JPH0976872A - Side face collision detector for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform production in a low cost and to improve reliability for collision decision. SOLUTION: G sensors 10, 13, each of which detects a sideways acceleration generated when a collision is caused on a side face of a vehicle, are individually arranged on the left side face and the right side face in the vehicle, and on the basis of respective outputs from the G sensors 10, 13, integral values for the predetermined duration are individually computed, and then, it is determined that a collision is caused on the side face in which one sensor is arranged, when the integral value based on an output from one sensor is the predetermined first threshold value or more while the integral value based on an output from the other sensor is the predetermined second threshold value or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle which is mounted on a vehicle such as a passenger car and is preferably used for deployment control of an airbag for protecting an occupant in a passenger compartment from a shock caused by a collision with another vehicle. The present invention relates to a side collision detection device.

[0002]

2. Description of the Related Art Recently, passenger cars equipped with an air bag for protecting an occupant from a shock at the time of a collision have become popular. General airbags include passenger cars and other vehicles,
This is a so-called front-collision airbag that is deployed when it collides with a wall or a utility pole from the front. Further, in order to further enhance safety, passenger cars equipped with so-called side airbags that can cope with side collisions are also on the market.

[0003]

As means for detecting whether or not a collision has occurred, an electric detecting means such as an acceleration sensor or a pressure sensor is used. For example, the output (acceleration) from the acceleration sensor is integrated over a predetermined period, and when the integrated value exceeds a predetermined threshold value, it is determined that a collision has occurred, and the airbag is deployed. By using the integral value in this way, it is possible to improve the accuracy of determination without accidentally determining a collision when an instantaneous increase in output occurs.

However, when a high output continues for a long period of time due to a sensor failure or the influence of strong radio waves, a collision may be erroneously generated even though no collision has actually occurred. I will judge. A so-called safing sensor is provided in order to prevent such an erroneous determination and improve the safety and reliability of airbag control. The safing sensor is provided, for example, in series with an ignition line that connects an ECU (electronic control unit) that controls an airbag and an ignition device that actually deploys the airbag. A mechanical switch is generally used as the safing sensor. The mechanical switch becomes conductive due to the impact of a collision. When the ECU determines that a collision has occurred based on the output of the acceleration sensor, it outputs an ignition signal to the ignition line, but if the collision actually occurs and the mechanical switch is not conducting, the ignition signal is the ignition signal. Not given to the device, the airbag does not deploy. In this way, the reliability of airbag control is improved.

Since the deployment of the air bag is meaningless unless it is performed immediately after the occurrence of the collision, a considerably high response speed of the mechanical switch is required. When the mechanical switch is used as a safing sensor in side airbag control, the response speed of the mechanical switch is required to be higher than that used for a frontal collision. This is because the time until the impact of the collision reaches the occupant is shorter in the side collision than in the front collision. Therefore, the mechanical switch used as the safing sensor for frontal collision cannot fulfill its function, and it is necessary to develop a new one with a high response speed, which causes an increase in manufacturing cost.

An object of the present invention is to provide a side collision detection device for a vehicle, which can be realized at low cost and has improved reliability of collision judgment.

[0007]

SUMMARY OF THE INVENTION The present invention is provided with left and right impact detection means, which are provided on both left and right side surfaces of a vehicle and detect lateral impact of the vehicle when a collision occurs on a side surface of the vehicle. A calculated value is calculated according to a predetermined calculation based on the outputs of the left and right impact detection means, and the calculated value based on the output of one detection means is equal to or greater than a predetermined first threshold value, and the calculated value of the other detection means A side collision of a vehicle, which includes a judging means for judging that a collision has occurred on the side surface provided with the one-side detecting means when the calculated value based on the output is equal to or more than a predetermined second threshold value. It is a detection device. According to the present invention, the calculated value based on the output of one of the left and right impact detecting means provided on both the left and right side surfaces is equal to or greater than the predetermined first threshold value and based on the output of the other detecting means. When the calculated value is equal to or larger than the second threshold value set in advance, it is determined that a collision has occurred on the side surface provided with the one-way detecting means. That is, when a collision occurs on one side surface of the vehicle, the impact on the one side surface due to the collision is detected by the one detection means. At this time, the impact of the collision is also transmitted to the other side surface side, and the impact is also detected by the other detecting means. Therefore, if the calculated values based on the two detection means are equal to or greater than the first and second threshold values that are respectively set in advance, it can be determined that a collision has clearly occurred. Even if a relatively large lateral impact is detected by one of the detection means due to a malfunction or the like and the calculated value is equal to or more than the first threshold value, the other detection means detects a normal impact (general running). The impact value is not detected and the calculated value does not exceed the second threshold value, and the presence or absence of a collision can be detected with high accuracy. Since the other detection means is used as a so-called safing sensor as described above, it is not necessary to separately provide a dedicated safing sensor, the number of parts is reduced, and it is not necessary to newly develop the device, thereby reducing the manufacturing cost. Can be planned.

In the present invention, the impact detecting means is a uniaxial acceleration sensor for detecting lateral acceleration of the vehicle,
It is characterized in that the judging means calculates an integrated value of the output of the acceleration sensor in a predetermined period as a calculated value. According to the present invention, the shock detecting means is realized by an acceleration sensor, and the judging means integrates the output of acceleration in a predetermined period to calculate an integrated value. That is, if a collision occurs on one side surface, naturally, a large acceleration is applied to the one side surface, and further, the vehicle itself moves in the collision direction due to the impact of the collision, so that the other side surface is also accelerated. . Therefore, the collision can be detected smoothly and surely by detecting the acceleration as the impact. Further, since the judgment is made based on the integrated value of the acceleration in a predetermined period, even if a large acceleration is momentarily detected due to an external factor or the like, the judgment of the collision is not made and the judgment accuracy is improved.

Further, according to the present invention, there are provided left and right side impact detection means for detecting a lateral impact of the vehicle, which are provided on both left and right side surfaces of the vehicle, and which are generated when a collision occurs on a side surface of the vehicle. Two-way impact detection means for detecting the longitudinal and lateral impacts of the vehicle that occur when a side collision occurs, and the calculated values are calculated according to a predetermined calculation based on the outputs of the detection means.
The calculated value based on one of the left and right impact detecting means is equal to or greater than a predetermined first threshold value, and the calculated value based on the lateral output of the two-way impact detecting means is predetermined second threshold value. When the above is the case, it is determined that a collision has occurred on the side surface provided with the one-sided detecting means, and when the calculated value based on the longitudinal output of the two-way impact detecting means is equal to or greater than a predetermined third threshold value. A side collision detection device for a vehicle, comprising: a determining unit that determines that a frontal collision has occurred. According to the present invention, the calculated value based on the output of one of the left and right side impact detection means provided on both the left and right side surfaces is equal to or greater than the predetermined first threshold value, and the lateral direction of the two-way impact detection means. The second calculated value based on the direction output is predetermined
When it is equal to or more than the threshold value, it is determined that a collision has occurred on the side surface provided with the one-side detecting means. That is, when a collision occurs on one side surface of the vehicle, the impact on the one side surface due to the collision is detected by the one detection means. At this time, the impact of the collision is transmitted to the entire vehicle, and the lateral impact is detected by the two-way impact detection means provided at an appropriate place on the vehicle. Therefore, if the calculated values based on the outputs of the two detecting means are equal to or greater than the predetermined first and second threshold values, it can be determined that a collision has occurred. Even if a relatively large lateral impact is detected by the one detection unit due to a malfunction or the like and the calculated value becomes equal to or more than the first threshold value, the two-direction impact detection unit detects normal operation (general running). Only the impact in the horizontal direction is detected, the calculated value does not exceed the second threshold value, and it is possible to determine with high accuracy whether or not a side collision has occurred.
If the calculated value based on the vertical impact of the two-way impact detection means is equal to or greater than the predetermined third threshold value, it is determined that a frontal collision has occurred. As described above, since the two-way impact detecting means is used not only as a safing sensor but also as a sensor for frontal collision detection, there is no need to provide a dedicated safing sensor separately, Reduced points, no need to develop new,
Manufacturing costs can be reduced.

Still further, according to the present invention, the two-way impact detecting means is a two-axis acceleration sensor which detects longitudinal and lateral accelerations of the vehicle, and the left and right impact detecting means are respectively in the lateral direction of the vehicle. Is a uniaxial acceleration sensor for detecting the acceleration, and the determining means calculates an integrated value of the output of the acceleration sensor during a predetermined period as a calculated value. According to the present invention, the shock detecting means is realized by an acceleration sensor, and the judging means calculates an integral value of acceleration in a predetermined period. That is, if a collision occurs on one side surface, a large acceleration is naturally applied to the one side surface, and further, the vehicle itself moves in the collision direction due to the impact of the collision, and thus the two-way impact detection means is also accelerated. become. Therefore, the collision can be detected smoothly and surely by detecting the acceleration as the impact.
In addition, since the judgment is made based on the integrated value of acceleration in a predetermined period, even if a large acceleration is momentarily detected due to external factors, it is not judged that a collision has occurred, and the accuracy of judgment is high. Is improved.

Further, according to the present invention, when the calculated value based on the output of the one-sided detecting means is equal to or more than a predetermined first threshold value, the judging means sets the second threshold value in accordance with the calculated value. It is characterized by changing. According to the invention, when the calculated value based on the output of the one-side detecting means is equal to or larger than the predetermined first threshold value, the second threshold value is changed according to the calculated value. In particular,
If the calculated value becomes large, the second threshold value is increased accordingly. On the other hand, if the calculated value based on the output of the detecting means is a value far exceeding the first threshold value, it is highly possible that a collision has occurred, and naturally the calculated value based on the output of the other detecting means or the two-way impact detecting means is also included. It should increase accordingly, and increasing the second threshold does not affect the judgment. Conversely, when the second threshold value is fixed, the second threshold value is set to a relatively low value because it is necessary to detect all collisions that affect the occupant. Therefore, while the calculated value based on the output of the one detection means is a value far exceeding the first threshold value, the calculated value based on the output of the other detection means or the like may slightly exceed the second threshold value. Sometimes,
On the other hand, there is a high possibility that the detection means malfunctions, but the present invention can prevent such misjudgment from occurring.

Further, the present invention is characterized in that the judging means calculates the calculated value when the output of the one-side detecting means is a predetermined value or more. According to the present invention, when the output of the one-way detecting means becomes equal to or greater than the predetermined value, the calculated value is calculated to determine whether or not a collision has occurred. In other words, if a collision occurs, the output will increase rapidly, so it is sufficient to make a predetermined calculation and make a judgment only when the output value exceeds a predetermined output value. Make a judgment with a low output value. Is a completely useless process. By thus performing the processing only when necessary, the load on the judging means is reduced.

[0013]

1 is a block diagram showing the basic construction of an airbag control device 1 according to an embodiment of the present invention. The airbag control device 1 includes a center sensor unit 2, a right sensor unit 3R, a left sensor unit 3L, a center airbag unit 4, and
It is configured to include a right airbag unit 5R and a left airbag unit 5L.

The center sensor unit 2 comprises a semiconductor G sensor 6 and a main control section 7 realized by a microcomputer or the like, and as shown in FIG.
Is provided in the vicinity of the center position in the width direction of the vehicle, for example, on the floor below the center console box.
The center airbag unit 4 is controlled by detecting the acceleration (G) generated in the right and left airbag units 5R and 5L based on the detection signals from the right and left sensor units 3R and 3L.

A detection signal from a front airbag sensor (not shown) is also given to the center sensor unit 2. One front airbag sensor is installed in each of the left and right front fenders. It senses the acceleration (deceleration) at the time of a vehicle collision, and conducts electricity when the acceleration is at a level above the level that will hinder the driver, etc. It is a switch. Further, the center sensor unit 2 is provided with a safing sensor (not shown), which conducts when a deceleration equal to or more than a preset value is applied. The safing sensor is provided in series with a control signal line or a power supply line to the center airbag unit 4.
The deceleration at which the safing sensor conducts is the same as the above G
A value lower than the deceleration at which the sensor 6 and the front airbag sensor are in conduction is set.

The main controller 7 integrates the output from the G sensor 6 over a predetermined period, and when the integrated value is equal to or larger than a predetermined threshold value, or when a detection signal from the front airbag sensor is received. Then, it determines that a collision has occurred and outputs an ignition signal to the control signal line of the center airbag unit 4. In this way, the center sensor unit 2 performs comprehensive control of the airbag control device 1, such as determining whether to activate the airbag and diagnosing the system failure.

The light sensor unit 3R comprises a semiconductor G sensor 10 and a control unit 11 realized by a microcomputer or the like, and is arranged at an appropriate position on the right side surface portion of the vehicle 8 as shown in FIG. To be done.

The G sensor 10 detects the acceleration (G) generated in the width direction of the vehicle 8, and the acceleration generated when moving from the right side surface to the left side surface in the direction of arrow R1 shown in FIG. Value, and the acceleration generated when moving in the opposite direction is detected as a negative value. The control unit 11 uses G
A predetermined calculation is executed based on the detected value from the sensor 10, and an ignition signal is output to the main controller 7 when the calculated value is equal to or larger than a predetermined threshold value. As the predetermined calculation, integration in a predetermined period is performed. The predetermined period is selected to be 10 msec, for example.

There are two types of ignition signals output by the control unit 11, an ignition determination signal and an ignition permission signal. The ignition determination signal is a signal that is output when it is determined that a collision from the right side has occurred, and the ignition permission signal is a signal that is output when a collision on the left side occurs. When a collision occurs from the right side, the G sensor 10 outputs a positive signal. Control unit 1
1 indicates time t1 to time t2 as shown in FIG.
Integration is performed for a predetermined period T1 up to, and if the integrated value is greater than or equal to a predetermined first threshold value, an ignition determination signal is output. Conversely, when a collision from the left side occurs G
The sensor 10 receives an acceleration in the direction opposite to the arrow R1 due to the influence of the collision, and outputs a negative signal. As shown in FIG. 3B, the control unit 11 executes integration over a predetermined period T1 from time t1 to time t2, and if the absolute value of the integrated value is equal to or greater than a second threshold value set in advance, Ignition permission signal is output.

The left sensor unit 3L comprises a semiconductor G sensor 12 and a control section 13 realized by a microcomputer or the like, and is installed at an appropriate position on the left side surface of the vehicle 8 as shown in FIG. To be done. The difference from the light sensor unit 3R is that the detection direction of the G sensor 12 is opposite.

The G sensor 12 detects the acceleration (G) generated in the width direction of the vehicle 8, and the acceleration generated when moving from the left side surface to the right side surface in the direction of arrow R2 shown in FIG. 2 is positive. The value is detected as a value, and the acceleration generated when moving in the opposite direction is detected as a negative value. The control unit 13 also performs the same calculation as the control unit 11, and outputs the ignition determination signal and the ignition permission signal. An ignition determination signal is output when a collision occurs from the left side, and an ignition permission signal is output when a collision occurs from the right side.

The collision judgment by the control units 11 and 13, that is, the judgment as to whether or not to output the ignition signal may be carried out at all times, but it is useless to carry out the judgment in the state where only a slight acceleration is detected. This process is unnecessary and puts a heavy burden on the control units 11 and 13 more than necessary. Therefore, the collision determination may be performed after the acceleration of a predetermined value or more is detected. For example, G sensor 10
When an acceleration of 1 G or more is detected at
Gives that fact to the main control unit 7 and starts the calculation of the integrated value. The main control unit 7 instructs the control unit 13 to start calculation in response to the detection signal from the control unit 11.
In this way, if the determination process is performed only when a relatively high acceleration in which a collision is expected to occur is detected, the processing load of the control units 11 and 13 is reduced, and in particular,
This is effective when the main control unit 7 and the control units 11 and 13 are realized by one microcomputer or the like, and when electronic control other than the airbag control is also executed.

In order to make the collision determination by the control units 11 and 13 with higher accuracy, when the ignition determination signal is output from the one sensor unit, the calculated value (integration) calculated by the one sensor unit is output. The second threshold value of the other sensor unit may be changed according to (value). Specifically, the second threshold value is increased as the calculated value is increased. For example, when the control unit 11 determines that the integrated value exceeds the first threshold value and the ignition determination signal is given to the main control unit 7, the main control unit 7 reads the integrated value from the control unit 11, and the value is read. The second threshold value is selected in accordance with the above and is given to the control unit 13. The control unit 13 determines whether to output the ignition permission signal based on the second threshold value set by the main control unit 7.

By executing such processing, it is possible to reduce the occurrence of erroneous judgment. That is, the fact that the calculated value detected by the sensor unit on one side is very large means that the impact of the collision is so great, and therefore the impact transmitted to the other side surface should also be quite large, so the second threshold value is set high. Even if the value is changed, it does not affect the judgment, and the judgment can be made accurately. Conversely, the second
If the threshold value is fixed, a relatively low value is selected because it is necessary to detect all collisions that affect the occupants. Therefore, when the calculated value becomes a large value due to a malfunction of one sensor, the other sensor unit also has a low second threshold value, so that it may be erroneously determined that a collision has occurred and an ignition permission signal may be output. Is not preferable.

The center airbag unit 4 and the right and left airbag units 5R and 5L have basically the same structure, and the ignition device 14 and the airbag 15 are basically the same.
And An ignition signal from the main control unit 7 is given to the ignition device 14, and when ignited, the transfer agent and the gas generating agent are sequentially ignited. When the gas generating agent burns, a large amount of nitrogen gas, for example, is generated, and this gas is blown into the airbag 15 and the airbag 15 expands.

FIG. 4 is a flow chart for explaining the processing of the main controller 7. When an ignition determination signal from one of the right and left sensor units 3R and 3L is input in step a1, the process proceeds to step a2,
It is determined whether or not the ignition permission signal from the other unit is input, and if it is input, the airbag on the side surface provided with the one unit is deployed in step a3.

As described above, since the collision determination (ignition determination) is performed by using each output of the sensors provided on the left and right side surfaces together, it is necessary to separately provide a safing sensor such as a mechanical switch. In addition, the number of parts and the manufacturing cost can be reduced. In addition, it is possible to accurately determine a collision by electrical processing without using a mechanical safing sensor.

In the above-mentioned embodiment, the other side of the two sensors is used as a so-called safing sensor, but in another embodiment, the G sensor 6 provided in the center sensor unit 2 is The biaxial acceleration sensor capable of detecting the directional acceleration may also be capable of detecting the lateral acceleration, and the ignition permission may be determined based on the lateral acceleration.

[0029]

As described above, according to the present invention, it is not necessary to separately provide a so-called safing sensor separately, the number of parts can be reduced, the installation space can be reduced, and the cost can be reduced. You can Moreover, since the collision determination is performed based on the calculated value based on the outputs of the two detection means, the determination can be performed accurately.

Further, according to the present invention, since the acceleration is used as the impact detected by the detecting means, the impact caused by the collision can be satisfactorily achieved even in the detecting means provided at a place different from the side surface where the collision occurs. It can be detected and the judgment accuracy is improved. Further, since the integrated value of the output in a predetermined period is used as the calculation value serving as the reference for the determination, erroneous determination due to the instantaneous change in the output is not made, and the determination accuracy is improved.

Further, according to the present invention, the second value is calculated based on the calculated value based on the output value of the one detecting means equal to or higher than the first threshold value.
Since the threshold value is changed, it is possible to prevent an erroneous determination due to a malfunction of the one-way detecting means,
The accuracy is improved.

Further, according to the present invention, the judgment processing is executed only when the output of the one-side detecting means exceeds a predetermined value, that is, when it is expected that a collision has occurred. Is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an airbag control device 1 according to an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement position of a sensor unit.

FIG. 3 is a control unit 1 included in sensor units 3R and 3L.
6 is a graph illustrating signal processing performed by 1 and 13.

FIG. 4 is a flowchart illustrating a process of a main control unit 7.

[Explanation of symbols]

 1 airbag control device 2 center sensor unit 3R right sensor unit 3L left sensor unit 4 center airbag unit 5R right airbag unit 5L left airbag unit 6,10,12 G sensor 7 main controller 8 vehicle 9 straight ahead direction 11, 13 Control Unit 14 Ignition Device 15 Airbag

Claims (6)

[Claims] 1. The vehicle is provided on both left and right sides of the vehicle,
Left side and right side impact detection means for detecting a lateral impact of the vehicle that occurs when a collision occurs on the side surface of the vehicle, and calculation values are respectively calculated according to predetermined calculations based on the outputs of the left side and right side impact detection means. However, when the calculated value based on the output of the one detection means is greater than or equal to a predetermined first threshold value and the calculated value based on the output of the other detection means is greater than or equal to a predetermined second threshold value, the one detection means A side collision detection device for a vehicle, comprising: a determining unit that determines that a collision has occurred on a side surface on which the vehicle is provided. 2. The impact detecting means is a uniaxial acceleration sensor for detecting lateral acceleration of the vehicle, and the judging means calculates an integrated value of outputs of the acceleration sensor in a predetermined period as a calculated value. The side collision detection device for a vehicle according to claim 1, wherein: 3. The vehicle is provided on both left and right side surfaces,
Left and right impact detection means for detecting the lateral impact of the vehicle that occurs when a collision occurs on the side of the vehicle, and the vertical and lateral impacts of the vehicle that occur when a collision occurs on the front and side of the vehicle And a two-way impact detecting means for detecting each of the two, and an operation value is calculated according to a predetermined operation based on each output of the detecting means, and an operation value based on one of the left and right impact detecting means is predetermined. When the value is equal to or more than the first threshold value and the calculated value based on the lateral output of the two-way impact detection means is equal to or more than the predetermined second threshold value, a collision occurs on the side surface provided with the one-side detection means. And a determination means for determining that a frontal collision has occurred when the calculated value based on the vertical output of the two-way impact detection means is equal to or larger than a predetermined third threshold value. Side impact detecting device for a vehicle according to claim. 4. The two-way impact detection means is a two-axis acceleration sensor that detects longitudinal and lateral accelerations of the vehicle, and the left and right impact detection means detect lateral accelerations of the vehicle, respectively. 4. The side collision detection device for a vehicle according to claim 3, wherein the determination means calculates an integrated value of an output of the acceleration sensor during a predetermined period as a calculated value. 5. The judging means, when the calculated value based on the output of the one-side detecting means is equal to or larger than a predetermined first threshold value, changes the second threshold value according to the calculated value. The side collision detection device for a vehicle according to claim 1 or 3, wherein. 6. The side collision detection device for a vehicle according to claim 1, wherein the determination means calculates the calculated value when the output of the one-side detection means is a predetermined value or more. .