JP2001294116A - Vehicle collision determination device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To determine a collision by predicting the magnitude of a collision impact. SOLUTION: A collision determination unit 1 of a vehicle collision determination device 10 is provided.
Reference numeral 2 denotes a collision determination data generation unit 23 that generates collision determination data based on the acceleration signal G output from the acceleration sensor 11, a threshold setting unit 24 that sets a predetermined threshold value for the collision determination data, And a part 25. The collision determination data generation unit 23 sets, for example, a speed change ΔV obtained by linearly integrating the acceleration signal G with respect to time as the collision determination data. The threshold setting unit 24 includes:
Ground vehicle speed V output from ground vehicle speed calculation unit 14
A predetermined threshold value for the collision determination data is set based on. The determination unit 25 determines whether or not a collision has occurred based on the relative relationship of the collision determination data to a predetermined threshold, for example, whether the speed change ΔV that is the collision determination data exceeds the predetermined threshold speed change ΔV _TH or the like. judge.

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.

[0003]

In the vehicle collision judging device according to an example of the prior art described above, the collision judgment is performed based on the acceleration generated in the vehicle immediately after the collision occurs. However, there is a problem that it is impossible to predict the magnitude of the shock generated in the early stage of the collision. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle collision determination device capable of predicting the magnitude of a collision impact and performing a collision determination.

[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 comprises: Ground vehicle speed calculating means (for example, ground vehicle speed calculating unit 14 in an embodiment described later) for calculating ground vehicle speed V in the embodiment, and acceleration acting on the vehicle (for example, an embodiment described later) Collision determination data generating means (for example, a collision determination data in an embodiment described later) that generates collision determination data (for example, collision determination data in an embodiment described later) based on the acceleration signal G). A data generation unit 23) and a predetermined threshold value (for example, a zero threshold speed change ΔV _TH0 , a first threshold speed change ΔV _TH1 , a first threshold speed change ΔV _TH1 in an embodiment described later) for the collision determination data according to the ground vehicle speed. 2 threshold speed Change [Delta] V _TH2) threshold setting means for setting (for example, the threshold setting unit 2 in the embodiment described below
4) and a collision determination unit (for example, a determination unit 25 in an embodiment described later) that determines the collision by comparing the collision determination data with the predetermined threshold.

[0005] According to the vehicle collision determination device having the above structure,
For example, by calculating the ground vehicle speed at all times, it is possible to estimate the kinetic energy of the vehicle body when a collision occurs, based on the ground vehicle speed. Since the magnitude of the kinetic energy indicates the magnitude of the impact at the time of the collision, that is, the magnitude of the danger of the occupant, collision determination data for determining the occurrence of a collision, for example, acceleration, speed change, By setting a predetermined threshold value corresponding to the vehicle body speed with respect to the occupant movement amount, in the initial stage immediately after the occurrence of the collision, for example, the activation timing of the occupant protection device such as an airbag device or a seatbelt / pretensioner, The operation, for example, the operation of deploying the airbag, can be controlled accurately. In addition, since the kinetic energy of the vehicle at the time of the collision can be estimated, a relatively small acceleration is detected, for example, in a collision in a low rigidity portion of the vehicle and the vehicle body is largely deformed in the early stage of the collision. Even in such a case, the state of the collision can be reliably grasped, and the occupant protection device can be appropriately operated according to the state of the collision.

Furthermore, in the vehicle collision judging device according to the present invention, the threshold value setting means sets the predetermined threshold value to a smaller value as the ground vehicle speed increases. . According to the vehicle collision determination device having the above configuration, it is determined that the impact at the time of the collision increases as the ground vehicle speed increases, and a relatively small value is set as a predetermined threshold value for the collision determination data. By determining that a collision occurs when the determination data exceeds a predetermined threshold, the collision can be determined in a shorter time as the occurrence of the collision becomes more severe.

[0007]

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 vehicle includes a collision determination unit 12, a start signal generation unit 13, a ground vehicle speed calculation unit 14, and a vehicle speed pulse detection unit 15.

The acceleration sensor 11 outputs an acceleration signal of a voltage level corresponding to the magnitude of the acceleration acting on the vehicle when a collision occurs. The collision determination unit 12 includes an acceleration signal G output from the acceleration sensor 11 and a ground vehicle speed calculation unit 14.
Is determined based on the vehicle body speed V output from the ground. The activation signal generation unit 13 generates an activation signal for activating an occupant protection device such as an airbag device or a seatbelt pretensioner, according to the determination result of the collision determination unit 12.

The ground vehicle speed calculating unit 14 calculates the ground vehicle speed V and outputs it to the collision judging unit 12. Here, a vehicle speed pulse detection unit 15 is connected to the ground vehicle speed calculation unit 14, and the vehicle speed pulse detection unit 15 detects the rotation speed of the wheels of the vehicle. Normally, when a collision occurs, the driver often operates a foot brake to avoid the collision in order to avoid the collision. In this case, for example, when the foot brake is suddenly operated, the wheels are locked, and the detected vehicle speed pulse does not accurately reflect the vehicle speed. Therefore, firstly, the speed of the current time obtained from the vehicle speed pulse and V _R, the previous value of the ground vehicle velocity V
_{As (n-1)} , the vehicle body speed change amount ΔV is calculated by the following equation (1).

[0010]

(Equation 1)

However, as shown in the following equation (2), a predetermined lower limit value ΔVm
in and the upper limit value ΔVmax are set, and the calculated vehicle body speed change amount ΔV is set to the lower limit value ΔVmin and the upper limit value ΔV.
If it exceeds the range of max, the lower limit value ΔVmin or the upper limit value ΔVmax is set for the vehicle speed change amount ΔV. Next, as shown in the following equation (3), the value obtained by adding the vehicle speed change amount ΔV to the previous value V _(n−1) of the ground vehicle speed is defined as the current ground vehicle speed V.

[0012]

(Equation 2)

[0013]

(Equation 3)

The collision judging unit 12 receives, for example, an acceleration signal G output from the acceleration sensor 11 and converts the signal into a digital signal, and a noise component from the digitized acceleration signal G. A filter processing unit 22 including a low-pass filter or the like for removing high-frequency components, a collision determination data generation unit 23 that generates collision determination data based on the filtered acceleration signal G, and a predetermined threshold value for the collision determination data Setting section 24 for setting
And a determination unit 25.

The collision judging data generation unit 23 of the collision judging unit 12 performs, for example, an acceleration signal G itself, a velocity change ΔV obtained by linearly integrating the acceleration signal G with respect to time, and a secondary integration of the acceleration signal G. The obtained occupant movement amount S, the acceleration signal G, the speed change ΔV, the rate of change of the occupant movement amount S over a predetermined time, and the like are set as collision determination data. The threshold setting unit 24 sets a predetermined threshold value for the collision determination data based on the ground vehicle speed V output from the ground vehicle speed calculation unit 14. The determination unit 25 determines whether a collision has occurred based on the relative relationship of the collision determination data to a predetermined threshold, for example, whether the speed change ΔV that is the collision determination data exceeds a predetermined threshold speed change ΔV _TH or the like. Is determined.

A vehicle collision determining apparatus 1 according to the present embodiment.
0 has the above configuration. Next, the operation of the vehicle collision determination device 10, particularly, the operation of setting a predetermined threshold value for the collision determination data in the collision determination unit 12 with reference to the accompanying drawings. explain. FIG. 2 is a graph showing the relationship between the ground vehicle speed V and the threshold setting data α.
FIG. 4 is a graph showing a time change of collision determination data, for example, a speed change ΔV. Threshold setting unit 24 of collision determination unit 12
Sets the threshold setting data α in accordance with the ground vehicle speed V, as shown in FIG. 2, for example. That is, when the ground vehicle speed V is 0 ≦ V ≦ V1, the threshold setting data α is set to zero, when V1 ≦ V ≦ V2, the threshold setting data α is set to a first predetermined value α1, and when V2 ≦ V, the threshold setting data α is set. The data α is a predetermined second value α2. However, α1 <α2. Then, for example, in FIG.
As shown in (2), a predetermined threshold speed change ΔV _TH is set for the collision determination data, for example, the speed change ΔV. That is, when the threshold setting data α is zero,
Setting a predetermined zeroth threshold speed change [Delta] V _TH0 to the threshold speed change [Delta] V _TH, in the case of the threshold value setting data alpha = [alpha] 1 sets the first threshold speed change [Delta] V _TH1 given the threshold speed change [Delta] V _TH, When the threshold setting data α = α2, the threshold speed change ΔV _TH
Is set to a predetermined second threshold speed change ΔV _TH2 . However,
ΔV _TH0 > ΔV _TH1 > ΔV _TH2 .

Thus, the determination unit 25 of the collision determination unit 12
For example, if the ground vehicle speed V is 0 ≦ V ≦ V1, it is determined that a collision occurs when the speed change ΔV exceeds the zeroth threshold speed change ΔV _TH0 , and if the ground vehicle speed V is V1 ≦ V ≦ V2, When the change ΔV exceeds the first threshold speed change ΔV _TH1 , it is determined that a collision has occurred, and when the ground vehicle speed V is V2 ≦ V, the speed change Δ
When V exceeds the second threshold speed change ΔV _TH2 , a collision is determined. That is, for example, as shown in FIG.
In the initial stage of the collision up to 0, the difference in vehicle speed at the time of the collision (high speed: dotted line a shown in FIG. 3, middle speed: dotted line b shown in FIG. 3, low speed: dotted line c shown in FIG. 3) Although each speed change ΔV shows almost the same change, it is determined that the impact at the time of the collision increases as the ground vehicle speed V increases, and a smaller value is set as the threshold speed change ΔV _TH with respect to the speed change ΔV. Set. Thus, the higher the ground vehicle speed V at the time of the collision, the earlier the collision can be determined.

As described above, according to the vehicle collision determination device 10 of the present embodiment, the ground vehicle speed calculation unit 14
, The kinetic energy of the vehicle at the time of the collision, that is, the magnitude of the impact, can be estimated. For example, an occupant protection device such as an airbag device or a seatbelt / pretensioner can be used. Thus, it is possible to accurately control according to the magnitude of the impact at the time of the collision. In addition, as the ground vehicle speed V increases, the predetermined threshold speed change ΔV with respect to the collision determination data, for example, the speed change ΔV,
_{Since the TH} is lowered, the collision can be determined in a shorter time as the impact at the time of the collision is larger, and the occupant protection device can be activated at an accurate activation timing.

In the present embodiment, the ground vehicle speed calculating unit 14 calculates the ground vehicle speed V by adding the vehicle speed change amount ΔV to the previous value V _(n-1) of the ground vehicle speed. However, the present invention is not limited to this, and a ground vehicle speed detection device using another method such as a Doppler method may be used.
For example, a ground vehicle speed calculating unit 14 serving as a Doppler ground vehicle speed detecting device is mounted on a vehicle body, and includes a transmitting unit that transmits a transmission wave in an oblique direction toward a road surface, and a transmission wave reflected on a road surface. The vehicle includes a receiving unit that receives a received wave, and a calculating unit that calculates a ground vehicle speed, which is a traveling speed of the vehicle on a road surface, based on a mutual relationship between the frequency of the transmitted wave and the frequency of the received wave. Here, the inclination angles of the transmission unit and the reception unit of the ground vehicle speed calculation unit 14 with respect to the road surface are set to a predetermined angle, and the amount of change in the inclination angle due to the traveling state of the vehicle, for example, the forward inclination posture at the time of vehicle deceleration. The vehicle speed pulse from the vehicle speed pulse detector 15 is used for correction. In the present embodiment, the ground vehicle speed V
The threshold setting data α is set stepwise according to the size of the threshold value. However, the present invention is not limited to this. For example, the threshold setting data α is set according to an appropriate function using the ground vehicle speed V as a variable, such as a linear function. You may.

In this embodiment, a speed change ΔV is used as collision judgment data used for collision judgment, and the speed change ΔV is determined by a predetermined threshold speed change corresponding to the ground vehicle speed V. Although ΔV _TH0 , ΔV _TH1 , and ΔV _TH2 are set, the invention is not limited to this. Other data for collision determination, for example, the acceleration signal G itself, the occupant movement amount S obtained by quadratic integration of the acceleration signal G, and the like. Alternatively, a change rate of the acceleration signal G, the speed change ΔV, and the occupant movement amount S in a predetermined time may be used. In the present embodiment, a plurality of, for example, three threshold speed changes ΔV _TH0 , ΔV _TH1 , and ΔV _TH2 are set according to the magnitude of the ground vehicle speed V, but the present invention is not limited to this, and at least one threshold speed change is set. The threshold speed change ΔV _TH0 may be set.

In this embodiment, the acceleration at the time of the collision is directly detected based on the acceleration signal G from the acceleration sensor 11, but the present invention is not limited to this. The acceleration may be calculated indirectly based on the time differential value of the ground vehicle speed V or the vehicle speed pulse output from the vehicle speed pulse detector 15. In this case, for example, a collision in the traveling direction of the vehicle is determined. In this case, the acceleration sensor 11 can be omitted. Further, based on the time differential value of the ground vehicle speed V output from the ground vehicle speed calculating unit 14 and the vehicle speed pulse output from the vehicle speed pulse detecting unit 15, collision determination data, for example, the speed change ΔV and the movement of the occupant are calculated. The distance S or the like may be calculated.

[0022]

As described above, according to the vehicle collision judging device of the present invention, the collision judging data for judging the occurrence of a collision is determined in accordance with the vehicle ground speed. By setting a predetermined threshold value, in the initial stage immediately after the occurrence of a collision, the start timing and operation of an occupant protection device such as an airbag device or a seatbelt pretensioner, for example, the deployment operation of the airbag, etc., are accurately controlled. be able to. Furthermore, according to the vehicle collision determination device of the present invention, the more severe the collision, the shorter the collision determination can be made.

[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 graph illustrating a relationship between a ground vehicle speed V and threshold setting data α.

FIG. 3 is a graph showing a time change of collision determination data, for example, a speed change ΔV.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Vehicle collision determination apparatus 14 Ground vehicle speed calculation unit (ground vehicle speed calculation unit) 23 Collision determination data generation unit (collision determination data generation unit) 24 Threshold setting unit (threshold setting unit) 25 determination unit (collision determination unit) )

Claims (2)

[Claims] 1. A ground vehicle speed calculating means for calculating a ground vehicle speed of a vehicle; a collision determining data generating device generating collision determining data based on an acceleration acting on the vehicle; A threshold setting unit that sets a predetermined threshold value for the collision determination data, and a collision determination unit that determines a collision by comparing the collision determination data with the predetermined threshold value. Collision determination device. 2. The vehicle collision judging device according to claim 1, wherein the threshold setting unit sets the predetermined threshold to a smaller value as the ground vehicle speed increases.