JP4387882B2 - Airbag control device - Google Patents

Description

  The present invention relates to an airbag control device that controls the operation of an airbag based on an impact acting on a vehicle body.

  In general, a control device for an airbag mounted on a vehicle detects an impact acting on a predetermined part of a vehicle body with an acceleration sensor or the like, and determines whether or not the airbag can be operated using the detected acceleration or the like as a parameter. In that case, in order to prevent the airbag from malfunctioning due to temporary impact such as impact on the curb of the vehicle or impact when the door is opened or closed, In general, an integral value obtained by integrating acceleration or the like at a predetermined time is used as a parameter, and the control device activates the airbag when the parameter such as the integral value exceeds a threshold value.

By the way, in order to realize accurate occupant protection at the time of a vehicle collision, it is usually a short time of about several tens of mm sec from the start of the collision (for example, about 60 mm sec for a front-impact airbag, The air bag is required to complete explosion in about 30 mm sec). Therefore, for example, Patent Document 1 discloses an airbag control that controls the operation of a front-impact airbag when a parameter based on an output signal of a floor sensor (acceleration sensor) disposed in the center of the vehicle body exceeds a threshold value. In the apparatus, a technology is disclosed in which a front sensor (acceleration sensor) for detecting an impact at the front of the vehicle body is provided, and the threshold value is changed to a small value when the impact detected by the front sensor is equal to or greater than a reference value.
Japanese Patent Laid-Open No. 10-152014

  However, as in the technique disclosed in Patent Document 1 described above, even in a configuration in which the threshold value for determining whether or not the airbag is activated is variably set, it is possible to accurately discriminate between the front collision of the vehicle and the riding on the curb or the like. In order to achieve this, acceleration sampled in a certain amount of time or more is necessary, and it has been difficult to further shorten the time for determining the operation of the front airbag.

  Moreover, in order to accurately discriminate between the side impact of a vehicle and the opening / closing of a door, acceleration and the like sampled in a certain amount of time or more are necessary, and it is difficult to shorten the time for judging the operation of a side impact airbag. Met.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an airbag control device that can accurately perform airbag operation control in a short time.

The present invention relates to a vehicle body impact detection means for detecting an impact acting on a predetermined part of the vehicle body, and an operation determination means for permitting the operation of the front impact airbag when the vehicle body impact detection means detects an impact exceeding a set threshold value. An airbag control device comprising: wheel impact detection means for detecting an impact acting on a wheel; and cancellation means for canceling the determination of permission of operation of the front impact airbag by the operation determination means, within the set time before the vehicle impact detection means setting the threshold value or more shock is detected, when detecting a predetermined or more impact at either one of at least the front wheels by the wheel impact detecting unit, the frontal collision by said canceling means A control device for an airbag, wherein the operation permission of the airbag is canceled.
Further, the present invention permits vehicle body impact detection means for detecting an impact in the vehicle width direction acting on the vehicle body, and operation of the side impact airbag when the vehicle body impact detection means detects an impact that exceeds a set threshold value. In the airbag control device including the operation determination unit, a wheel impact detection unit that detects an impact acting on the wheel, and a cancel unit that cancels the determination of the operation permission of the side collision airbag by the operation determination unit. The side impact airbag when the vehicle body impact detection means detects no impact greater than a predetermined value for any wheel within a set time before and after the impact detected by the vehicle body impact detection means is detected. The operation permission is canceled.

  According to the airbag control apparatus of the present invention, the airbag operation control can be accurately performed in a short time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention, FIG. 1 is a system configuration diagram of a front-impact airbag device, and FIG. 2 is a flowchart showing an operation determination routine of the front-impact airbag.

  In FIG. 1, reference numeral 1 denotes a control device that controls the operation of the airbag 31. Here, for example, the control device 1 of the present embodiment controls the operation of the airbag 31 for front collision that is deployed mainly at the time of the front collision of the vehicle and interposed between the occupant and the vehicle-mounted components. The airbag 31 constitutes an airbag module 30 together with, for example, a known drive circuit 32 and an inflator 33, and is accommodated in a steering wheel, an instrument panel, etc. (not shown).

  The control device 1 includes front sensors 5l and 5r that detect a front-rear impact acting on the front portion of the vehicle body 20, and a floor sensor as a vehicle impact detection unit that detects a front-rear impact acting on the approximate center of the vehicle body 20. 6, stress detection sensors 7 fl and 7 fr as wheel impact detection means for detecting an impact acting on the front wheels 23 fl and 23 fr, and an electronic control unit (hereinafter referred to as ECU) 8.

  The front sensors 5l and 5r are composed of, for example, acceleration sensors (deceleration sensors) respectively disposed on the left front and right front side members 21l and 21r of the vehicle body 20, and before and after acting on the side members 21l and 21r. Outputs a deceleration signal according to the magnitude of the direction impact.

  The floor sensor 6 is composed of, for example, an acceleration sensor (deceleration sensor) disposed substantially at the center of the floor panel 22 of the vehicle body 20, and a deceleration signal corresponding to the magnitude of the impact in the front-rear direction acting on the floor panel 22. Is output.

  The stress detection sensors 7fl and 7fr are constituted by, for example, stress detection sensors each having a plurality of strain gauges oriented in a predetermined direction, and are embedded in suspension housings (not shown) of the respective wheels 23fl and 23fr. Each stress detection sensor 7fl, 7fr is, for example, a front wheel 23fl. A stress signal corresponding to the magnitude of the triaxial impact acting on the 23fr wheel center is output.

  The ECU 8 includes a central processing unit (CPU) 8a, a read only memory (ROM) 8b, a random access memory (RAM) 8c, an input / output circuit (I / O circuit) 8d, and the like. Each of these elements is connected by a bus. Among these, the CPU 8a performs various processing operations for controlling the operation of the airbag 31 in accordance with a program stored in the ROM 8b. The RAM 8c is a memory for storing data obtained from signals from the sensors 5l, 5r, 6, 7fl, and 7fr, results calculated by the CPU 8a based on the data, and the like. The I / O circuit 8d is a circuit for inputting signals from the sensors 5l, 5r, 6, 7fl, and 7fr and outputting an operation signal to the drive circuit 32 of the airbag module 30.

  In this ECU 8, the CPU 8a controls the operation of the airbag 31 by performing the following processing, for example, according to a program stored in the ROM 8b. That is, the CPU 8a calculates the parameter f (G) corresponding to the longitudinal impact acting on the floor panel 22 based on the deceleration G detected by the floor sensor 6, and detected by the front sensors 5l and 5r. A threshold value T is set based on the decelerations gl and gr. Then, when the parameter f (G) is larger than the threshold value T, the CPU 8a determines that the operation of the airbag 31 is permitted. Further, when determining the operation permission of the airbag 31, the CPU 8a sets the set time before the floor sensor 6 detects an impact equal to or greater than the set threshold based on the stresses Ffl and Ffr detected by the stress detection sensors 7fl and 7fr. It is checked whether or not an impact of a predetermined level or more is applied to at least one of the front wheels 23fl and 23fr within the set time (that is, within a set time before f (G)> T). If it is, the operation permission of the airbag 31 is cancelled. That is, ECU8 implement | achieves each function as an operation | movement determination means and a cancellation means by the process of CPU8a. Then, when the determination of the operation permission is maintained (that is, when the determination of the operation permission is not canceled), the CPU 8a outputs an operation signal to the drive circuit 32 through the I / O circuit 8d, and the inflator 33 In this way, the airbag 31 is activated (deployed) by generating gas.

  Next, the operation control of the airbag for front collision executed by the CPU 8a described above will be specifically described with reference to the flowchart shown in FIG. This routine is repeatedly executed every set time. When the routine starts, the CPU 8a first calculates a parameter f (G) based on the deceleration G detected by the floor sensor 6 in step S101. . Here, in step S101, as the parameter f (G), for example, a speed value obtained by integrating the deceleration G once for a set time (for example, about several tens of mm sec), or the deceleration G is set to 2 for the set time. A moving average value obtained by integrating the number of times is calculated.

  In subsequent step S102, the CPU 8a sets a threshold value T for the parameter f (G) based on the decelerations gl and gr detected by the front sensors 5l and 5r with reference to, for example, a map stored in the ROM 8b. To do. Specifically, the CPU 8a sets the threshold value T to a predetermined low value when at least one of the decelerations gl and gr detected by the front sensors 5l and 5r is greater than or equal to a predetermined value set in advance. In other cases, the threshold value T is set to a predetermined high value.

  When the process proceeds from step S102 to step S103, the CPU 8a checks whether or not an impact greater than the set threshold value is applied to the vehicle body 20 (floor panel 22) by comparing the parameter f (G) with the threshold value T. ) <T, and if it is determined that an impact equal to or greater than the set threshold is not acting on the floor panel 22, the routine is exited as is.

  On the other hand, if it is determined in step S103 that f (G)> T and an impact greater than or equal to the set threshold value is acting on the floor panel 22, the CPU 8a proceeds to step S104 and determines permission to operate the airbag 31. Then, it progresses to step S105.

  When the process proceeds from step S104 to step S105, the CPU 8a, based on the stresses Ffl and Ffr detected by the stress detection sensors 7fl and 7fr, within the set time before the impact greater than the threshold acts on the floor panel 22, the front wheels 23fl, It is checked whether or not a predetermined impact or more has acted on at least one of 23fr.

  If it is determined in step S105 that no more than a predetermined impact is applied to either of the front wheels 23fl and 23fr, the CPU 8a proceeds to step S106, and sends an operation signal to the airbag 31 through the I / O circuit 8d to the drive circuit. After outputting to 32, the routine is exited.

  On the other hand, if it is determined in step S105 that at least one of the front wheels 23fl and 23fr has a predetermined or higher impact, the CPU 8a proceeds to step S107, cancels the operation permission of the airbag 31, and then executes the routine. Exit.

  According to such a form, the factor for determining the operation permission of the airbag 31 in the process of determining the operation permission of the airbag 31 when an impact greater than or equal to the threshold value acting on the vehicle body 20 (for example, the floor panel 22) is detected. Since the determined operation permission is canceled when at least one of the front wheels 23fl and 23fr is detected within a set time before the detected shock is detected, the operation permission of the airbag 31 is activated. Control can be performed accurately in a short time.

  In other words, when an impact is applied to the vehicle body 20 due to the vehicle running on a curb or the like, attention is paid to the fact that the corresponding impact is always applied to at least one of the front wheels 23fl and 23fr before that. The control device 1 according to this embodiment includes stress detection sensors 7fl and 7fr that detect impacts acting on the front wheels 23fl and 23fr, and the front wheel 23fl is determined when the operation of the airbag 31 is permitted based on the deceleration G from the floor sensor 6. , 23fr, when the corresponding or higher impact is detected, the operation permission is canceled. Therefore, it is not necessary to make the operation determination based on the deceleration G strictly, and the operation control of the airbag 31 is performed for a short time. Can be done accurately.

  In other words, even if it is determined that the airbag 31 is permitted to operate based on the deceleration G due to riding on a curb or the like, the determination is based on the stresses Ffl and Ffr detected on the front wheels 23fl and 23fr. Therefore, it is not necessary to set the sampling time of the deceleration G for calculating the parameter f (G) longer than necessary, shortening the operation determination time of the airbag 31, and preventing the malfunction of the airbag 31. And both.

  In the above-described embodiment, an example in which the threshold value T for the impact (deceleration G) detected by the floor sensor 6 is variably set based on the impact (deceleration gl, gr) detected by the front sensors 5l, 5r has been described. However, this process can be omitted.

  Next, FIGS. 3 and 4 relate to a second embodiment of the present invention, FIG. 3 is a system configuration diagram of a side-impact airbag device, and FIG. 4 is a flowchart showing a side-impact airbag operation determination routine.

  In FIG. 3, reference numeral 50 denotes a control device that controls the operation of the airbag 41. Here, for example, the control device 50 of the present embodiment controls the operation of the airbag 41 for side collision that is deployed mainly at the time of a side collision of the vehicle and interposed between the occupant and the vehicle-mounted component. The airbag 41 constitutes an airbag module 40 together with, for example, a known drive circuit 42 and inflator 43, and is accommodated in a front seat (not shown) or a roof rail in the vicinity thereof.

  The control device 50 includes pillar sensors 51l and 51r serving as vehicle body impact detection means for detecting impacts in the vehicle width direction acting on the center pillars 24l and 24r of the vehicle body 20, and impacts acting on the wheels 23fl, 23fr, 23rl, and 23rr. It includes a stress detection sensor 7fl, 7fr, 7rl, 7rr serving as a wheel impact detection means for detecting the above and an electronic control unit (hereinafter referred to as ECU) 52.

  The stress detection sensors 7fl, 7fr, 7rl, 7rr are constituted by, for example, stress detection sensors each having a plurality of strain gauges oriented in a predetermined direction, and suspension housings (not shown) of the respective wheels 23fl, 23fr, 23rl, 23rr. ) Each stress detection sensor 7fl, 7fr, 7rl, 7rr is, for example, a front wheel 23fl. Stress signals corresponding to the magnitude of the triaxial impact acting on the wheel centers 23fr, 23rl, and 23rr are output.

  The ECU 52 includes a central processing unit (CPU) 52a, a read only memory (ROM) 52b, a random access memory (RAM) 52c, an input / output circuit (I / O circuit) 52d, and the like. Each of these elements is connected by a bus. Among these, the CPU 52a performs various processing operations for controlling the operation of the airbag 41 in accordance with a program stored in the ROM 52b. The RAM 52c is a memory for storing data obtained from signals from the sensors 7fl, 7fr, 7rl, 7rr, 51l, and 51r, results calculated by the CPU 52a based on the data, and the like. The I / O circuit 52 d is a circuit for inputting signals from the sensors 7 fl, 7 fr, 7 rl, 7 rr, 51 l, 51 r and outputting an operation signal to the drive circuit 42 of the airbag module 40.

  In the ECU 52, the CPU 52a controls the operation of the airbag 41 by performing the following processing, for example, according to a program stored in the ROM 52b. That is, the CPU 52a calculates the parameters f (Gl) and f (Gr) corresponding to the longitudinal impact acting on the center pillars 24l and 24r based on the decelerations Gl and Gr detected by the pillar sensors 51l and 51r. . Then, the CPU 52a determines whether the airbag 41 is permitted to operate when at least one of the parameters f (Gl) and f (Gr) is larger than a preset threshold value T. Further, when determining whether to permit the operation of the airbag 41, the CPU 52a uses the stresses Ffl, Ffr, Frl, Frr detected by the stress detection sensors 7fl, 7fr, 7rl, 7rr to be equal to or greater than a set threshold value by the pillar sensors 51l, 51r. Within the set time before and after the impact is detected (that is, within the set time before and after f (Gl)> T, or at least one of the wheels 23fl, 23fr, 23rl, 23rr). It is checked whether or not a predetermined or greater impact has been applied, and if the predetermined or greater impact has not been applied, the operation permission of the airbag 41 is cancelled. That is, the ECU 52 realizes each function as an operation determination unit and a cancellation unit by the processing of the CPU 52a. Then, when the determination of the operation permission is maintained (that is, when the determination of the operation permission is not canceled), the CPU 52a outputs an operation signal to the drive circuit 42 through the I / O circuit 52d, and the inflator 43 In this way, the airbag 41 is activated (deployed) by generating gas.

  Next, the operation control of the airbag for front collision executed by the CPU 8a described above will be specifically described with reference to the flowchart shown in FIG. This routine is repeatedly executed every set time. When the routine is started, the CPU 52a first determines the parameter f (Gl based on the decelerations Gl and Gr detected by the pillar sensors 51l and 51r in step S201. ), F (Gr). Here, in step S201, as the parameters f (Gl) and f (Gr), for example, the speed values obtained by integrating the decelerations Gl and Gr once for a set time (for example, about 10 mm sec) A moving average value obtained by integrating Gl and Gr twice for a set time is calculated.

  When the process proceeds from step S201 to step S202, the CPU 52a compares the parameters f (Gl) and f (Gr) with the threshold T to determine whether or not an impact greater than the set threshold is applied to the vehicle body 20 (center pillars 24l and 24r). If it is determined that f (Gl) and f (Gr) <T, and it is determined that the center pillars 24l and 24r are not impacted by the set threshold or more, the routine is directly exited.

  On the other hand, in step S202, it is determined that at least one of f (Gl) and f (Gr) is T, and an impact equal to or greater than the set threshold value is acting on at least one of the center pillars 24l and 24r. Then, the CPU 52a proceeds to step S203, determines whether the operation of the airbag 41 is permitted, and then proceeds to step S204.

  When the process proceeds from step S203 to step S204, the CPU 52a acts on the center pillars 24l, 24r on the center pillars 24l, 24r based on the stresses Ffl, Ffr, Frl, Frr detected by the stress detection sensors 7fl, 7fr, 7rl, 7rr. It is checked whether or not a predetermined or more impact is applied to at least one of the wheels 23fl, 23fr, 23rL, and 23rr within the set time before and after.

Then, in step S204, the wheels 23FL, 23FR, 23RL, when a predetermined or more impact at least one of 23rr is determined that the action, CPU 52a proceeds to step S205, the airbag 41 through the I / O circuit 8d Is output to the drive circuit 42, and then the routine is exited.

  On the other hand, if it is determined in step S204 that no more than a predetermined impact is applied to any of the wheels 23fl, 23fr, 23rl, and 23rr, the CPU 52a proceeds to step S206 and cancels the operation permission of the airbag 41. , Exit the routine.

According to such a form, the operation permission of the airbag 41 is determined in the process of determining the operation permission of the airbag 41 when an impact greater than a threshold value acting on the vehicle body 20 (for example, the center pillars 24l and 24r) is detected. factors and became shock detection before and after the set time in the respective wheels 23fl that, 23FR, 23RL, the one of if not detected more than predetermined impact even wheels 23RR, so as to cancel the operation permission was determined Since it comprised, the operation control of the airbag 41 can be performed accurately in a short time.

  That is, the impact caused by the opening and closing of the door is a local effect that acts only on the vehicle body 20, while the impact at the time of vehicle collision (side collision) is not only the vehicle body 20 but also each wheel 23 fl, 23 fr, 23 rl, Paying attention to the fact that it acts on 23 rr, the control device 50 of this embodiment is provided with stress detection sensors 7 fl, 7 fr, 7 rl, 7 rr for detecting impacts acting on the wheels 23 fl, 23 fr, 23 rl, 23 rr, and the pillar sensor 51 l , 51r when determining whether to permit the operation of the airbag 41 based on the decelerations Gl, Gr, if no corresponding impact is detected from any of the wheels 23fl, 23fr, 23rl, 23rr, the operation is permitted. Since the canceling configuration is adopted, it is not necessary to strictly perform the operation determination based on the decelerations Gl and Gr, and the operation control of the airbag 41 can be shortened. It can be performed with high accuracy between.

  In other words, even if it is determined that the operation of the airbag 41 is permitted based on the decelerations Gl and Gr due to the opening and closing of the door, the determination is based on the stress detected in each wheel 23fl, 23fr, 23rl, and 23rr. Since cancellation is performed based on Ffl, Ffr, Frl, and Frr, it is not necessary to set the sampling times of the decelerations Gl and Gr for calculating the parameters f (Gl) and f (Gr) longer than necessary. It is possible to achieve both shortening of the operation determination time of 41 and prevention of malfunction of the airbag 41.

The system block diagram of the airbag apparatus for front-impact related to the 1st form of this invention Same as above, flowchart showing the operation determination routine of the airbag for front collision The system block diagram of the airbag apparatus for a side collision concerning the 2nd form of this invention The flowchart which shows the operation | movement determination routine of a side impact airbag same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Control apparatus 6 ... Floor sensor (vehicle body impact detection means)
7fl, 7fr, 7rl, 7rr ... Stress detection sensor (wheel impact detection means)
8 ... Electronic control unit (operation judging means, canceling means)
DESCRIPTION OF SYMBOLS 20 ... Car body 23fl, 23fr, 23rl, 23rr ... Wheel 31 ... Air bag 41 ... Air bag 50 ... Control apparatus 51l, 51r ... Pillar sensor (vehicle body impact detection means)
52 ... Electronic control unit (operation determination means, cancellation means)
Agent Patent Attorney Susumu Ito

Claims (2)

Vehicle impact detection means for detecting an impact acting on a predetermined part of the vehicle body, and an operation determination means for permitting the operation of the front impact airbag when the vehicle impact detection means detects an impact greater than a set threshold value. In the airbag control device,
Wheel impact detection means for detecting an impact acting on the wheel;
Canceling means for canceling the determination of the operation permission of the airbag for front collision by the operation determining means,
When the vehicle impact detection means detects an impact greater than a predetermined value at least on one of the front wheels within a set time before an impact greater than a set threshold is detected, the cancellation means detects the front A control device for an airbag, wherein the operation permission of the crash airbag is canceled. Vehicle impact detection means for detecting an impact in the vehicle width direction acting on the vehicle body, and an operation determination means for permitting the operation of the side impact airbag when the vehicle impact detection means detects an impact greater than a set threshold value. In the airbag control device,
Wheel impact detection means for detecting an impact acting on the wheel;
Cancellation means for canceling the determination of the operation permission of the side airbag by the operation determination means,
The canceling means activates the side impact airbag when no impact is detected in any of the wheels within a set time before and after the vehicle body impact detection means detects an impact greater than a set threshold value. An airbag control device, wherein the permission is canceled.

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