JP2006044432A - Method for determining deployment of vehicle occupant protection apparatus, and vehicle occupant protection apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining deployment of a vehicle occupant protection device capable of deploying an airbag according to the collision mode by determining the collision mode when a vehicle is collided. <P>SOLUTION: The acceleration in the longitudinal direction of a vehicle 100 detected by a front G sensor 2 mounted on a front part of the vehicle 100 is time-integrated to obtain the front G integrated value 16a. The acceleration in the longitudinal direction of the vehicle detected by a center G sensor 3 mounted on a substantially center part of the vehicle is time-integrated to obtain the center G integrated value 17a. The difference in the collision mode is determined by using the difference (the subtraction 18a) between the front G integrated value 16a and the center G integrated value 17a, and an airbag (not shown) is deployed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an occupant protection device deployment determination method for protecting an occupant by deploying an airbag corresponding to a collision mode when a vehicle collides, and an occupant protection device using the method.

  As a conventional occupant protection device, there is known a device that determines the magnitude of a collision speed from a change with time of an acceleration detected by a single acceleration sensor (an integral value by acceleration time and a differential value by acceleration time). (See Patent Document 1).

  In this occupant protection device, each inflator is not operated when the magnitude of the collision speed is extremely small, and only the first inflator is operated when the magnitude of the collision speed is medium, and the airbag is semi-deployed (low-pressure inflation). When the collision speed is large, the first inflator is operated and then the second inflator is operated to fully deploy the airbag (high-pressure inflation).

  In addition, after detecting the deceleration acceleration of the vehicle by a single acceleration sensor, calculate the first integral value that is the time integral value, and further calculate the second integral value by calculating the time integral of the first integral value, There is also known an occupant protection device that weights each of the first and second integral values and then performs an addition operation, predicts the movement of the occupant from the addition operation value, and deploys the airbag (see Patent Document 2). ).

Further, the acceleration detected by the front acceleration sensor attached to the front part of the vehicle is time-integrated to obtain a front G integral value, and the acceleration detected by the center acceleration sensor attached to the substantially central part of the vehicle is time-integrated. An occupant protection device is also considered in which an airbag is deployed when one of the front G integral value and the center G integral value exceeds a preset threshold value by calculating the center G integral value. .
Japanese Patent Laid-Open No. 10-29494 Japanese Patent Publication No. 08-25430

  By the way, when protecting an occupant from a collision impact by deploying the airbag, it takes up to 30 milliseconds (0.03 seconds) before the impact that has a harmful effect on the occupant is applied in order to consider the time for the airbag to inflate. Therefore, it is necessary to determine the collision mode and to deploy the airbag according to the collision mode.

  That is, there are a case where the airbag is fully deployed (high-pressure inflation) and a case where the airbag is half-deployed (low-pressure inflation) according to the collision mode.

  However, in the above-described occupant protection device, a distinction is made between a collision mode in the case of a frontal collision (full lap collision) at a low speed, a collision mode in the case of an offset collision at a high speed, and a collision mode in the case of an oblique collision at a high speed. There was a problem that could not.

  In other words, in the case of a frontal collision at a low speed, the impact on the occupant is relatively small because of the low speed, but the collision area is large and the generated acceleration at the beginning of the collision is large because it collides with a hard wall (fixed wall) from the front. .

  On the other hand, in the case of an offset collision at a high speed or an oblique collision at a high speed, the impact on the occupant increases because the speed is high, but since the collision area is small, the acceleration generated at the initial stage of the collision is small.

  In particular, in the case of an offset collision, since it is assumed that the vehicle will collide with the vehicle, the collision target is soft, and the generated acceleration at the initial stage of the collision is relatively small compared to the impact applied to the occupant.

  Therefore, the front G integral value is not greatly different in each collision mode from 30 msec after the occurrence of the collision, as shown in FIG. 4A, and the collision type can be accurately determined from the front G integral value. It was difficult. In addition, when the code | symbol A in the figure carries out the frontal collision at low speed, the code | symbol B shows the offset collision at high speed, and the code | symbol C shows each front G integral value in case of the diagonal collision at high speed.

  The center G integral value is 30 ms after the occurrence of the collision, as shown in FIG. 4B, when the frontal collision at a low speed is performed when the offset collision is performed at a high speed, or the oblique collision is performed at a high speed. Therefore, it is difficult to accurately determine the collision form from the center G integral value. As in FIG. 4 (a), the center G integral values in the case where the symbol A in the figure collides head-on at a low speed, the symbol B in an offset collision at a high velocity, and the symbol C in a diagonal collision at a high velocity. Is shown.

  Accordingly, the present invention provides an occupant protection device deployment determination method and an occupant protection device using the method, which can determine a collision mode when a vehicle collides, and deploy an airbag according to the collision mode. The issue is to provide.

  In order to solve the above-mentioned problem, the invention according to claim 1 calculates the front G integral value by time-integrating the acceleration in the longitudinal direction of the vehicle detected by the front G sensor attached to the front portion of the vehicle. In addition, the front G integration value and the center G integration value are obtained by time integrating the longitudinal acceleration of the vehicle detected by the center G sensor attached to the center of the vehicle to obtain a center G integration value. It is characterized by determining the difference in the form of collision using the difference between the two and deploying the airbag.

  According to a second aspect of the present invention, there is provided a front G sensor that is attached to a front portion of a vehicle and detects acceleration in the vehicle longitudinal direction of the vehicle, and an acceleration in the vehicle longitudinal direction of the vehicle that is attached to a substantially central portion of the vehicle. A center G sensor for detecting the acceleration, an integration start control means for generating an integration start command when the acceleration detected by the front G sensor exceeds a preset collision determination threshold, and integration by the integration start control means A front G integration means for obtaining a front G integral value by time-integrating an acceleration detected by the front G sensor based on a start command, and detected by the center G sensor based on an integration start command by the integration start control means. Center G integration means for obtaining a center G integral value by time-integrating the acceleration obtained, and the front G integral value and the center G integral value. 2. Subtracting means for obtaining a difference from the G integrated value, and collision form judging means for judging a difference in collision form using the difference obtained by the subtracting means and deploying an airbag. It is characterized by the use of

  According to the invention described in claim 1 of the present invention configured as described above, the difference in the collision form is determined using the difference (subtraction value) between the front G integral value and the center G integral value. Regardless of the magnitude of the generated acceleration, it is possible to appropriately determine the collision form from the attenuation amount indicating how much the acceleration is attenuated while the acceleration is transmitted from the front G sensor to the center G sensor.

  Therefore, in a short period of time after the occurrence of a vehicle collision, it is possible to reliably discriminate between low-speed frontal collision with a relatively low impact level and high-speed offset and high-speed oblique collisions with a relatively high level of impact. Become. The airbag can be fully deployed or semi-deployed according to each collision mode.

  According to the second aspect of the present invention, after determining the difference in the collision form using the difference (subtraction value) obtained by the subtraction means for obtaining the difference between the front G integral value and the center G integral value, In addition to the collision type determining means for expanding the bag and using the expansion determining method according to claim 1, the acceleration is transmitted from the front G sensor to the center G sensor regardless of the magnitude of the generated acceleration at the initial stage of the collision. Therefore, it is possible to appropriately determine the collision mode from the attenuation amount indicating how much acceleration is attenuated. The airbag can be fully deployed or semi-deployed according to the collision mode.

  Next, an occupant protection device according to the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of an occupant protection device according to an embodiment of the present invention. An occupant protection device 1 according to the present invention includes a front G sensor (front acceleration sensor) 2, a center G sensor (center acceleration sensor) 3, an airbag deployment determination unit 4, an airbag deployment drive unit 5, and an airbag. And a device 6.

  On the other hand, a bumper armature 101 is provided in the front portion of the vehicle 100 shown in FIG. 2 along the left-right direction of the vehicle, and a radiator 103 for cooling the engine 102 is disposed on the rear side of the bumper armature 101. ing.

  A pair of side members 104, 104 extend along the vehicle front-rear direction on both sides of the engine 102, respectively. The front ends of the side members 104, 104 are connected to the rear surface of the bumper armature 101, and the rear ends are connected to a front pillar (not shown) that forms the vehicle interior 105.

  The front G sensor 2 is attached to a radiator core (not shown) that supports the radiator 103, and the center G sensor 3 is disposed substantially at the center of the passenger compartment 105.

  The front G sensor 2 is attached to the approximate center of the front portion of the vehicle (for example, in the vicinity of the radiator grill). The front G sensor 2 detects the longitudinal acceleration of the vehicle and outputs a front acceleration detection output signal.

  The center G sensor 3 is attached to a substantially central portion of the vehicle in the front-rear direction and the left-right direction (for example, a floor tunnel portion in the vehicle interior or a floor near the shift lever). The center G sensor 3 detects the acceleration in the longitudinal direction of the vehicle and outputs a center acceleration detection output signal.

  The center G sensor 3 does not have to be strictly disposed at the approximate center in the front-rear direction of the vehicle, and may be disposed on the vehicle rear side with respect to the front G sensor 2.

  Further, the front G sensor 2 and the center G sensor 3 output the acceleration in the deceleration direction (deceleration acceleration) as a positive (+) value when the output voltage in a state where no acceleration is applied is 0, and the acceleration direction Is output as a negative (-) value.

  The airbag deployment determination means 4 includes a front LPF (low-pass filter) 11, a center LPF 12, a front A / D converter 13, a center A / D converter 14, an integration start control means 15, and a front G integration means. 16, a center G integrating means 17, a subtracting means 18, and a collision type judging means 20.

  The front LPF 11 and the center LPF 12 remove high frequency noise components from the acceleration detection output signals respectively input from the front G sensor 2 and the center G sensor 3 and extract low frequency components related to a vehicle collision.

  Note that a high-pass filter (not shown) may be provided in front of the front LPF 11 to eliminate the influence of drift in the output voltage of the front G sensor 2. Further, a high-pass filter (not shown) may be provided in front of the center LPF 12 to eliminate the influence of drift of the output voltage of the center G sensor 3.

  The front A / D converter 13 and the center A / D converter 14 convert a low frequency component related to a collision input through the front LPF 11 and the center LPF 12 into a digital signal.

  The front acceleration digital signal (front acceleration data) output from the front A / D converter 13 is supplied to the integration start control means 15 and the front G integration means 16. The center acceleration digital signal (center acceleration data) output from the center A / D converter 14 is supplied to the center G integration means 17.

  The integration start control means 15 constantly monitors the front acceleration based on the front acceleration digital signal (front acceleration data), and when the front acceleration exceeds a preset collision determination threshold (for example, 2G to 4G). An integration start command 15a is generated.

  Further, the integration start control means 15 resets the reset command 15b when the state where the front acceleration is less than a preset collision determination threshold value (eg, 2G to 4G) continues for a preset time (eg, 100 milliseconds). Is generated.

  The integration start command 15a is supplied to the front G integrating means 16, the center G integrating means 17, the first stage ignition threshold value generating means 22 described later, and the second stage ignition threshold value generating means 24 described later. The reset command 15b is supplied to the front G integrating means 16 and the center G integrating means 17, respectively.

  The front G integration means 16 starts time integration calculation of front acceleration based on a front acceleration digital signal (front acceleration data) from the time when the integration start command 15a is supplied. The front G integration means 16 continues the time integration calculation of the front acceleration until the reset command 15b is supplied, and clears the integration value to zero when the reset command 15b is supplied. The time integral value (front G integral value) 16 a of the front acceleration is supplied to the subtracting means 18.

  The center G integration means 17 starts time integration calculation of the center acceleration based on the center acceleration digital signal (center acceleration data) from the time when the integration start command 15a is supplied. The center G integration means 17 continues the time integration calculation of the center acceleration until the reset command 15b is supplied, and clears the integration value to zero when the reset command 15b is supplied. A center acceleration time integral value (center G integral value) 17 a is supplied to the subtracting means 18.

  The subtracting means 18 subtracts the time integration value (center G integration value) 17a of the center acceleration from the time integration value (front G integration value) 16a of the front acceleration to obtain a difference (subtraction value) 18a (= 16a-17a). , To output. Thereby, it is possible to extract an acceleration attenuation amount indicating how much the acceleration is attenuated while the acceleration is transmitted from the front G sensor 2 to the center G sensor 3.

  The subtraction value 18a output from the subtraction means 18 is supplied to the first stage ignition determination means 21 and the second stage ignition determination means 23 of the collision mode determination means 20, respectively.

  The collision mode determining means 20 includes a first stage ignition determining means 21, a first stage ignition threshold value generating means 22, a second stage ignition determining means 23, and a second stage ignition threshold value generating means 24. ing. The collision mode determination unit 20 determines the difference in the vehicle collision mode using the subtraction value 18 a supplied from the subtraction unit 18.

  The first stage ignition threshold value generating means 22 generates a first stage ignition threshold value TH1 set in advance corresponding to the elapsed time from the time when the integration start command 15a is supplied. The first stage ignition threshold value TH1 is supplied to the first stage ignition determination means 21.

  The first stage ignition determination means 21 includes a subtraction value 18a obtained by subtracting the time integral value (center G integral value) 17a of the center acceleration from the time integral value (front G integral value) 16a of the front acceleration and the first stage ignition. The threshold value TH1 is compared, and when the subtraction value 18a exceeds the first stage ignition threshold value TH1, the first stage ignition command 21a is output.

  The second stage ignition threshold value generation means 24 generates a second stage ignition threshold value TH2 set in advance corresponding to the elapsed time from the time when the integration start command 15a is supplied. The second stage ignition threshold value TH2 is supplied to the second stage ignition determination means 23.

  The second-stage ignition determination means 23 includes a subtraction value 18a obtained by subtracting the time integral value (center G integral value) 17a of the center acceleration from the time integral value (front G integral value) 16a of the front acceleration and the second-stage ignition. The threshold value TH2 is compared, and when the subtraction value 18a exceeds the second stage ignition threshold value TH2, the second stage ignition command 22a is output.

  Here, the first stage ignition threshold value TH1 is set so that a low-speed collision can be detected. The second stage ignition threshold value TH2 is larger than the first stage ignition threshold value TH1, and is set so that a high-speed collision can be detected.

  The airbag device 6 is of a two-stage type including a first-stage inflator 61 and a second-stage inflator 62, and each gas generating material (illustrated) ignited by the first-stage squib 611 and the second-stage squib 621. Not) and an airbag (not shown) that is inflated by the generated gas.

  The airbag deployment drive means 5 includes a first stage ignition circuit 51 that energizes and ignites the first stage squib 611 based on the first stage ignition command 21a, and a second stage squib 621 based on the second stage ignition command 22a. And a second stage ignition circuit 52 for igniting and igniting.

  Note that the second stage ignition determination means 23 sets the subtraction value 18a to the second stage ignition timing until a predetermined time (for example, 100 milliseconds) elapses after the first stage ignition command is output by the first stage ignition determination means 21. If the ignition threshold TH2 is not exceeded, a second stage ignition command (forced ignition command) is output when a predetermined time (for example, 100 milliseconds) elapses from the time when the first stage ignition command is output. You may do it.

  Thereby, unused explosives are not left after the airbag apparatus 6 act | operates. Instead of outputting the above-mentioned forced ignition command by the second-stage ignition determining means 23, the second-stage ignition circuit 52 may output the above-mentioned forced ignition command.

  Next, the operation of the occupant protection device 1 of the present invention will be described.

  As shown in FIG. 2A, when such a vehicle 100 has a frontal collision (full lap collision) at a low speed, for example, when it has a frontal collision with a barrier (concrete fixed wall) 106 at a speed of 26 km / h, Almost all the front surface of the vehicle 100 hits the barrier 106 substantially perpendicularly.

  At this time, since the collision area of the vehicle 100 is large, the collision load input to the vehicle 100 is transmitted to the passenger compartment 105 through many transmission paths such as both of the side members 104 and 104 provided on both sides of the engine 102. Communicated. In addition, the arrow shown in the figure is a transmission path of the collision load.

  Therefore, the amount of acceleration attenuation (subtraction value 18a) from the front G sensor 2 to the center G sensor 3 becomes relatively small, and as shown by symbol A in FIG. The threshold value TH2 is not exceeded.

  Thereby, in the case of a frontal collision at a low speed, the second-stage ignition command 22a is not output from the second-stage ignition determination means 23 even if the acceleration generated at the initial stage of the collision increases, and the airbag can be semi-deployed. .

  Next, when the vehicle 100 has an offset collision at a high speed as shown in FIG. 2B, about 40% of the front of the vehicle collides with an aluminum barrier (aluminum honeycomb structure barrier) 107 at a speed of 64 km / h, for example. In this case, the front surface of the vehicle 100 on the passenger seat side hits the aluminum barrier 107.

  At this time, since the collision area of the vehicle 100 is small, the collision load input to the vehicle 100 is in the passenger compartment via a transmission path in which only one of the side members 104 and 104 provided on both sides of the engine 102 is equally limited. 105. In addition, the arrow shown in a figure shows the transmission path | route of a collision load.

  Therefore, the amount of acceleration attenuation (subtraction value 18a) from the front G sensor 2 to the center G sensor 3 becomes relatively large, and as shown by the symbol B in FIG. The threshold value TH2 is exceeded.

  Thus, in the case of an offset collision at a high speed, the second-stage ignition command 22a is output from the second-stage ignition determining means 23 in a short time from the occurrence of the collision to 30 milliseconds even if the initial acceleration is small. The airbag can be fully deployed.

  As shown in FIG. 2C, when the vehicle 100 collides diagonally at a high speed, for example, when the vehicle 100 collides with a barrier (concrete fixed wall) 106 set diagonally at 48 km / h, the barrier 106 Are set obliquely, the front surface of the vehicle 100 on the passenger seat side hits the barrier 106.

  At this time, since the collision area of the vehicle 100 is small, the collision load input to the vehicle 100 is in the passenger compartment via a transmission path in which only one of the side members 104 and 104 provided on both sides of the engine 102 is equally limited. 105. In addition, the arrow shown in a figure shows the transmission path | route of a collision load.

  For this reason, the amount of acceleration attenuation (subtraction value 18a) from the front G sensor 2 to the center G sensor 3 becomes relatively large, and as shown by the symbol C in FIG. The threshold value TH2 is exceeded.

  Thus, in the case of an offset collision at a high speed, the second stage ignition command 22a is output from the second stage ignition determining means 23 in a short time from the occurrence of the collision to 30 milliseconds even if the generated acceleration at the initial stage of the collision is small. The airbag can be fully deployed.

  Thus, by outputting the second stage ignition command 22a based on the comparison result between the subtraction value 18a and the second stage ignition threshold value TH2, the impact degree is relatively small, and the second stage inflator 62 is always ignited. A low-speed frontal collision that may not be required, and a high-speed offset collision and a high-speed oblique collision that require ignition of the second-stage inflator 62 and have a high degree of impact can be reliably separated and determined.

  Furthermore, the second-stage inflator 62 can be ignited at an appropriate timing according to the collision mode when the vehicle collides, and the airbag can be fully deployed in a timely manner.

  As described above, in the deployment determination method for the occupant protection device 1 according to the present invention, the front-rear acceleration of the vehicle 100 detected by the front G sensor 2 attached to the front portion of the vehicle 100 is time-integrated to calculate the front. The G integral value 16a is obtained, and the longitudinal acceleration of the vehicle 100 detected by the center G sensor 3 attached to the substantially central portion of the vehicle 100 is time-integrated to obtain the center G integral value 17a. An air bag (not shown) is deployed after judging the difference in the collision mode using the difference (subtraction value 18a) between the integral value 16a and the center G integral value 17a.

  As a result, regardless of the magnitude of the generated acceleration at the beginning of the collision, the collision mode is appropriately determined from the attenuation amount indicating how much the acceleration is attenuated while the acceleration is transmitted from the front G sensor 2 to the center G sensor 3. It becomes possible. Therefore, the airbag can be fully deployed or semi-deployed depending on the collision mode.

1 is a block configuration diagram of an occupant protection device according to an embodiment of the present invention. (A) is explanatory drawing which shows typically a frontal collision experiment of a vehicle, (b) is explanatory drawing which shows typically an offset collision experiment of a vehicle, (c) is typical of an oblique collision experiment of a vehicle. It is explanatory drawing shown in. It is a graph explaining operation | movement of the passenger | crew protection apparatus concerning embodiment of this invention. (A) is a graph explaining the change of the front G integral value of the conventional occupant protection device, and (b) is a graph explaining the change of the center G integral value of the conventional occupant protection device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crew protection device 2 Front G sensor 3 Center G sensor 16a Front G integral value 17a Center G integral value 18a Subtraction value 100 Vehicle

Claims (2)

A time-integral calculation of the longitudinal acceleration of the vehicle detected by a front G sensor attached to the front of the vehicle to obtain a front G integral value;
A center G integral value is obtained by time-integrating the longitudinal acceleration of the vehicle detected by a center G sensor attached to a substantially central portion of the vehicle;
A deployment determination method for an occupant protection device, wherein a difference in a collision mode is determined using a difference between the front G integral value and the center G integral value, and an airbag is deployed. A front G sensor that is attached to the front of the vehicle and detects acceleration in the vehicle longitudinal direction of the vehicle;
A center G sensor that is attached to a substantially central portion of the vehicle and detects acceleration in the vehicle longitudinal direction of the vehicle;
Integration start control means for generating an integration start command when the acceleration detected by the front G sensor exceeds a preset collision determination threshold;
Front G integration means for obtaining a front G integral value by time-integrating the acceleration detected by the front G sensor based on an integration start command from the integration start control means;
Center G integration means for obtaining a center G integral value by time-integrating the acceleration detected by the center G sensor based on an integration start command from the integration start control means;
Subtracting means for obtaining a difference between the front G integral value and the center G integral value;
A occupant protection using the deployment determination method according to claim 1, further comprising: a collision mode determination unit that determines a difference in collision mode using the difference obtained by the subtracting unit and deploys the airbag. apparatus.

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