JP3965513B2 - Collision determination device for airbag system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a collision determination device for an airbag system, and more particularly to a collision determination device that improves the inoperative safety factor of an airbag device when a large impact is applied to a vehicle body due to a vehicle curb ride or the like. It is.
[0002]
[Prior art]
Conventionally, there are two types of collision sensors that are generally used for the operation of airbags, an electric type using a sensing mass and an electronic type using an acceleration sensor. Recently, the electronic type has become mainstream. ing. The basic method in the case of the electronic method is to time-integrate the acceleration value output from the acceleration sensor, and when the time integrated value exceeds a predetermined threshold value, the operation signal is output to the airbag. In performing this calculation, various calculation methods have been proposed, such as devising that the occupant protection device does not operate at the acceleration change level during rough road driving by reducing a certain acceleration value (for example, Japanese Patent Laid-Open 49-55031, JP-A-3-253441 and JP-A-3-253441).
[0003]
However, the conventional method can cope with the acceleration change due to the vertical movement of the vehicle body on a bad road, but the case where the jaw part of the vehicle body (the front lower part of the vehicle body) rides on a hard obstacle such as a curb, When a large impact is applied to the vehicle body, the acceleration sensor is mounted so as to detect a change in the acceleration of the vehicle body, so that a large acceleration change occurs in the acceleration sensor. The device could malfunction.
[0004]
For example, FIG. 5 is a chart showing an example of the change over time of acceleration when climbing the curb together with the change over time of acceleration of high-speed frontal collision (front collision at high speed) and soft crash (collision at medium speed, etc.). The former two are collisions that require the operation of the airbag device. As described above, the necessity of the operation of the airbag device is that the time integral value of the acceleration G is compared with a predetermined threshold value, and the airbag device is activated when the time integral value is equal to or greater than the threshold value. Since the integral value is represented by the area in the waveform in the figure, as is clear from the figure, the area in the case of curb climbing shows a large value from the first wave. Therefore, simply comparing the time integral value and the threshold value will cause the airbag device to operate.
[0005]
As a method of avoiding this, a method of setting the threshold value to a sufficiently large value is conceivable, but in this method, the airbag device does not operate unless the time integration value becomes sufficiently large. Therefore, in the case of a soft crash, there is a risk of malfunction, and in the case of a serious collision such as a high-speed collision, there is a risk that the operation may be delayed, which reduces the passenger protection function of the airbag device. Become.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the problems associated with the prior art, and an object of the present invention is to provide a collision determination device for an airbag system that does not malfunction due to an impact caused by curb climbing or the like. It is to provide.
[0007]
[Means for Solving the Problems]
The present invention solves the above-mentioned problem, paying attention to the first wave of acceleration output from the acceleration sensor, and a first wave time integration value obtained by time integration based on the first wave, and The duration of the first wave is compared with a predetermined threshold value, and when both are within a predetermined range, the time integral value for collision judgment or the threshold value is corrected. As a correction method, the first wave time integral value is subtracted from the time integral value to reduce the initial time integral value, or the first wave time integral value is added to the threshold value to increase the threshold value itself. In this way, the airbag device is prevented from being deployed by a large impact of the first wave waveform such as curb climbing.
[0008]
The calculation for collision determination starts when the acceleration signal exceeds a predetermined acceleration value, and the predetermined first wave threshold value starts when the first wave of the acceleration signal exceeds the calculation start acceleration value. It is preferable to set the time until the following time as the first wave duration.
[0009]
Further, as a specific configuration of the calculation device, first peak cut means for cutting an acceleration value equal to or lower than a predetermined acceleration value from the acceleration signal after the calculation start time, and the peak-cut acceleration value are time-integrated. First time integration means for calculating a first time integral value, first subtraction means for calculating a first subtraction integral value by subtracting a predetermined first speed subtraction value from the first time integration value, The first subtraction integral value is compared with a predetermined first speed threshold value, and when the first subtraction integral value is equal to or greater than the first speed threshold value, the first comparison means for outputting an operation signal and the acceleration sensor output Second time integration means for calculating the second time integral value by time integrating the acceleration value; and second calculating the second subtraction integral value by subtracting a predetermined second speed subtraction value from the second time integration value. Subtraction means, the first wave time integral value and the duration of the first wave A first wave comparator that compares the first wave time integration threshold and the first wave time threshold, and the first wave time integration value and the duration of the first wave are within a predetermined range. An integral value correction means for calculating a corrected integral value by subtracting the first wave time integral value from a second subtracted integral value; and comparing the corrected integral value with a predetermined second speed threshold value, When the second speed threshold value is exceeded, the second comparison means for outputting the operation signal, and both the operation signal from the first comparison means and the operation signal from the second comparison means are inputted and the operation signal is sent to the trigger circuit. What comprises the AND circuit which outputs is preferable.
[0010]
In place of the integral value correcting means, when the first wave time integral value and the duration of the first wave are within a predetermined range, the first wave time integral value is set to the second speed threshold value. Even if a threshold correction means for adding and calculating the second correction threshold is provided, the same effect is obtained.
[0011]
Further, a subtraction speed change amount per predetermined time is calculated based on the subtraction integral value obtained by the first subtraction means, the subtraction speed change amount is compared with a predetermined subtraction speed change threshold, and the subtraction speed change is calculated. When the amount is equal to or greater than the subtraction speed change threshold value, there is provided third comparison means for outputting an operation signal, and this operation signal and the operation signal from the first comparison means are connected to the AND circuit via the operation signal connection means. The operation signal connecting means is an AND circuit, an OR circuit, a switching circuit, or a combination thereof, and those that change with time are also a preferable mode.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. In this specification, the acceleration on the deceleration side is described as a positive value, but if this is made negative, the same effect is obtained if the positive / negative logic of each explanation is reversed. First, FIG. 1 is a block diagram for explaining the basic concept of a collision determination device for an airbag system according to the present invention. In the figure, an acceleration sensor 1 is connected to a trigger circuit 5 via an arithmetic circuit 3. The trigger circuit 5 is configured to deploy the airbag 6.
[0013]
Next, the arithmetic circuit 3 will be described. In block 11, a time t0 when the acceleration value G measured by the acceleration sensor 1 exceeds a predetermined acceleration G1 is detected, and calculation for collision determination is started from this time. When the calculation is started, in block 50, the acceleration signal G is time-integrated to calculate a time integration value V, and in block 41, a time point te at which the acceleration signal G drops below a predetermined acceleration value G1 ′ is detected. Then, the first wave duration St is detected during the period from the calculation start time t0 to the te, and then the integrator 42 performs a constant integration of the acceleration signal G from the time t0 to the te to obtain the first wave. The time integration value V1p is calculated.
[0014]
Here, the above calculation will be described with reference to FIG. 5. The calculation is started from the time t0 when the acceleration G exceeds G1, and the time when the acceleration G becomes equal to or less than the first wave determination threshold G1 ′ is defined as te. Then, the acceleration between t0 and te is regarded as the first wave, the time between t0 and te is the first wave duration St, and the time integration value (area) during this period is the first wave time integration value V1p. It becomes.
[0015]
Next, the first wave time integration value V1p and the first wave duration St are compared with a predetermined maximum speed threshold value Sx and minimum speed threshold value Sm and maximum time threshold value Tx and minimum time threshold value Tm by the comparator 43. Are both within the threshold range, that is, when Sm <V1p <Sx and Tm <St <Tx, it is determined that an abnormal first wave acceleration such as curb climbing has occurred.
[0016]
That is, as is clear from the acceleration waveform of FIG. 5, in the case of a high-speed forward acceleration waveform, the crash zone in the front part of the vehicle is subject to sequential destruction, crushing and deformation due to buckling. In contrast to the curbstone climbing, a rapid deceleration occurs by rubbing the bottom part of the front part of the vehicle, but the deformation of the vehicle body as described above occurs. Since it does not accompany it, a large pulse with a low frequency appears first, and thereafter gradually attenuates. On the other hand, in the case of a soft crash, an acceleration waveform that gradually increases with time is shown, and it does not have a clear pulse-shaped first wave waveform in the initial stage. From this fact, it can be seen that it is possible to distinguish high-speed frontal collision and soft crash from curb climbing from the duration St of the first wave and its time integral value V1p (area). That is, in the high-speed collision, the first wave time integration value V1p1 shows a relatively large value, but since the duration St1 is short, the minimum time threshold value Tm of the first wave duration St is set to Tm> St1. In this case, both companies can be identified. However, if the minimum speed threshold value Sm of the first wave time integration value V1p is set to Sm> V1p1, the two can be identified more reliably.
[0017]
On the other hand, in the case of a soft crash, the time St3 from the acceleration start time t0 to the time te at which the first wave determination threshold G1 ′ is cut off is a long time. Therefore, if the maximum time threshold value Tx is set to a value larger than the first wave duration St2 in the case of curb climbing, it is easy to discriminate soft crash from curb climbing.
[0018]
As described above, the first wave time integration value V1p and the duration St thereof are compared with the predetermined maximum threshold value and the minimum threshold value. It can be determined that acceleration occurs. Needless to say, these threshold values differ depending on the vehicle type, and are set based on various types of collision tests.
[0019]
Next, when the first wave time integration value V1p and its duration St are in a predetermined range, that is, when Sm <V1p <Sx and Tm <St <Tx, an abnormal first wave such as curb climbing It is determined that acceleration has occurred, and the signal is transmitted to a block 51 which is a time integral value corrector. In this block, the first wave time integral value V1p is subtracted from the time integral value V (V− V1p), a correction time integration value V ′ is obtained, and this is compared with the threshold value Vs for collision determination by the comparator 53. If the correction time integration value V ′ is equal to or greater than the threshold value Vs (V ′ ≧ Vs), it is determined that the airbag needs to be deployed, and a trigger signal is output to the trigger circuit 5. Expand. On the other hand, if V ′ <Vs, the calculation is further continued. When the first wave time integration value V1p and its duration St are out of a predetermined range, that is, when V1p ≦ Sm or V1p ≧ Sx, or St ≦ Tm or St ≧ Tx, the vehicle collision Therefore, the time integral value V is not corrected at all, and a normal determination is made by the comparator 53 for collision determination with V ′ = V.
[0020]
In the above description, an example in which the time integration value V for collision determination is corrected when an abnormal first wave acceleration such as curb climbing is detected has been described. However, as shown in FIG. The method of correcting the determination threshold value Vs is also effective. That is, in FIG. 2, the first wave time integration value V1p and its duration St are compared with predetermined maximum and minimum threshold values, and when both are within the predetermined range as described above, the threshold value corrector is used. In block 55, the first wave time integration value V1p is added to the threshold value Vs (Vs + V1p) to calculate a correction threshold value Vs ′, and this correction threshold value Vs ′ and the time integration value V are used for collision determination. In the comparator 57, the necessity of air bag deployment is determined. In FIG. 2, the same components as those in FIG.
[0021]
In the above description, in order to facilitate understanding of the concept of the present invention, the collision determination flow shows only the main part, but a specific collision determination flow will be described below. FIG. 3 shows an example. When the calculation start time is determined in block 11, the acceleration signal G is transmitted to the block 12 as the first peak cut means, where the acceleration value G after the time t0. Further, the acceleration G3 equal to or greater than G2 is calculated by cutting the predetermined acceleration G2 or less (the acceleration G2 or less is regarded as G2). Next, the first time integration means 13 performs time integration of the acceleration G3 to calculate the first time integration value V, and the next first speed subtraction means 14 calculates a predetermined first per unit time from the time integration value V. The first subtraction integral value V1 is calculated by subtracting the subtraction speed value ΔV1. The first subtraction speed value ΔV1 may be a constant value or a time function value.
[0022]
Next, the first subtraction integral value V1 is transmitted to the block 15 as the first comparison means and the block 16 as the third comparison means, and the results of both the comparison means 15 and 16 are ANDed via the connection means 17 or the block 18. It is transmitted to the circuit 36 or the reset circuit 4. In the first comparison means 15, the comparator 21 compares the first speed threshold Vs1 output from the first speed threshold setter 22 with the first subtraction integral value V1, and the first subtraction integral value V1 is the first subtraction integral value V1. When the speed threshold value is Vs1 or more (V1 ≧ Vs1), an operation signal is output from the line 23 to the block 17 which is a connecting means. On the other hand, when the first subtraction integral value V1 is less than the first speed threshold value Vs1 (V1 <Vs1), it is output to the block 18 from the line 24, where V1 is set to 0 (zero) or in the vicinity thereof. When the value is equal to or lower than the set value (indicated as V1 ≦ 0 in the figure), a signal is sent to the reset circuit 4 to stop the calculation operation, and V1 and t are set to 0 (zero). Reset. If V1 ≧ 0, the calculation is further continued.
[0023]
The first comparison means 15 detects a normal high-speed oblique collision or pole collision while classifying a low-speed frontal collision, and issues a start signal at an operation request timing. Here, the first time threshold value is a predetermined time function that changes with the passage of time, but may be set as a constant value.
[0024]
Next, in block 25, the first subtraction integral value V1 is time-differentiated to calculate a change amount (ΔV3 = dV1 / dt) of the first subtraction integral value V1 per predetermined time. In the device 26, a preset speed change amount threshold value ΔVs output from the block 27 is compared with the change amount ΔV3. Is output. On the other hand, when ΔV3 is less than ΔVs (ΔV3 <ΔVs), it is output from the line 29 to the block 18, and the above-mentioned determination is made to determine whether to reset the circuit or continue the calculation. The third comparing means 16 is used in place of the first comparing means 15 when sufficient acceleration is not transmitted to the room by the operation request time due to the vehicle body characteristics, the collision mode, etc. Focusing on the rapid increase in the subtraction acceleration V1, an operation signal is issued.
[0025]
Next, the block 17 as the connection means changes the OR circuit, the AND circuit, the switching circuit and the combination form thereof with the passage of time. In the case of the OR circuit, any one of the comparison means 15 and 16 is used. If an operation signal is output from the above, this signal is output to the AND circuit 36. In the case of an AND circuit, an operation signal is output to the AND circuit 36 when an operation signal is output from both the comparison means 15 and 16. In the case of a switching circuit, for example, the connecting means 17 is connected to a speedometer, and the comparator 15 and the AND circuit 36 are connected if the speed is equal to or higher than a predetermined speed, and the comparator 16 is connected if the speed is lower than the predetermined speed. It is also possible to connect the AND circuit 36 so that either one outputs an operation signal to the AND circuit 36. Further, the combination form of the comparators 15 and 16 is changed over time. For example, the first half of the operation request timing is only the comparator 15, and the second half of the operation request timing is the OR circuit of the comparators 15 and 16. It can also be used as a connection means. These are appropriately determined depending on the characteristics of the automobile in which the collision sensor is incorporated or how to set the inoperative condition.
[0026]
On the other hand, based on the acceleration value G output from the acceleration sensor 1 after the above-mentioned time t0, in the block 31 that is the second time integration means, the time integration of the acceleration G is performed and the second time integration value V2 is calculated. Then, the second subtraction means 32 subtracts a predetermined second subtraction speed value ΔV2 from the integral value V2 to obtain a second subtraction integral value V2 ′. Here, the second subtraction speed value ΔV2 may be a constant value or may be a time function, but is sufficiently smaller than the first subtraction speed value ΔV1 (ΔV2 << ΔV1). It is set.
[0027]
Here, as shown in FIG. 4, in the block 40 as the second peak cutting means, an acceleration value equal to or lower than a predetermined acceleration G4 is cut from the acceleration value G output from the acceleration sensor 1 after the above-mentioned time t0. Then, an acceleration G5 equal to or greater than G4 is calculated (acceleration G4 or less is regarded as G4). Similarly to the case of FIG. Then, the second subtracting means 32 can subtract a predetermined second subtraction speed value ΔV2 from the integral value V2 to calculate the second subtracted integral value V2 ′. In this case, G4 is set to a value (G4 << G2) that is sufficiently smaller than G2 that is the cutting reference of the first peak cutting means.
[0028]
On the other hand, in block 41, the first wave duration St is obtained by detecting a time te when the acceleration signal G after the calculation start time t0 is equal to or lower than a predetermined first wave determination threshold G1 ′ (G <G1 ′). Further, the integrator 42 performs a constant integration of the acceleration G from the time t0 to the time te to calculate a first wave time integration value V1p, which is compared with a predetermined threshold value in the block 43 and is abnormal such as a curb ride. The point of determining whether or not the state is as described above. When the first wave time integration value V1p and the first wave duration St are both within a predetermined range, the block 44 corrects the second subtraction integration value V2 ′. That is, the first wave time integration value V1p is subtracted from the second subtraction integration value V2 ′ (V2′−V1p) to calculate a corrected second subtraction integration value V3. Two comparison means 37
Send to.
[0029]
In the second comparison means 37, the comparator 33 compares a predetermined second speed threshold value Vs2 output from the block 35 with the corrected second time integrated value V3, and the corrected integrated value V3 is a second value. When the speed threshold Vs2 or more (V3 ≧ Vs2), an operation signal is output from the line 38 to the AND circuit 36. When the corrected integral value V3 is less than the second speed threshold Vs2 (V3 <Vs2), the line 39 is sent to block 18, where it is determined whether to reset or continue the operation as described above.
[0030]
This second comparison means pays attention to the fact that the vibration acceleration waveform generated in the acceleration sensor due to the bottom of the body in a bad road or the like hardly changes in speed, and even if the peak cut is not performed or the peak cut is performed, the noise filter By comparing the time-integrated value of the acceleration waveform with a peak cut of a certain degree with a predetermined second speed threshold value Vs2, an operation signal is generated in a normal high-speed oblique collision, a pole collision, or a vehicle collision with low body rigidity. However, an operation signal is not generated depending on the vibration component.
[0031]
As described above, the results of the comparison means 15 and 16 are input to the AND circuit 36 via the connection means 17, and the result of the comparison means 37 is also input to the AND circuit 36. In the AND circuit 36, the connection means 17 When the operation signal from the comparison means 37 is input, the operation signal is output to the trigger circuit 5. As a result, the first comparison means 15 and the third comparison means 16 discriminate normal high-speed oblique collisions and pole collisions from low-speed frontal collisions, and identify collisions in the case of a vehicle with low body rigidity at an early stage. It is possible to identify the acceleration change due to the slamming of the bag cover, and to prevent the malfunction on the rough road by the second comparison means 37. Here, the AND circuit 36 may be any AND means, and outputs an operation signal for the signals from both the connection means 17 and the comparison means 37 by determination using fuzzy theory or weighting. It is also possible to configure.
[0032]
3 and 4 show the case where the second time integration value V2 ′ is corrected when the first wave time integration value V1p is within a predetermined range, the example shown in FIG. Similarly to the above, it is possible to correct the second speed threshold value Vs2.
[0033]
In addition, since a normal collision involves deceleration, it basically has a one-sided amplitude in the positive direction, but the vibration component due to rough road is merely mere vibration of the vehicle body caused by bottoming out of the body and so there is almost no deceleration. The acceleration waveform has amplitude on both the positive and negative sides. Therefore, the peak cut in block 40 and the subtraction in block 32 in FIG. 4 are preferably performed to the extent that noise is removed. Thus, by setting the predetermined second speed threshold value Vs2 appropriately, it becomes easy to prevent malfunction even in severe rough roads.
[0034]
The above is a basic embodiment of the present invention, and the present invention is not limited to this. Various modifications may exist based on the idea described in the claims. Needless to say. For example, FIGS. 1 to 4 show a case where the first time time integral value V1p is directly subtracted or added to the time integral value for collision determination or its threshold value to calculate a corrected time integral value or a correction threshold value. However, in this correction, instead of the first wave time integration value V1p, a value that changes in accordance with the first wave time integration value V1p (V1p ′ = f (V1p)) is determined in advance. One wave time integration value V1p ′, for example, a value proportional to V1p as indicated by V1p ′ = A × V1p (A is a constant), or a time represented by V1p ′ = f (V1p, t) and V1p In particular, the method of gradually decreasing the value with time has the effect of limiting the influence of the first wave only at the initial stage of calculation and reducing the possibility of misjudgment in the case of a serious collision. is there.
[0035]
3 and 4, the predetermined first subtraction speed value ΔV1 of the block 14 can be a function value, for example, a function value of the integration value V1 at that time, and the acceleration G3 of the block 13 can be changed. Instead of integration, low-speed frontal collision, high-speed diagonal collision, and soft vehicle body collision may be performed by time-integrating the acceleration G3 to the Kth power (K ≧ 1), integrating the acceleration G3 by n-th order, or a combination thereof. It is also possible to further clarify the classification. Further, in the block 18, the circuit is reset by the reset circuit 4 when V1 is less than or equal to a small predetermined value near zero. However, the predetermined value can be made a function of the acceleration G3 at that time. is there. Further, before the block 11, the value Gx obtained by subtracting the value Gf subjected to the filter processing of the time constant of 5 ms or more from the acceleration G is used in place of the acceleration G, thereby eliminating the influence of the zero drift of the accelerometer. It is also possible to increase the accuracy.
[0036]
Furthermore, the mounting structure of the acceleration sensor 1 is vibrated at 50 to 2000 Hz (in the vibration characteristics in the traveling direction of the automobile) to amplify the acceleration G, or to amplify a specific frequency band in the electric circuit of the acceleration sensor 1. It is also possible to have a range.
[0037]
3 and 4, when a low-pass filter is inserted between the block 11 and the block 31, the vibration component due to rough road is a high frequency, so that the distinction from the collision becomes clearer. If a low-pass filter is inserted between them, the acceleration waveform that affects the speed change is low frequency, so that the distinction from the vibration component due to rough road becomes clearer and the effect can be further enhanced.
[0038]
【The invention's effect】
As described above, in the present invention, the acceleration waveform of a high-speed collision requiring a deployment of an airbag or a soft crash, and the acceleration waveform in an abnormal situation such as when the jaw of the vehicle body rides on the curb are the first. Based on the knowledge of the fact that there is a clear difference in the waveform of one wave, by comparing the time integral value of the first wave and its duration with a predetermined threshold, Is clearly distinguished, and if it is determined that there is an abnormal situation such as curb climbing, the time integral value of the first wave is subtracted from the time integral value of the acceleration signal for determining whether the airbag needs to be deployed. Or by adding the time integral value of the first wave to the threshold value to increase the threshold value so that the time integral value for collision judgment does not easily exceed the threshold value. Air bag misfolding in non-collision abnormalities such as raising The will be like can be reliably prevented, it will be to improve the safety of the air bag.
[0039]
Further, the comparison means for judging the collision is made up of a plurality of systems. In particular, as shown in FIGS. 3 and 4, the first comparison means 15 classifies the high-speed oblique collision and the pole collision as the low-speed normal collision, The comparison means 37 determines whether or not there is a speed change by comparing the second subtraction integral value V2 ′ of the acceleration waveform that is not substantially peak-cut with the second speed threshold value Vs2. The AND of the first comparison means 15 is taken, and the second comparison means 37 accurately determines whether the first comparison means 15 is activated or deactivated. Can be classified as a collision, and malfunctions in severe rough roads can also be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a basic system of the present invention.
FIG. 2 is a block diagram showing a modification of FIG.
FIG. 3 is a block diagram showing a specific embodiment of the present invention.
4 is a block diagram showing a modification of FIG. 3. FIG.
FIG. 5 is a Gt diagram showing a time-dependent change in acceleration value in the case of a high-speed collision, soft crash, and curb ride.
[Explanation of symbols]
1 Accelerometer
3 Arithmetic circuit
4 Reset circuit
5 Trigger circuit,
6 Airbag
12 First peak cutting means
13 First time integration means
14 First subtraction means
15 First comparison means
16 Third comparison means
17 Actuation signal connection means
31 Second time integration means
32 Second subtraction means
36 AND circuit
37 Second comparison means
41 First wave end point detector
42 First wave time integrator
43 comparator
44, 51 Time integral correction unit
55 threshold corrector

Claims (12)

The time integration value (V) obtained by calculation based on the acceleration signal (G) output from the acceleration sensor (1) is compared with a predetermined threshold value (Vs), and the time integration value exceeds the threshold value. In the case of a collision determination device for an airbag system in which the trigger circuit (5) of the airbag is activated in the case (V ≧ Vs),
The first wave time integral value (V1p) obtained by time integration based on the first wave of acceleration output from the acceleration sensor (1) and the duration (St) of the first wave are set as a predetermined threshold value. In comparison, when both are within a predetermined range, the time integral value (V) for the collision determination is changed from the first wave time integral value (V1p) or the first wave time integral value. The corrected time integral value (V ′) obtained by subtracting the transformed first wave time integral value (V1p ′) that changes with the threshold value (Vs) for the collision determination is compared with the threshold value (Vs). The correction threshold value (Vs ′) obtained by adding the first wave time integral value (V1p) or the modified first wave time integral value (V1p ′) that changes according to the first wave time integral value to Vs). Is compared with the time integral value (V). Cutting device The collision determination device for an airbag system according to claim 1, wherein the transformed first wave time integral value (V1p ') is a value proportional to the first wave time integral value (V1p). The airbag according to claim 1, wherein the transformed first wave time integral value (V1p ') is a function of the first wave time integral value (V1p) and time (t), and gradually decreases with time. System collision judgment device From the time point (t0) when the acceleration signal (G) exceeds a predetermined acceleration value (G1), time integration based on the acceleration signal and calculation for predetermined collision determination are started, and the acceleration signal The first wave duration (St) is from the time when the first wave exceeds the calculation start acceleration value (G1) to the time (te) when the first wave falls below a predetermined first wave determination threshold (G1 ′). The collision determination device for an airbag system according to any one of claims 1 to 3 The acceleration signal (G) is definitely integrated between the calculation start time (t0) and the first wave end time (te) to obtain a first wave time integration value (V1p), and the first wave time integration value Is a value between a preset minimum value (Sm) and a maximum value (Sx) (Sm <V1p <Sx), and the first wave duration (St) is a preset minimum value (Tm) And the maximum value (Tx) (Tm <St <Tx), the time integral value (V) for the collision determination to the first wave time integral value (V1p) or the first wave The amount (V1p ′) corresponding to the time integral value is subtracted and compared with the threshold value (Vs) for the collision determination, or the first wave time integral value (V1p) or the threshold value (Vs) is compared with the threshold value (Vs). An amount (V1p ') corresponding to a first wave time integration value is added and compared with the time integration value (V). Collision determining apparatus for an air bag system according to First peak cut means (12) for cutting an acceleration value equal to or lower than a predetermined acceleration value (G2) from an acceleration signal (G) after the calculation start time (t0);
First time integration means (13) for time-integrating the peak-cut acceleration value (G3) to calculate a first time integration value (V);
First subtraction means (14) for calculating a first subtraction integral value (V1) by subtracting a predetermined first speed subtraction value (ΔV1) from the first time integral value (V);
The first subtraction integral value (V1) is compared with a predetermined first speed threshold value (V1p), and when the first subtraction integral value is equal to or higher than the first speed threshold value (V1 ≧ Vs1), an operation signal ( First comparison means (15) for outputting 23),
Second time integration means (31) for time integrating the acceleration value (G) output from the acceleration sensor (1) to calculate a second time integration value (V2);
A second subtracting means (32) for calculating a second subtracted integral value (V2 ′) by subtracting a predetermined second speed subtracted value (ΔV2) from the second time integrated value (V2);
The first wave time integration value (V1p) and the first wave duration (St) are compared with a predetermined first wave time integration threshold (Sm, Sx) and a first wave time threshold (Tm, Tx). A first wave comparator (43);
When the first wave time integration value (V1p) and the first wave duration (St) are within predetermined ranges, respectively, the first wave time integration value is calculated from the second subtraction integration value (V2 ′). (V1p) or an integral value correction means (44, 51) for calculating a corrected integral value (V3) by subtracting the amount (V1p ′) corresponding to the first wave time integral value;
The corrected integral value (V3) is compared with a predetermined second speed threshold value (Vs2), and when the corrected integral value is equal to or greater than the second speed threshold value (V3 ≧ Vs2), an operation signal (38) is output. A second comparison means (37);
An AND circuit that receives both the operation signal (23) from the first comparison means (15) and the operation signal (38) from the second comparison means (37) and outputs the operation signal to the trigger circuit (5). The collision determination device for an airbag system according to claim 5, further comprising: First peak cut means (12) for cutting an acceleration value equal to or lower than a predetermined acceleration value (G2) from an acceleration signal (G) after the calculation start time (t0);
First time integration means (13) for time-integrating the peak-cut acceleration value (G3) to calculate a first time integration value (V);
First subtraction means (14) for calculating a first subtraction integral value (V1) by subtracting a predetermined first speed subtraction value (ΔV1) from the first time integral value (V);
The first subtraction integral value (V1) is compared with a predetermined first speed threshold value (Vs1), and if the first subtraction integral value is equal to or greater than the first speed threshold value (V1 ≧ Vs1), an operation signal ( First comparison means (15) for outputting 23),
Second time integration means (31) for time integrating the acceleration value (G) output from the acceleration sensor (1) to calculate a second time integration value (V2);
A second subtracting means (32) for calculating a second subtracted integral value (V2 ′) by subtracting a predetermined second speed subtracted value (ΔV2) from the second time integrated value (V2);
The first wave time integration value (V1p) and the first wave duration (St) are compared with a predetermined first wave time integration threshold (Sm, Sx) and a first wave time threshold (Tm, Tx). A first wave comparator (43);
When the first wave time integral value (V1p) and the first wave duration (St) are within a predetermined range, the first wave time integral value (V1p) or the second velocity threshold value (Vs2) Threshold correction means (55) for calculating a second correction threshold (Vs2 ′) by adding an amount (V1p ′) corresponding to the first wave time integral value;
The second subtraction integral value (V2 ′) is compared with the second correction threshold value (Vs2 ′), and when the second subtraction integration value is equal to or greater than the second correction threshold value (V2 ′ ≧ Vs2 ′), the operation is performed. Second comparison means (37) for outputting a signal (38);
An AND circuit that receives both the operation signal (23) from the first comparison means (15) and the operation signal (38) from the second comparison means (37) and outputs the operation signal to the trigger circuit (5). The collision determination device for an airbag system according to claim 5, further comprising: The acceleration value integrated by the second time integration means (31) is less than or equal to a predetermined value (G4) from the acceleration value (G) output from the acceleration sensor (1) by the second peak cut means (40). The collision determination device for an airbag system according to any one of claims 4 to 7, wherein the acceleration value is an acceleration value (G5) with a peak cut. The acceleration value (G4) peak-cut by the second peak cutting means (40) is sufficiently smaller than the acceleration value (G2) peak-cut by the first peak cutting means (12). The collision determination device for an airbag system according to claim 8. The collision determination device for an airbag system according to any one of claims 4 to 9, wherein the first speed threshold (Vs1) is a function of time. A subtraction speed change amount (ΔV3) per predetermined time is calculated based on the subtraction integral value (V1) obtained by the first subtraction means, and the subtraction speed change amount and a predetermined subtraction speed change threshold value (ΔVs) are calculated. In comparison, when the subtraction speed change amount is equal to or greater than the subtraction speed change threshold (ΔV3 ≧ ΔVs), there is a third comparison means (16) for outputting an operation signal (28), and this operation signal (28). 11. The operation signal (23) from the first comparison means (15) is input to the AND circuit (36) via the operation signal connection means (17). Collision judgment device for the described airbag system The collision determination device for an airbag system according to claim 11, wherein the operation signal connection means (17) is an AND circuit, an OR circuit, a switching circuit, or a combination thereof.

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