory diagram (No. 8) of the determination process in the main determination unit and the safing determination unit. FIG. 5I is a process explanatory diagram (No. 9) of the determination process in the main determination unit and the safing determination unit. FIG. 5J is a process explanatory diagram (No. 10) of the determination process in the main determination unit and the safing determination unit. FIG. 6 is an explanatory view of an angled forward collision. FIG. 7A is a flowchart illustrating a processing procedure executed by the collision detection device according to the embodiment. FIG. 7B is an explanatory diagram of conditions for establishing the first to third normal collision determinations. FIG. 7C is a flowchart illustrating a processing procedure of sensor value acquisition calculation processing. FIG. 7D is a flowchart illustrating a processing procedure of main determination processing. FIG. 7E is a flowchart illustrating a processing procedure of the safing determination process. FIG. 8A is a diagram (part 1) illustrating a modification of the determination map. FIG. 8B is a diagram (No. 2) illustrating a modification of the determination map. FIG. 8C is a diagram illustrating a modification of the arrangement position of each front sensor. FIG. 9A is an explanatory diagram (part 1) of a collision detection method according to another embodiment. FIG. 9B is an explanatory diagram (part 2) of the collision detection method according to another embodiment. FIG. 9C is an explanatory diagram (part 3) of the collision detection method according to another embodiment. Drawing 9D is an explanatory view (the 4) of a collision detection method concerning other embodiments. FIG. 9E is an explanatory diagram (part 5) of a collision detection method according to another embodiment. FIG. 9F is an explanatory diagram (part 6) of a collision detection method according to another embodiment. FIG. 9G is an explanatory diagram (part 7) of a collision detection method according to another embodiment. FIG. 9H is an explanatory diagram (No. 8) of the collision detection method according to the other embodiment. FIG. 9I is an explanatory diagram (part 9) of a collision detection method according to another embodiment.

  Hereinafter, embodiments of a collision detection device and a collision detection method disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  Moreover, below, after describing the outline | summary of the collision detection method which concerns on this embodiment using FIG. 1A-FIG. 1E, the collision detection apparatus 10 which applied the collision detection method which concerns on this embodiment, and an occupant protection system provided with the same 1 will be described with reference to FIGS. In addition, collision detection methods according to other embodiments will be described with reference to FIGS. 9A to 9I.

  Hereinafter, as a definition of terms related to a vehicle collision, a so-called full lap collision in which the entire front surface of the vehicle collides is referred to as “normal collision”. An offset collision in which one side of the vehicle collides with a full lap collision is referred to as “offset”. In addition, when the front left side collides, it is set as “left offset”, and when the front right side collides, it is set as “right offset”.

  In the following description, it is assumed that the sensor used for collision detection is an acceleration sensor. Note that “acceleration” may be appropriately referred to as “G” for convenience of explanation. In the following, collision detection is basically performed by determining whether or not the sensor value of each sensor exceeds a predetermined threshold value indicating the magnitude of impact. Is true may be referred to as “ON determination”, and conversely, the determination result may be false as “OFF determination”.

  First, the outline | summary of the collision detection method which concerns on this embodiment is demonstrated using FIG. 1A-FIG. 1E. FIG. 1A is a schematic explanatory diagram of a collision detection method according to a comparative example. FIG. 1B is a comparison diagram of the “conventional capacity” and “high capacity” of the airbag 20 (see FIG. 2). 1C to 1E are schematic explanatory views (No. 1) to (No. 3) of the collision detection method according to the present embodiment.

  For ease of explanation, FIG. 1A shows a three-dimensional orthogonal coordinate system including a Z-axis having a vertical upward direction as a positive direction and a vertical downward direction as a negative direction. Such an orthogonal coordinate system may be shown in other drawings used in the following description.

  As shown in FIG. 1A, in the collision detection method according to the comparative example, for example, a front left sensor 2b disposed on the front left side of the vehicle C, a front right sensor 2c disposed on the front right side, and an airbag ECU (Electronic Control Unit). The collision of the vehicle C is detected based on the acceleration detected by the floor sensor 2d disposed in the collision detection device 10 corresponding to the above.

  Specifically, in the collision detection method according to the comparative example, for example, “floor sensor Hi determination” in which the sensor value of the floor sensor 2d is determined by a predetermined high threshold value, and the sensor value of the floor sensor 2d is determined by a predetermined low threshold value. “Floor sensor Lo determination”, “front left sensor determination” for determining the sensor value of the front left sensor 2b by a predetermined threshold, and “front right sensor determination” for determining the sensor value of the front right sensor 2c by a predetermined threshold "Airbag deployment" is performed according to the combination of the respective determination results.

  More specifically, in the collision detection method according to the comparative example, as shown in FIG. 1A, for example, the determination result of “floor sensor Hi determination” is set as one system of “airbag deployment” determination. In addition, another system is provided as a redundant configuration. For example, the logical sum of the determination results of “front left sensor determination” and “front right sensor determination” (refer to OR gate gt1) and “floor sensor Lo determination” are determined. A logical product with the result (see AND gate gt2) is used as a determination result. If the logical sum of the determination results of both systems (refer to OR gate gt3), that is, if the determination result of at least one of the systems is ON determination, the airbag 20 is deployed.

  By the way, with respect to the collision safety of the vehicle C, further improvement of the passenger protection performance is always a demanded issue. One of the countermeasures for this problem is to increase the capacity of the airbag 20.

  By increasing the capacity of the airbag 20, the occupant can be received at an earlier timing and the degree of injury can be reduced. The occupant can be prevented from slipping through the gap between the airbags 20, and the pressure of the airbag 20 can be prevented. Since the adjustment range is widened, the effect of increasing the degree of freedom of pressure tuning can be expected.

  However, there are points to be cleared when the capacity of the airbag 20 is increased. Specifically, as shown in FIG. 1B, when comparing “conventional capacity” and “high capacity”, from “collision” to “airbag deployment completion” as shown in “deployment completion is conventional”. You may be asked not to change. However, since the “high capacity” airbag 20 has “the deployment time is longer than before”, it is necessary to “start the airbag deployment” earlier than before.

  For “start airbag deployment”, “deployment determination establishment” of the airbag 20 is required. For this reason, as shown in FIG. 1B, “if the deployment determination is not established earlier than before after the collision, it will not be in time for completion of deployment”.

  As described above, with the increase in capacity of the airbag 20, for example, it is considered that the establishment time of “deployment determination establishment” needs to be surely accelerated in the case of high-speed collision, but on the other hand, the collision such as offset For other types of collision, it is known that the movement speed of the occupant at the time of collision is slower than that at the time of a collision. For this reason, if the deployment time of the airbag 20 is advanced, the time at which the airbag 20 begins to deflate is also accelerated, so that there is a possibility that sufficient occupant protection performance cannot be exhibited in a collision mode other than a normal collision. Therefore, it is preferable to apply the advancement of “deployment determination establishment” in FIG. 1B only when the collision mode is a normal collision.

  Therefore, in the collision detection method according to the present embodiment, first, as shown in FIG. 1C, in addition to the front left sensor 2b and the front right sensor 2c, the front center portion of the vehicle C (see the M11 portion in the figure) is further moved to the front. The central sensor 2a is arranged. The airbag 20 can be determined for deployment only by the front center sensor 2a, front left sensor 2b, and front right sensor 2c on the front side.

  Specifically, as shown in FIG. 1C, in the collision detection method according to the present embodiment, two types of determinations of “main determination” and “safting determination” are performed based on the sensor values of the front sensors 2a to 2c. Do. The “main determination” is performed using the front sensors 2a to 2c as main sensors, and the “safing determination” is performed by the remaining front sensors 2a to 2c other than the main sensor.

  For example, FIG. 1C shows a case where the front center sensor 2a is the main sensor and performs “main determination”, and the front left sensor 2b and the front right sensor 2c each perform “safing determination”. The front left sensor 2b and the front right sensor 2c may be main sensors. The overall configuration including such a case will be shown in FIG. 1E later.

  Note that the “safing determination” is a separate system for ensuring redundancy in the expansion determination with respect to the “main determination”. In the present embodiment, in the expansion determination using only the front sensors 2a to 2c, At least one “main determination” system and two “safing determination” systems are provided.

  In addition, as shown in FIG. 1C, in the collision detection method according to the present embodiment, the logical product of the determination result of each “safing determination” (see AND gate gt4) and the determination result of “main determination”. (See AND gate gt5) is the result of the airbag 20 deployment determination using only the front sensors 2a to 2c. That is, if the determination result is ON determination in both “main determination” and the two “safing determinations”, the airbag 20 is deployed.

  As described above, in the collision detection method according to the present embodiment, the airbag 20 is determined to be deployed using only the front center sensor 2a, front left sensor 2b, and front right sensor 2c on the front side, which does not include the floor sensor 2d. Made it possible. That is, the “development determination establishment” time is advanced by not using the sensor value of the floor sensor 2d that is behind the front sensors 2a to 2c and is less susceptible to impact than the front sensors 2a to 2c. It becomes possible.

  Note that the collision detection method according to the present embodiment has a signal holding function for “main judgment” and “safting judgment” as shown in FIG. Make it. That is, even if the “pre-holding signal” is determined to be OFF after the ON determination, the ON signal is output as indicated by the “post-holding signal” for a predetermined holding time HT after the OFF determination.

  In the collision detection method according to the present embodiment, each of the “safing determinations” shown in FIG. 1C uses a determination map that is set to be OFF determination when the collision mode is other than a normal collision. Make a decision.

  Therefore, in the collision detection method according to the present embodiment, as shown in FIG. 1C, the logical product of the determination results of the “safing determination” (see AND gate gt4) and the determination result of the “main determination”. Since the deployment determination result of the airbag 20 is the result of the airbag 20 (see AND gate gt5), the airbag 20 can be undeployed in a collision mode other than a normal collision such as an offset. Specific examples of the determination map are shown in FIG.

  The development determination logic according to the present embodiment can be combined with “conventional development determination” as shown in FIG. 1E. That is, the logical sum (see OR gate gt6) of the determination result of “conventional deployment determination” and the determination result of “deployment determination according to the present embodiment” is the deployment determination result of the airbag 20. That is, the airbag 20 can be deployed if at least one of the determination result of “conventional deployment determination” and the determination result of “deployment determination according to the present embodiment” is ON determination.

  Therefore, when the collision is a normal collision, the airbag 20 can be deployed earlier than the case of the conventional capacity by “deployment determination according to the present embodiment”. Further, as described above, in the “development determination according to the present embodiment”, collisions other than normal collisions such as offset are determined OFF by “safing determination”, but in the case of collisions other than such normal collisions, The airbag 20 can be deployed by “deployment determination”. Therefore, in the case of a collision mode other than a normal collision, it is possible to prevent the occupant protection performance from being deteriorated due to the start of deployment of the airbag 20 being accelerated than before.

  As shown in FIG. 1E, “development determination according to this embodiment” includes “front center sensor deployment determination (first forward collision determination)” using the front center sensor 2a as a main sensor, and front left sensor 2b. Is a combination of “front left sensor deployment determination (second forward collision determination)” and “front right sensor deployment determination (third forward collision determination)” with the front right sensor 2c as the main sensor. .

  Then, the logical sum (see OR gate gt7) of the determination results of the respective expansion determinations becomes the determination result of “development determination according to the present embodiment”, and is output to the OR gate gt6. Therefore, if at least one of the determination results of each of the “first normal collision determination” to “third normal collision determination” is ON determination, the airbag 20 is deployed at an earlier timing than before. It becomes.

  Hereinafter, the collision detection apparatus 10 to which the collision detection method according to the present embodiment described above is applied and the occupant protection system 1 including the collision detection apparatus 10 will be described more specifically.

  FIG. 2 is a block diagram of the occupant protection system 1 according to the present embodiment. In FIG. 2, only components necessary for explaining the features of the present embodiment are represented by functional blocks, and descriptions of general components are omitted. For this reason, description was also omitted about the component which makes the conventional deployment determination.

  2 are functionally conceptual, and need not be physically configured as illustrated. For example, the specific form of distribution / integration of each functional block is not limited to the one shown in the figure, and all or a part thereof is functionally or physically distributed in arbitrary units according to various loads or usage conditions.・ It can be integrated and configured.

  As shown in FIG. 2, the occupant protection system 1 includes a collision detection device 10. The collision detection device 10 is communicably connected to each of a front center sensor 2a, a front left sensor 2b, and a front right sensor 2c disposed on the front side of the vehicle C. Further, the collision detection device 10 is provided so as to ignite a squib (not shown) in order to deploy the airbag 20.

  Here, the arrangement positions of the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c will be specifically described. FIG. 3 is a diagram showing the arrangement positions of the front sensors 2a to 2c.

  As shown in FIG. 3, the front center sensor 2a is disposed at a position ahead of the vehicle C with respect to the front left sensor 2b and the front right sensor 2c. For example, the front center sensor 2a is connected to the front cross member 4 of the vehicle C or a bumper beam (not shown). Be placed.

  Further, the front left sensor 2b and the front right sensor 2c are disposed at both ends of the radiator support 3 of the vehicle C. Each of the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c detects an impact received by the vehicle C upon a collision as an acceleration, and outputs a sensor value that is a detection value to the collision detection device 10.

  Returning to the description of FIG. The collision detection device 10 includes a control unit 11 and a storage unit 12. The control unit 11 includes an acquisition calculation unit 11a, a main determination unit 11b, a safing determination unit 11c, and an activation determination unit 11d. The main determination unit 11 b and the safing determination unit 11 c constitute a normal collision determination unit 15.

  The storage unit 12 is a storage device such as a hard disk drive, a nonvolatile memory, or a register, and stores threshold information 12a. The threshold information 12a is information including the determination map described above. In the present embodiment, the determination map is, for example, a two-dimensional map of acceleration and its integral value, and a determination threshold is set on the map. The determination map is provided for each of the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c, for example.

  The control unit 11 controls the entire collision detection device 10. The acquisition calculation unit 11a acquires sensor values from the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c, and then performs calculation processing necessary for “main determination” and “safing determination”.

  The acquisition calculation unit 11a will be described more specifically. FIG. 4 is a process explanatory diagram of the acquisition calculation unit 11a. As shown in FIG. 4, the acquisition calculation unit 11 a acquires sensor values from the front sensors 2 a to 2 c, that is, performs “acceleration acquisition”, and performs the “main determination” and “safting determination” for the two systems, respectively. Perform filtering.

  For example, a low-pass filter is used for the filter processing. By passing through such filter processing, for example, noise is removed from the sensor value. The low-pass filter can be set separately for “main determination” and “safing determination”.

  In the present embodiment, as described above, a two-dimensional map of acceleration and its integrated value is used. Therefore, after the filter process is executed, the acquisition calculation unit 11a sets the “integral value calculation” of acceleration for “main determination” and “ This is done for each “safing judgment”. The integrated value may be rephrased as “deceleration”.

  In “integral value calculation”, the calculation method can be selected from 1) total integration by constant switching, 2) interval integration, and 3) total integration with start / end conditions.

  1) is a total integration operation in which the previously calculated integral value is weighted, where the current time is t and the weight is k, the integral value (t) = k × integral value (t−1) + It can be calculated by acceleration (t). For example, k is weighted so as to increase when acceleration (t) ≧ 2G, and is weighted so as to decrease when acceleration (t) <2G.

  2) is an integral calculation for a predetermined interval in the past of acceleration (t), and the predetermined interval is, for example, about 100 milliseconds. Since the collision is said to end in about 100 to 150 milliseconds, 2) corresponds to the total integration calculation at the time of the collision.

  3) is a simple integration operation with a start condition and an end condition. For example, the start condition is acceleration (t) ≧ 2G, and the integral value (t) = integral value (t−1) + acceleration (t) The calculation is started, and the calculation ends with an end condition / acceleration (t) <2G.

  In the above description, the integral value = deceleration has been described, but a movement amount may be used instead of the deceleration. The movement amount corresponds to the second-order integral value of acceleration.

  Then, the integrated value that has undergone such “integral value calculation” and the acceleration that has undergone “filter processing” in each system are used for “main determination” and “safting determination”, respectively.

  Returning to the description of FIG. The acquisition calculation unit 11a outputs the acceleration and integral value for “main determination” of each of the front sensors 2a to 2c to the main determination unit 11b. Further, the acquisition calculation unit 11a outputs the acceleration and integral value for “safing determination” of each of the front sensors 2a to 2c to the safing determination unit 11c.

  The main determination unit 11b maps the acceleration and integral value input from the acquisition calculation unit 11a to the determination map included in the threshold information 12a, and determines whether or not the determination threshold (main threshold) set in the determination map is exceeded. judge. If the determination threshold is exceeded, the main determination unit 11b outputs a signal indicating ON determination to the activation determination unit 11d. On the other hand, when the determination threshold is not exceeded, the main determination unit 11b outputs a signal indicating OFF determination to the activation determination unit 11d.

  The safing determination unit 11c maps the acceleration and the integral value input from the acquisition calculation unit 11a to the determination map included in the threshold information 12a, and whether or not the determination threshold (safing threshold) set in the determination map is exceeded. Determine whether. If the determination threshold value is exceeded, the safing determination unit 11c outputs a signal indicating ON determination to the activation determination unit 11d. On the other hand, when the determination threshold is not exceeded, the safing determination unit 11c outputs a signal indicating OFF determination to the activation determination unit 11d.

  In the determination map, when the collision mode is other than the normal collision, the safing threshold is set so that the “safing determination” is determined to be OFF.

  Here, the determination process of the main determination unit 11b and the safing determination unit 11c will be described more specifically with reference to FIGS.

  FIGS. 5A to 5J are process explanatory diagrams (No. 1) to (No. 10) of determination processes in the main determination unit 11b and the safing determination unit 11c.

  FIG. 5A is a schematic diagram of two-dimensional map determination of acceleration and integral value. As shown in FIG. 5A, the main determination unit 11b and the safing determination unit 11c perform determination processing using a determination map that is a two-dimensional map with the vertical axis representing acceleration and the horizontal axis representing integrated values. A determination threshold value (main threshold value or safing threshold value) is set in the determination map. For example, an upper region divided by the determination threshold value is a “determination ON region”, and a lower region is a “determination OFF region”.

  As shown in FIG. 5A, when the waveform at the time of collision enters the “determination ON region”, the main determination unit 11b and the safing determination unit 11c output a signal indicating ON determination as a determination result. If the waveform at the time of collision does not enter the “determination ON region”, the main determination unit 11b and the safing determination unit 11c output a signal indicating OFF determination as a determination result.

  As described above, when the determination map has a collision mode other than the normal collision, the safing threshold is set so that the “safing determination” is determined to be OFF. This point will be specifically described.

  FIG. 5B shows an example of a temporal transition of acceleration detected by each of the front sensors 2a to 2c (hereinafter sometimes referred to as “front acceleration”) in the case of “normal collision”. FIG. 5C shows an example of temporal transition of the front acceleration in the case of “left offset” as one of the collision modes other than the normal collision. In both cases, time 0 is the moment of collision.

  As shown in FIG. 5B, in the case of “normal collision”, it can be seen that a large G is detected in any of the “center”, “left”, and “right” front sensors 2a to 2c.

  On the other hand, as shown in FIG. 5C, in the case of “left offset”, a large G is detected by the “left” front left sensor 2b, and then a large G is detected by the “center” front center sensor 2a. I understand that. It can also be seen that G detected by the “right” front right sensor 2c is not so large.

  Therefore, in the case of “offset” including “left offset”, it is predicted that the detected G has a relationship of collision side sensor> center sensor> anti-collision side sensor. In the present embodiment, based on such a relationship, in the “safing determination”, the safing threshold is set so that the determination is OFF when the collision mode is other than the normal collision.

  Further, as can be seen from FIG. 5B and FIG. 5C, in the “center” front center sensor 2a, in the case of “left offset”, the opponent vehicle does not directly hit the front center sensor 2a. G detected in this way becomes smaller. By setting the determination threshold using such a feature difference, for example, it is possible to determine “normal collision” and “offset”.

  Further, in the “safing determination”, when setting the safing threshold value so that the determination is OFF when the collision mode is other than the normal collision, “development determination according to the present embodiment” (see FIG. 1E) Since the logical sum of the determination results of the first to third normal collision determinations is taken, it is necessary to make the OFF determination in all of the first to third normal collision determinations.

  In this respect, since “safting determination” takes the logical product of two sensors other than the main sensor, at least one “safing determination” of the two sensors may be determined to be OFF.

  Therefore, in the present embodiment, as shown in FIG. 5D, for example, in the case of “offset”, the safing threshold is set so that OFF is determined by “safting determination” of the anti-shock side sensor in which G is not detected to be large. To do.

  Specifically, as shown in FIG. 5D, in the first collision determination, the safing threshold is set so that “front left sensor safing determination” is determined to be OFF if the offset is right. If the offset is left, the safing threshold is set so that “front right sensor safing determination” is determined to be OFF.

  In the second forward collision determination, the safing threshold is set so that “front center sensor safing determination” is determined to be OFF if it is a right offset. If the offset is left, the safing threshold is set so that “front right sensor safing determination” is determined to be OFF.

  In the third forward collision determination, the safing threshold is set so that “front center sensor safing determination” is determined to be OFF if it is a left offset. If it is right offset, the safing threshold is set so that “front left sensor safing judgment” is judged OFF.

  Specific examples of determination maps in which determination thresholds are set based on this concept are shown in FIGS. 5E to 5G. FIGS. 5E to 5G show, in order, a determination map example of the front center sensor 2a, a determination map example of the front left sensor 2b, and a determination map example of the front right sensor 2c.

  As shown in FIG. 5E, the determination map of the front center sensor 2a is set such that, for example, if a main threshold G is detected that is equal to or greater than a predetermined value, it is determined to be ON as “normal collision”. Further, the safing threshold is set so that it is determined to be OFF in both cases of “left offset” and “right offset”.

  Further, as shown in FIG. 5F, the determination map of the front left sensor 2b is set such that, for example, if a main threshold value G of a predetermined value or more is detected, it is determined to be ON as “normal collision”. Further, the safing threshold is set so as to be determined to be ON in the case of “left offset” and to be determined to be OFF in the case of “right offset”.

  Further, as shown in FIG. 5G, the determination map of the front right sensor 2c is set such that, for example, if the main threshold value G is detected to be equal to or greater than a predetermined value, it is determined to be ON as “normal collision”. The safing threshold is set so that it is determined to be ON when it is “right offset” and OFF when it is “left offset”. As shown in FIGS. 5E to 5G, in the region where the integral value is small, the safing threshold can be set to be lower than the main threshold.

  Using such a determination map, the temporal transition of acceleration at each of the front sensors 2a to 2c in the case where the “normal collision” is detected in the first normal collision determination, that is, the “front center sensor deployment determination”. An example is shown in FIGS.

  Since it is “front center sensor deployment determination”, the main sensor is the front center sensor 2a. As shown in FIG. 5H, according to the present embodiment, in the “front center sensor main determination” of the “front center sensor deployment determination”, the “normal collision” is determined by the main threshold earlier than the “conventional capacity deployment request time”. Can be detected.

  Further, as shown in FIG. 5I, according to the present embodiment, in the “front left sensor safing determination” of the “front center sensor deployment determination”, the safing threshold “ It is possible to detect a “normal collision”.

  Further, as shown in FIG. 5J, according to the present embodiment, in the “front right sensor safing judgment” of the “front center sensor deployment judgment”, the safing threshold value “ It is possible to detect a “normal collision”.

  However, due to the time difference based on the positional relationship between the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c, in FIG. 5I and FIG. 5J, the detection time for “front hit” is slightly later than in FIG. 5H. For this reason, in the “development determination according to the present embodiment” that takes a logical product, the airbag 20 is deployed around 8 milliseconds when “normal collision” is detected in FIGS. 5I and 5J. The airbag 20 can be deployed sufficiently earlier than the “conventional deployment time”.

  According to the description of FIGS. 5H to 5J, it is possible to accelerate the start of deployment of the airbag 20 by only “front center sensor deployment determination”, that is, only the first frontal collision determination. However, even if it says a normal collision, the collision form is various, for example, there may be a case where an angle is attached to the normal collision.

  Such a case will be described. FIG. 6 is an explanatory view of an angled forward collision. As shown in FIG. 6, “an angled collision”, here, a case where the opponent vehicle collides with the entire front surface of the vehicle C from the diagonally left front of the vehicle C is considered.

  In such a case, as shown in FIG. 6, the front left sensor 2b is "high acceleration", and the front center sensor 2a and the front right sensor 2c are "acceleration", that is, the acceleration is relatively higher than that of the front left sensor 2b. There is a possibility of becoming smaller.

  Then, as shown in FIG. 6, in the “front center sensor main determination” of the first frontal collision determination, since the acceleration is small, the ON determination may be delayed. However, as shown in FIG. 6, for example, in the second frontal collision determination, since the threshold value (safing threshold value) is lower than the main determination in “front center sensor safing determination”, the ON determination up to the required time can be expected. Accordingly, the airbag 20 can be deployed by the required time.

  Thus, by combining not only the first normal collision determination but also the second and third normal collision determinations, the high-capacity airbag 20 can be installed at an early stage while dealing with the diversity of the normal collision types. It becomes possible to develop.

  Returning to the description of FIG. 2, the activation determination unit 11d will be described. The activation determination unit 11d deploys, that is, activates the airbag 20, when signals indicating ON determination are input from both the main determination unit 11b and the safing determination unit 11c.

  The activation determination unit 11d receives the determination results from the main determination unit 11b and the safing determination unit 11c corresponding to each of the first to third collision detections described above, and performs activation determination for each of them. If the deployment determination is established in any of the first to third collision determinations, the activation determination unit 11d deploys the airbag 20.

  Next, a processing procedure executed by the collision detection apparatus 10 according to the present embodiment will be described with reference to FIGS. 7A to 7E. FIG. 7A is a flowchart illustrating a processing procedure executed by the collision detection apparatus 10 according to the present embodiment. Moreover, FIG. 7B is explanatory drawing of the satisfaction conditions of the 1st-3rd frontal collision determination.

  Moreover, FIG. 7C is a flowchart which shows the process sequence of a sensor value acquisition calculation process. FIG. 7D is a flowchart illustrating a processing procedure of main determination processing. FIG. 7E is a flowchart showing the procedure of the safing determination process.

  As shown in FIG. 7A, the acquisition calculation unit 11a first executes sensor value acquisition calculation processing for the number of sensors (steps S101 to S103). In the present embodiment, step S101 corresponds to the front center sensor 2a. Step S102 corresponds to the front left sensor 2b. Step S103 corresponds to the front right sensor 2c. The order of steps S101 to S103 may be changed.

  And the main determination part 11b performs the main determination process for the front center sensor 2a (step S104). Also, the safing determination unit 11c executes safing determination processing for the front center sensor 2a (step S105).

  Similarly, the main determination unit 11b executes main determination processing for the front left sensor 2b (step S106). In addition, the safing determination unit 11c executes safing determination processing for the front left sensor 2b (step S107).

  Similarly, the main determination unit 11b executes main determination processing for the front right sensor 2c (step S108). Also, the safing determination unit 11c executes safing determination processing for the front right sensor 2c (step S109). The order of steps S104 to S109 may be changed.

  Subsequently, the activation determination unit 11d determines whether or not the first to third normal collision determinations are satisfied. Here, the conditions for the determination will be described. As shown in FIG. 7B, in the first collision determination, the satisfaction condition is that all of the C_main determination flag, the L_safting determination flag, and the R_safing determination flag are ON.

  The C_main determination flag is turned ON when ON determination is made in “front center sensor main determination”. The L_safing determination flag is turned ON in the case of ON determination in “front left sensor safing determination”. The R_safing determination flag is turned ON when the “front right sensor safing determination” is determined to be ON.

  Further, as shown in FIG. 7B, in the second collision determination, the satisfaction condition is that all of the L_main determination flag, the R_safting determination flag, and the C_safing determination flag are ON.

  The L_main determination flag is turned ON in the case of ON determination in “front left sensor main determination”. Since the R_safing determination flag has already been described, it will be omitted. The C_safing determination flag is turned on when the “front center sensor safing determination” is determined to be ON.

  Further, as shown in FIG. 7B, in the third collision determination, the satisfaction condition is that all of the R_main determination flag, the L_safting determination flag, and the C_safing determination flag are ON.

  The R_main determination flag is turned ON in the case of ON determination in “front right sensor main determination”. Since the L_safting determination flag and the C_safing determination flag have already been described, the description thereof will be omitted.

  Returning to the description of FIG. The activation determination unit 11d determines whether or not the first normal collision determination is established (step S110). Here, when the first normal collision determination is not satisfied (step S110, No), the activation determination unit 11d determines whether the second normal collision determination is satisfied (step S111). If the second normal collision determination is not satisfied (No at Step S111), the activation determination unit 11d determines whether the third normal collision determination is satisfied (Step S112).

  Then, when the forward collision determination is established in any of steps S110 to S112 (step S110, Yes / step S111, Yes / step S112, Yes), the activation determination unit 11d deploys the airbag 20 (step S113). ), The process is terminated.

  Further, when the collision determination is not established in any of steps S110 to S112 (step S110, No / step S111, No / step S112, No), the activation determination unit 11d sets the airbag 20 to be non-deployed (step S110). S114), the process is terminated.

  Next, the processing procedure of the sensor value acquisition calculation process will be described. As shown in FIG. 7C, in the sensor value acquisition calculation process, the acquisition calculation unit 11a acquires sensor values from the front sensors 2a to 2c (step S201).

  Then, the acquisition calculation unit 11a performs a filter process for main determination (step S202) and a filter process for safing determination (step S203).

  Then, the acquisition calculation unit 11a executes an integral value calculation process for main determination (step S204) and an integral value calculation process for safing determination (step S205), and ends the process.

  Next, the processing procedure of the main determination process will be described. As shown in FIG. 7D, in the main determination process, the main determination unit 11b refers to the determination map, and whether or not the combination of the acceleration and the integral value that is the calculation result of the acquisition calculation unit 11a exceeds the main threshold on the determination map. That is, it is determined whether or not the main determination is established (step S301).

  Here, when the main determination is established (step S301, Yes), the main determination unit 11b sets the * _main determination flag to ON (step S302) and ends the process. * Is “C” when the main sensor is the front center sensor 2a, as shown in the figure. When the main sensor is the front left sensor 2b, it is “L”. When the main sensor is the front right sensor 2c, “R” is set.

  On the other hand, when the main determination is not established (step S301, No), the main determination unit 11b determines whether or not a predetermined time has elapsed since the non-establishment (step S303). Here, when a predetermined time has elapsed since the failure (step S303, Yes), the main determination unit 11b turns OFF the * _main determination flag (step S304) and ends the process.

  On the other hand, when the predetermined time has not elapsed since the non-establishment (step S303, No), the main determination unit 11b sets the * _main determination flag to ON (step S305) and ends the process. Step S305 corresponds to the signal holding function described in FIG. 1D.

  A procedure of the safing determination process will be described. As shown in FIG. 7E, in the safe determination process, the safing determination unit 11c refers to the determination map, and the combination of the acceleration and the integral value that is the calculation result of the acquisition calculation unit 11a exceeds the safing threshold on the determination map. It is determined whether or not the safing determination is established (step S401).

  Here, when the safing determination is established (step S401, Yes), the safing determination unit 11c sets the * _ safing determination flag to ON (step S402) and ends the process. * Is “C” in the case of the front center sensor 2a as shown in the figure. When it is the front left sensor 2b, it is “L”. In the case of the front right sensor 2c, it becomes “R”.

  On the other hand, when the safing determination is not established (step S401, No), the safing determination unit 11c determines whether or not a predetermined time has elapsed since the non-establishment (step S403). Here, when a predetermined time has elapsed since the failure (step S403, Yes), the safing determination unit 11c sets the * _ safing determination flag to OFF (step S404) and ends the process.

  If the predetermined time has not elapsed since the non-establishment (step S403, No), the safing determination unit 11c sets the * _ safing determination flag to ON (step S405) and ends the process. Step S405 corresponds to the signal holding function described with reference to FIG. 1D.

  As described above, the collision detection apparatus 10 according to the present embodiment corresponds to an acquisition calculation unit 11a (corresponding to an example of “acquisition unit”) and a normal collision determination unit 15 (corresponding to an example of “first determination unit”). ) And an activation determination unit 11d (corresponding to an example of a “second determination unit”).

  A plurality of acquisition calculation units 11a are provided at the front of the vehicle body, and acquire sensor values of a front sensor that detects an impact applied to the vehicle C. The normal collision determination unit 15 determines whether or not the calculation value based on the sensor value acquired by the acquisition calculation unit 11a exceeds a predetermined threshold value for each front sensor. The activation determination unit 11d determines whether the impact is at least a normal collision (full lap collision) based on a combination of determination results for each front sensor by the normal collision determination unit 15.

  Therefore, according to the collision detection apparatus 10 according to the present embodiment, the collision detection at the time of a normal collision can be accelerated.

  Further, at least three front sensors are provided, and the normal collision determination unit 15 includes a main determination unit 11b and a safing determination unit 11c. The main determination unit 11b performs a main determination in which an ON determination is made when the calculated value based on the sensor value of the first front sensor acquired by the acquisition calculating unit 11a exceeds a predetermined main threshold value.

  The safing determination unit 11c determines ON when the calculated value based on the sensor value exceeds a predetermined safing threshold for each of the second front sensor and the third front sensor acquired by the acquisition calculating unit 11a. Make a safing decision. In addition, the activation determination unit 11d determines that the collision is normal when the main determination is ON determination and any of the plurality of safing determinations is ON determination.

  Therefore, according to the collision detection device 10 according to the present embodiment, it is possible to accelerate the collision detection at the time of a normal collision, and to establish the deployment determination early for the high-capacity airbag 20 at the time of the normal collision.

  Further, the activation determination unit 11d deploys (corresponds to an example of “activation”) the airbag 20 (corresponding to an example of “occupant protection device”) mounted on the vehicle C when it determines that the collision is normal. .

  Therefore, according to the collision detection device 10 according to the present embodiment, the collision detection at the time of a normal collision can be accelerated, and the high-capacity airbag 20 can be deployed early at the time of a normal collision.

  Further, the front center sensor 2a (corresponding to an example of “first front sensor”) is provided at the center of the front part of the vehicle body, and includes a front left sensor 2b and a front right sensor 2c (“second front sensor and third sensor”). Is equivalent to an example of “front sensor”) at both ends of the front portion of the vehicle body.

  Therefore, according to the collision detection apparatus 10 according to the present embodiment, it is possible to determine the normal collision or the offset according to the relationship between the sensor values of the front sensors 2a to 2c.

  The front center sensor 2a is provided on the front side of the vehicle C with respect to the front left sensor 2b and the front right sensor 2c.

  Therefore, according to the collision detection apparatus 10 according to the present embodiment, it is possible to accurately determine the collision mode using the time difference between the front center sensor 2a and the other front sensors 2b and 2c. Moreover, it can contribute to speeding up the collision detection at the time of a frontal collision.

  Further, the forward collision determination unit 15 determines that the impact is caused by an offset collision when the calculated value based on the sensor value of the front center sensor 2a is smaller than the calculated value based on the sensor value of any of the other front sensors 2b and 2c. judge.

  Therefore, according to the collision detection device 10 according to the present embodiment, the offset can be accurately determined according to the relationship between the sensor values of the front sensors 2a to 2c.

  Moreover, the safing determination part 11c makes safing determination OFF determination, when it determines with it being an offset collision.

  Therefore, according to the collision detection device 10 according to the present embodiment, the airbag 20 can not be deployed early at the time of offset.

  Further, the main threshold value and the safing threshold value are set on a two-dimensional map having a calculated value based on the sensor value of the front sensor and an integrated value of the calculated value as dimensions.

  Therefore, according to the collision detection apparatus 10 according to the present embodiment, it is possible to determine the deployment of the airbag 20 with high accuracy that is not easily affected by noise or the like.

  By the way, in the above-described embodiment, the case where the determination map is a two-dimensional map of acceleration and its integral value is taken as an example, but the present invention is not limited to such an example. 8A and 8B are views (No. 1) and (No. 2) showing modified examples of the determination map.

  As illustrated in FIG. 8A, the determination map may be a one-dimensional map in which the determination ON region is a case where the acceleration is equal to or greater than a predetermined determination threshold regardless of the integral value.

  Further, as shown in FIG. 8B, the determination map may be a one-dimensional map having a determination ON region when the integral value is equal to or greater than a predetermined determination threshold regardless of acceleration.

  Moreover, although the case where each front sensor 2a-2c was an acceleration sensor was given as an example in the above-described embodiment, the type of sensor is not limited and may be a pressure sensor, for example. In the case of a pressure sensor, the two-dimensional parameter “acceleration” in the acceleration sensor may be replaced with “pressure change amount”, and “integral value (deceleration)” may be replaced with “pressure integrated value”.

  In the embodiment described above, the case where each of the front center sensor 2a, the front left sensor 2b, and the front right sensor 2c performs “main determination” and “safing determination” is described as an example. The role of ~ 2c may be limited. For example, the front center sensor 2a may be dedicated to “main determination”, and the front left sensor 2b and the front right sensor 2c may be dedicated to “safting determination”.

  In the above-described embodiment, the case where the number of sensors arranged on the front side of the vehicle C is three is described as an example. However, the number may be three or more, for example, four. FIG. 8C is a diagram illustrating a modification of the arrangement position of each front sensor.

  As shown in FIG. 8C, each front sensor includes, for example, front sensors (a) and (d) disposed at both ends of the radiator support 3 (see FIG. 3), and a front cross member 4 (see FIG. Four front sensors (b) and (c) may be arranged as shown in FIG.

  In such a case, as shown in FIG. 8C, for example, the front sensors (b) and (c) on the front side are used for “main determination”, and the front sensors (a) and (d) on the rear side are used for “safing determination”. Can be used. Note that the determination result between the “main determinations” can be, for example, a logical sum (see OR gate gt8).

  Thereby, it is possible to make the front sensors (b) and (c) considered to be easily hit by a direct hit at the time of a normal collision, and it is possible to contribute to enhancing the reliability of the collision detection and the deployment of the airbag 20. .

(Other embodiments)
By the way, in the above-described embodiment, the description has been given of the case where “normal collision” and “offset” are mainly determined as the collision mode based on the sensor values of the three front sensors arranged. However, the present invention is not limited to this. Various collision modes can be discriminated.

  A collision detection method according to another embodiment that enables such determination will be described with reference to FIGS. 9A to 9I. 9A to 9I are explanatory views (No. 1) to (No. 9) of a collision detection method according to another embodiment.

  In the collision detection method according to another embodiment, by using three front sensors, as shown in FIG. 9A, the collision mode of the vehicle C is first set to “symmetrical collision”, “asymmetrical collision”, and “pole”. (Pole collision) can be classified into three types.

  In addition, in the collision detection method according to another embodiment, in the case of “symmetrical collision”, it can be determined as “normal collision” or “underride” depending on the magnitude of G detected. “Underride” is, for example, a collision mode in which the vehicle C enters under a large truck.

  In the collision detection method according to another embodiment, in the case of “asymmetrical collision”, it can be determined as “left offset” or “right offset”. This will be specifically described below.

  First, a determination example of “symmetrical collision” will be described with reference to FIGS. 9B to 9D. In the determination example of “symmetrical collision”, in the case of “symmetrical collision”, the G generation timings in the front left sensor 2b and the front right sensor 2c are almost the same, in other words, the acceleration difference between the two sensors 2b and 2c is small. Use.

  FIG. 9B shows a discrimination example (part 1) of symmetrical collision. Note that “normal collision_left” in FIG. 9B is an example of a detection waveform of the front left sensor 2b at the time of “normal collision”. Similarly, “normal collision_right” is an example of a detection waveform of the front right sensor 2c at the time of “normal collision”. Similarly, “left offset_left” is an example of a detection waveform of the front left sensor 2b at the time of “left offset”. Similarly, “left offset_right” is an example of a detection waveform of the front right sensor 2c at the time of “left offset”.

  In this discrimination example (Part 1), both the front left sensor 2b and the front right sensor 2c detect accelerations greater than or equal to a predetermined value, and the time difference between the sensors 2b and 2c at the time of such acceleration detection is less than or equal to a predetermined time. Then, it is determined that it is a “symmetrical collision”.

  Specifically, in such a determination example (part 1), as shown in M91 part of FIG. 9B, the “normal collision_left” waveform is “corrected” within a predetermined time T_diff after the waveform exceeds the determination threshold value TH1_G. When a waveform such as “Crash_Right” exceeds the determination threshold TH1_G, it is determined that a collision indicating these waveforms is a “symmetrical collision”.

  On the other hand, as indicated by M92 in FIG. 9B, even if a predetermined time T_diff elapses after a waveform such as “left offset_left” exceeds the determination threshold TH1_G, a waveform such as “left offset_right” is obtained. If the determination threshold TH1_G is not exceeded, it is determined that the collision indicating these waveforms is not a “symmetrical collision”.

  FIG. 9C shows a discrimination example (part 2) of symmetrical collision. In this determination example (part 2), the absolute value of the acceleration difference between the front left sensor 2b and the front right sensor 2c is equal to or less than a predetermined value before the predetermined time elapses from the deployment time (deployment start time) of the airbag 20. In this case, it is determined that it is a “symmetrical collision”.

  Specifically, in this determination example (part 2), as shown in FIG. 9C, for example, the absolute difference in acceleration between the front left sensor 2b and the front right sensor 2c before the predetermined time α elapses from the airbag deployment time. If the value (| right and left G difference | in the figure) does not exceed the determination threshold value TH2_G, it is determined that it is a “symmetrical collision” such as “normal collision”. On the other hand, when the determination threshold value TH2_G is exceeded, it is determined that it is “offset” or the like and not “symmetrical collision”.

  Further, FIG. 9D shows an example of discrimination between a normal collision and an underride. Note that “underride_left” in FIG. 9D is an example of a detection waveform of the front left sensor 2b at the time of “underride”. Similarly, “underride_right” is an example of a detection waveform of the front right sensor 2c at the time of “underride”.

  As shown in FIG. 9D, in the collision detection method according to another embodiment, among “symmetrical collisions”, a waveform exceeding a predetermined normal collision determination threshold such as “normal collision_right” or “normal collision_left”. Those that indicate are judged as “normal”. Further, a waveform indicating a waveform that does not exceed a predetermined collision detection threshold such as “underride_left” or “underride_right” is determined as “underride”.

  Next, a determination example of “asymmetrical collision” will be described with reference to FIGS. 9E and 9F. In the determination example of “asymmetrical collision”, in the case of “asymmetrical collision”, the fact that the G generation timings in the front left sensor 2b and the front right sensor 2c are different is used.

  FIG. 9E shows an example of discrimination of asymmetrical collision (part 1). In this discrimination example (part 1), one of the front left sensor 2b and the front right sensor 2c detects an acceleration equal to or greater than a predetermined value, and the acceleration difference between the sensors 2b and 2c at the time of detecting the acceleration is a predetermined value. In the case of the above, it is determined that it is an “asymmetrical collision”.

  Specifically, in this discrimination example (part 1), as shown in M93 part of FIG. 9E, the other “normal collision” when the waveform corresponding to “normal collision_left” exceeds the determination threshold TH3_G. If the acceleration difference from the waveform corresponding to “_right” is less than the predetermined acceleration difference G1_diff, it is determined that the asymmetrical collision is not occurring.

  On the other hand, as shown in the M94 part of FIG. 9E, when the waveform corresponding to “left offset_left” exceeds the determination threshold TH3_G, the acceleration difference from the waveform corresponding to the other “left offset_right” is If the predetermined acceleration difference G1_diff is exceeded, it is determined that an “asymmetrical collision”.

  In addition, as shown in the M94 part in the figure, the collision side sensor can be determined by the side of the “left offset_left” and “left offset_right” that first exceeds the determination threshold TH3_G. , “Left offset” or “right offset” in “asymmetrical collision” can be determined.

  FIG. 9F shows a determination example (part 2) of the asymmetrical collision. In this determination example (part 2), the absolute value of the acceleration difference between the front left sensor 2b and the front right sensor 2c is greater than or equal to a predetermined value before the predetermined time elapses from the deployment time (deployment start time) of the airbag 20. In this case, it is determined that it is an “asymmetrical collision”.

  Specifically, in this determination example (part 2), as shown in FIG. 9F, for example, the absolute difference in acceleration between the front left sensor 2b and the front right sensor 2c before the predetermined time α elapses from the airbag deployment time. When the value (| left-right G difference | in the figure) exceeds the determination threshold TH4_G, it is determined that the vehicle is “asymmetrical collision” (see the waveform of | left-right G difference | of left offset in the figure). On the other hand, when it does not exceed the determination threshold TH4_G, it is determined that it is not “asymmetrical collision” (see the waveform of | right-left G difference |

  Next, an example of determining a pole collision will be described with reference to FIGS. 9G to 9I. In the determination example of the pole collision, in the case of “pole collision”, the fact that G appears noticeably in the front center sensor 2a is used.

  FIG. 9G shows an example (part 1) of determining a pole collision. In this discrimination example (part 1), the front center sensor 2a detects an acceleration of a predetermined value or more, the acceleration difference between the front center sensor 2a and the front left sensor 2b at the time of detecting the acceleration, and the front center sensor 2a and the front right sensor. When the acceleration difference from the sensor 2c is equal to or greater than a predetermined value and the front center sensor 2a is larger, it is determined that the “pole collision” has occurred.

  Specifically, in this determination example (part 1), as shown in M95 part of FIG. 9G, when the acceleration of the front center sensor 2a exceeds the determination threshold TH5_G, the acceleration difference from the front left sensor 2b, and When the acceleration difference with the front right sensor 2c is equal to or greater than the predetermined acceleration difference G2_diff and the acceleration of the front center sensor 2a is larger, it is determined that the “pole collision” has occurred.

  On the other hand, as shown in the discrimination example (No. 2) of the pole collision in FIG. 9H, for example, when the “waveform at the time of normal collision” is given as an example, the acceleration of the front center sensor 2a is If the acceleration difference from the front left sensor 2b and the acceleration difference from the front right sensor 2c when the determination threshold TH5_G is exceeded are both less than the predetermined acceleration difference G2_diff, it is determined that at least “it is not a pole collision”. To do.

  Further, as shown in the pole collision determination example (No. 3) in FIG. 9I, for example, when the “waveform at the time of left offset” is taken as an example, the acceleration of the front center sensor 2a is increased as shown in the M97 portion in the figure. When the determination threshold TH5_G is exceeded, the acceleration difference with the front right sensor 2c is equal to or greater than a predetermined acceleration difference G2_diff, but if the acceleration difference with the front left sensor 2b is less than the acceleration difference G2_diff, at least “in a pole collision” Is determined.

  As described above, in the collision detection method according to another embodiment, for example, the collision detection unit 15 determines that the impact is a full lap collision, an underride collision, an offset collision, and a pole collision based on the time difference between the sensor values of the front sensors. It is determined according to at least one of the following.

  Therefore, according to the collision detection device 10 according to the other embodiment, the collision mode can be determined. Therefore, for example, in the traffic accident in which the airbag 20 or the like is activated, the determination result is obtained from the vehicle C before and after the accident. In order to record information, it may be recorded in an event data recorder or the like installed in the vehicle C. Thereby, the discrimination result can be utilized for accident analysis or the like.

  In each of the above-described embodiments, the case where the occupant protection device is the airbag 20 has been mainly described. However, as with the airbag 20, other occupants such as a pretensioner that is activated when a collision of the vehicle C is detected. You may apply this embodiment about a protective device.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Crew protection system 2a Front center sensor 2b Front left sensor 2c Front right sensor 2d Floor sensor 10 Collision detection apparatus 11a Acquisition calculation part 11b Main determination part 11c Safe-fighting determination part 11d Start-up determination part 15 Normal collision determination part 20 Airbag C Vehicle

Claims (10)

A plurality of acquisition units for acquiring a sensor value of a front sensor for detecting an impact applied to the vehicle;
A first determination unit that determines whether a calculated value based on the sensor value acquired by the acquisition unit exceeds a predetermined threshold value for each front sensor;
A collision detection apparatus comprising: a second determination unit that determines whether or not the impact is at least a full-wrap collision based on a combination of determination results for each of the front sensors by the first determination unit. At least three front sensors are provided,
The first determination unit includes:
A main determination unit that performs a main determination with an ON determination when the calculated value based on the sensor value of the first front sensor acquired by the acquisition unit exceeds a predetermined main threshold;
Safe for performing a safing determination for each of the second front sensor and the third front sensor acquired by the acquiring unit to determine ON when the calculated value based on the sensor value exceeds a predetermined safing threshold. And a determination unit for
The second determination unit includes:
2. The collision detection device according to claim 1, wherein when the main determination is ON determination and all of the plurality of safing determinations are ON determination, it is determined that the full lap collision occurs. . The second determination unit includes:
The collision detection apparatus according to claim 2, wherein when it is determined that the full-lap collision occurs, an occupant protection device mounted on the vehicle is activated. The first front sensor is provided at a central portion of the front portion of the vehicle body,
The collision detection device according to claim 2, wherein the second front sensor and the third front sensor are provided at both ends of the front portion of the vehicle body. The collision detection device according to claim 4, wherein the first front sensor is provided on the front side of the vehicle with respect to the second front sensor and the third front sensor. The first determination unit includes:
When the calculated value based on the sensor value of the first front sensor is smaller than the calculated value based on the sensor value of any of the other front sensors, it is determined that the impact is due to an offset collision. The collision detection device according to any one of claims 2 to 5, wherein The safing determination unit
The collision detection device according to claim 6, wherein when it is determined that the collision is an offset collision, the safing determination is set to OFF determination. The main threshold and the safing threshold are:
The calculation value based on the sensor value of the front sensor and an integral value of the calculation value are set on a two-dimensional map having each dimension. The collision detection device described. The first determination unit includes:
The collision detection according to claim 1, wherein the impact is determined based on at least one of the full-wrap collision, underride collision, offset collision, and pole collision based on a time difference between the sensor values of the front sensors. apparatus. An acquisition step of acquiring a sensor value of a front sensor that is provided in front of the vehicle body and detects an impact applied to the vehicle;
A first determination step of determining whether a calculated value based on the sensor value acquired by the acquisition step exceeds a predetermined threshold value for each of the front sensors;
And a second determination step of determining whether or not the impact is at least a full lap collision based on a combination of determination results for each front sensor in the first determination step.

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