JP2003095058A - Occupant protecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant protecting device for vehicle capable of properly protecting the vehic occupants by setting the optimal operation threshold value of the protection means for occupants. SOLUTION: The occupant protecting device 10 for vehicle is provided with a occupant protection means 70 for protecting occupants and an impact detection means 50 for detecting the magnitude of impact working on an own vehicle, and activates the occupant protection means when the magnitude of the impact detected by the impact detection means 50 exceeds a prescribed threshold value. The device 10 is further provided with a following distance detection means 60 for detecting the following distance between the own vehicle and a precedent car traveling in front of the own vehicle in the protecting device for occupants, a relative velocity direction means 20 for detecting the relative velocity between the own vehicle and the preceding vehicle, a vehicle state deciding means 30 for deciding the possibility of collision of the own vehicle with the preceding vehicle based on the relative velocity obtained by the following distance obtained by the following distance detection means 60 and the relative velocity obtained by relative velocity detection means 20, and a threshold value changing means 40 for changing the threshold value that activates the occupant protecting means 70 corresponding to the decided results of the vehicle state deciding means 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle occupant protection device. More specifically, the operating threshold of the occupant protection means is optimally set, and the occupant is appropriately protected.

[0002]

2. Description of the Related Art Conventionally, an air bag device always measures an acceleration acting on a vehicle by an acceleration sensor, and FIG.
As shown in, when the acceleration applied to the vehicle due to the vehicle collision exceeds a predetermined threshold value, the airbag is deployed.

However, noise may be added to the acceleration sensor, so that the threshold value for deploying the airbag needs to be set relatively high. On the other hand, if the threshold value is too high, the airbag may not be deployed even if the vehicle collides, and there is a problem that the occupant may not be properly protected.

Therefore, in order to properly protect the occupant by the airbag device, the inter-vehicle distance warning means and the airbag as the occupant protection means are connected, and the inter-vehicle distance warning means collides with the preceding vehicle on the airbag. When a signal indicating the danger of being output is output, there is a technique for accelerating the deployment operation by advancing the timing of sending the airbag detonation signal itself (JP-A-9-
132111).

[0005]

However, if the deployment threshold of the airbag is high if the deployment operation of the airbag is accelerated only when the danger of collision is detected as in the technique described in the above publication, the airbag is not likely to be deployed. There is a possibility that the occupant may not be properly protected because the unfolding operation itself may not start.

[0006]

A vehicle occupant protection system according to claim 1 of the present invention which solves the above problems, detects an occupant protection means for protecting an occupant and the magnitude of an impact acting on the host vehicle. And a vehicle occupant protection device for activating the occupant protection means when the magnitude of the impact by the impact detection means exceeds a predetermined threshold value. An inter-vehicle distance detecting means for detecting an inter-vehicle distance to the preceding vehicle, a relative speed detecting means for detecting a relative speed between the own vehicle and the preceding vehicle, and the inter-vehicle distance and the relative speed detecting means by the inter-vehicle distance detecting means. Based on the relative speed, a vehicle state judging means for judging the possibility of collision between the own vehicle and the preceding vehicle, and the threshold for operating the occupant protecting means according to the judgment result of the vehicle state judging means. Characterized by comprising a threshold value changing means for changing.

An occupant protection device for a vehicle according to a second aspect of the present invention which solves the above problem is an occupant protection means for protecting an occupant, and an impact detection means for detecting the magnitude of an impact acting on the host vehicle. In the vehicle occupant protection device for activating the occupant protection means when the magnitude of the impact by the impact detection means becomes equal to or greater than a predetermined threshold value, a distance between the vehicle and a preceding vehicle traveling in front of the vehicle. An inter-vehicle distance detecting means for detecting a distance, a vehicle state determining means for determining a possibility of collision between the own vehicle and a preceding vehicle based on the inter-vehicle distance by the inter-vehicle distance detecting means, and a determination by the vehicle state determining means. Threshold value changing means for changing the threshold value for operating the occupant protection means according to a result.

A vehicle occupant protection system according to a third aspect of the present invention for solving the above-mentioned problems is the vehicle occupant protection system according to the first or second aspect, wherein the impact detection means detects the acceleration acting on the host vehicle and The occupant protection device activates the occupant protection means when the absolute value of the acceleration exceeds a predetermined threshold value.

A vehicle occupant protection system according to a fourth aspect of the present invention which solves the above-mentioned problems is the vehicle occupant protection system according to the first, second or third aspect, wherein the threshold value changing means causes the vehicle state judging means to set the own vehicle to the preceding vehicle. When it is determined that there is a high possibility of collision, the threshold value for operating the occupant protection means is lowered.

A vehicle occupant protection system according to a fifth aspect of the present invention which solves the above-mentioned problems is the vehicle occupant protection system according to the first, second, third or fourth aspect, wherein the vehicle state determination means is the inter-vehicle distance detected by the inter-vehicle distance detection means. And a relative speed detected by the relative speed detection means, the vehicle has a collision time calculating means for calculating a time until the own vehicle collides with the preceding vehicle, and the own vehicle and the preceding vehicle are based on the collision time calculating means. Characterized by determining the possibility of collision.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. [First Embodiment] FIG. 1 is a block diagram of a vehicle occupant protection system according to a first embodiment of the present invention. As shown in FIG. 1, the vehicle occupant protection system according to this embodiment is an airbag deployment command unit 1 that is an electronic control unit (ECU).
0, the relative speed calculation unit 20 (relative speed detection unit), the vehicle state determination unit 30 (vehicle state determination unit), and the threshold value change unit 40.
(Threshold changing means).

That is, the airbag deployment command unit 10 is connected to an acceleration sensor 50 (impact detection means) for detecting the acceleration acting on the vehicle, and the absolute value of the acceleration detected by the acceleration sensor 50 is a predetermined threshold value. When the above is reached,
A signal for operating the airbag 70 (passenger protection means) is output from the airbag deployment command unit 10. The “acceleration” mentioned here includes deceleration that is a negative acceleration. still,
Instead of the acceleration sensor 50, a shock detecting means for detecting the magnitude of the shock acting on the vehicle may be provided. In that case, the airbag 70 is activated when the detected shock becomes equal to or more than a predetermined threshold value. It may be allowed to.

The airbag 70 is a device that is deployed at the time of a collision to reduce the impact that acts on the occupant. The airbag 70 is not limited to the one incorporated in the steering wheel of the driver's seat or the one installed on the passenger seat side, but a so-called side. It also includes what is called an airbag. Further, as long as it is an occupant protection means that protects an occupant in the event of a collision, a so-called seat belt pretensioner that winds up the slack of the seat belt in the event of a collision can be used instead of the airbag 70.

[0014] threshold changing unit 40, according to the judgment result of the vehicle state determination unit 30, G _rigid as described below the airbag deployment threshold is set to an air bag deployment command unit 10, G
Change to one of _nomal . A laser radar 60 (inter-vehicle distance detecting means) that detects an inter-vehicle distance between the own vehicle and a preceding vehicle traveling in front of the own vehicle is connected to the relative speed calculation unit 20 and the vehicle state determination unit 30. As the laser radar 60, a laser radar used for adaptive cruise control (ACC) can be used.

The relative velocity calculation unit 20 includes a laser radar 6
The relative speed is calculated from the time change of the inter-vehicle distance detected by 0. The vehicle state determination unit 30 includes a laser radar 60.
The possibility of collision between the host vehicle and the preceding vehicle is determined based on the inter-vehicle distance detected by and the relative speed calculated by the relative speed calculator 20. For example, when the inter-vehicle distance detected by the laser radar 60 becomes a certain value or less due to the sudden deceleration of the preceding vehicle or the sudden acceleration of the host vehicle, or the relative speed calculated by the relative speed calculating unit 20 is a certain value or more. Then, the possibility of collision is determined based on these combinations.

It should be noted that detected by the laser radar 60
Inter-vehicle distance and relative speed calculated by the relative speed calculator 20
Depending on the degree of collision, when your vehicle collides with the preceding vehicle
Interval T _cCollision time calculation means for calculating
It may be set to 0. Providing such collision time calculation means
Then, as shown in the flowchart shown in FIG. 3 described later.
And the collision time T_cAccurately judge the possibility of collision based on
You can

When the vehicle state judging section 30 judges that the possibility of collision is high, the threshold changing section 40
_{Reduces the} threshold value from the threshold value G _nomal to the threshold value G _rigid , and when the vehicle state determination unit 30 determines that the possibility of collision is low, the threshold value change unit 40 sets the threshold value G _rigid .
_The threshold is set high from _rigid to the threshold G _nomal . still,
By using a millimeter wave radar instead of the laser radar 60, it is possible to detect the inter-vehicle distance and the relative speed at the same time. That is, the millimeter-wave radar functions as an inter-vehicle distance detecting means for detecting the inter-vehicle distance between the host vehicle and a preceding vehicle traveling in front of the host vehicle based on the time from the millimeter-wave transmission to the reception, and at the time of millimeter-wave transmission. From the difference between the frequency of the waveform of and the frequency of the waveform at the time of reception after being reflected by the preceding vehicle, it also functions as a relative speed detection means that directly detects the relative speed between the own vehicle and the preceding vehicle. If a radar is used, the relative speed calculation unit 20 can be omitted, which contributes to cost reduction.

FIG. 3 shows a flowchart for automatically changing the airbag deployment threshold in the vehicle occupant protection system described above. First, the preceding vehicle is detected by the laser radar or the millimeter wave radar, and the inter-vehicle distance between the preceding vehicle and the host vehicle and their relative speeds V _c are detected (step S).
1). Next, by dividing the relative speed V _c from the inter-vehicle distance, the collision time T estimated to collide with the preceding vehicle.
_c is calculated (step S2).

Subsequently, as shown in the following equations (1) and (2), when the collision time T _c is smaller than a certain threshold value T ₀ and the relative velocity V _c is larger than a certain threshold value V ₀ , the possibility of collision is high. Is high and the risk is high (step S3). T _c <T ₀ (1) and V _c > V ₀ (2)

That is, as shown in the equation (1), the own vehicle is likely to collide with the preceding vehicle soon, and as shown in the equation (2), the speed of the own vehicle is higher than that of the preceding vehicle. When it is fairly fast, there is a high possibility of collision and it is judged that the danger is high. If it is determined in step S3 that the possibility of collision is high, the airbag deployment threshold is set to G _rigid (step S4), and if it is determined that the possibility of collision is not high, the airbag deployment threshold is set to G above. G _nomal larger than _rigid is set (step S5).

Therefore, when there is a high possibility of collision between the host vehicle and the preceding vehicle, the threshold value for deploying the airbag 70 is lowered as shown in FIG. 4, so the possibility that the airbag 70 will not deploy is reduced. it can. Further, when the possibility of collision between the host vehicle and the preceding vehicle is low, in other words, the threshold value for deploying the airbag 70 as shown in FIG. 4 is increased during normal traveling, so the airbag 70 is deployed by mistake. The possibility of such a defect can be reduced.

In particular, even when the acceleration sensor 50 contains noise, since the comparatively high threshold value G _nomal is used during general traveling, the possibility of the airbag 70 being inflated by mistake can be reduced. In this way, the threshold changing unit 4
When 0, the optimum threshold value for operating the airbag 70 is set according to the state of the vehicle, and the occupant is appropriately protected.

In this embodiment, two kinds of threshold values G are used.
_{Although rigid} and G _normal are switched and used, the threshold may be set in multiple stages or linearly depending on the possibility of collision. For example, as shown in FIG. 6, a map is created in which the horizontal axis indicates the time until a collision with a preceding vehicle and the vertical axis indicates the threshold value. The shorter the collision time, the lower the airbag deployment threshold value. The threshold value may be changed linearly, and in this case, the threshold value can be finely set. Further, in the present embodiment, the possibility of collision of the vehicle is judged based on the collision time T _c and the relative speed V _c , but naturally, it may be judged based on the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle. .

[Second Embodiment] FIG. 2 is a block diagram of a vehicle occupant protection system according to a second embodiment of the present invention. The vehicle speed control device according to this embodiment is the vehicle speed control device shown in FIG. 1 in which the relative speed calculation unit 20 is omitted.

Therefore, when the inter-vehicle distance between the host vehicle and the preceding vehicle traveling in front of the host vehicle is detected by the laser radar 60, the vehicle state judging section 30 determines the inter-vehicle distance based on only the inter-vehicle distance. And the preceding vehicle will collide with each other. In this way, the relative speed calculation unit 20
In addition to the cost reduction by omitting, the vehicle state determination unit 30 can immediately determine the possibility of collision between the host vehicle and the preceding vehicle, which contributes to shortening the response time. In addition to the configurations of the first and second embodiments described above, the configuration may be such that the deployment operation of the airbag is accelerated when it is determined that there is a high possibility of collision of the host vehicle.

[0026]

As described above in detail, according to the present invention, the threshold value for operating the occupant protection means is lowered when the possibility of collision between the host vehicle and the preceding vehicle is increased, and the host vehicle is also activated. By increasing the threshold value for activating the occupant protection means when the possibility that the vehicle and the preceding vehicle collide is reduced, the optimum operation threshold value for the occupant protection means is set, and the occupant is appropriately protected. Further, if the acceleration acting on the host vehicle is detected, the impact acting on the vehicle can be detected more accurately. Further, normally, by setting the threshold value relatively high, it is possible to prevent malfunction of the occupant protection means, and when the possibility of a vehicle collision is high, the threshold value is changed to a low value to appropriately protect the occupant. In particular, if the collision time estimated to collide with the preceding vehicle is used, the vehicle state can be determined more accurately.

[Brief description of drawings]

FIG. 1 is a block diagram showing a vehicle occupant protection system according to a first exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing a vehicle occupant protection device according to a second embodiment of the present invention.

FIG. 3 is a flowchart for automatically changing the airbag deployment threshold value by the vehicle occupant protection system according to the first embodiment of the present invention.

FIG. 4 is a graph showing a relationship between acceleration and its threshold value in the vehicle occupant protection system according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between acceleration and its threshold value in a conventional vehicle occupant protection system.

FIG. 6 is a graph showing the relationship between the collision time and the airbag deployment threshold value of the present invention.

[Explanation of symbols]

10 Airbag Deployment Command 20 Relative speed calculator 30 Vehicle status determination unit 40 Threshold change unit 50 acceleration sensor 60 laser radar 70 airbags

Claims (5)

[Claims] 1. An occupant protection means for protecting an occupant, and an impact detection means for detecting the magnitude of an impact acting on the host vehicle,
In the vehicle occupant protection device for activating the occupant protection means when the magnitude of the impact by the impact detection means becomes equal to or greater than a predetermined threshold value, a distance between the vehicle and a preceding vehicle traveling in front of the vehicle. Based on the inter-vehicle distance detecting means for detecting the distance, the relative speed detecting means for detecting the relative speed between the own vehicle and the preceding vehicle, the inter-vehicle distance by the inter-vehicle distance detecting means and the relative speed by the relative speed detecting means. A vehicle state determining means for determining a possibility of collision between the own vehicle and a preceding vehicle, and a threshold changing means for changing the threshold for operating the occupant protection means according to a determination result of the vehicle state determining means. A vehicle occupant protection device characterized by the above. 2. An occupant protection means for protecting an occupant, and an impact detection means for detecting the magnitude of an impact acting on the host vehicle.
In the vehicle occupant protection device for activating the occupant protection means when the magnitude of the impact by the impact detection means becomes equal to or greater than a predetermined threshold value, a distance between the vehicle and a preceding vehicle traveling in front of the vehicle. An inter-vehicle distance detecting means for detecting a distance, a vehicle state determining means for determining a possibility of collision between the own vehicle and a preceding vehicle based on the inter-vehicle distance by the inter-vehicle distance detecting means, and a determination by the vehicle state determining means. An occupant protection device for a vehicle, comprising: a threshold changing unit that changes the threshold for operating the occupant protecting unit according to a result. 3. The impact detection means detects an acceleration acting on the host vehicle, and the vehicle occupant protection device includes:
When the absolute value of the acceleration exceeds a predetermined threshold value,
The vehicle occupant protection device according to claim 1 or 2, wherein the occupant protection means is activated. 4. The threshold value changing means lowers the threshold value for operating the occupant protection means when the vehicle state judging means judges that the own vehicle is highly likely to collide with a preceding vehicle. The vehicle occupant protection device according to claim 1, 2, or 3. 5. The collision time, wherein the vehicle state determination means calculates a time until the host vehicle collides with the preceding vehicle based on the inter-vehicle distance detected by the inter-vehicle distance detection means and the relative speed detected by the relative speed detection means. 2. A calculation means is provided, and the possibility of collision between the own vehicle and the preceding vehicle is determined based on the collision time calculation means.
The vehicle occupant protection device according to 2, 3, or 4.