JP2001277998A - Vehicular collision judging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly judge a collision in a short time according to violence of a collision with simple and inexpensive constitution. SOLUTION: A collision judging part 12 generates a starting signal of an air bag device on the basis of an acceleration signal G from an acceleration sensor 11. An occupant moving distance calculating part 21 of a severe collision detecting part 13 calculates an occupant moving distance S by integrating the acceleration signal G twice. A difference calculating part 24 calculates integral values of the acceleration signal G on time intervals different in a prescribed time width n when the occupant moving distance S is not more than STH, and calculates a difference ΔG between these integral values. An elapsed time calculating part 26 calculates elapsed time ΔT when the difference ΔG exists between a first threshold difference value ΔGTH1 and a second threshold difference value ΔGTH2, and judges whether or not the elapsed time is smaller than threshold elapsed time ΔTTH. An air bag is rapidly unfolded or gently unfolded according to a judging result.

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 air bag device, and more particularly to a vehicle collision judging device according to the magnitude of an impact at the time of a collision. The present invention relates to a technique for controlling the operation of an occupant protection 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. 1
When the integrated values exceed the predetermined threshold values after the integration is performed twice or twice, 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 the secondary collision between the occupant and the interior components.

[0003]

In the vehicle collision determining apparatus according to one example of the prior art, the detected acceleration signal is independent of the magnitude of the impact at the time of the collision and the position of the occupant in the vehicle. There is a case where the airbag is set to deploy with a certain characteristic only when the calculated value exceeds a predetermined threshold, and even if there is a difference in the collision situation, there is a problem that only the same control can be performed. is there. The present invention has been made in view of the above circumstances, and by using the acceleration at the initial stage of a collision, it is possible to perform a proper collision determination in a short time with a simple and inexpensive configuration according to the severity of the collision. It is an object to provide a vehicle collision determination device.

[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. (For example, an acceleration sensor 11 in an embodiment described later) and an acceleration signal detected by the acceleration detection unit are compared with a first time interval (for example, 0 ≦ t in an embodiment described later). ≤ n) and the second
(For example, n ≦ t in an embodiment described later)
≤2n) a difference calculating means for calculating a difference value (for example, a difference ΔG in an embodiment to be described later) with the section integral value in (≦ 2n) (for example, a difference calculating unit 24 in an embodiment to be described later)
And a severe collision determination unit (for example, first and second difference determination units 25a and 25b and an elapsed time calculation unit 26 in an embodiment described later) that determines whether a time change with respect to the difference value is equal to or less than a predetermined threshold value. And an elapsed time determination unit 27) and a control signal generation for generating a control signal for controlling an operation of an occupant protection device (for example, an airbag device in an embodiment described later) according to a determination result by the severe collision determination unit. (E.g., a severe collision signal generation unit 28 and a non-severe collision signal generation unit 29 in the embodiments described later).

[0005] According to the vehicle collision determination device having the above structure,
During a short time at the time of the collision, the magnitude of the impact at the time of the collision is detected by utilizing the acceleration different according to the vehicle speed, that is, the difference in the repulsion deceleration of the vehicle body, and according to the magnitude of the impact, For example, it is possible to appropriately control the activation timing and operation of an occupant protection device such as an airbag device and a seatbelt pretensioner, for example, the operation of deploying an airbag. For example, FIGS. 1A to 1C are graphs showing a time change of an acceleration signal G (positive in the deceleration direction) in a frontal collision with different vehicle speeds, and FIG.
It is a graph which shows initial acceleration and repulsion time (duration of initial acceleration) with respect to (a)-(c). Here, FIG.
(A) is a collision at a high speed (for example, about 50 km / h), FIG. 1 (b) is a collision at a medium speed (for example, about 20 km / h),
FIG. 1C shows a collision at a low speed (for example, about 12 km / h). The initial acceleration increases and the rebound time decreases as the vehicle speed at the time of collision increases, and the initial acceleration decreases as the vehicle speed decreases. Small and long repulsion time. That is, the vehicle speed is 50 km / h, 20 km / h, 12 km
m / h, the maximum initial deceleration is G
Assuming that G1, G2 and G3 and the repulsion times are t1, t2 and t3, G1>G2> G3 and t1 <t2 <t3.

Here, the following equation (1) is set to extract the relationship between the initial acceleration and the rebound time according to the vehicle speed at the time of the collision.

[0007]

(Equation 1)

That is, an integral value of the acceleration signal G for a predetermined time width n is calculated, and a time change of the integral value, that is, a different time section (for example, 0 ≦ t ≦ n, n ≦ t ≦ 2n).
Is calculated as the difference ΔG between the integral values. This difference ΔG is
For example, each difference Δ with respect to FIGS. 1 (a) to 1 (c) shown in FIG.
As shown in the diagram showing the time change of G, the change varies depending on the magnitude of the vehicle speed at the time of the collision. Here, for the difference ΔG, for example, two threshold difference values ΔG _TH1 , ΔG _TH2 (ΔG _TH
1 ≦ ΔG _TH2 ) is set, and the elapsed time ΔT until the difference ΔG exceeds one threshold difference value ΔG _TH1 and reaches the other threshold difference value ΔG _TH2 is measured. Then, the elapsed time ΔT becomes shorter as the collision speed increases, and for example, as shown in FIG.
Elapsed time Δ in high-speed collision (solid line a in FIG. 3)
T1 is shorter than the elapsed time ΔT2 in the collision at medium speed (solid line b in FIG. 3), and in the collision at low speed (solid line c in FIG. 3), the difference ΔG is equal to the other threshold difference value ΔG _TH2 . Decrease without reaching.

Therefore, at least one or more (for example, one) threshold elapsed time ΔT _TH is set for the elapsed time ΔT, and the elapsed time ΔT is compared with the threshold elapsed time ΔT _TH , so that the collision time ΔT _TH can be determined. Of the impact, that is, the intensity of the impact can be determined. For example, the elapsed time ΔT is equal to the threshold elapsed time ΔT _TH
If it is below, it is determined that the collision is at a high speed, that is, a severe collision. If it is determined that the collision is severe, for example, the airbag is rapidly deployed to give priority to protecting the occupant. Conversely, if it is determined that the collision is not severe,
For example, the airbag is gradually deployed by deploying the airbag in multiple stages. Thereby, the occupant protection device such as the airbag device can be appropriately controlled according to the situation of the collision. Although the integration interval of the acceleration signal G is not particularly limited, when determining a high-speed collision as described above, for example, the time width n is set to about the repulsion time t1 for a high-speed collision. By doing so, the difference ΔG for a collision at a high speed can be made more remarkable as compared with a collision at a low speed.

Further, in the vehicle collision judging device according to the present invention, the severe collision judging means may determine that the difference value is two threshold difference values (for example, a first threshold value in an embodiment described later). Elapsed time detecting means (for example, in an embodiment described later) for detecting an elapsed time (for example, an elapsed time ΔT in an embodiment described later) located between the difference value ΔG _TH1 and the second threshold difference value ΔG _TH2. Elapsed time calculating unit 26) and an elapsed time determination unit (for example, an embodiment described later) that determines whether the elapsed time is equal to or less than a threshold time (for example, a threshold elapsed time ΔT _{TH in} an embodiment described later). Elapsed time determination unit 2
7).

According to the vehicle collision determination device having the above configuration,
If the elapsed time at which the difference value is located between the two threshold difference values is less than or equal to the threshold time, the time change of the difference value is small and it can be determined that the collision is severe, and conversely, the elapsed time is shorter than the threshold time. When the difference is also large, it can be determined that the time change of the difference value is relatively large and the collision is not severe.

Further, the vehicle according to the third aspect of the present invention.
The collision judging device moves the occupant based on the acceleration signal.
Amount (for example, the occupant movement amount S in the embodiment described later)
Moving amount calculating means for calculating (for example, an embodiment described later)
The occupant movement amount calculation unit 21) determines that the occupant movement amount is
Movement amount (for example, threshold movement amount in the embodiment described later)
S _TH) The movement amount determination means (for example,
The occupant movement amount determination unit 22) in the embodiment described later,
Calculating the difference according to the determination result by the movement amount determining means
Control means for controlling the operation of the means (for example,
And a difference processing control unit 23) in the form of
The step shows the difference when the movement amount is equal to or larger than the threshold movement amount.
The calculation of the minute value is stopped.

According to the vehicle collision determination device having the above configuration,
If the movement amount of the occupant is smaller than the threshold movement amount, a difference value is calculated based on the acceleration signal, and based on the difference value, the magnitude of the impact at the time of the collision, that is, whether the collision is severe or not. Is performed. Then, when it is determined that the collision is severe, for example, the airbag is rapidly deployed to protect the occupant. On the other hand, when the movement amount of the occupant is equal to or larger than the threshold movement amount, the determination process of whether or not the collision is severe is not performed, and regardless of the magnitude of the impact at the time of the collision, for example, the airbag has a constant characteristic. To slowly deploy. Thus, the occupant protection device such as the airbag device can be appropriately operated according to the amount of movement of the occupant in the vehicle in addition to the magnitude of the impact at the time of the collision.

Further, according to a fourth aspect of the present invention, there is provided a vehicle collision judging device comprising a collision judging means (for example, a collision judging unit 12 in an embodiment described later) for detecting a collision based on the acceleration signal. The control signal generation means is characterized in that the control signal generation means generates the control signal based on a result of the determination by the severe collision determination means and detection of a collision by the collision determination means.

According to the vehicle collision determination device having the above configuration,
For example, if the collision is determined by the collision determination unit, the airbag is set to be slowly deployed, and further, the collision is determined by the collision determination unit, and the severe collision is determined by the severe collision determination unit. If it is determined, by setting to deploy the airbag rapidly,
An occupant protection device such as an airbag device can be appropriately controlled according to the state of the collision. In addition, when a severe collision is determined, the determination is made based on two determination results, that is, the determination result of the collision determination unit and the determination result of the severe collision determination unit, so that the determination is made more reliably. Processing can be performed.

[0016]

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. 4 is a configuration diagram of the 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,
It is provided with a collision determination unit 12 and a severe collision detection unit 13. The collision determination unit 12 includes, for example, a filter processing unit including, for example, a low-pass filter that removes a high-frequency component that is a noise component from the acceleration signal G output from the acceleration sensor 11, and an acceleration signal G after filtering.
And an A / D converter for converting the digitalized acceleration signal G into a digital signal once with respect to time.
Alternatively, there is provided a determination unit that performs integration twice and determines that a collision has occurred when these integrated values exceed predetermined threshold values.

The severe collision detection unit 13 includes an occupant movement amount calculation unit 21, an occupant movement amount determination unit 22, a difference processing control unit 23, a difference calculation unit 24, and a first difference determination unit 25.
a, a second difference determination unit 25b, an elapsed time calculation unit 26,
An elapsed time determination unit 27 and a severe collision signal generation unit 28 are provided. The occupant movement amount calculating unit 21 calculates the occupant movement amount S in the vehicle by integrating the acceleration signal G output from the acceleration sensor 11 twice with respect to time. Occupant moving amount determining section 22 determines whether or not the occupant movement amount S calculated by the occupant moving amount calculating unit 21 is larger than the threshold amount of movement S _TH, and outputs a command signal based on the determination result .

The differential processing control unit 23, in accordance with the determination result in the occupant moving amount determining unit 22, for example, when the occupant moving amount S is greater than the threshold amount of movement S _TH, the difference calculation unit 2 described later
4 is stopped. That is, the difference processing control unit 23 includes, for example, a switch, and interrupts the input of the acceleration signal G to the difference calculation unit 24 according to the determination result of the occupant movement amount determination unit 22. The difference calculator 24 calculates the acceleration signal G
The difference ΔG is calculated on the basis of, for example, the above equation (1).

The first difference judging section 25a includes a difference calculating section 24
Is a predetermined first threshold difference value ΔG
_It is determined whether or not it is greater than _TH1 , and for example, a time x at which the difference ΔG exceeds a predetermined first threshold difference value ΔG _TH1 is output. The second difference determination unit 25b determines whether the difference ΔG calculated by the difference calculation unit 24 is larger than a predetermined second threshold difference value ΔG _TH2 .
The time y exceeding the threshold difference value ΔG _TH2 is output. Note that, for the first and second threshold difference values ΔG _TH1 and ΔG _TH2 , for example, ΔG _TH1 <ΔG _TH2 .

Based on the times x and y output from the first and second difference determination sections 25a and 25b, the elapsed time calculation section 26 calculates the difference ΔG as a first threshold difference value ΔG _TH1 and a second threshold difference value ΔG _TH1 . Elapsed time ΔT existing between _TH and _{T H2} (ΔT = y−
x) is calculated. The elapsed time determination unit 27 determines that the elapsed time ΔT calculated by the elapsed time calculation unit 26 is equal to the threshold elapsed time ΔT
_It determines whether or not it is less than _TH, and outputs a command signal based on the result of this determination.

The severe collision signal generator 28 determines whether or not the impact of the generated collision is large, and outputs, for example, a command for rapidly deploying the airbag. For this reason,
The severe collision signal generation unit 28 receives a signal from the collision determination unit 12
An activation signal indicating that a collision that needs to activate an occupant protection device such as an airbag device has occurred, and a severe collision determination signal indicating that a severe collision has occurred is input from the severe collision detection unit 13. And the AND of both signals
When the condition is satisfied, for example, a simultaneous ignition command for rapidly deploying the airbag is output. On the other hand, AND of both signals
The NOT signal for the condition and the activation signal from the collision determination unit 12 are input to the non-severe collision signal generation unit 29, and the AND condition of both signals, that is, the need to activate the occupant protection device such as an airbag device, is required. A collision occurred,
When it is determined that the collision is not a severe collision, a multi-stage (for example, two-stage) ignition command for slowly expanding the air bag is output, for example. In addition, the multi-stage ignition command is not to generate gas at the maximum output at once when generating gas from the inflator and deploying the air bag, for example, to sequentially ignite a plurality of gas generating agents in a stepwise manner. It generates gas.

Vehicle collision determining apparatus 1 according to this embodiment
0 has the above-described configuration. Next, the operation of the vehicle collision determination device 10, in particular, the processing of determining whether or not the generated collision is a severe collision in the severe collision detection unit 13 is described with reference to FIG. This will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the vehicle collision determination device 10. First, in step S1 shown in FIG.
1 to read the acceleration signal G detected. Next, in step S2, the acceleration signal G is sent to the occupant movement amount calculation unit 21, and is integrated twice with respect to time to calculate the occupant movement amount S. Whether the occupant movement amount S is equal to or greater than the threshold movement amount S _TH Determine whether or not. If the result of this determination is "YES", the operation proceeds to step S7, and a series of processing ends.

On the other hand, if the result of the determination is "NO", the operation proceeds to step S3, where the acceleration signal G is sent to the difference calculation unit 24 via the difference processing control unit 23, and a predetermined value is obtained from the above-mentioned equation (1). A continuous time section with a time width n (for example, 0 ≦
The difference ΔG of each integral value at (t ≦ n, n ≦ t ≦ 2n) is calculated. Note that the time width n is set to about the repulsion time t1 for a collision at a high speed (for example, about 50 km / h) as shown in FIG. 2, for example.

Next, in step S4, the gradient of the difference ΔG with respect to time change, that is, the elapsed time ΔT when the difference ΔG changes from a predetermined first threshold difference value ΔG _TH1 to a second threshold difference value ΔG _TH2 is calculated. . Next, in step S5, it is determined whether the slope of the calculated difference ΔG with respect to time change is equal to or greater than a predetermined threshold. That is, the difference Δ
G is a predetermined first threshold difference value ΔG _TH1 to a second threshold difference value ΔG
The elapsed time ΔT when changing to _TH2 is the threshold elapsed time ΔT
It is determined whether it is less than _TH . When this determination result is “N
In the case of "O", the process proceeds to step S7, and a series of processing ends. On the other hand, if the result of the determination is "YES", the flow proceeds to step S6, in which it is determined that a severe collision has occurred, for example, a command for rapidly deploying an airbag is output, and the flow proceeds to step S7. A series of processing ends.

That is, when it is determined that an occupant protection device such as an air bag device needs to be activated, the occupant movement amount S is smaller than the threshold movement amount S _TH and the elapsed time ΔT with respect to the difference ΔG is the threshold elapsed time. If it is equal to or less than ΔT _TH , it is determined that the collision is severe and, for example, the airbag is rapidly deployed. On the other hand, the occupant movement amount S is equal to or greater than the threshold movement amount S _TH , or
If the elapsed time ΔT with respect to the difference ΔG is larger than the threshold elapsed time ΔT _TH , for example, the airbag is gradually deployed in multiple stages.

As described above, according to the vehicle collision judging device 10 according to the present embodiment, when the collision judging unit 12 judges that a collision has occurred and the activation of the airbag device is instructed, the severe collision detecting unit 13 Since the deployment operation of the airbag is controlled in accordance with the determination result in the above, it is possible to appropriately deploy the airbag in accordance with the collision situation. Moreover, in addition to the magnitude of the impact at the time of the collision, the deployment operation of the airbag is controlled according to the amount of movement of the occupant in the vehicle,
The airbag can be more appropriately deployed. In addition, since the severe collision is determined based on the difference value of the integral of the acceleration signal G, the severity of the collision can be determined in a short period of time and reliably. , The severity of the collision can be significantly detected for a vehicle having a relatively large initial acceleration at the time of the collision. Further, the amount of movement of the occupant in the vehicle can be calculated based on the acceleration signal G. For example, there is no need for a camera for monitoring the inside of the vehicle or an appropriate sensor for detecting the position of the occupant on a seat, for example. The vehicle collision determination device 10 can be configured at low cost.

In the present embodiment, the time width n is set to about the repulsion time t1 for a collision at a high speed (for example, about 50 km / h). However, the present invention is not limited to this.
Other time intervals may be set. Also, the difference ΔG
To a continuous time interval (for example, 0 ≦ t
≦ n, n ≦ t ≦ 2n), but the present invention is not limited to this, and two time sections may have overlapping sections. That is, assuming that k <n, the difference ΔG
With the integral value in the time interval 0 ≦ t ≦ n and the time interval (n−
k) It may be a difference from an integral value at ≦ t ≦ (2n−k).

In this embodiment, one threshold elapsed time ΔT _TH corresponds to the elapsed time ΔT when the difference ΔG changes from the first threshold difference ΔG _TH1 to the second threshold difference ΔG _TH2. was set to is not limited to this, a plurality of threshold elapsed time _{ΔT TH1, ..., ΔT T Hm} (m is an arbitrary natural number) may be set. In this case, the magnitude of the impact at the time of collision can be classified in more detail, and the airbag can be deployed in, for example, three or more stages according to the magnitude of the impact.

Further, in the present embodiment, the difference ΔG
And the first and second threshold difference values ΔG _TH1, ΔG_TH2The set
However, the present invention is not limited to this. For example, one threshold difference
Value ΔG_TH3Is set, and the difference ΔG becomes the threshold difference value ΔG_TH3
May be determined to be a violent collision at the point of exceeding. This
, The second difference determination unit 25b and the elapsed time calculation unit 26
And the elapsed time determination unit 27 can be omitted.
Configuration can be simplified to help reduce production costs
It is.

[0030]

As described above, according to the vehicle collision judging device of the first aspect of the present invention, during a short time at the time of a collision, different accelerations depending on the vehicle speed, that is, rebound of the vehicle body. Using the difference in deceleration, the magnitude of the impact at the time of the collision is detected, and according to the magnitude of the impact, the activation timing and operation of an occupant protection device such as an airbag device or a seatbelt pretensioner are determined. It can be controlled appropriately. Further, according to the vehicle collision determination device of the present invention, when determining the time change of the difference value, the elapsed time in which the difference value is located between the two threshold difference values is detected. Since the comparison with the threshold time is performed, the determination can be performed in a shorter time as the collision becomes more severe. Furthermore, according to the vehicle collision determination device of the present invention described in claim 3, in addition to the magnitude of the impact at the time of the collision, in accordance with the amount of movement of the occupant in the vehicle,
An occupant protection device such as an airbag device can be appropriately operated. Furthermore, according to the vehicle collision determination device of the present invention, it is possible to more appropriately control the occupant protection device such as the airbag device according to the state of the collision.

[Brief description of the drawings]

FIG. 1 is a graph showing a time change of an acceleration signal G in a frontal collision with different vehicle speeds according to an embodiment of the present invention.

FIG. 2 is a graph showing initial acceleration and repulsion time for FIGS. 1 (a) to 1 (c).

FIG. 3 is a graph showing a time change of a difference ΔG with respect to FIGS. 1 (a) to 1 (c).

FIG. 4 is a configuration diagram of a vehicle collision determination device according to one embodiment of the present invention.

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

[Description of Signs] 10 Collision determination device for vehicle 11 Acceleration sensor (acceleration detection means) 12 Collision determination section (collision determination means) 21 Occupant movement amount calculation section (movement amount calculation means) 22 Occupant movement amount determination section (movement amount determination) Means) 23 Difference processing control unit (Control unit) 24 Difference calculation unit (Difference calculation unit) 25a First difference determination unit (Severe collision determination unit) 25b Second difference determination unit (Severe collision determination unit) 26 Elapsed time calculation unit ( Elapsed time detection means, severe collision determination means) 27 Elapsed time determination section (elapsed time determination means, severe collision determination means) 28 Severe collision signal generation section (control signal generation means) 29 Non-severe collision signal generation section (control signal generation means) )

Claims (4)

[Claims] An acceleration detecting means for detecting an acceleration acting on a vehicle, a section integration value in a first time section with respect to an acceleration signal detected by the acceleration detecting means, and a second time section A difference calculation means for calculating a difference value with the interval integral value in the above, a severe collision determination means for determining whether a time change with respect to the difference value is equal to or less than a predetermined threshold value, and a determination result by the severe collision determination means. And a control signal generating means for generating a control signal for controlling the operation of the occupant protection device in response to the control signal. 2. The severe collision determination means, wherein the elapsed time detection means detects an elapsed time in which the difference value is located between two threshold difference values, and determines whether the elapsed time is equal to or less than a threshold time. The vehicle collision determination device according to claim 1, further comprising an elapsed time determination unit. 3. A moving amount calculating unit for calculating a moving amount of an occupant based on the acceleration signal; a moving amount determining unit for determining whether the moving amount of the occupant is equal to or more than a threshold moving amount; Control means for controlling the operation of the difference calculation means in accordance with the determination result by the means, wherein the control means stops the calculation of the difference value when the movement amount is equal to or greater than the threshold movement amount. The vehicle collision determination device according to claim 1 or 2, wherein: 4. A control device, comprising: a collision determination unit configured to detect a collision based on the acceleration signal; wherein the control signal generation unit performs the control based on a determination result by the severe collision determination unit and a collision detection by the collision determination unit. The vehicle collision judging device according to any one of claims 1 to 3, wherein the signal is generated.