JPH11192920A - Air bag device for side impact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation judgment device capable of performing an operation judgment at an appropriate timing and capable of remarkably reducing the possibility of mis-operation due to shock by the opening and closing of a door. SOLUTION: In an air bag device for side impact which judges the necessity of expansion using an acceleration value G transmitted from an acceleration sensor 1 installed at the side part of a vehicle, acceleration values at the integration start time points t0 and subsequent where an acceleration value G is a specified value G1 or higher are time-integrated so as to calculated a first time-integration value V, and a specified speed subtraction value (ΔV) is subtracted from the first time- integration value V so as to calculate a subtracted integrated value V1. Then the subtracted integrated value V1 is compared with a preset second speed threshold Vsb. When the subtracted integrated value is equal to or higher than the threshold V1>=Vsb, an air bag 14 is expanded, the acceleration value G transmitted from the acceleration sensor 1 is time-integrated so as to calculate a second time integration value Vb for a specified time until an integration start time point t0 is reached. Then the absolute value of the second time integration value is added to a specified first speed threshold value Vs so as to calculate the second speed threshold value Vsb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for judging the necessity of an operation for operating a side collision airbag apparatus by detecting a side collision of a vehicle.

[0002]

2. Description of the Related Art In recent years, the occupant protection concept in vehicles has been increasing, and the spread of airbag devices has been remarkable. In particular, driver-side airbag devices and passenger-side airbag devices are becoming standard equipment. These are airbag devices premised on a frontal collision, but side collision airbag devices for protecting an occupant from a side collision are also being provided, although in part.

In the case of a frontal collision of a vehicle, an impact is given to an occupant after a crash zone such as a bumper or an engine room in the front of the vehicle is destroyed. The occupant can be protected by activating the airbag 10 to 15 ms (milliseconds) later, whereas in the case of a side collision, it is deformed at the moment when a relatively thin and fragile door or pillar part collides. Immediately causing harm to the occupant, it is necessary to activate the airbag in about 5 ms in the event of a collision at a speed of, for example, 50 km / h. Therefore, the sensor system of the airbag device for front collision is used as it is. It is difficult to convert to a side collision airbag device.

[0004] In addition, it is conceivable to increase the collision sensitivity of the sensor system of the front collision airbag device. However, in this case, there is a risk of malfunction due to an impact at the time of opening and closing the door, which is difficult to apply. On the other hand, a system using a mechanical collision sensor called a flapper system has also been proposed, but there is a problem in performance in responding to various types of vehicles, and there is a problem in widespread practical use.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to use an acceleration signal from an acceleration sensor as in the case of a front collision airbag device. The present invention provides a novel side-impact airbag device operation judging device that makes it possible to make an operation judgment at an appropriate timing in a calculation method and significantly reduces the possibility of malfunction due to an impact due to opening and closing of a door. It is for the purpose.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and uses an electronic acceleration sensor conventionally used in a front-impact airbag device. There are two methods. First, the first method is a side collision airbag device that performs a predetermined calculation using an acceleration value from an acceleration sensor to determine whether or not the deployment of the side collision airbag is necessary. A first time integrated value is calculated by time-integrating the acceleration value after the integration start time at which the acceleration value has become a predetermined value or more, and a predetermined speed subtraction value is subtracted from the first time integrated value to perform subtraction integration. A value is calculated, the subtracted integral value is compared with a second speed threshold set in advance, and when the subtracted integral value is equal to or greater than the threshold value, the airbag is deployed, and from the acceleration sensor. The second speed integral value is calculated by integrating the acceleration value of the second time integral over a predetermined period of time up to the integration start time, and the absolute value of the second time integral value is added to a predetermined first speed threshold value. The threshold is calculated.

Next, as a second method, a first time integrated value is calculated by time-integrating the acceleration value after the start of integration when the acceleration value of the acceleration sensor has become a predetermined value or more. A predetermined speed subtraction value is subtracted from the first time integration value to calculate a subtraction integration value, and the subtraction integration value is compared with a preset first speed threshold value by a first comparator, and the subtraction integration value is calculated. If the value is equal to or greater than the threshold value, an airbag activation permission signal is output to the AND circuit, and the acceleration value after the integration start time is compared with a predetermined acceleration threshold value at predetermined time intervals. The number of the acceleration values exceeding the acceleration threshold is counted, and the count is compared with a predetermined count threshold by a second comparator. If the count is equal to or greater than the threshold, an airbag activation permission signal is issued. Output to the AND circuit, and the AND circuit If both the air bag operation permission signal of the air bag operation permission signal from the second comparator is input, it is made in the manner and outputs a trigger instruction signal to the trigger circuit of the air bag. Further, as a modified example, there are a method using a first time integral value before subtraction instead of the subtraction integral value, and a method using the second speed threshold value instead of the first speed threshold value.

As a modification of the first method, a method of comparing a first time integrated value before subtraction with the second speed threshold instead of comparing the subtracted integrated value with the second speed threshold is used. Also, as a modified example of the second method, a method using a first time integral value before subtraction instead of the subtraction integral value, and using the second speed threshold value instead of the first speed threshold value There is a method. Further, in both methods, when the second time integration value is equal to or more than a predetermined value, the second time integration value is regarded as zero (0), and the second speed threshold value and the first speed threshold value are determined. There is also a method for making the same.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a block diagram showing an example of an operation necessity determination circuit of a side collision airbag device of the present invention. In FIG. 1, an acceleration sensor 1 is located near a door beam in a center portion of a door of a vehicle body, or An electronic acceleration sensor which is installed near the center pillar portion at the center of the front and rear doors or near the seal portion of the vehicle body at the lower portion of the door, and has conventionally been used as an acceleration sensor of a front-impact airbag device in general. It is.

An acceleration signal G detected by the acceleration sensor 1 is connected to a reset circuit 11 and a trigger circuit 13 of an inflator via an arithmetic circuit 2, and the trigger circuit 13 ignites an inflator (not shown). The airbag 14 is configured to be deployed.

Next, the operation circuit 2 will be described.
The acceleration signal G detected by the acceleration sensor 1 is first transmitted to a block 4, which is an integration start determination circuit, after a small signal noise is removed by a low-pass filter 3, and the acceleration value G exceeds a predetermined acceleration G1. Then, from this time t0, the time integration is started in the block 5 as the integrating means, and the first time integrated value V is calculated. Subsequently, in a block 6 which is a subtraction means, a predetermined speed subtraction value ΔV is subtracted from the first time integral value V to calculate a subtraction integral value V1. This subtraction means is called so-called offset processing, and serves to enhance the malfunction prevention effect by eliminating accumulation of the noise-like acceleration signal integral value in the time integral value. However, it can be omitted as described later.

Next, the obtained subtraction integral value V1 is compared with a small threshold value (zero or a value near the same; described as zero (0) in the figure) preset by a comparator 7,
If it is less than the threshold, the operation is reset by the system reset circuit 11. On the other hand, if it is equal to or greater than the predetermined threshold,
The value of the subtraction integral value V1 is transmitted to the block 10 and compared with a second speed threshold value Vsb described later. When the subtraction integral value is equal to or greater than the threshold value (V1 ≧ Vsb), a trigger signal is transmitted to the trigger circuit 13. Then, the airbag 14 is deployed by igniting an inflator (not shown) to protect the occupant from a shock at the time of a side collision. On the other hand, when the subtraction integral value is less than the second speed threshold value (V1 <Vsb), the calculation is continued.

In the present invention, there is a great feature in setting the second speed threshold value Vsb. The acceleration signal G from which minute noise has been removed through the low-pass filter 3 is transmitted to a block 8 as an integrating means. During a certain period of time up to the integration start time t0 in the block 4, the acceleration signal G is time-integrated to calculate a second time integration value Vb, and the obtained second time integration value Vb is transmitted to the block 9, Here, a new second speed threshold value V is obtained by adding the first speed threshold value Vs preset as a time function threshold value in block 12 and the absolute value of the second time integral value Vb.
sb is calculated, and the threshold value is compared with the subtraction integral value V1 by the comparator 10 as described above. That is, the second speed threshold value Vsb to be compared with the subtraction integral value V1 is a threshold value of the time function, and at the same time, the second time integral value dependent on the change of the acceleration signal G until the calculation of the subtraction integral value V1 is started. It has a great feature in that it is a function of the value Vb (in other words, a function of G). Note that the calculation of the second time integral value Vb in the block 8 is one in which time integration is always performed for a fixed time regardless of the presence or absence of a collision.

The process of the above calculation will be described with reference to the example of FIG. FIG. 6A shows a change with time of the acceleration value G in a hammering state such as when the door is strongly opened and closed.
It is a -t diagram, the sign of the inside direction of the door is (positive),
The outside direction of the door is (negative). Also, FIG.
FIG. 5 is a V1-t diagram showing a temporal change of the subtraction integral value V1 based on the acceleration value G. In FIG.
At time t0 when the acceleration value G exceeds a predetermined acceleration value G1, a time integration of the acceleration value G is started, and the subtraction integration value V1 changes as indicated by m in FIG. , And becomes zero (0) at time t1. At this time, the comparator 7 in FIG. 1 transmits a reset signal to the system reset circuit 11 to reset the first calculation.

Next, as shown in FIG. 6A, when the acceleration value G exceeds G1 again, this point is changed to a new integration start point t.
Time integration is started as 0, and the subtracted integral value V1 changes as indicated by n in FIG. Here, the second subtraction integral value V1 exceeds the first speed threshold value Vs, which is a normal speed threshold value, at point a, so that the airbag deployment signal is output as it is. The second time integration value Vb is obtained by time-integrating the acceleration value G at a certain time tb before the start of the second integration, and this absolute value is added to the first speed threshold value Vs to obtain a second speed threshold value Vs
b is calculated and compared with V1.
As shown in FIG. 8B, Vsb is a value higher by Vb than the line of Vs. Therefore, the subtraction integral value V1 obtained by the second calculation is also smaller than the second speed threshold value Vsb, and the operation of the airbag does not occur. Since the value of G has a positive or negative sign, the second time integral value Vb generally takes a negative value. However, in the calculation of the second speed threshold value Vsb, its absolute value is calculated by using the first speed threshold value Vs. In the following description, the expression "addition" also means adding the absolute value.

The second speed threshold Vsb is made equal to the sum of Vs and Vb only for a certain period at the beginning of the calculation so that the second speed threshold Vsb becomes equal to the first speed threshold Vs after the time ts.
What is necessary is just to prevent the initial malfunction. Also, in the first calculation, the calculation of the second time integral value Vb and the calculation of the second speed threshold value Vsb are performed, but are omitted for convenience of explanation.

This determination method will be described in further detail. As is clear from the graph of the acceleration value G in FIG. 6A, the change in the acceleration value of the hammering gradually changes from the first small amplitude waveform. Although not shown, the waveform is similar to a simple vibration that gradually attenuates and disappears. Therefore, as for the value of G, if the area of the positive portion is large, the area of the corresponding negative portion is also large.
The calculation is repeated three times. When V1 increases in the calculation, the value of Vb obtained by integrating the acceleration value G immediately before the calculation also increases, so the second speed threshold Vsb also increases, and V1 does not exceed Vsb. Absent. As a result, the operation of the airbag device due to an impact caused by abuse such as hammering is avoided.

Next, FIG. 7 is a graph showing the change over time of the acceleration value G and the subtraction integral value V1 in a low-speed side collision where the operation of the airbag device is not required.
(B) is a V1-t diagram. In this case, the acceleration waveform changes from an initial small amplitude waveform to a large amplitude waveform as shown in FIG. (A), and although not shown, it gradually attenuates and disappears. . Accordingly, the integration is started at time t0 when the acceleration value G first exceeds the predetermined acceleration value G1, and the subtracted integrated value V1 calculated based on the acceleration value is indicated by p in FIG. As described above, the calculation converges to zero while repeating the increase and decrease, and the calculation is terminated. In this first calculation, the threshold value Vs is not exceeded. still,
Also in this case, the point that the second time integration value Vb before the start of the first calculation is added to the threshold value Vs is omitted. Next, in the second calculation, G has a waveform in which the area of the relatively large positive portion and the area of the relatively small negative portion are alternately repeated. As shown in the figure, the subtraction integral value V1 is a relatively large value. However, as in the case of FIG. 6, the second time integral value obtained by time-integrating the acceleration value for a certain time before the start of the calculation into the first speed threshold value Vs. Since the value Vb is added to make the second speed threshold value Vsb a high value, it is possible to prevent V1 from exceeding the threshold value Vsb and malfunctioning at the initial stage even during a low-speed collision.

In FIGS. 6 and 7, in the case of a collision that requires the operation of the airbag device such as a high-speed side collision, the waveform of the acceleration value G has a large value in the direction toward the inside of the door (positive). Therefore, the positive value of V1, which is the accumulated value of the time integration, also increases in a short time and exceeds the second speed threshold value Vsb, so that the airbag apparatus operates.

Next, another example of the present invention will be described with reference to FIG. In the example of FIG. 1, the subtraction integral value V1 is compared with a predetermined second speed threshold value Vsb. However, the first time integral value V before subtraction is compared with a predetermined speed threshold value Vsb. FIG. 2 shows an example in this case. That is, since the first time integration value V is a value larger by ΔV than the subtraction integration value V1, if the second speed threshold Vsb to be compared with this is also made larger by ΔV than when comparing with V1, There is no change in the relative relationship. Therefore, in the case of this example, the first speed threshold Vs
Is set in advance to a value that is higher by ΔV than the case of FIG. 1, and the first time integration value V is used instead of the subtraction integration value. The same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. However, even in this case, in the block 7 for determining whether the system needs to be reset, the subtraction integration It is important to use the value V1.

Next, another example of the present invention will be described with reference to FIG. In the examples of FIGS. 1 and 2, the second time integration value Vb
Is a method of calculating the second speed threshold Vsb by adding its absolute value to the first speed threshold Vs, regardless of the magnitude of the value
Adding the absolute value of the second time integral value means raising the threshold value, and at the same time means delaying the trigger instruction time. In the case of a severe collision such as a high-speed side collision, it is preferable to promptly issue a trigger instruction. Therefore, it is desirable to lower the threshold value so that the trigger instruction is output early. FIG. 3 shows an example of this. Compared to FIGS. 1 and 2, the second time integral value Vb is compared with a predetermined integral threshold value V0 in block 16, and when Vb> V0,
By setting Vb = 0 (0) in block 17 and adding this to the first speed threshold Vs in block 9, the second speed threshold Vsb is made equal to the value of the first speed threshold Vs before the addition. It is what we did.

That is, in the case of a serious collision such as a high-speed side collision, a sudden large change in acceleration occurs in the vehicle compartment direction (positive direction), and the so-called first wave itself has a large positive acceleration. The change in acceleration immediately before is extremely small. Therefore, if the second time integral value Vb, which is the integral value of the immediately preceding acceleration, is a value near zero (0), there is a possibility of a serious collision, so the threshold value is kept low and the trigger instruction is issued early. In order to make it possible, the raising of the threshold value by the addition of the absolute value of Vb is stopped, and the comparator 10 compares the first speed threshold value Vs before the addition with the subtraction integral value V1. The value of the second time integration value Vb is, as can be seen from FIGS.
Generally, it is an integral value of a negative acceleration value and has a negative value. Therefore, the integration threshold value V0 itself is also set to a negative value,
b ≦ V0 (in the absolute value comparison, | Vb | ≧ | V0
|), The threshold value is raised by adding the absolute value of Vb to the Vs, and when Vb> V0 (in the absolute value comparison, | V
b│ <│V0│), Vb is considered to be a small value near zero (0), and it is determined that the possibility of a serious collision such as a high-speed side collision is high. = 0 and Vbs = Vs.

FIG. 3 shows a system in which Vb is set to zero (0) in block 17 and added to Vs in block 9. However, if Vb> V0, this is the case. It is also possible to transmit the first speed threshold value Vs from the comparator 12 to the comparator 10 and compare V1 and Vs. In this case, the trigger operation can be performed in a short operation time because the operation in the block 9 can be omitted. Although there is an advantage in which necessity is determined, it goes without saying that any of the methods can be adopted in the present invention.

Next, FIG. 4 shows another embodiment of the present invention. In the above-mentioned embodiments of FIGS. 1 and 2, the necessity of the operation of the airbag device is determined by the subtraction integral value V1 or the first time integral value V1. In this example, the first speed threshold Vs is used instead of the second speed threshold Vsb, and the magnitude of the absolute value of the acceleration value G is also added to the determination factor. Is different. That is, the acceleration value G after the integration start time t0 is calculated in block 20 by an acceleration threshold value Gs set in advance in block 24 every predetermined time.
For example, a comparison is made every 0.2 ms, it is determined whether or not G exceeds Gs (G ≧ Gs) at that time, the number of times G exceeds Gs is measured, and the accumulated number within that fixed time Count number N
To the second comparator 21. Here, it is compared with a count threshold value Ns set in advance in block 22, and N
When ≧ Ns, a trigger permission signal for an inflator (not shown) is transmitted to the AND circuit 23, and when N <Ns, the operation is continued. On the other hand, the subtracted integral value V1 is compared with the first speed threshold value Vs preset in the block 12 by the first comparator 10 to obtain V1.
If ≧ Vs, a trigger enable signal for the inflator is transmitted to the AND circuit 23. In the AND circuit, when these two trigger permission signals are input, the trigger circuit 13
To the airbag 1
4 is developed. Other configurations are shown in FIG.
Therefore, the same reference numerals are given and detailed description is omitted.

Next, this operation determination will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 8A is a Gt diagram showing an example of a temporal change of the acceleration value G at the time of a low-speed side collision that does not require the deployment of the airbag, and FIG. 8B shows the deployment of the airbag device. It is a Gt diagram which shows an example of the temporal change of the acceleration value G at the time of the required middle-speed side collision. FIG. 9A is a V1-t diagram showing a temporal change of the subtraction integral value V1 in the above-mentioned two-side collision, and FIG. 9B is a graph showing a change in the count value N of G exceeding the acceleration threshold value Gs. It is a graph shown.

First, in FIG. 8 (A), the acceleration value G exceeds a predetermined acceleration value G1 at time t0, so that the time integration of the acceleration value is started from this point in time, and the subtraction integration value V
7 is an increase curve as shown by (a) in FIG. 7 (A), and exceeds the first speed threshold value Vs at time t2, so that the first comparator 10 of FIG. A trigger permission signal is output. On the other hand, as shown in FIG.
Since the portion where the acceleration value G exceeds the predetermined acceleration threshold value Gs does not exist within the operation request time t9, the count N output from the block 20 becomes zero (0), and the second comparator 21 triggers. No permission signal is output. Therefore, even in the low-speed side collision having such a waveform, the airbag device does not operate.

On the other hand, in the case of a middle-speed side collision that requires the operation of the airbag apparatus shown in FIG. 8B, the subtraction integral value V1 in FIG. And exceeds the first speed threshold Vs at time t3,
When the trigger enable signal is output from the first comparator 10 to the AND circuit 2
3 is output. Also, as is clear from FIG. 8B, in the acceleration value G in this case, since a portion exceeding the acceleration value threshold value Gs exists within the required operation time, the block 2
The cumulative count N exceeding Gs measured every predetermined time at 0 is a graph as shown in FIG. 9B. FIG.
In (B) and 9 (B), time t4 is the time when the acceleration value G first exceeds the acceleration threshold value Gs, and from this time to time t5 when G becomes equal to or less than Gs, the time t4 is counted every predetermined time. The accumulated count value N is rapidly increasing. From time t5 to t6, since G is less than Gs, the value of N does not change and remains constant, but again at time t6,
Exceeds Gs, the value of N also increases rapidly,
It continues until time t7 when G becomes equal to or less than Gs. This count value is held until time t8, but at time t10 when the count value N exceeds the count threshold value Ns, the second comparator 21 outputs
A trigger permission signal is output to the D circuit. still,
It goes without saying that an appropriate time within the operation request time t9 is selected as the count holding time t8.

As a result, in the example of the middle-speed side collision, at the time t10 when N exceeds the threshold value Ns, the second comparator 21
Outputs a trigger permission signal to the AND circuit, while a trigger permission signal is output from the first comparator 10 to the AND circuit 23 at time t3 when the subtracted integral value V1 exceeds the first speed threshold value Vs. Time t when input to AND circuit
At 3, the AND circuit 23 outputs a trigger signal to the trigger circuit 13 and the airbag 14 starts to deploy.

In the example of FIG. 4, the subtracted integral value V1
Is compared with the first speed threshold Vs. This may be a method of comparing the first time integral value V before subtraction with the first speed threshold Vs as in the case described above. In this case, It goes without saying that the value of the first speed threshold value Vs is higher by ΔV than the case where the subtraction integral value V1 is used.

Further, it is also possible to use the second speed threshold Vsb instead of the first speed threshold Vs in the same manner as in the case of FIG. 1, and this example is shown in FIG. That is, in FIG.
In the first comparator 10, the subtracted integral value V1 and the second speed threshold value Vs
b, and if V1 ≧ Vsb, the AND circuit 23
And outputs a trigger permission signal, and similarly to the case of FIG.
When the second comparator 21 determines that N ≧ Ns, a trigger permission signal is output from the second comparator 21 to the AND circuit 23, and when both permission signals are input to the AND circuit 23, the trigger circuit 13 is triggered. A signal is issued to deploy the airbag 14.

That is, in the above-described example of FIG. 4, as shown in FIG. 9A, even in the case of a low-speed side collision that does not require the deployment of the airbag, the first speed threshold Vs is set at the time t2. Since it has exceeded, the trigger enable signal is output from the first comparator 10, but in the example of FIG. 5, a high value obtained by adding the above-mentioned second time integral value Vb to the first speed threshold value Vs is obtained. Since the second speed threshold Vsb is used, as shown in FIG. 9A, in the case of a low-speed side collision, the speed does not exceed the second speed threshold Vsb. Therefore, the possibility of malfunction is reduced as compared with the case where the first speed threshold value Vs is used, and the safety of the system is improved.

In this embodiment, instead of comparing the subtracted integral value V1 and the second speed threshold value Vsb in the first comparator 10, the first time integral value V and the second speed threshold value Vsb before subtraction are used instead. Further, as shown in FIG. 3, the second time integration value Vb is compared with a predetermined integration threshold value V0, and the absolute value of the second time integration value Vb is added according to the magnitude of the comparison. Needless to say, a method of selecting whether to use the second speed threshold value Vsb thus set or to use the first speed threshold product value Vs without addition can be adopted.

In the above description, the first speed threshold Vs
Is, as shown in FIGS. 6 (B), 7 (B) and FIG.
It is preferable to set a time function whose value changes with the passage of time, and the form of the function may be a discontinuous function composed of a plurality of straight lines as shown in the illustrated example, or a continuous function represented by a curved line. Is also good. The acceleration threshold Gs is shown in FIG.
As shown in the above, a method using a constant value is simple,
A time function that increases with the passage of time may be used to clearly distinguish large collisions from small collisions. Further, as shown in FIG. 9 (B), it is a simple method to use a constant value for the count threshold value Ns. However, this also causes a large collision as a function of time that increases with time. It is also possible to make a clear distinction from small collisions.

[0034]

As described above, according to the present invention, based on the acceleration signal from the acceleration sensor, the time integration value obtained by time integration of the acceleration signal is simply compared with a predetermined speed threshold value to determine the air speed. Rather than determining whether the bag device needs to be activated, the threshold itself is a function of the acceleration value immediately before the start of integration by adding the time integral obtained by time-integrating the acceleration value immediately before the start of integration to the threshold. By doing so, it becomes possible to prevent a low-speed side collision that does not require the operation of the airbag device and a malfunction in hammering.

Further, the magnitude of the acceleration value after the start of the integration is compared with a predetermined acceleration threshold value at a predetermined interval, and the number of acceleration values exceeding the threshold value within a predetermined time is counted. If the threshold value is exceeded, a trigger permission signal is output, and a time integral value obtained by time-integrating the acceleration value is compared with a predetermined speed threshold value, and the time integral value exceeds the speed threshold value. For example, in a system in which a trigger permission signal is output and the airbag device is operated only when both trigger signals are output, the time integration value is low like a low-speed side collision and a medium-speed side collision. Even in similar cases, the two can be clearly distinguished, so the middle-speed side collision that requires deployment of the airbag ensures that the airbag device is activated, and the low-speed side collision that does not require deployment of the airbag. Let's check the operation of the airbag device. It is possible to prevent the, it is possible to further improve the accuracy of the malfunction prevention.

Further, a method of correcting the speed threshold value to be compared with the time integral value by the time integral value of the acceleration value before the start of integration and a method of counting the number of times the acceleration value exceeds a predetermined acceleration threshold value can be used together. If this is the case, it will be possible to more clearly determine the difference between various types of collisions, not only to improve the accuracy of preventing malfunctions, but also to enable advanced control such as control of the deployment type of the airbag according to the type of collision. In addition, it is possible to further enhance the safety by the airbag device.

Further, a speed threshold value to be compared with the time integral value is
When the correction is made based on the time integral value of the acceleration value before the start of the integration, the necessity of the correction is determined based on the magnitude of the time component value. And various effects such as more reliable occupant protection can be expected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an operation necessity determination circuit of a side collision airbag device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of an operation necessity determination circuit of the side collision airbag device according to the present invention.

FIG. 3 is a block diagram showing still another embodiment of an operation necessity determination circuit of the side collision airbag device according to the present invention.

FIG. 4 is a block diagram showing a further embodiment of a circuit for determining the necessity of operation of the side collision airbag device according to the present invention.

FIG. 5 is a block diagram showing still another embodiment of a circuit for judging the necessity of operation of the side collision airbag device according to the present invention.

FIGS. 6A and 6B are diagrams showing an example of a temporal change of an acceleration value G in hammering and a subtraction integral value V1 used in the calculation of the present invention, wherein FIG. 6A is a Gt diagram, and FIG. FIG.

FIGS. 7A and 7B are diagrams showing an example of a temporal change of an acceleration value G in a low-speed side collision and a subtraction integral value V1 used in the calculation of the present invention, wherein FIG. 7A is a Gt diagram, and FIG. FIG.

FIG. 8A is another Gt diagram in a low-speed side collision, and FIG. 8B is a Gt diagram in a medium-speed side collision.

FIG. 9A is a V1-t diagram showing a temporal change of the subtraction integral value V1 used in the calculation of the present invention based on the Gt diagrams of FIGS. 6A and 6B; (B) is an Nt diagram showing a temporal change of the count value N of the number of times that the acceleration value G in the middle-speed side collision exceeds a predetermined threshold value.

[Explanation of symbols]

 Reference Signs List 1 acceleration sensor 2 arithmetic circuit 5, 8 integrator 10 comparator (first comparator) 11 system reset circuit 13 trigger circuit 14 airbag 21 second comparator 23 AND circuit G acceleration value Gs acceleration threshold V first integrated value V1 Subtraction integral value Vb Second time integral value V0 Integration threshold value Vs First speed threshold value Vsb Second speed threshold value N Count value Ns Count threshold value

Claims (11)

[Claims] A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side surface portion of a vehicle to determine whether the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. An integral value (V) is calculated, and a predetermined speed subtraction value (ΔV) is calculated from the first time integral value (V).
Is subtracted to calculate a subtraction integral value (V1). The subtraction integral value (V1) is compared with a preset second speed threshold (Vsb), and the subtraction integral value is equal to or greater than the threshold value (V1).
≧ Vsb), the airbag (14) is deployed, and the acceleration value (G) from the acceleration sensor (1) is integrated over time to obtain a predetermined time until the integration start time (t0). The second time integral value (Vb) is calculated, and the absolute value of the second time integral value is calculated as a predetermined first speed threshold value (Vb).
s) to calculate the second speed threshold value (Vsb). 2. A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side portion of a vehicle to determine whether the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. An integral value (V) is calculated, and the first time integral value (V) is compared with a preset second speed threshold value (Vsb), and the time integral value is equal to or greater than the threshold value (Vsb).
≧ Vsb), the airbag (14) is deployed, and the acceleration value (G) from the acceleration sensor (1) is integrated over time to obtain a predetermined time until the integration start time (t0). The second time integral value (Vb) is calculated, and the absolute value of the second time integral value is calculated as a predetermined first speed threshold value (Vb).
s) to calculate the second speed threshold value (Vsb). 3. A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side surface of a vehicle to determine whether or not the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. An integral value (V) is calculated, and a predetermined speed subtraction value (ΔV) is calculated from the first time integral value (V).
Is subtracted to calculate a subtraction integral value (V1). The subtraction integral value (V1) is compared with a preset first speed threshold value (Vs) by a first comparator (10). If the integrated value is equal to or larger than the threshold value (V1 ≧ Vs), an operation permission signal of the airbag (14) is output to an AND circuit (23), and the acceleration value (G) after the integration start time (t0) is obtained. Is compared with a predetermined acceleration threshold value (Gs) at predetermined time intervals, the number (N) of the acceleration values exceeding the acceleration threshold value within a predetermined time period is counted, and the count (N) is compared with the second comparison value. The counter (21) compares the count value with a predetermined count threshold value (Ns) or more (N ≧
Ns), an operation permission signal of the airbag (14) is output to the AND circuit (23), and the AND circuit (23) is permitted to operate the airbag from the first comparator (10). When both a signal and an airbag activation permission signal from the second comparator (21) are input, a trigger instruction signal is output to the trigger circuit (13) of the airbag. Side collision airbag device 4. A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side surface portion of a vehicle to determine whether the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. The first integrated value (V) is calculated by the first comparator (10).
When the first time integration value is equal to or larger than the predetermined first speed threshold value (Vs) (V ≧ Vs), the operation permission signal of the airbag (14) is output to an AND circuit ( 2
3), the acceleration value (G) after the integration start time (t0) is compared with a predetermined acceleration threshold value (Gs) every predetermined time, and the acceleration value within a predetermined time period is determined as the acceleration threshold value. The counted number (N) is counted, and the counted number (N) is compared with a predetermined counting threshold value (Ns) by the second comparator (21).
Ns), an operation permission signal of the airbag (14) is output to the AND circuit (23), and the AND circuit (23) is permitted to operate the airbag from the first comparator (10). When both a signal and an airbag activation permission signal from the second comparator (21) are input, a trigger instruction signal is output to the trigger circuit (13) of the airbag. Side collision airbag device 5. A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side portion of a vehicle to determine whether the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. An integral value (V) is calculated, and a predetermined speed subtraction value (ΔV) is calculated from the first time integral value (V).
Is subtracted to calculate a subtraction integral value (V1). The subtraction integral value (V1) is compared with a second speed threshold value (Vsb) set in advance by a first comparator (10). When the integral value is equal to or larger than the threshold value (V1 ≧ Vsb), the operation permission signal of the airbag (14) is transmitted to the AND circuit (2).
3), the acceleration value (G) after the integration start time (t0) is compared with a predetermined acceleration threshold value (Gs) every predetermined time, and the acceleration value within a predetermined time period is determined as the acceleration threshold value. The counted number (N) is counted, and the counted number (N) is compared with a predetermined counting threshold value (Ns) by the second comparator (21).
Ns), an operation permission signal of the airbag (14) is output to the AND circuit (23), and the AND circuit (23) is permitted to operate the airbag from the first comparator (10). When both a signal and an airbag activation permission signal from the second comparator (21) are input, a trigger instruction signal is output to a trigger circuit (13) of the airbag, and the acceleration sensor ( The acceleration value (G) from 1) is time-integrated to calculate a second time integration value (Vb) for a fixed time period up to the integration start point (t0), and the absolute value of the second time integration value is determined by a predetermined value. First speed threshold (V
s) to calculate the second speed threshold value (Vsb). 6. A predetermined calculation is performed using an acceleration value (G) from an acceleration sensor (1) installed on a side surface portion of a vehicle to determine whether the side collision airbag (14) needs to be deployed. In the side collision airbag device, the acceleration value (G) is integrated over time after the integration start time (t0) when the acceleration value (G) becomes equal to or greater than a predetermined value (G1), and the acceleration value is integrated for a first time. The first integrated value (V) is calculated by the first comparator (10).
When the first time integration value is equal to or greater than the predetermined second speed threshold value (Vsb) (V ≧ Vsb) as compared with a preset second speed threshold value (Vsb), the operation permission signal of the airbag (14) is output to an AND circuit ( 23), the acceleration value (G) after the integration start time (t0) is compared with a predetermined acceleration threshold value (Gs) every predetermined time, and the acceleration value within a certain time period is determined as the acceleration threshold value. The exceeded number (N) is counted, and the count value (N) is compared with a predetermined count threshold value (Ns) by the second comparator (21), and the count value is equal to or larger than the threshold value (N ≧
In the case of Ns), an operation permission signal of the airbag (14) is output to the AND circuit (23), and the AND circuit (23) is permitted to operate the airbag from the first comparator (10). When both a signal and an airbag activation permission signal from the second comparator (21) are input, a trigger instruction signal is output to a trigger circuit (13) of the airbag, and the acceleration sensor ( The acceleration value (G) from 1) is time-integrated to calculate a second time integration value (Vb) for a fixed time period up to the integration start point (t0), and the absolute value of the second time integration value is determined by a predetermined value. First speed threshold (V
s) to calculate the second speed threshold value (Vsb). 7. The second time integration value (Vb) is compared with a preset integration threshold value (V0), and when the second time integration value is equal to or less than the integration threshold value (Vb ≦ V0), The second speed threshold (Vsb) is calculated by adding the absolute value of the second time integration value to the first speed threshold (Vs), and when the second time integration value is equal to or greater than the integration threshold (Vb > V0), the second time integral value (Vb) is regarded as zero and the second speed threshold value (Vsb) is calculated. Side airbag device described in 8. The second time integration value (Vb) is compared with a preset integration threshold value (V0), and when the second time integration value is equal to or less than the integration threshold value (Vb ≦ V0), The second speed threshold (Vsb) is calculated by adding the absolute value of the second time integration value to the first speed threshold (Vs), and when the second time integration value is equal to or greater than the integration threshold (Vb > V0), the first speed threshold (Vs) is subtracted from the subtracted integral value (Vs).
The side airbag device according to any one of claims 1, 2, 5, and 6, wherein the airbag device is compared with 1) or the first time integral value (V). 9. The side collision airbag device according to claim 7, wherein the time threshold value (V0) is a negative value. 10. The side collision airbag device according to claim 1, wherein the first speed threshold (Vs) is a threshold of a time function. 11. The side collision airbag device according to claim 1, wherein the acceleration threshold value (Gs) is a constant value.