JP3482435B2 - Airbag deployment control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuation control device for actuating an air bag system by detecting a collision of a vehicle, and more particularly to an air bag system in which one air bag is inflated by a plurality of inflators. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag deployment control device that determines the operating mode (number of operations and operating timing) of each inflator and the necessity of operating each inflator according to the degree of collision.

[0002]

2. Description of the Related Art Conventionally, an air bag device generally used is a system in which one inflator deploys one air bag. In this method, the acceleration sensor mounted on the vehicle constantly detects a change in the acceleration of the vehicle, and the acceleration signal is subjected to appropriate calculation processing such as one-time integration or two-time integration, and the acceleration signal is compared with a predetermined threshold value. When it exceeds the value, an operation signal is issued to the ignition circuit of the inflator to operate the inflator and deploy the airbag.

According to the safety standard, this system is 50 k
It is designed to exert its maximum ability in the case of a head-on collision at a speed of m / h. Therefore, regardless of the severity of the collision and the position or posture of the occupant, if the threshold value is exceeded, the airbag will have a constant level. It is designed to develop with characteristics. Therefore, in the case of a collision of medium to low speed, the bag is deployed with excessive deployment energy to protect the occupant, and when the position of the occupant is close to the bag or the physique of the occupant is small, There was a risk of injury due to the deployed bag.

Therefore, one of the solutions to these problems is
One is the so-called "smart airbag system" that optimizes the output of the inflator and optimizes the injury value of the occupant according to various conditions such as the degree of collision, the physique and position of the occupant, and the presence or absence of seat belts. A new system called is proposed. In this smart airbag system, in order to optimize the output of the inflator, a plurality of inflators are arranged with respect to one airbag, and various conditions such as the severity of the collision, the sitting position and posture of the occupant, and various other conditions are set. Accordingly, it is necessary to configure the inflator so that the output of the inflator is optimized by controlling the operating mode of the inflator, that is, the number and timing of inflators to be operated. Has not been put to practical use.

The reason for this is that the acceleration signal from the acceleration sensor installed in the passenger compartment is time-integrated, and the obtained time integration value is compared with a predetermined threshold value to determine whether or not the airbag device needs to be actuated. The method of determining
Depending on the structure of the vehicle body and the form of the collision, there is no great difference in the time integrated value immediately after the collision, and the severity of the collision is judged when the difference occurs. If both the necessity and the mode of operation of the inflator are judged by only the above, it is too late for the inflator operation control, and there is a problem that it is difficult to optimize the operation of the inflator.

Therefore, the present invention proposes a system in which acceleration sensors are installed at two locations, a vehicle interior and a crash zone, and whether or not the inflator needs to be actuated and whether or not it should be actuated are determined based on the difference in acceleration changes detected by both sensors. Proposed by the inventors. In the case of this method, there is a clear difference in the acceleration waveforms output from the two accelerations depending on the collision mode, so it is possible to accurately determine whether or not the inflator should be operated and the operation mode. However, since two acceleration sensors are used, there is a problem that the cost becomes high.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to use one acceleration sensor to operate an airbag device. A system that can judge the severity of the collision, that is, by appropriately determining whether or not the inflator needs to be operated and determining the operating mode, and performing the optimal control of the inflator output, the air that matches the severity of the collision can be obtained. An object of the present invention is to provide a low cost airbag deployment control device that realizes bag deployment.

[0008]

The present invention has been made to achieve the above object, and is based on an acceleration signal from an acceleration sensor mounted on a vehicle, which is provided with a plurality of inflators for one airbag. In a deployment control device for an airbag device, which detects a collision of a vehicle by arithmetic processing and controls the operation of the inflator according to the degree of the collision, the acceleration value is calculated as time based on the arithmetic processing based on the acceleration signal. An integrating means, an operating necessity determining means for comparing the time integrated value obtained by the time integrating means with a predetermined first speed threshold value to determine whether the inflator needs to operate, and the acceleration sensor. A high-pass filter that removes the low-frequency component of the acceleration signal, a maximum value detection means that detects the maximum value of the acceleration value that has passed through the high-pass filter, and the detected maximum value. The acceleration value is compared with a predetermined first acceleration threshold value indicating the severity of the collision, and a first operation mode determination means for determining the operation mode of the inflator is provided. It is characterized in that the time integration is performed based on the time, the necessity of the operation of the inflator is determined using the obtained time integration value, and the mode of operation of the inflator is determined using the maximum acceleration value.

Incidentally, instead of the first operation mode judging means for judging the operation mode of the inflator using the maximum acceleration value, the first wave for detecting the peak value of the first wave of the acceleration signal from the acceleration sensor. It is also effective to use a second operation mode determination means for detecting the operation mode of the inflator by comparing the peak acceleration value of the first wave with a predetermined second acceleration threshold value indicating the severity of collision. There is also a method in which both are used in combination.

As the operation necessity determination means, a first determination unit for comparing the time integrated value with the first speed threshold value,
A second judging unit for judging whether or not the inflator needs to be actuated by comparing the rate of change of the time integral value with a predetermined third acceleration threshold value. A method of switching over time is also a preferable method.

Further, the operating mode of the inflator is divided into two types, that is, rapid deployment for rapidly deploying the airbag and gentle deployment for gradually deploying the airbag. In the case of rapid deployment,
The most typical mode of deployment is to operate all inflators at the same time or with a short time difference, and in the case of slow expansion, only some inflators are activated. The method using is the most general.

Further, the initial value of the operation form judgment is set to the gentle expansion form, and when the operation form judging means judges the rapid expansion, the set value is not changed to the rapid expansion form. It is also possible to operate the inflator in the slow deployment mode unless the determination of the operation necessity is made in the operation necessity determination and the quick deployment is not made in the operation mode determination.

Further, the first slow deployment for judging whether or not the deployment of the airbag in the initially set slow deployment mode should be suspended by comparing the time integrated value with a predetermined second speed threshold value. The output suspension judging means is provided, and even if the operation necessity judging means judges that the operation is “necessary”, the first embodiment is performed when the operation form judging means does not make a rapid expansion judgment. When the time integration value is determined to be equal to or more than the second speed threshold value as the determination by the slow expansion output hold determination means, an operation instruction in a slow expansion mode is issued to the inflator, and the time integration value is the first integral value. When it is determined that the speed is less than the two speed threshold value, it is a more preferable method to suspend the gentle expansion output and continue the calculation.

Further, instead of the first slow deployment output suspension judging means, whether or not the deployment of the airbag in the slow deployment mode should be suspended by comparing the elapsed time after the start of calculation with a predetermined time threshold value. A second slow expansion output hold judging means for judging is provided, and in the slow expansion output hold judging means, when the elapsed time is equal to or longer than a predetermined time threshold, an operation instruction in a slow expansion mode is issued to the inflator, and If the elapsed time is less than the time threshold value, there is also a method of suspending the gentle expansion output and continuing the calculation.

Further, in the actuating mode determination of the inflator, even after the first inflator is actuated due to the judgment that the deployment is slow, the operation for determining the actuating mode is continued, and the predetermined operation after actuation of the first inflator is continued. It is also a preferable method to activate the second inflator when a rapid deployment is determined in the operation mode determination within the time. In this case, there is a method in which all the calculations are completed when a predetermined time has elapsed after the operation of the first inflator.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The contents of the present invention will be described in detail below with reference to the embodiments of the drawings. FIG. 1 is an upper step showing a control flow of the airbag deployment control device of the present invention, and FIG. 2 is a lower step thereof. First, in FIG. 1, in the arithmetic circuit, all arithmetic values are reset by the reset circuit 1,
The acceleration signal g from the acceleration sensor 2 is obtained by the acceleration reader 3
Is transmitted to the block 21, and when the acceleration value g reaches a predetermined value or more, the calculation is started, the predetermined acceleration value g1 is subtracted / offset-processed, and the offset-processed acceleration value is further accelerated. Set as G1.

At the same time, the acceleration signal g is passed through the high pass filter 22 to obtain the acceleration component G2 passed through the high pass filter 22. This high pass filter processing will be described with reference to FIG. FIG. 5A shows an acceleration waveform before passing through the high pass filter, and FIG. 5B shows an acceleration waveform after passing through the same filter. The acceleration waveform in FIG. 3A includes a high-frequency acceleration component a with a large amplitude and a low-frequency acceleration component b shown by a dotted line, and the low-frequency component b is removed by passing the filter. Only high-frequency components. As a result, as will be described later, an acceleration waveform generated by a low-speed collision that does not require rough road or airbag deployment, or a light collision that does not require rapid airbag deployment but rapid deployment and rapid airbag deployment. Is distinguished from the acceleration waveform generated by the heavy collision, and the acceleration waveform due to rough road is removed in particular. That is, in the case of a collision such as a high-speed head-on collision, the crash zone at the front of the vehicle body is first destroyed, crushed, deformed, etc.
High-frequency acceleration changes occur, but in the case of rough road, it is due to deceleration caused by rubbing the bottom of the vehicle body,
Since the vehicle body is not deformed, the acceleration waveform has a low frequency. Therefore, by passing the acceleration g through the high-pass filter 22, low-frequency components due to rough road and the like are removed, and erroneous judgment in judging the severity of collision is prevented.

Next, the acceleration component G2 that has passed through the high pass filter 22 is transmitted to the second comparator 23, where the maximum acceleration G2x detected by the calculation up to that point.
When it is larger than the maximum acceleration G2x (G2> G2x), the acceleration value G2 is transmitted to the maximum acceleration setter 24, and the acceleration value G2 at that time is set as a new maximum acceleration value G2x. After setting, the same processing is performed thereafter. For example, in the case of FIG. 5B, if the maximum value of acceleration at a certain stage is set to G2x1, the set value is changed to G2x2 larger than that at the next stage, and then G2x3, It is sequentially changed to G2x4 and G2x5.

Next, the offset and cut-off acceleration value G1 is time-integrated by the integrator 8 through the time setter 7, and the accumulated value is set as the time integrated value V1. It

Next, the time integrated value V1 is compared with a predetermined value (described as 0 in the figure) near 0 (zero) in the third comparator 9, and when it is smaller than the predetermined value ( In the case of V1 <0 in the figure), the operation determination device 25 of the first inflator determines whether the first inflator has been operated. If the first inflator is not operated, the reset circuit 1 To reset the operation. The calculation to reach the reset circuit 1 is a calculation when a relatively gentle acceleration that does not require deployment of the airbag is input. If the first inflator is already operating, the calculation ends.

On the other hand, when the time integration value for each minute time ti is accumulated and the time integration value V1 becomes equal to or more than the predetermined value (V1 ≧ 0 in the figure), the next first wave detector 26 The first wave of the acceleration waveform is detected. That is, as shown in FIG. 6, the change rate J of the acceleration change rate J in the previous calculation is calculated.
(T-ti) and the change in the current change rate J (t) are detected,
When the rate of change is positive (J> 0), it means that the acceleration value is in the increasing process, and when J <0, it means that the acceleration value is in the decreasing process, and J = 0. The point of (zero) means a peak, but since the acceleration g is detected at the minute time ti intervals, it is not always possible to detect the time point of J = 0. Therefore, J (t-ti) ≧ 0 and J (t) <
In the case of 0, it is determined that the peak Gp of the acceleration waveform is detected, and the setter 27 sets the flag P = 1, which means the first wave peak, and subsequently, in block 45, sets the detected Gp. The acceleration waveform used for this peak detection is preferably the waveform of the acceleration G1 that has not passed through the high pass filter 22, but the high pass filter 22
The acceleration G2 that has passed through may be used. Since the initial setting value of the code in the first wave detector 26 is set to P = 0, after the peak of the first wave is detected, P =
The setting is changed to 1, and in the next and subsequent calculations, the process proceeds to the next calculation without going through the setter 27.

Next, the acceleration value G of the detected first wave
p is compared with the second acceleration threshold value SA2 for the determination of the severity of the collision, that is, the inflator deployment configuration determination in the second operation mode determination device 28, and the first wave peak acceleration is equal to or higher than the second acceleration threshold value (Gp > SA2), it is determined to be a heavy collision, and the setter 29 corrects the flag S from S = 0, which means an initial value light collision, to S = 1, which means a rapid airbag deployment. . On the other hand, when Gp ≦ SA2, the flag continues to be operated with S = 0 for a light collision.

Next, as shown in FIG. 2, when the signal from the setting device 29 or the condition of the first wave detector 26 is not satisfied, for example, the first wave detection after the first wave is detected. Bowl 2
The signal from No. 6 is transmitted to the next first operation mode determiner 35, and here, the maximum acceleration value G of the acceleration waveform that has passed through the high-pass filter 22 set by the setter 24.
2x is compared with a predetermined first acceleration threshold value SA1, and when the threshold value is equal to or more than the threshold value (G2x ≧ SA1), it is determined that the collision is a heavy collision, and the flag S is set in the setter 32 to indicate rapid deployment of the airbag. Set to 1 (S = 1). On the other hand, G2
When x <SA1, the flag indicates that a light collision S =
The fact that the calculation is continued with 0 being the same as in the above case.

Next, when G2x <SA1, and when the setting device 32 sets the flag for rapid deployment of the airbag, the signal indicating that the first inflator has been activated is used as a signal indicating that the first inflator has been activated. When the first inflator is not operating, the confirmation device 31 confirms whether or not a flag signal (E = 1), which has been determined to be necessary for operation described later, is input, and E = 1 If not input, it is transmitted to the next operation necessity determination device 10. The operation necessity determination unit includes a first determination unit that compares the time integration value V1 with a predetermined first speed threshold value Vs1, and a rate of change G ′ (= ΔV1 / Δt) of the time integration value V1. A second judgment unit for making a comparison with a predetermined third acceleration threshold Gs3, and when the judgment in the first judgment unit is V1 ≧ Vs1 and the judgment in the second judgment unit is G ′ ≧ Gs3, or
The judgment by the one judgment unit is V1 ≧ Vs1 or the judgment by the second judgment unit
If the judgment in G satisfies one of G ′ ≧ Gs3
Performs determination operation "must" as the determination in the operation necessity determination unit 10, by setter 33 sets the flag E to 1 (E = 1), which means inflator actuating "main". In the other cases, the flag remains at the initial setting value of E = 0, which means that the inflator does not operate, and the process proceeds to the next calculation.

In the operation necessity judgment device 10, since there is a possibility that an operation delay may occur in the case of a heavy collision only with the first judgment part based on the time integration value V1, the change rate G'of the time integration value V1. There is provided a second operation judging section for judging whether or not the operation is necessary by using. That is, a large value of the rate of change G'means a rapid increase in acceleration, in other words, a rapid deceleration of the vehicle body. When the rate G ′ shows a large value, it is determined that the airbag should be deployed. This prevents an operation delay in a heavy collision, and in the case of a vehicle with low vehicle rigidity, the crash zone in the front part of the vehicle body is deformed or crushed at the initial stage of the collision, so the acceleration sensor installed in the vehicle compartment At the initial stage, a low acceleration value appears, and when deformation of the vehicle interior subsequently starts, a rapid acceleration change occurs and the time integration value V1 rapidly increases. Therefore, by detecting the change rate G ', It is also possible to prevent the operation delay of the airbag device in a vehicle with low rigidity.

Further, the first judgment unit and the second judgment unit are A
It is connected through an ND circuit or an OR circuit, and it is preferable to connect it with an AND circuit at the initial stage of collision so as to prevent malfunction, and to switch to the OR circuit after a certain period of time. Is the way of.

Next, the signal from the operation necessity setting device 33 is transmitted to the rapid expansion judging device 34, and the rapid expansion flag S is judged by the judgment of the first operating condition judging device 35 or the second operating condition judging device 28. If = 1 is set, this is confirmed, and an actuation signal is output to the trigger circuit 37 to actuate the first inflator and the second inflator at the same time, and the airbag is rapidly deployed.

On the other hand, when the rapid deployment flag is not set, the calculation is performed by the next first slow deployment output hold determiner 36.
Then, the time integration value V1 is compared with a predetermined second speed threshold value SV2. If V1 ≧ SV2, the trigger circuit 38 outputs an operation signal for operating only the first inflator. The airbag is slowly inflated, and at the same time, the time setter 39 detects the time from the start of calculation to the actuation of the first inflator, sets this as TTF, and returns to the above-mentioned acceleration reader 3 to perform the above calculation. To continue. In the operation necessity determination device 10, V1 <Vs
Also in the case of 1 and G ′ <Gs3, the calculation is returned to the acceleration reader 3 and the above calculation is continued. As described above, in the first gentle expansion output suspension judging unit 36, when the rapid expansion form is not judged by the operation form judging unit, that is, the expansion form judgment is the initial expansion of the gentle expansion form (S = 0). When the state is maintained, it is determined whether the inflator should output an actuation signal for slowly inflating the airbag or hold it. Instead of deploying it, we make a more careful judgment to improve the safety of the airbag.

When the time TTF from the start of the calculation to the operation of the first inflator is set, this time is input to the time comparator 40. Then, when the first inflator actuation determination device 30 determines that the first inflator has been actuated, the time comparator 40 determines the elapsed time t after the start of calculation as the elapsed time until the first inflator is actuated. Comparing with the allowable elapsed time represented by the sum (te + TTF) with the time te preset in TTF,
When the elapsed time from the start of the calculation is smaller than the allowable elapsed time (t <te + TTF), the rapid expansion flag S = 1 is set in the first operation mode determiner 28 or the second operation mode determiner 35. If you do, this is a rapid deployment confirmation device 4
This is confirmed in step 1, and an operation instruction signal is immediately transmitted to the trigger circuit 42 of the second inflator to operate the second inflator.

If the rapid expansion flag S = 1 is not set in the rapid expansion confirmation device 41, the calculation is further continued. Further, in the time comparator 40, when the elapsed time t from the start of calculation exceeds a predetermined allowable time (t
For ≧ te + TTF), it is determined that if the output of the inflator is increased from this point of time, the occupant may be injured, and the calculation is ended.

Next, FIG. 3 is a flow chart showing another embodiment of the present invention, showing only the latter half portion corresponding to FIG. 3 is different from FIG. 2 in that the time integration value V1 in FIG. 2 is replaced with the first slow expansion output suspension determiner 36 that compares the second speed threshold Vs2 with the elapsed time t from the start of calculation. The second gentle expansion output hold judging device 43 for comparing with a predetermined time threshold value ts is provided. Since other parts are the same as those in FIG. 2, the same components are designated by the same reference numerals and the description thereof will be omitted. . In the second slow expansion output hold determiner 43, the elapsed time t after the start of calculation is the predetermined time threshold t
When the predetermined time has elapsed after the start of the calculation (t ≧ ts), an actuation signal is immediately issued to the trigger circuit 38 of the first inflator, and the airbag is inflated only by the first inflator. If t <ts,
The calculation is continued by returning to the acceleration reader 3.

This is because the second slow expansion output hold judging device 43
The comparison operation is performed by the operation necessity determination device 1
Since it is only when it is judged that the operation is “necessary” in 0, it is judged that there is a possibility that the function of protecting the occupant may not be fulfilled if the airbag is deployed after a further delay. After a certain period of time, the airbag is slowly deployed.

Next, FIG. 4 is a flow chart showing another embodiment of the present invention. The difference from FIG. 2 and FIG. 3 is that the first and second slow expansion output suspension judging devices 36 and 43 are By omitting, if the rapid deployment signal S = 1 is not input to the rapid deployment confirmation device 34, an actuation signal is immediately issued to the trigger circuit 38 of the first inflator so that only the first inflator deploys the airbag. It was done. This is because the rapid expansion confirmation device 34 calculates
Only in the case where the operation necessity determination device 10 determines that the operation is "necessary", first, the airbag is gently deployed only by the first inflator, and then the second inflator is activated to operate the airbag. Whether or not to rapidly deploy is determined by the judgments of the first operation mode determination means 35, the second operation mode determination means 28, and the time comparator 40, and the acceleration value at the initial stage of the collision is relatively large. This is an effective method in the case of a collision that appears low.

As is apparent from the above description, in the present invention, the determination of whether or not to operate the inflator is made by the first determination that determines whether or not to operate the inflator based on the time integration value V1 of the normal acceleration signal. And a second determination unit for determining whether or not the inflator needs to be actuated based on the rate of change G ′ of the time integrated value V1. Further, the rapid expansion determination in the inflator actuation mode determination is performed by high pass. This is performed by the first operation mode determination means that determines using the maximum value G2x of the acceleration component G2 that has passed through the filter, and the second operation mode determination means that determines the operation mode using the peak value Gp of the first wave of acceleration. ,
Further, the operation judgment in the slow deployment is the first slow expansion output hold judging means for judging the suitability of the operation by using the time integration value V1, and the first judgment for the suitability of the operation by using the elapsed time after the start of the calculation. (2) A time comparison means for determining whether or not the operation of the second inflator is necessary by using the elapsed time after the operation of the first inflator, and a combination of these organically and appropriately. Needless to say, the present invention is not limited to the above-described embodiments, and various modifications exist based on the concept described in the claims.

For example, it is possible to simplify the system by determining whether or not the operation is required only by the first determination section, and by determining the operation mode and only the first operation mode, it is possible to simplify the system. For example, in consideration of the rigidity of the vehicle body, the presence / absence and size of the crash zone, the mounting position of the acceleration sensor, and the like, an optimal system for the vehicle type is adopted.

Each threshold value may be a constant value, but it is also a preferable method to make it easy to follow various collision modes by using a time function.

In the above embodiment, the case where two inflators, the first and second inflators, are used has been described. However, the present invention can be similarly applied to the case where three or more inflators are used. There is no end. Further, among a plurality of inflators, only a part of the inflators can be deployed in the case of a slight collision.

Further, the inflator used in the present invention is
In some cases, multiple independent inflators are used, but 1
The inside of the housing of one inflator may be divided into a plurality of combustion chambers, and an ignition device may be arranged in each combustion chamber, whereby each combustion chamber may be independently operated. The plurality of inflators referred to in the present invention include all of these forms, and as long as the inflators have a plurality of gas generating portions that can be independently ignited, regardless of whether the forms are combined into one, in the present invention. Needless to say, it can be used.

Further, although the above description does not refer to the control system in combination with the seating position and posture of the occupant when the present invention is applied to the passenger seat or rear seat airbag device, the present invention does not mention these. Needless to say, it is possible to control by a combination of. For example, immediately before or after the circuit that outputs the operation signal to the first and second inflators, a circuit for determining whether or not the airbag device should be operated depending on the seating position and posture of the occupant is provided to make a final determination of whether or not the airbag should be deployed. It is also possible to do so. In addition, the seating position and posture of the occupant is used to judge whether the airbag is loose or suddenly deployed, and this is combined with the judgment system of the present invention, and the seating position and posture and the severity of the collision are compared. It is also possible to give priority to this and control the deployment form of the airbag. The point is that various application forms exist within the scope of the gist of the present invention, and the present invention does not exclude them.

[0040]

As described above, according to the method of the present invention, a low frequency acceleration component such as rough road is removed at this portion by performing calculation using the acceleration signal G2 that has passed through the high pass filter. As a result, even if the bottom of the vehicle body is rubbed by a curbstone or other obstacle and a large acceleration change occurs, these are low-frequency acceleration waveforms, so they are removed by a high-pass filter.
An erroneous judgment in the judgment of the severity of the collision is surely prevented.

In the case of a heavy collision, the operating form is determined by using the peak value Gp of the first wave of the acceleration waveform which can be confirmed in the early stage after the collision and the maximum value G2x of the acceleration passed through the high pass filter. Since the determination is made in parallel with the determination as to whether or not the operation should be performed based on the time integration value V1, there is no delay in determining the deployment form in a heavy collision, and optimization of the airbag device is achieved. Will be

Further, in the case of a heavy collision, it is possible to make a decision at a fast stage, and as a result, a time margin can be taken until the operation. As a result, a fine control in which the operation control of the airbag device is divided into a plurality of steps is also possible. This makes it possible to protect passengers at a higher level.

Further, even if it is judged that the operation is "necessary" in the operation necessity judgment, if the first slow expansion output hold judging device 36 or the second slow expansion output holding judgment device 43 does not exceed the predetermined threshold value. Since the operation signal output of the inflator is suspended and the calculation is continued, it is less likely that the severity of the collision will be erroneously determined by the information that is small in the initial stage of the collision. Further, even if the first or second slow expansion output hold determiner determines that the operation mode is a light collision and the first inflator is operated, the calculation is further continued and the first operation mode determiner 35 or the second operation mode is determined. If the operation mode determiner 28 determines that there is a heavy collision, the second inflator is actuated immediately. Therefore, depending on the type of collision, only the first inflator operates and the second inflator operates after the first inflator operates. (2) When the inflator operates and when both inflators operate at the same time, the deployment mode of the airbag is classified into three types, and the deployment mode of the airbag is optimized according to the collision mode, and the occupant's airbag is optimized. It is expected that safety will be further improved.

[Brief description of drawings]

FIG. 1 is a flowchart of a first half portion of a control system showing an embodiment of an airbag deployment control device according to the present invention.

FIG. 2 is a flowchart of the latter half of FIG.

FIG. 3 shows another embodiment of the present invention and is a flowchart of a portion corresponding to FIG.

FIG. 4 is a flow chart of a portion corresponding to FIG. 2, showing another embodiment of the present invention.

FIG. 5 is a gt diagram showing an acceleration waveform, (A)
Shows the waveform before passing through the high pass filter,
(B) shows the waveform after passing.

FIG. 6 is a gt diagram showing a method of detecting a first wave of an acceleration waveform according to the present invention.

[Explanation of symbols]

1 reset circuit 2 Accelerometer 5 Cut-off processing means 8 time integration means 10 Operation necessity judgment means 22 High-pass filter 23 Maximum acceleration value setting means 26 First Wave Detection Means 28 Second operation mode determination means 35 First Actuation Form Judging Means 36 First slow expansion output suspension judging means 43 Second slow expansion output hold determination means 40 hour comparator

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-323812 (JP, A) JP-A-11-278198 (JP, A) JP-A-11-165608 (JP, A) JP-A-11- 78770 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60R 21/16-21/32 G01P 15/00

Claims (17)

(57) [Claims] 1. A degree of collision when a collision of a vehicle is detected by arithmetic processing based on an acceleration signal (g) from an acceleration sensor (2) mounted on a vehicle, which is provided with a plurality of inflators for one airbag. According to the above, in the airbag deployment control device for controlling the mode of operation of the inflator, a time integration means (8) for integrating the acceleration value with time by a calculation process based on the acceleration signal (g), Time integration value (V1) obtained by the time integration means (8)
Is compared with a predetermined first speed threshold value (Vs1) to determine whether or not the inflator needs to be operated.
0) and, and at least one of the following (a) and (b) as an operating mode determination method of the inflator, which is characterized in that: Device (a) Acceleration signal (g) from the acceleration sensor (2)
A high-pass filter (22) for removing the low frequency component of
Maximum value detecting means (23, 24) for detecting the maximum value (G2x) of the acceleration value (G2) that has passed through the high pass filter.
And comparing the maximum acceleration value (G2x) with a predetermined first acceleration threshold value (SA1) indicating the severity of the collision,
First operation mode determination means (35) for determining the operation mode of the inflator (b) A first wave for detecting the peak value (Gp) of the first wave of the acceleration waveform based on the acceleration signal from the acceleration sensor (2) A detection means (26) is provided, and the peak acceleration value (Gp) of the first wave is compared with a predetermined second acceleration threshold value (SA2) indicating the severity of collision to determine the mode of operation of the inflator. Second operation mode determination means (28) 2. A predetermined value (g1) is subtracted from an acceleration value (g) from the acceleration sensor (2) to perform offset processing, and a predetermined acceleration value (Gc) among the offset-processed acceleration values. The airbag deployment control device according to claim 1, wherein the time integration value (V1) is calculated using an acceleration value G1 that is cut off and cut-off processed. 3. A predetermined value (g1) is subtracted from the acceleration value (g) from the acceleration sensor (2) to perform offset processing, and a predetermined acceleration value (Gc) among the offset-processed acceleration values. The time integration value (V1) is calculated using the acceleration value G1 that is cut off and cut off, and the peak acceleration value (Gp) of the first wave is further calculated.
Is the peak acceleration value of the acceleration value G1 that has been subjected to the offset processing and the cutoff processing. 4. The peak acceleration value (Gp) of the first wave
Is the acceleration value G after passing through the high pass filter (22).
The airbag deployment control device according to claim 1 or 2, wherein the peak acceleration value is 2. 5. The first judgment for judging whether or not the operation is necessary, by comparing the time integral value (V1) with a predetermined first speed threshold value (Vs1). Together with the section, the rate of change (G ′) of the time integrated value (V1)
= ΔV1 / Δt) is compared with a predetermined third acceleration threshold value (Gs3) to determine whether or not the inflator needs to be actuated, and the first determination unit and the second determination unit make a determination. The airbag deployment control device according to any one of claims 1 to 4, wherein the results are combined to determine whether or not the inflator needs to be actuated. 6. The first determination unit and the second determination unit, the AN
The airbag deployment control device according to claim 5, wherein the airbag deployment control device is connected by a D circuit. 7. The OR of the first judgment unit and the second judgment unit
The airbag deployment control device according to claim 5, wherein the airbag deployment control device is connected by a circuit. 8. The first determination unit and the second determination unit, AN
The airbag deployment control device according to claim 5, comprising a D circuit and an OR circuit, and being connected via a switching means for switching the connection state of both of them with the passage of time. 9. The operating mode of the inflator is divided into two types, a rapid deployment for rapidly deploying the airbag and a slow deployment for gradually deploying the airbag. Airbag deployment control device 10. The inflator operating mode determination result indicates that all of the plurality of inflators are activated at the same time or with a short time difference in the case of the rapid deployment, and the plurality of inflators in the case of the slow deployment. 10. The airbag deployment control device according to claim 9, wherein only a part of the 11. The plurality of inflators comprises a first inflator and a second inflator, the rapid expansion actuates both inflators, and the slow expansion actuates only the first inflator. The airbag deployment control device according to claim 10, wherein 12. The initial setting of the slow expansion pattern in the first operation pattern determining means (35) and the second operation pattern determining means (28) is set to the slow expansion (S = 0). 11. The airbag deployment control device according to any one of 11 above. 13. The time integrated value (V1) is compared with a predetermined second speed threshold value (SV2) to determine whether or not the deployment of the airbag in the initially set slow deployment mode should be suspended. A first slow expansion output suspension judging means (36) for judging is provided, and even if the operation necessity judgment means (10) judges that the operation is "necessary", the first and second operations are performed. When the form determination means (35, 28) has not made a rapid deployment determination, the time integration value is equal to or greater than the second speed threshold value (V1 ≧ SV2) as the determination by the first slow deployment output suspension determination means (36). ) Is issued, the inflator is instructed to operate in a slow deployment mode, and if the time integration value is less than the second speed threshold (V1 <SV2), the inflator is released. Hold the expanded output and update 13. The airbag deployment control device according to claim 12, wherein the calculation is continued. 14. A comparison is made between an elapsed time (t) after the start of calculation and a predetermined time threshold value (ts) to judge whether or not the deployment of the airbag in the initially set slow deployment mode should be suspended. A second slow expansion output suspension judging means (43)
Even when the operation necessity determination means (10) determines that the operation is “necessary”, the first and second operation mode determination means (35, 28) do not make a rapid deployment determination. In this case, when it is determined that the elapsed time is equal to or longer than the time threshold (t ≧ ts) as the determination by the second slow expansion output suspension determination means (43), the inflator is instructed to operate in the slow expansion mode. 13. The airbag according to claim 12, wherein when the elapsed time is judged to be less than the time threshold value (t <ts), the slow expansion output of the inflator is suspended and the calculation is continued. Deployment control device 15. The operation necessity judgment means (10) judges that the operation is “necessary”, and the first and second operation form judgment means (35, 28) judges that the operation is rapid. The airbag deployment control device according to claim 12, wherein if not, an operation instruction in a slow deployment mode is immediately output to the inflator. 16. The operation for determining the operation mode is continued even after the operation instruction in the slow expansion mode is output to the inflator, and a predetermined time (te) after the operation of the inflator in the slow expansion mode. The airbag deployment control device according to any one of claims 10 to 15, wherein the remaining inflator is activated when a rapid deployment is determined in the operation mode determination. 17. The airbag deployment control device according to claim 16, wherein when a predetermined time (te) elapses after the operation of the first inflator, all calculations are finished.