JP2001277993A - Vehicular collision judging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly judge a collision in a short time with simple and inexpensive constitution. SOLUTION: When an acceleration signal G of an acceleration sensor 11 is larger than threshold acceleration G0, a speed change V (t) is calculated by integrating up to the present time t from the reference time t1. When speed change time ΔT required for the speed change V (t) to become a first threshold speed change VTHO or more is smaller than threshold time TTH, an occupant protecting device is started. When elapsed time (t-t1) is shorter than prescribed threshold time T0 and the speed change V (t) is larger than a second threshold speed change VTH, when a speed change rate J=V (t)/(t-t1) exceeds a threshold speed change rate JTH, the occupant protecting device is started. When the elapsed time (t-t1) is shorter than the prescribed threshold time T0 and the speed change V (t) is smaller than the second threshold speed change VTH, a moving distance calculating part 22 calculates a moving distance S of an occupant. A moving distance judging part 23 starts the occupant protecting device when the moving distance S of the occupant is larger than a threshold moving distance STH.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle collision judging device for judging a collision of a vehicle and activating an occupant protection device such as an airbag device.

[0002]

2. Description of the Related Art Conventionally, an acceleration sensor for detecting, for example, acceleration (or deceleration) applied to a vehicle is provided, and a change in vehicle acceleration is detected by an acceleration signal output from the acceleration sensor. When a first-order integration or a second-order integration is performed and these integrated values exceed predetermined threshold values, a vehicle collision determination device that activates an occupant protection device such as an airbag device or a seatbelt pretensioner is known. Have been. When a collision is determined by such a vehicle collision determination device, for example, the airbag device ignites the gas generating agent by a squib in the inflator to generate gas from the inflator,
The gas inflates the airbag to suppress secondary collision between the occupant and the vehicle interior parts.

[0003]

In the vehicle collision determining apparatus according to one example of the prior art, when an offset collision occurs in which a part of the front of the vehicle collides at a high speed, for example, in the early stage of the collision, the vehicle body is determined. Is greatly deformed, for example, the speed change obtained by integrating the acceleration signal from the acceleration sensor once may show a relatively small change. For this reason, for example, in order to accurately detect an offset collision, a vehicle collision determination device including a front sensor is known, but the front sensor is expensive, and the manufacturing cost of the vehicle collision determination device itself increases. There's a problem. The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a vehicle collision determination device that can perform appropriate collision determination in a short time with a simple and inexpensive configuration.

[0004]

In order to solve the above-mentioned problems and achieve the above object, a vehicle collision judging device according to the present invention according to a first aspect of the present invention provides an acceleration detecting means for detecting an acceleration acting on a vehicle. (E.g., an acceleration sensor 11 in an embodiment described later) and an acceleration signal (e.g., an acceleration signal G in an embodiment described later) detected by the acceleration detection unit are linearly integrated to change the speed (e.g., described later). Speed change calculating means (for example, a speed change calculating unit 14 in an embodiment described later) for calculating a speed change V (t) in the preferred embodiment, and the speed change calculated by the speed change calculating means. , A predetermined threshold speed change (for example,
Speed change determining means (for example, a second threshold speed change V _TH in an embodiment described later) that determines whether or not the speed change is smaller than a second threshold speed change V _TH .
Second speed change determination unit 19 in an embodiment described later)
An occupant movement amount calculating means (for example, a movement amount in an embodiment described later) for calculating a occupant movement amount (for example, an occupant movement amount S in an embodiment described later) by quadratic integrating the acceleration signal with respect to time. Calculation unit 22) and whether or not the occupant movement calculated by the occupant movement calculation means is larger than a predetermined threshold occupant movement (for example, a threshold movement S _TH in an embodiment described later). The occupant protection device (for example, according to the determination result by the speed determination unit and the determination result by the occupant movement amount determination unit) Control signal generating means for generating a control signal for controlling the operation of an airbag device in an embodiment described later (for example, a start signal generating unit 24 in an embodiment described later) It is characterized by having.

[0005] According to the vehicle collision determination device having the above structure,
A collision determination is made based on the speed change obtained by linearly integrating the acceleration signal output from the acceleration sensor with respect to time and the occupant movement amount obtained by secondary integration. Even if the speed change of the vehicle shows a small change in the initial stage of the collision, such as an offset collision that occurs, the contact area with the collision object increases as the deformation of the vehicle body progresses, and the collision time decreases. Even when the speed increases, so to speak, the speed change greatly increases after an appropriate time delay, when the occupant movement amount exceeds a predetermined threshold movement amount, it is determined that a collision has occurred and an airbag device or the like is determined. By activating the occupant protection device, it is possible to appropriately protect the occupant within a short time after the occurrence of the collision. In addition, for example, a high-speed offset collision involves a large deformation of the vehicle and requires the activation of an occupant protection device such as an airbag device. In addition, it is possible to clearly distinguish a state in which the occupant protection device does not need to be activated, such as a case where the speed change at the initial stage of the collision becomes relatively large but the occupant movement amount is small.

Further, in the vehicle collision judging device according to the present invention, the occupant movement amount judging means is provided within a predetermined time section after the occurrence of the collision (for example, a reference time t1 in an embodiment described later). To the current time t).
It is characterized in that it is determined whether or not the occupant movement amount is larger than the predetermined threshold occupant movement amount.

According to the vehicle collision judging device having the above structure,
When the occupant movement calculated from the acceleration signal exceeds a predetermined threshold occupant movement within a predetermined time period after the occurrence of the collision, an occupant protection device such as an airbag device is activated. On the other hand, if the occupant movement amount does not exceed the predetermined threshold occupant movement amount within a predetermined time section after the occurrence of the collision, it is determined that the collision is not a collision.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle collision judging device according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a vehicle collision determination device 10 according to one embodiment of the present invention. The vehicle collision determination device 10 according to the present embodiment includes an acceleration sensor (G sensor) 11,
The filter processing unit 12, the acceleration determination unit 13, the speed change calculation unit 14, the first speed change determination unit 15, the speed change time calculation unit 16, the speed change time determination unit 17, the elapsed time determination unit 18, A second speed change determining unit 19, a speed change rate calculating unit 20, a speed change rate determining unit 21, a moving amount calculating unit 22, a moving amount determining unit 23, and a start signal generating unit 24. Have been.

The acceleration sensor 11 outputs an acceleration signal (G data) G at a voltage level corresponding to the magnitude of the acceleration acting on the vehicle. The filter processing unit 12 includes, for example, a low-pass filter or the like, and removes a high-frequency component that is a noise component from the acceleration signal G output from the acceleration sensor 11. The acceleration determination unit 13 calculates the acceleration G (t at an appropriate reference time t1 with respect to the acceleration signal G after the filtering.
1) determines whether or not a predetermined閾加speed G ₀ or greater than. When the determination result of the acceleration determination unit 13 is “YES”, that is, when the acceleration signal G exceeds a predetermined threshold acceleration G ₀ , the speed change calculation unit 14 determines, for example, the time from the reference time t1 to the current time t. The speed change V (t) is calculated by integrating the acceleration signal G for the section.

The first speed change judging section 15 determines the speed change V
It is determined whether (t) is greater than a predetermined first threshold speed change V _TH0 . The speed change time calculation unit 16 requires the speed change V (t) to become equal to or more than a predetermined first threshold speed change V _TH0 when the determination result of the first speed change determination unit 15 is “YES”. The speed change time ΔT is calculated by ΔT = t−t1. The speed change time determination unit 17 calculates the speed change time Δ
T is determined whether shorter than a predetermined threshold time T _TH, when the determination result is "YES", the start signal generator 24
Is instructed to generate an activation signal for activating an occupant protection device such as an airbag device.

[0011] elapsed time determining unit 18 determines the elapsed time from the reference time t1 to the current time t (t-t1) is, whether or not shorter than a predetermined threshold time T _0. Second speed change determination unit 1
9 indicates that the speed change V (t) is equal to a predetermined second threshold speed change V _TH when the determination result of the elapsed time determination unit 18 is “YES”.
It is determined whether it is greater than. Speed change rate calculation unit 20
Indicates that the determination result in the second speed change determination unit 19 is “YES”.
, The speed change rate J at the elapsed time (t-t1)
= V (t) / (t-t1). The speed change rate determination unit 21 determines whether the speed change rate J is greater than a predetermined threshold speed change rate J _TH, and when the determination result is “YES”, the speed change rate determination unit 21 Then, an instruction is issued to generate an activation signal for activating an occupant protection device such as an airbag device.

When the determination result of the second speed change determination section 19 is "NO", the movement amount calculation section 22 performs a quadratic integration of the acceleration signal G for a time section from the reference time t1 to the current time t, that is, The movement amount S of the occupant is calculated. The movement amount determination unit 23 determines whether the movement amount S of the occupant is greater than a predetermined threshold movement amount S _TH, and when the determination result is “YES”, the movement signal determination unit 23 For example, a command is issued to generate an activation signal for activating an occupant protection device such as an airbag device.

[0013] A vehicle collision judging device 1 according to the present embodiment.
0 has the above-described configuration. Next, the operation of the vehicle collision determination device 10 will be described with reference to the accompanying drawings. FIG. 2 is a flowchart showing the operation of the vehicle collision determination device 10, FIG. 3A is a graph showing a time change of the acceleration signal G when a collision occurs, and FIG.
FIG. 3C is a graph showing a time change of a speed change V calculated from the acceleration signal G shown in FIG. 3A, and FIG.
FIG. 3D is a graph showing the time change of the movement amount S of the occupant calculated from the acceleration signal G shown in FIG.
FIG. 7 is a graph showing a change between an occupant's movement amount S.

First, in step S01 shown in FIG. 2, the acceleration sensor 11 detects the acceleration acting on the vehicle. Next, in step S02, the acceleration signal G output from the acceleration sensor 11 is subjected to a filtering process using, for example, a low-pass filter or the like to remove noise components and the like. Next, in step S03, the acceleration G (t1) at an appropriate reference time t1, whether a predetermined閾加speed G ₀ or greater than. If the result of this determination is “NO”, the above-described processing of step S03 and thereafter is repeated. On the other hand, if the determination result is “YES”, the reference time t1 is regarded as the collision start time, time measurement by a timer or the like is started from the reference time t1, and the process proceeds to step S04. Linear integration of the acceleration signal G for the time interval up to
After calculating (t), the process proceeds to step S05 and step S09 described below.

In step S05, the speed change V
It is determined whether (t) is greater than a predetermined first threshold speed change V _TH0 . If the result of this determination is "NO", the operation proceeds to step S04 described above. On the other hand, when the determination result is “YE
In the case of "S", the process proceeds to step S06. Step S0
6, the speed change time ΔT required until the speed change V (t) becomes equal to or more than the predetermined first threshold speed change V _TH0 is _calculated by Δ
It is calculated by T = t−t1, and the process proceeds to step S07.

In step S07, it is determined whether or not the speed change time ΔT is shorter than a predetermined threshold time T _TH . If the result of this determination is "NO", it is determined that no collision has occurred, and the routine proceeds to step S02 described above. On the other hand, if the result of the determination is "YES", it is determined that a collision such as a head-on collision has occurred, and the process proceeds to step S08, where an activation signal is generated for an occupant protection device such as an airbag device.

On the other hand, in step S09, the elapsed time (t-t1) from the reference time t1 to the current time t is
It determines shorter or not than a predetermined threshold time T _0. If the result of this determination is "NO", it is determined that no collision that could injure the occupant has occurred, and the aforementioned step S0
Proceed to 2. On the other hand, when the determination result is "YES", the operation proceeds to step S10, the speed change V (t) is equal to or greater than a predetermined second threshold speed change V _TH. If the result of this determination is "NO", the operation proceeds to step S13 described below. The magnitude relationship between the first and second threshold speed changes V _TH0 and V _TH is not particularly limited, and both threshold speed changes V _TH0 and V _TH may be set to be equal to each other.

On the other hand, if the determination result in step S10 is "Y
In the case of “ES”, the process proceeds to step S11, and the speed change rate J = V (t) / (t−) at the elapsed time (t−t1).
t1) is calculated. Next, in step S12, the speed change rate J is equal to or greater than a predetermined threshold speed change ratio J _TH. If this determination result is “NO”, it is determined that no collision has occurred, and the above-described step S02
Proceed to. On the other hand, if the result of the determination is "YES", it is determined that a collision has occurred, and the flow proceeds to step S08.

On the other hand, in step S13, the quadratic integration of the acceleration signal G, that is, the movement amount S of the occupant is calculated for the time section from the reference time t1 to the current time t, and the process proceeds to step S14. Next, in step S14,
It is determined whether the movement amount S of the occupant is greater than a predetermined threshold movement amount S _TH . If this determination result is “NO”, it is determined that no collision has occurred, and the above-described step S02
Proceed to. On the other hand, if the result of the determination is “YES”, it is determined that a collision such as an offset collision has occurred, and the process proceeds to step S08.

That is, for example, as shown in FIG. 3 (a), the acceleration signal G becomes a predetermined threshold acceleration G at a reference time t1.
_When the speed change becomes larger than _0, the speed change V (t) calculated by integrating the acceleration signal G once with respect to time is smaller than a predetermined second threshold speed change V _TH (shown in FIG. 3B). In the region α), the movement amount S of the occupant calculated by integrating the acceleration signal G twice with respect to time is equal to the predetermined threshold movement amount S.
If it is larger than _TH (region β shown in FIG. 3C), the occupant protection device such as the airbag device is activated. Thereby, for example, a frontal collision of the vehicle (solid line A shown in FIG. 3D)
In addition, even if the speed change V (t) is relatively small due to the deformation of the vehicle at the time of collision, such as an offset collision (solid line B shown in FIG. 3D), the collision state Is long, the movement amount S of the occupant is accumulated and becomes large (the region γ shown in FIG. 3D).
The occupant protection device can be activated to protect the occupant from a secondary collision.

As described above, according to the vehicle collision judging device 10 according to the present embodiment, for example, when a collision occurs at a part of the front of the vehicle, that is, when a collision occurs at a place where the vehicle body is easily deformed, Even when the speed change V (t) is small, the occupant protection device such as the airbag device can be activated based on the occupant movement amount S.
For example, even if an offset collision occurs, it is necessary to clearly distinguish it from a low-speed head-on collision, etc., to reliably determine that a collision has occurred within a short time after the collision has occurred, and to protect the occupant from a secondary collision. it can. For this reason, a special detection device for detecting an offset collision, such as a front sensor, is not required, and the collision can be determined only by the acceleration sensor 11, thereby reducing the manufacturing cost of the vehicle collision determination device 10. In addition to this, it is possible to prevent the configuration of the device from becoming complicated.

[0022]

As described above, according to the vehicle collision judging device according to the first aspect of the present invention, for example, an air bag device, a seat belt pretensioner, or the like can be used in a short time when a collision occurs. The activation timing and operation of the occupant protection device can be appropriately controlled. Further, according to the vehicle collision determination device of the present invention, it is possible to appropriately determine a collision.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle collision determination device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the vehicle collision determination device shown in FIG.

FIG. 3A is a graph showing a time change of an acceleration signal G at the time of occurrence of a collision, and FIG. 3B is a graph showing FIG. 3A.
FIG. 3C is a graph showing the time change of the speed change V calculated from the acceleration signal G shown in FIG. 3C, and FIG. 3C shows the time change of the movement amount S of the occupant calculated from the acceleration signal G shown in FIG. FIG. 3D is a graph showing a change in a speed change V and a movement amount S of an occupant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Collision determination apparatus for vehicles 11 Acceleration sensor (acceleration detection means) 14 Speed change calculation part (speed change calculation means) 19 Speed change determination part (speed change determination means) 22 Movement amount calculation part (occupant movement amount calculation means) 23 Movement Amount determination unit (occupant movement amount determination unit) 24 Start signal generation unit (control signal generation unit)

Claims (2)

[Claims] 1. An acceleration detecting means for detecting an acceleration acting on a vehicle; a speed change calculating means for calculating a speed change by linearly integrating an acceleration signal detected by the acceleration detecting means; The speed change calculated in
First speed change determination means for determining whether or not the speed change is smaller than a predetermined first threshold speed change; occupant movement amount calculation means for calculating the occupant movement amount by secondarily integrating the acceleration signal with respect to time; An occupant movement amount determination unit that determines whether the occupant movement amount calculated by the occupant movement amount calculation unit is greater than a predetermined threshold occupant movement amount, a determination result by the speed determination unit, and the occupant movement amount A vehicle collision judging device comprising: control signal generating means for generating a control signal for controlling the operation of the occupant protection device in accordance with a result of the judgment by the judging means. 2. The occupant movement amount determining means determines whether or not the occupant movement amount is greater than the predetermined threshold occupant movement amount within a predetermined time period after the occurrence of a collision. The vehicle collision determination device according to claim 1.