JP2019073088A - Air bag development control system and air bag development control method - Google Patents

Abstract

To provide an air bag development control system which can control expansion and development of an air bag on the basis of a belt draw-out quantity of a seat belt device, and an air bag development control method.SOLUTION: According to this air bag development control method, an air bag 21 is expanded and developed when a belt draw-out quantity P is a prescribed first threshold α or more at the time of collision of a vehicle, the air bag 21 is not expanded and developed when the belt draw-out quantity P is less than the first threshold α, and thereafter, the air bag 21 is expanded and developed when a belt 31 is drawn out in the state that the air bag 21 is not expanded and developed and the belt draw-out quantity P is a prescribed second threshold β or more, and when the belt draw-out quantity P is less than a second threshold β, the state in that the air bag 21 is not expanded and developed is maintained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an airbag deployment control system and an airbag deployment control method, and more particularly to an airbag deployment control system and an airbag deployment control method suitable for a vehicle provided with a seat belt device and an airbag device.

   2. Description of the Related Art In vehicles such as automobiles, it has become common to mount an airbag device for inflating and deploying an airbag in a vehicle at the time of a vehicle collision to absorb an impact generated by a passenger. An air bag system generally includes an air bag that is normally folded and inflated and deployed in an emergency, and an inflator that supplies gas to the air bag. A vehicle provided with such an air bag device includes, for example, a collision detection sensor for detecting a collision of the vehicle, and an ECU (Electronic control unit: electronic control unit) for transmitting an ignition signal to the inflator based on the output of the collision detection sensor. And.

  In a vehicle equipped with an air bag device, the impact absorption capacity of the air bag varies depending on conditions such as the physical size of the occupant, the position of the occupant, the posture of the occupant, and the like. Is an important technology in the field of airbag devices.

  For example, Patent Document 1 discloses ignition timing prediction means for judging the collision based on the output from the acceleration sensor, and predicting the timing when the head of the occupant reaches a predetermined position, and outputting an ignition signal; It comprises: an expansion force control means for outputting a control signal for controlling the expansion force of the air bag based on the position of the head of the occupant from a predetermined reference position, and an inflator provided with a plurality of detonators. The ignition mode of the plurality of detonators provided in the inflator is controlled based on the ignition signal from the ignition timing prediction means and the control signal from the expansion force control means, and the expansion speed and timing of the air bag are controlled. An occupant protection device is disclosed.

  Patent Document 1 also discloses that the expansion force control means creates a signal for controlling the expansion speed of the airbag based on output signals from the seat longitudinal position sensor, the reclining angle sensor, and the seat belt withdrawal amount sensor. It is done.

JP 10-236268 A

  By the way, in the invention described in patent document 1, it was invented in order to solve the subject that a passenger | crew's head does not hit an airbag in the state in which the airbag was inflate-deployed to the maximum. Therefore, it is necessary to predict and control both the movement position of the head and the maximum inflation and deployment timing of the air bag, and it is necessary to process complex calculations in a short time using a plurality of control parameters. There is. In addition, in order to obtain a plurality of control parameters, a plurality of sensors are required, which may cause problems such as an increase in vehicle weight and a rise in price.

  The present invention has been made in view of the above problems, and provides an airbag deployment control system and an airbag deployment control method capable of controlling the inflation and deployment of the airbag based on the belt withdrawal amount of the seat belt device. The purpose is to

  According to the present invention, an air bag device including an air bag inflated and deployed in front of an occupant at the time of a vehicle collision, a seat belt device including a belt for restraining the occupant on a seat, and a withdrawal amount for detecting the withdrawal amount of the belt A detection sensor, a collision detection sensor for detecting a collision of a vehicle, and a control device for transmitting an expansion and deployment signal to the air bag device based on an output of the collision detection sensor, the control device detecting the collision When the collision signal is received from the sensor, the airbag is inflated and deployed if the amount of withdrawal of the belt is equal to or greater than a predetermined first threshold α, and the amount of withdrawal of the belt is less than the first threshold α Control so as not to inflate and deploy the air bag, and thereafter, the belt is pulled out in a state where the air bag is not inflated and expanded, and the amount of withdrawal of the belt is a predetermined amount. An air bag deployment control system is provided, characterized in that the air bag is controlled to inflate and deploy when the air pressure is equal to or greater than a second threshold value β.

  The control device is configured to determine whether the belt is pulled out in a state where the air bag is not inflated and deployed, based on any one parameter of the withdrawal amount, the withdrawal speed, or the withdrawal acceleration of the belt. May be Further, the control device may determine that the belt is pulled out when the parameter exceeds a predetermined set value.

  Further, the control device is configured to complete the airbag when the amount of withdrawal of the belt is equal to or greater than the first threshold α and the amount of withdrawal of the belt is less than a predetermined third threshold γ. The airbag may be inflated and deployed so that the internal pressure is lower than the complete state when the amount of withdrawal of the belt is equal to or greater than the third threshold γ.

  Further, according to the present invention, when the vehicle collides, the airbag of the air bag device is inflated and deployed if the pulled amount of the belt of the seat belt device is equal to or more than the predetermined first threshold α, and the belt is pulled out. In the case where the amount is less than the first threshold value α, the airbag is not inflated and deployed, and thereafter, the belt is withdrawn in a state where the airbag is not inflated and deployed, and the amount of withdrawal of the belt is The airbag deployment control method is provided, wherein the airbag is inflated and deployed when the predetermined second threshold value β or more is satisfied.

  The air bag deployment control method determines whether the belt is pulled out in a state where the air bag is not inflated and deployed, based on any one parameter of the withdrawal amount, the withdrawal speed or the withdrawal acceleration of the belt. You may do it. Further, in the air bag deployment control method, it may be determined that the belt is pulled out when the parameter exceeds a predetermined set value.

  In the airbag deployment control method, in the case where the amount of withdrawal of the belt is equal to or greater than the first threshold α, the airbag is selected when the amount of withdrawal of the belt is less than a predetermined third threshold γ. The airbag may be inflated and deployed in a complete state, and the airbag may be inflated so that the internal pressure is lower than that in the complete state when the amount of withdrawal of the belt is equal to or greater than the third threshold γ.

  According to the airbag deployment control system and the airbag deployment control method according to the present invention described above, since the inflation and deployment of the airbag is controlled based on one control parameter (belt withdrawal amount), complicated calculation is performed. It is not necessary to reduce the load of arithmetic processing. Further, according to the present invention, since other control parameters such as a seating sensor and a position sensor are not required, the number of sensors to be disposed can be reduced, and an increase in vehicle weight and a rise in price can be suppressed. .

It is a flowchart which shows the airbag deployment control method which concerns on 1st embodiment of this invention. It is explanatory drawing of the air bag deployment control method shown in FIG. 1, (A) is shown in the case of collision event A, (B) in the case of collision event B. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows the air bag expansion | deployment control system which concerns on one Embodiment of this invention, (A) is an initial state, (B) has shown the belt mounting state. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows the air bag deployment control system which concerns on one Embodiment of this invention, (A) shows the case of collision event A, (B) shows the case of collision event B. FIG. It is explanatory drawing of the air bag deployment control method shown in FIG. 1, (A) is a case where air bag deployment OFF state is maintained after collision event C, (B) is a case where it switches to airbag deployment ON state after collision event C Is indicated. It is a whole block diagram showing the air bag deployment control system concerning one embodiment of the present invention, and (A) shows in case of collision event C, (B) when switching to an air bag deployment on state after collision event C. ing. It is a flowchart which shows the airbag deployment control method which concerns on 2nd embodiment of this invention. FIG. 8 is an explanatory view of an air bag deployment control method shown in FIG. 7, showing a case of a collision event D. FIG. 1 is an overall configuration view showing an air bag deployment control system according to an embodiment of the present invention, showing a case of a collision event D.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9. Here, FIG. 1 is a flow chart showing an air bag deployment control method according to the first embodiment of the present invention. FIG. 2 is an explanatory view of the air bag deployment control method shown in FIG. 1, in which (A) shows a case of collision event A and (B) shows a case of collision event B. FIG. FIG. 3 is an overall configuration diagram showing an air bag deployment control system according to an embodiment of the present invention, in which (A) shows an initial state and (B) shows a belt attached state. FIG. 4 is an overall configuration diagram showing an air bag deployment control system according to an embodiment of the present invention, in which (A) shows a case of collision event A and (B) shows a case of collision event B.

  An air bag deployment control system 1 according to an embodiment of the present invention includes an air bag 21 that is inflated and deployed in front of an occupant 11 at the time of a vehicle collision, as shown in FIGS. 3 (A) to 4 (B). The airbag apparatus 2, a seat belt apparatus 3 including a belt 31 for restraining the occupant 11 in the seat 12, a drawn amount detection sensor 4 for detecting the drawn amount of the belt 31, a collision detection sensor 5 for detecting a collision of the vehicle And a control device 6 for transmitting an inflation and deployment signal to the airbag device 2 based on the output of the collision detection sensor 5.

  As illustrated, when the system is adopted for the driver's seat, the airbag device 2 is disposed in the steering wheel 13. Although not shown, when this system is adopted for the front passenger seat, the air bag device 2 is disposed in the instrument panel. The airbag apparatus 2 includes an inflator (not shown) that supplies gas to the airbag 21. Therefore, the inflation and deployment signal transmitted to the air bag device 2 is specifically an ignition signal for operating the inflator.

  The seat belt device 3 includes, for example, a retractor 32 for winding the belt 31, a guide anchor 33 for guiding the belt 31 into the vehicle, a buckle 34 disposed on the side of the seat 12, and the belt 31 inserted into the buckle 34. It has a tongue 35 to be worn, and a belt anchor (not shown) for fixing the end of the belt 31 to the vehicle body.

  As shown in FIG. 3A, the occupant 11 is not seated on the seat 12, and the belt 31 is completely wound up (a state where the belt 31 from the belt anchor to the retractor 32 is not slackened) ) Is set as the initial state (belt withdrawing amount P = 0). Further, as shown in FIG. 3B, the belt 11 is in the belt mounted state (belt pull-out amount P = Ps) in the state where the occupant 11 is seated on the seat 12 and the belt 31 is mounted (the tongue 35 is fitted to the buckle 34). And).

  The withdrawal amount detection sensor 4 is, for example, a sensor that is disposed in the retractor 32 and detects the number of rotations of a spool (not shown) that takes up the belt 31. Such a sensor includes, for example, a ring that rotates in response to the rotation of the spool, and an operation unit that counts the number of rotations of the ring. The withdrawal amount detection sensor 4 may employ a sensor having another configuration as long as it can detect the number of rotations of the spool.

  The collision detection sensor 5 is, for example, a satellite sensor disposed on a vehicle body. The satellite sensor is a sensor that detects an impact generated on the vehicle body. When the vehicle collides, the collision detection sensor 5 detects an impact value generated on the vehicle body and transmits it to the control device 6. As the collision detection sensor 5, other commercially available sensors can be used.

  The control device 6 is, for example, an ECU (Electronic Control Unit) disposed in an instrument panel. The control device 6 is electrically connected to the collision detection sensor 5 and transmits an expansion and deployment signal to the airbag device 2 when the impact value transmitted from the collision detection sensor 5 is equal to or greater than a predetermined threshold. . Note that "electrically connected" is meant to include both wired connection and wireless connection.

  The control device 6 is also electrically connected to the extraction amount detection sensor 4. The control device 6 calculates the withdrawal amount of the belt 31 (belt withdrawal amount P) based on the number of rotations of the spool transmitted from the withdrawal amount detection sensor 4, and inflating and developing the airbag 21 based on the belt withdrawal amount P. Control. Hereinafter, an airbag deployment control method according to the first embodiment of the present invention will be described based on FIG.

  The airbag deployment control method according to the first embodiment of the present invention inflates and deploys the airbag 21 when the belt withdrawal amount P is equal to or more than the predetermined first threshold α when the vehicle collides, and the belt withdrawal amount When P is less than the first threshold value α, the airbag 21 is not inflated and deployed, and thereafter, the belt 31 is pulled out in a state where the airbag 21 is not inflated and deployed, and the belt withdrawal amount P is a predetermined amount. The air bag 21 is inflated and expanded when it is equal to or more than the second threshold value β, and a state where the air bag 21 is not inflated and expanded when the belt withdrawal amount P is less than the second threshold value β is maintained.

  In the belt storage state (Step 1), as shown in FIG. 3A, the state in which the belt 31 is not attached, ie, the state in which the belt 31 is completely wound up, is taken as the initial state. The belt withdrawal amount P is set to 0, with the amount P as a reference value.

  In the belt mounted state (Step 2), as shown in FIG. 3B, the occupant 11 is seated on the seat 12, and the belt mounted state is the belt mounted state, and the belt withdrawal amount P at that time is Ps. Do. As shown in FIG. 2A, the belt withdrawal amount Ps in the belt mounted state is included, for example, in the illustrated belt mounting area. The lower limit Pf of the belt attachment area is set assuming a small occupant (for example, a 5% tile of an adult female), and the upper limit Pm of the belt attachment area is a large occupant (for example, a 95% tile of an adult male) ) Is set. The range of the belt attachment area can be set arbitrarily.

  The control device 6 determines that the occupant 11 wears the belt 31 when the belt withdrawal amount Ps is included in the belt attachment area, and the belt withdrawal amount Ps is not included in the belt attachment area. In this case, it can be determined that the occupant 11 is not wearing the belt 31. Therefore, in the air bag deployment control method according to the present embodiment, it is possible to omit the seating sensor for detecting whether the occupant 11 is seated on the seat 12 and the position sensor for detecting the position of the seat 12.

  In the belt mounted state, when the collision detection sensor 5 detects a collision (Step 3), the control device 6 determines whether the belt withdrawal amount P is equal to or more than the first threshold value α (Step 4). Here, as shown in FIG. 2A, the first threshold value α is set to a value larger than the upper limit value Pm of the belt mounting area. For example, the first threshold value α is set between the upper limit value Pm + 30 to 100 mm.

  As shown in FIG. 2A, when the belt withdrawal amount Pa in the collision event A is equal to or greater than the first threshold α, the airbag 21 is inflated and deployed as shown in FIG. 4A. Step 5). At this time, as shown in FIG. 4A, the airbag 21 is fully deployed (inflating and deploying the airbag in a complete state). In the present specification, inflating and deploying the air bag 21 will be referred to as "air bag deployment on".

  On the other hand, as shown in FIG. 2B, when the belt withdrawal amount Pb in the collision event B is less than the first threshold value α, as shown in FIG. 4B, the airbag 21 is inflated and developed. Do not let it go (Step 6). In the present specification, not inflating and deploying the air bag 21 will be referred to as "air bag deployment off".

  That is, in the airbag deployment control method according to the present embodiment, as shown in FIG. 4A, when the amount of forward movement of the occupant 11 at the time of a vehicle collision is large, a large load is already applied to the occupant 11. As it occurs, the air bag 21 is immediately inflated and deployed. On the other hand, as shown in FIG. 4B, when the amount of forward movement of the occupant 11 at the time of a vehicle collision is small, this is considered to be a minor collision in which no large load is generated on the occupant 11. In the stage, the air bag 21 is not inflated and deployed.

  Next, in the state of the air bag unfolding (Step 6), it is determined whether or not the belt withdrawal change amount ΔP exceeds the predetermined set value ε (Step 7). Here, as shown in FIGS. 5A and 6A, it is assumed that a collision event C occurs in which the belt withdrawal amount P at the time of a vehicle collision is Pc.

  Now, since the belt withdrawal amount Pc <the first threshold value α, the air bag is in the deployment OFF state. When the belt 31 is further pulled out from this state, it means that the occupant 11 is moving forward, so it may be preferable to inflate and deploy the airbag 21.

  Therefore, the control device 6 calculates how much the belt 31 has been pulled out from the belt pull-out amount Pc at the time of a vehicle collision based on the signal of the pull-out amount detection sensor 4. The change amount of the belt 31 pulled out after the vehicle collision is referred to as a belt withdrawal change amount ΔP. If the belt withdrawal change amount ΔP does not exceed the set value ε, as shown in FIG. 5A, the airbag deployment OFF state in which the airbag 21 is not inflated and deployed is maintained (Step 8).

  On the other hand, as shown in FIG. 5B, when the belt withdrawal change amount ΔP exceeds the set value ε, the belt withdrawal amount P (here, the belt withdrawal amount Pc + the belt withdrawal change amount ΔP) is predetermined. It is determined whether it is the second threshold value β or more (Step 9). The second threshold β is set to a value smaller than the first threshold α. For example, the second threshold value β is set between the upper limit Pm-30 to 100 mm of the belt attachment area.

  Even when the belt withdrawal change amount ΔP exceeds the set value ε, when the entire belt withdrawal amount P (belt withdrawal amount Pc + belt withdrawal change amount ΔP) is small, the load generated on the occupant 11 is small. There is no need to inflate and deploy the air bag 21.

  Therefore, in the present embodiment, even if the belt withdrawal amount P at the time of a vehicle collision is small and the airbag deployment is set to the OFF state, the belt withdrawal change amount ΔP exceeds the set value ε and the entire belt When the amount P of withdrawal is equal to or greater than the second threshold value β, the airbag 21 is inflated and deployed (Step 10) to switch to the airbag on state. At this time, as shown in FIG. 6B, the air bag 21 is fully expanded (inflating and expanding the air bag in a complete state).

  On the other hand, even if the belt withdrawal variation amount ΔP exceeds the set value ε, the airbag 21 is not inflated and deployed if the entire belt withdrawal amount P is less than the second threshold β (Step 8). The air bag is kept off.

  The set value ε described above is set, for example, between 30 and 100 mm. In the case shown in FIG. 5A, since the belt withdrawal amount Pc is a value sufficiently smaller than the first threshold value α, the set value ε is set at a position not exceeding the first threshold value α. When the belt withdrawal amount Pc is a value close to the first threshold value α, the set value ε may be set at a position exceeding the first threshold value α.

  In the present embodiment, it is determined whether or not the belt 31 has been pulled out based on the amount of withdrawal of the belt 31 (specifically, the belt withdrawal change amount ΔP) as a parameter in Step 7. Whether or not the belt 31 is pulled out may be determined based on the speed and the pulling out acceleration. Also in this case, if the drawing speed or the drawing acceleration does not exceed the predetermined set value, the airbag deployment OFF state is maintained (Step 8), and if the predetermined set value is exceeded, the process proceeds to Step 9.

  According to the air bag expansion control method according to the first embodiment described above, since the expansion and expansion of the air bag 21 can be controlled based on one control parameter (belt withdrawal amount), it is necessary to perform complicated calculations. Instead, the load of arithmetic processing can be reduced. In addition, since other control parameters such as a seating sensor and a position sensor are not required, the number of sensors to be disposed can be reduced, and an increase in vehicle weight and a rise in price can be suppressed.

  Next, an air bag deployment control method according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. Here, FIG. 7 is a flow chart showing an air bag deployment control method according to the second embodiment of the present invention. FIG. 8 is an explanatory view of the air bag deployment control method shown in FIG. 7 and shows the case of the collision event D. As shown in FIG. FIG. 9 is an entire configuration view showing an air bag deployment control system according to an embodiment of the present invention, and shows a case of a collision event D. As shown in FIG. In addition, the duplicate description is abbreviate | omitted about the same Step1-Step10 as the airbag expansion | deployment control method which concerns on 1st embodiment mentioned above.

  The airbag deployment control method according to the second embodiment shown in FIG. 7 is the case where the belt withdrawal amount P is equal to or greater than the first threshold α (Step 4, Yes), and the belt withdrawal amount P is a predetermined third threshold. If it is less than γ, the airbag 21 is fully inflated and deployed (full deployment) (Step 5), and if the belt withdrawal amount P is equal to or more than the third threshold γ, the internal pressure is more than the airbag 21 is completely The expansion and expansion (soft expansion) is performed so as to be lower (Step 12).

  As shown in FIG. 8, the third threshold γ is set to a value larger than the first threshold α, and is set, for example, between the first threshold α + 150 to 250 mm. Here, it is assumed that a collision event D occurs in which the belt withdrawal amount P at the time of a vehicle collision is Pd. Now, since the belt withdrawal amount Pd ≧ the first threshold value α, the airbag deployment state is on.

  At this time, in the case where the belt withdrawal amount Pd ≧ third threshold value γ, this means that the occupant 11 has moved largely forward as shown in FIG. When deployed, the load applied to the occupant 11 by the air bag 21 may be increased.

  Therefore, in the present embodiment, full deployment for inflating and deploying the airbag 21 in a complete state and soft deployment for inflating and deploying such that the internal pressure is lower than that in a complete state are distinguished, Control is performed so that full development is performed when P is greater than or equal to the first threshold α and less than the third threshold γ, and soft development is performed when the belt withdrawal amount P is greater than or equal to the third threshold γ.

  The control device 6 performs a process (Step 11) of determining whether the belt withdrawal amount P at the time of a vehicle collision is equal to or more than the third threshold value γ. Further, when the air bag 21 is fully expanded, the entire amount of fuel of the inflator is burned to generate gas, and when the air bag 21 is softly expanded, only a part of the fuel of the inflator is burned to generate gas Should be generated.

  Further, in the case of the airbag device 2 provided with a plurality of inflators, the airbag 21 is fully expanded by activating all the inflators, and the airbag 21 is soft-deployed by activating a part of the inflators. You may do so.

  Although the first embodiment and the second embodiment described above describe the case where the seat 12 is a front seat (front seat), the present invention includes the airbag device 2 and the seat belt device 3 It can be applied to the rear seat (rear seat).

  The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Airbag deployment control system 2 Airbag device 3 Seatbelt device 4 Withdrawal amount detection sensor 5 Collision detection sensor 6 Control device 11 Occupant 12 Seat 13 Steering wheel 21 Airbag 31 Belt 32 Retractor 33 Guide anchor 34 Buckle 35 Tong

Claims (8)

An air bag apparatus including an air bag inflated and deployed in front of an occupant at the time of a vehicle collision;
A seat belt device including a belt for restraining an occupant on a seat;
A withdrawal amount detection sensor that detects the withdrawal amount of the belt;
A collision detection sensor that detects a collision of the vehicle;
A control device that sends an inflation and deployment signal to the air bag device based on the output of the collision detection sensor;
The control device, upon receiving a collision signal from the collision detection sensor, inflates and deploys the airbag when the withdrawal amount of the belt is equal to or more than a predetermined first threshold α, and the withdrawal amount of the belt is The air bag is controlled so as not to inflate and deploy when the first threshold value α is less than α, and then the belt is pulled out in a state where the air bag is not inflated and deployed, and the amount of withdrawal of the belt is The air bag is controlled to expand and deploy when it is equal to or greater than a predetermined second threshold value β,
An airbag deployment control system characterized by   The control device determines whether or not the belt is pulled out in a state where the airbag is not inflated and deployed, based on any one parameter of the withdrawal amount, the withdrawal speed or the withdrawal acceleration of the belt. The air bag deployment control system according to claim 1, characterized in that   The air bag deployment control system according to claim 2, wherein the control device determines that the belt is pulled out when the parameter exceeds a predetermined set value.   The control device inflates the airbag to a complete state when the belt withdrawal amount is equal to or greater than the first threshold α and the belt withdrawal amount is less than a predetermined third threshold γ. The airbag is expanded and expanded so that the internal pressure becomes lower than the complete state when the belt withdrawal amount is equal to or more than the third threshold value γ. Airbag deployment control system. When the vehicle collides, the airbag of the airbag device is inflated and deployed if the amount of withdrawal of the belt of the seat belt device is equal to or greater than a predetermined first threshold α, and the amount of withdrawal of the belt is less than the first threshold α. And inflating and deploying the air bag,
Thereafter, the airbag is inflated and deployed when the belt is pulled out in a state where the airbag is not inflated and deployed, and the amount of withdrawal of the belt is a predetermined second threshold β or more.
An airbag deployment control method characterized in that.   It is determined whether or not the belt is pulled out in a state in which the air bag is not expanded and deployed, based on any one parameter of the pulling amount of the belt, the pulling speed, or the pulling acceleration. The air bag deployment control method according to Item 5.   The airbag deployment control method according to claim 6, wherein it is determined that the belt has been pulled out when the parameter exceeds a predetermined set value. The airbag is inflated and expanded to a complete state when the amount of withdrawal of the belt is equal to or greater than the first threshold α and the amount of withdrawal of the belt is less than a predetermined third threshold γ. The airbag deployment control method according to claim 5, characterized in that the airbag is inflated and deployed so that the internal pressure becomes lower than the complete state when the amount of withdrawal of the third bag is the third threshold γ or more. .