JP2004061226A - Collision subject distinguishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collision subject distinguishing device which suitably distinguishes a collision subject. <P>SOLUTION: If the collision subject is a pedestrian, a deceleration G generated in a vehicle is as shown in the figure by a thin line, in which a large deceleration G is generated at the stage that the whole body of the pedestrian got on the vehicle and a large deceleration G is generated in the second half of the collision. In the case of a light collision that the collision subject is a building or another vehicle, etc., a relatively large deceleration G is generated initially, and then decreased, as shown in the figure by a thick line (rear-end collision (low speed)). Consequently, as shown in the figure by a dashed line, by setting in advance threshold values for determining a collision subject at an increasing inclination every moment after collision detecting, a collision subject is distinguished based on a deceleration G detected with a floor G sensor and the relevant threshold value. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a collision object discriminating apparatus, and particularly, when a collision object is a pedestrian, a hood airbag system having an airbag device for absorbing an impact to the pedestrian, or a shock to a pedestrian. The present invention relates to a collision object determination device applicable to a vehicle equipped with a system for protecting a pedestrian such as a hood lift-up system that lifts up a hood for absorption.
[0002]
[Prior art]
When a running vehicle collides with a pedestrian, the pedestrian that has collided may be flipped up, or the lower body may be paid off by the front of the vehicle body, depending on the speed of the vehicle at the time of the collision, and may be placed on the hood or the like at the front of the vehicle body. It is known that a secondary collision occurs. In order to absorb the impact when a pedestrian makes a secondary collision on the hood or the like, an airbag device is deployed on the hood or the like. A hood airbag system has been proposed which protects pedestrians by absorbing the impact at the time of a secondary collision.
[0003]
Since the food airbag system is for protecting pedestrians as described above, the deployment of the airbag device of the food airbag system is performed by determining whether the collision target of the vehicle is a pedestrian or not. It is desired to reliably deploy the airbag device when a collision is a protection target.
[0004]
Examples of the collision target determination device used in the hood airbag system include a technology described in JP-A-8-216826, a technology described in JP-A-2000-326808, and a technology described in JP-A-10-194158. Techniques have been proposed.
[0005]
In the technique described in Japanese Patent Application Laid-Open No. Hei 8-216826, a bumper sensor for detecting a load from substantially the front in the horizontal direction and a hood sensor for detecting a load from substantially the upper side in the vertical direction are provided. If the sensor is turned on, the collision target is determined to be a pedestrian, and the hood airbag device is deployed.If the bumper sensor is turned on and the hood sensor is not turned on, the collision target is a building other than a pedestrian. Judging that there is, the hood airbag device is not deployed.
[0006]
Further, in the technique described in Japanese Patent Application Laid-Open No. 2000-326808, when a different collision object collides with the collision surface, the counter electrode is interposed between the counter electrodes arranged at a fixed interval on the collision surface. Paying attention to the change in capacitance due to the collision of the collision detection means made of a dielectric material composed of an elastic body, when a pedestrian collides, unlike a vehicle or obstacle other than a pedestrian, Since the capacitance has increased due to the collision after the capacitance has decreased, the collision target is determined by detecting the decrease in the capacitance prior to the collision and detecting the increase in the capacitance due to the collision are doing.
[0007]
Further, in the technology described in Japanese Patent Application Laid-Open No. H10-194158, it has been proposed to detect a collision with an acceleration sensor and distinguish between a collision with a pedestrian and a light collision with a certain threshold value and duration. .
[0008]
[Problems to be solved by the invention]
However, in the technology described in Japanese Patent Application Laid-Open No. Hei 8-216826, since the collision target is determined based on the detection and the detection order of the two sensors, the bumper sensor is turned on depending on the collision conditions such as the vehicle speed at the time of the collision. At the same time, there is a problem that the hood sensor is turned on, and the collision target may be determined to be a pedestrian even when the collision target is not a pedestrian.
[0009]
Further, in the technology described in Japanese Patent Application Laid-Open No. 2000-326808, in order to determine that the collision target is a pedestrian, a decrease in capacitance is detected, and an increase in capacitance due to the collision is detected. Therefore, there is a problem that it is difficult to determine the detection of the increase in the capacitance for the determination.
[0010]
Furthermore, in the technology described in Japanese Patent Application Laid-Open No. H10-194158, the detection value of an acceleration sensor when the vehicle collides with a pedestrian at a high speed, and the acceleration value when a vehicle or a building other than the pedestrian collides at a low speed. There is a problem that the detection values of the sensors are relatively similar and it is difficult to determine.
[0011]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a collision object determination device that can appropriately determine a collision object.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a detecting means for detecting a physical quantity that changes at the time of a collision of a vehicle, and a detecting means that increases with a lapse of time from the collision with respect to a predetermined reference value at the time of the collision. Setting means for setting a threshold value for the physical quantity for determining the collision target so as to include the calculated value, and determination means for determining the collision target based on the detection result of the detection means and the threshold value. And
[0013]
According to the first aspect of the present invention, the detecting means detects a physical quantity that changes at the time of a vehicle collision. For example, the detecting means detects the amount of change in the speed of the vehicle and the deceleration caused by the collision as in the second aspect of the invention.
[0014]
Here, taking the deceleration as an example, the physical quantity that changes at the time of a collision differs depending on whether the collision target is a pedestrian or a building or another vehicle. In other words, if the collision target is a pedestrian, a large deceleration occurs with the passage of time after the collision, and if the collision target is a building or another vehicle, a large deceleration occurs immediately after the collision. appear.
[0015]
In view of this, the setting means sets a threshold value for a physical quantity for determining a collision target so as to include a value that increases with time from the collision with respect to a predetermined reference value at the time of the collision. In other words, a threshold value for a physical quantity for determining a collision target is set such that the collision target is increasing every moment from the collision timing. The setting of the threshold value includes, for example, a threshold value that increases every moment, a threshold value that includes a section having a constant value, a threshold value that increases stepwise, and a threshold value that combines these.
[0016]
That is, when the physical quantity detected by the detection means exceeds the threshold, the collision target can be determined to be a building or another vehicle, and when the physical quantity does not exceed the threshold, the collision target is determined to be a pedestrian. can do.
[0017]
Therefore, the determination means can suitably determine the collision target based on the detection result of the detection means and the threshold value set by the setting means.
[0018]
The collision object determination device of the present invention can be applied to a pedestrian protection system that absorbs impact on pedestrians, such as a hood airbag system or a hood lift-up system.
[0019]
According to a third aspect of the present invention, in the first or second aspect of the invention, the collision speed detecting means for detecting a collision speed at the time of a collision, and the discriminating means according to a detection result of the collision speed detecting means. And a determination setting means for setting a determination time according to.
[0020]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the vehicle further comprises a collision speed detecting means and a discriminating setting means, and the collision speed detecting means reduces the collision speed at the time of collision. The detected time is set by the determination setting means in accordance with the collision speed. That is, the time until the collision target is determined by the determination means is set according to the speed at the time of the collision. For example, when the present invention is applied to a hood airbag system, it is possible to set the time for deploying the airbag device in accordance with the determination time set by the determination setting means, which allows the air to be aired at a good timing. The bag device can be deployed. Similarly, even when the present invention is applied to a hood lift-up system, it is possible to set the time for lifting up the hood according to the discrimination time set by the discrimination setting means. Food can be lifted up.
[0021]
According to a fourth aspect of the present invention, there is provided a physical quantity detecting means for detecting a deceleration and a speed change as a physical quantity which changes at the time of a vehicle collision, and a collision target which includes a value increased with an increase in the speed change. A threshold setting means for setting a threshold value for the deceleration for determination, and a collision determination means for determining a collision target based on a detection result of the physical quantity detection means and the threshold value.
[0022]
According to the fourth aspect of the present invention, the physical quantity detecting means detects the deceleration and the speed change as the physical quantities that change when the vehicle collides.
[0023]
Here, the deceleration and the amount of speed change that change at the time of a collision differ depending on whether the collision target is a pedestrian or a building or another vehicle. That is, when the collision target is a pedestrian, the deceleration with respect to the speed change amount tends to be smaller, and the deceleration tends to increase as the speed change amount increases.
[0024]
Therefore, the setting unit sets a threshold value for the deceleration for determining the collision target so as to include the value increased with the increase in the speed change amount. Thus, when the deceleration detected by the detection means exceeds the threshold, the collision target can be determined to be a building or another vehicle, and when the deceleration does not exceed the threshold, the collision target is a pedestrian. Can be determined.
[0025]
Therefore, the determination means can suitably determine the collision target based on the detection result of the detection means and the threshold value set by the setting means.
[0026]
The collision object determination device of the present invention can be applied to a pedestrian protection system that absorbs impact on pedestrians, such as a hood airbag system or a hood lift-up system.
[0027]
According to a fifth aspect of the present invention, in the invention according to the fourth aspect, a collision speed detecting means for detecting a collision speed at the time of a collision, and a determination time by the collision determining means according to a detection result of the collision speed detecting means. And determination time setting means for setting
[0028]
According to the fifth aspect of the present invention, in the fourth aspect of the present invention, the vehicle further comprises a collision speed detection unit and a determination time setting unit, and the collision speed detection unit detects a collision speed at the time of collision. In the determination time setting means, a determination time in the collision determination means is set according to the collision speed. That is, the time until the collision target is determined by the collision determination means is set according to the speed at the time of the collision. For example, when the present invention is applied to a hood airbag system, it is possible to set the time for deploying the airbag device according to the determination time set by the collision determination means, and thereby, the air can be aired at a good timing. The bag device can be deployed. Similarly, even when the present invention is applied to a hood lift-up system, it is possible to set the time for lifting up the hood according to the discrimination time set by the collision discrimination means. Food can be lifted up.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to a hood airbag system.
[0030]
FIG. 1 shows a schematic configuration of a hood airbag system 10 according to an embodiment of the present invention, and FIG. 2 shows an arrangement of the hood airbag system 10 in a vehicle 12.
[0031]
The hood airbag system 10 according to the embodiment of the present invention mainly includes a bumper sensor 14, a vehicle speed sensor 16, an airbag device 18 having a well-known structure, and an airbag ECU 20 that controls deployment of the airbag device 18. It is configured.
[0032]
As shown in FIG. 2, the bumper sensor 14 is provided on the front bumper 22 of the vehicle and detects a collision with a building, a pedestrian, or the like. A collision is detected by detecting a contact with a collision object. For example, the bumper sensor 14 may be a sensor that conducts when compressed by a load input in the horizontal direction from the front and sends a detection signal to the airbag ECU 20. The formed pressurized conductive rubber is sandwiched between two electrodes composed of a flat braided wire bundle from both sides, and the outside thereof is integrally covered with silicone rubber to form a long length. The bumper hose inside the front bumper 22 Between the bumper foam, which is a shock-absorbing material attached to the front side of the vehicle, and a bumper skin covering the outside of the bumper foam, with the electrodes and the pressurized conductive rubber laminated in the vehicle front-rear direction. Provided over substantially the entire length. When a load is applied to a part of the front bumper 22 from the horizontal direction in front of the vehicle, both electrodes of the conductive rubber pressurize, the bumper sensor is turned on, and a detection signal is output to the airbag ECU 20. Can be configured.
[0033]
The airbag device 18 is provided in a cowl portion of the vehicle, and when the airbag ECU 20 supplies a current to the inflator of the airbag device 18, the airbag bag body 18A folded and stored in the case by gas from the inflator is provided. The upper part of the case is broken to unfold on the rear part of the hood 24 and on the front part of the front shield glass 26.
[0034]
As shown in FIG. 2, the airbag ECU 20 is provided in the cabin of the vehicle, and is disposed, for example, between a center console and a floor panel, under a driver's seat or a passenger's seat, in an instrument panel, and the like. As described above, the CPU 30, the ROM 32, the RAM 34, and the I / O 36 are each configured by a microcomputer interconnected to the bus 38.
[0035]
The ROM 32 stores various programs for operating the airbag device 18, threshold values for operating the airbag device 18, and the like, and the RAM 34 stores detection signals and the like by various sensors. The control of the CPU 30 controls the deployment of the airbag device 18.
[0036]
A floor G sensor 40 for detecting a deceleration applied to the floor of the vehicle is connected to the airbag ECU 20 via an I / O 36. The floor G sensor 40 is built in the airbag ECU 20. It is configured. The floor G sensor 40 does not have to be built in the airbag ECU 20, and may be provided at a position different from the airbag ECU 20, such as a front side member.
[0037]
Further, the bumper sensor 14, the airbag device 18, and the vehicle speed sensor 16 are connected to the I / O 36. As the vehicle speed sensor 16, a known vehicle speed sensor that detects the speed of the vehicle can be applied, and a vehicle speed signal is input to the airbag ECU 20.
[0038]
By the way, the deceleration G generated in the vehicle due to the collision has the following characteristics depending on whether the collision target is a pedestrian or a building or another vehicle.
[0039]
When the collision target is a pedestrian, a large deceleration G occurs when the whole body of the pedestrian gets on the vehicle, and a large deceleration G occurs in the latter half of the collision, as shown by the thin line in FIG.
[0040]
On the other hand, when the collision target is a light collision of a building, another vehicle, or the like, as shown by a bold line (rear collision (low speed)) in FIG.
[0041]
Therefore, when a collision with a pedestrian at a high speed and a collision with a building or another vehicle at a low speed are made, the collision target is a pedestrian if the threshold for discriminating the collision target is set to a constant value. Or a building or another vehicle.
[0042]
Therefore, in the hood airbag system 10 according to the embodiment of the present invention, as shown by the dashed line in FIG. 3, the hood airbag system 10 includes a value that increases with time from the collision with respect to the predetermined reference value S after the collision is detected. As described above, the threshold value for determining the collision target is set in advance, and the threshold value is stored in the ROM 32. That is, the threshold value is set so as to increase every moment. This makes it possible to suitably determine that the collision target is a pedestrian.
[0043]
Here, FIG. 3 shows the occurrence of deceleration G when the pedestrian is at the upper limit of the standard physique. In the present embodiment, a threshold for determining a collision target is set using a pedestrian, which is the upper limit of the standard physique, as a model. This makes it possible to determine the collision of many pedestrians.
[0044]
In order to deploy the airbag device 18 in a timely manner, as shown in FIG. 4, a time for outputting an ignition signal for deploying the airbag device 18 in accordance with the collision speed is set in advance. Is stored in That is, the discrimination time Δt between a pedestrian and a light collision changes according to the collision speed.
[0045]
Note that the floor G sensor 40 corresponds to the detecting means of the present invention, and the airbag ECU 20 corresponds to the setting means and the determining means of the present invention.
[0046]
Next, the deployment process of the airbag device 18 performed by the airbag ECU 20 of the hood airbag system 10 configured as described above will be described with reference to the flowchart of FIG.
[0047]
In the hood airbag system 10 according to the embodiment of the present invention, a signal from the bumper sensor 14 is always detected to detect a collision. That is, in step 100, it is determined whether or not the bumper sensor 14 is on, and it is constantly monitored whether or not a signal that detects a collision is input from the bumper sensor 14, and when the bumper sensor 14 is on, the process proceeds to step 102.
[0048]
In step 102, the vehicle speed is measured. That is, the collision speed at the time of the collision is calculated based on the vehicle speed signal input from the vehicle speed sensor 16. The collision speed can be calculated from the vehicle speed signal at the timing when the bumper sensor 14 is turned on. In the case of a pedestrian collision, the vehicle speed at the time of the collision / the collision speed can be obtained. Step 102 corresponds to the collision speed detecting means of the present invention.
[0049]
Subsequently, at step 104, the above-described pedestrian-light collision determination time Δt is set. Step 104 corresponds to the determination setting means of the present invention.
[0050]
In step 106, the deceleration G occurring in the vehicle is measured. That is, the vehicle generated deceleration G is measured from the signal obtained from the floor G sensor 40.
[0051]
In step 108, it is determined whether or not the level of the vehicle generated deceleration G is a level when the collision target is a pedestrian. This determination is made based on whether or not the level of the vehicle generated deceleration G has exceeded the above-described momentarily changing threshold. That is, since the threshold value for determining the collision target changes so as to increase every moment, the collision target is determined to be at the pedestrian level if the threshold value is not exceeded, and the collision target is determined if the threshold value is exceeded. Is determined to be the level of a building, another vehicle, or the like, thereby making it possible to appropriately determine the collision target.
[0052]
If the determination in step 108 is negative, it is determined that the collision target is a building or another vehicle, and after a predetermined period of time (for example, 0.5 seconds) after which the collision phenomenon with them is terminated, , And returns to step 100 to repeat the above-described processing. If the determination in step 108 is affirmative, the process proceeds to step 110, where it is determined whether or not the time Δt for determining a light collision with the pedestrian has elapsed. That is, it is determined whether or not it is time to deploy the airbag device 18. If the determination is negative, the process proceeds to step 106, and the above processing is performed until the time Δt for determining a light collision with the pedestrian elapses. The process moves to step 112 repeatedly.
[0053]
In step 112, the airbag device 18 is deployed. That is, it is determined that the collision target is a pedestrian, and at a deployment timing suitable for the collision speed, the CPU 30 outputs an ignition signal to the airbag device 18 so that a current flows through the inflator of the airbag device 18. The airbag bag 18A folded and stored in the case by the gas from the inflator breaks the upper part of the case and is deployed on the rear part of the hood 24 and the front part of the front shield glass 26. Thereby, the impact of the collision with the pedestrian is absorbed and the pedestrian is protected.
[0054]
As described above, in the hood airbag system 10 according to the embodiment of the present invention, as shown in FIG. 3, when the collision target is a pedestrian, the deceleration G generated in the vehicle tends to increase in the latter half of the collision. When the collision target is a building or another vehicle, etc., the deceleration G generated in the vehicle is relatively large immediately after the collision. Therefore, the collision target is determined based on the deceleration G generated in the vehicle. By setting the threshold value to increase from time to time, if the collision target is a pedestrian, the threshold value is not exceeded, and the collision target is a building or another vehicle, etc. Since the threshold value is exceeded, the collision target can be suitably determined based on the threshold value and the detected deceleration G.
[0055]
In addition, since the time for discriminating a pedestrian from a light collision is changed according to the collision speed, the airbag device 18 can be deployed at an appropriate timing according to the collision speed.
[0056]
In the above-described embodiment, the threshold value for determining the collision target so as to include a value that has increased with the lapse of time from the collision with respect to a predetermined reference value at the time of the collision, that is, has a tendency to increase. Has been described as shown in FIG. 3, but the present invention is not limited to this, and a threshold value for judging a collision may be set so that it tends to increase every moment. For example, as shown in FIG. 6A, a threshold value (a straight line rising rightward until a predetermined time) is set so that the deceleration Ga increases from a predetermined reference value S1 to a time t at the time of collision. 6B, it may be set to be a straight line and a curve rising to the right as shown in FIG. 6B, or may be set to become a step line rising to the right as shown in FIG. 6C. As shown in FIG. 6 (D), a straight line rising to the right may be used, and the latter half may be lowered as a step line, or a curve rising right may be used. You may do so.
[0057]
In the above embodiment, the presence or absence of a collision is detected by the bumper sensor 14. However, the present invention is not limited to this. For example, the presence or absence of a collision is detected by a bumper that is provided in a front bumper or the like and detects deceleration. A G sensor may be used. As shown in FIG. 6 (E), a threshold value for detecting the presence or absence of a collision in addition to a threshold value for determining a collision target may be set for the output value of the floor G sensor 40. It may be provided. With this, the same operation as in the above embodiment can be obtained.
[0058]
Further, in the above embodiment, the deceleration is detected as the physical quantity generated in the vehicle. However, the present invention is not limited to this. For example, in addition to the deceleration as the physical quantity, the speed change amount of the vehicle is detected. Alternatively, the threshold value for the vehicle body generation G may be set as shown in FIG. 6F in accordance with the increase in the speed change amount from the moment of the collision.
[0059]
In this case, the speed change amount can be obtained from the integration of the occurrence G of the deceleration occurring in the vehicle. FIG. 7 shows a waveform example of the vehicle body generation G (deceleration) with respect to the speed change amount. FIG. 7 shows a waveform when the vehicle collides with a pedestrian at a high speed and a case where the vehicle collides with a building or the like at a low speed. Since the occurrence G is smaller when the vehicle collides with the pedestrian than the speed change amount, a threshold value for the deceleration for discriminating the collision target is set so as to include the value increased with the increase in the speed change amount. In this case, the same operation as in the above embodiment can be obtained.
[0060]
Further, in the above-described embodiment, the deceleration as a physical quantity generated in the vehicle is detected using the floor G sensor 40. However, the present invention is not limited to this. A satellite G sensor may be used.
[0061]
Further, in the above-described embodiment, the present invention is applied to the hood airbag system 10. However, the present invention is not limited to this. For example, as shown in FIG. The present invention can also be applied to a hood lift-up system that lifts up in the direction of the arrow 8 to absorb the impact on pedestrians.
[0062]
【The invention's effect】
As described above, according to the present invention, by setting a threshold for a physical quantity for determining a collision target so as to increase momentarily from the timing of a collision, based on the threshold and the physical quantity generated at the time of the collision, There is an effect that the collision target can be appropriately determined.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a hood airbag system according to an embodiment of the present invention.
FIG. 2 is a diagram showing an arrangement of a hood airbag system according to an embodiment of the present invention in a vehicle.
FIG. 3 is a graph showing a deceleration G occurring in a vehicle and a threshold value for collision determination.
FIG. 4 is a graph showing a determination time Δt.
FIG. 5 is a flowchart showing a deployment process of the airbag device in the hood airbag system according to the embodiment of the present invention.
FIG. 6 is a diagram illustrating another example of a threshold value for collision determination.
FIG. 7 is a diagram illustrating a waveform example of a vehicle body generation G (deceleration) with respect to a speed change amount.
FIG. 8 is a diagram showing a hood lift-up system.
[Explanation of symbols]
10 Hood airbag system 16 Vehicle speed sensor 20 Airbag ECU
30 CPU
32 ROM
34 RAM
36 I / O
38 Bus 40 Floor G sensor

Claims (5)

Detecting means for detecting a physical quantity that changes at the time of a vehicle collision;
Setting means for setting a threshold value for the physical quantity for discriminating a collision target to include a value increased with time from the collision with respect to a predetermined reference value at the time of collision,
Determining means for determining a collision target based on the detection result of the detecting means and the threshold value,
Collision object discriminating device provided with The collision object discriminating apparatus according to claim 1, wherein the detection unit detects a deceleration generated by the collision. 2. The apparatus according to claim 1, further comprising: a collision speed detection unit configured to detect a collision speed at the time of a collision; and a determination setting unit configured to set a determination time by the determination unit according to a detection result of the collision speed detection unit. Alternatively, the collision object determination device according to claim 2. Physical quantity detecting means for detecting deceleration and speed change as physical quantities that change at the time of vehicle collision,
Threshold setting means for setting a threshold for the deceleration for determining a collision target to include a value increased with an increase in the speed change amount,
Collision determination means for determining a collision target based on the detection result of the physical quantity detection means and the threshold,
Collision object discriminating device provided with The apparatus according to claim 1, further comprising: a collision speed detecting unit configured to detect a collision speed in a collision; and a determination time setting unit configured to set a determination time by the collision determination unit in accordance with a detection result of the collision speed detection unit. Item 5. The collision object determination device according to Item 4.

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