JPH05288765A - Collision determining apparatus - Google Patents

Abstract

PURPOSE:To determine a collision in a specific state such as a collision starting at a bumper, a collision to a pole, and the like. CONSTITUTION:A high frequency component of a G signal detected by an acceleration (G) sensor 1 mounted on a vehicle is removed by an LPF 2. Then, a differential value is calculated by a dG/dt operating part 3 for every time interval A. A correlative value operating part 6 obtains the correlative value of the differential value and a reference pattern held by a reference pattern holding part 5. The obtained correlative value is integrated by an integrating part 7, and compared with a preliminarily set threshold value in a comparison part 9. The threshold value is set so as to determine the collision. When the integrating value is detected to be not smaller than the threshold value in the comparison part 9, a trigger signal is output, thereby to actuate a squib activation device. Accordingly, even the collision in a specific state generating an acceleration signal of the small level can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collision determination device,
In particular, by correlating the G signal output from the acceleration sensor (hereinafter abbreviated as G sensor) with the reference pattern,
The present invention relates to a collision determination device that enables early collision determination.

[0002]

2. Description of the Related Art A conventional collision determination device integrates a G signal output from a G sensor for a certain period of time, and when the integrated value ΔV indicating the deceleration of a vehicle exceeds a predetermined reference value, a collision occurs. The determination is made and the airbag drive device is activated.

However, the differential value ΔV indicating the deceleration of the vehicle differs depending on the position of the vehicle on which the G sensor is installed. For this reason, conventionally, a plurality of G sensors are installed in each part of the vehicle, and the integrated value ΔV of each part of the vehicle is measured to determine the collision.

[0004]

As described above, in the conventional collision determination device, a plurality of G sensors are installed in each part of the vehicle,
Since the collision is determined by measuring the integrated value ΔV of each part of the vehicle, there is a problem that the collision determination algorithm is complicated and the system is expensive.

An object of the present invention is to eliminate the above-mentioned problems of the conventional device and to provide a collision determination device having a simple and inexpensive structure using less G sensors.

[0006]

In order to achieve the above object, the present invention provides a dG / dt calculator for calculating a differential value of an acceleration signal detected by an acceleration sensor and a reference for holding a reference pattern of collision. A pattern holding unit, a correlation value calculation unit that calculates the correlation value of the differential value and the reference pattern output from the dG / dt calculation unit, an integration unit that integrates the correlation value, and an integration value by the integration unit. It is characterized in that it is provided with a comparison unit for comparing with a predetermined threshold value.

[0007]

According to the present invention, the acceleration signal detected by the acceleration sensor is compared with the reference pattern of the collision, and the collision is judged based on the magnitude of the correlation, so that it is possible to identify a collision such as a collision with different speeds or a collision with the pole. The collision can be determined in the same manner as in the case of a normal collision.

Further, it is possible to determine a collision with a simple and inexpensive structure by using less G sensors.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the function of one embodiment of the present invention.

In the figure, 1 is a G sensor mounted on a vehicle, 2 is an LPF (low-pass filter) that receives the G signal detected by the G sensor 1, and 3 is a differential value of the output signal of the LPF 2 dG / dt arithmetic unit, 4 is a certain time A
The time (t) measuring unit 5 that outputs the signal A each time is measured is a reference pattern holding unit that holds the reference pattern of the G signal generated at the time of collision.

FIG. 2 shows an example of the reference pattern held in the reference pattern holding section 5. The reference pattern holding unit 5 stores, for example, reference patterns such as a collision starting from a bumper and a collision of a pole.

Further, 6 is a correlation value calculation unit for taking a correlation of the dG / dt calculation value with the reference pattern, 7 is an integration unit for integrating the correlation value, and 8 is a threshold value for collision determination. Is a threshold holding unit. The threshold holding unit 8
Holds a threshold value based on the correlation value.

Reference numeral 9 is a comparing section for comparing the integrated value output from the integrating section 7 with the threshold value, and 10 is a squib activating device which is activated by an output signal from the comparing section 9 and inflates an airbag. is there.

Next, the operation of this embodiment will be described.

The G signal detected by the G sensor 1 is the LPF.
At 2, high frequency components are removed. The waveform in FIG. 3 is the LPF2.
An example of the output waveform of is shown. On the other hand, the time (t) measuring unit 4 repeatedly outputs the signal A indicating the first time interval A. This signal A is input to the dG / dt calculator 3 and the reference pattern holder 5.

Upon receiving the notification of the first time interval A from the time (t) measuring unit 4, the dG / dt calculating unit 3 sequentially calculates the change amounts k1, k2, k3, ... Of the G signal in each section A. To do. Also,
The reference pattern holding unit 5 corresponds to G corresponding to each section A.
The signal variations K1, K2, K3, ... Are sequentially output.

When the correlation value calculating unit 6 receives the change amount input from the dG / dt calculating unit 3 and the reference pattern holding unit 5, it calculates the correlation value. The calculation for obtaining the correlation value is performed by the following method, for example.

First, the relative value Xn is obtained by the following equation. Xn = kn / Kn Then, the relative value Xn is applied to the graph of the correlation function as shown in FIG. 4 to obtain the correlation value Rn. Correlation value R
When n is obtained, the correlation value is sent to the integrator 7 and integrated.

The comparison unit 9 compares the correlation value integrated by the integration unit 7 with the threshold value held by the threshold value holding unit 8, and when the former is equal to or higher than the latter, a trigger signal is output and the squib activator 10 is operated. To start.

As described above, according to the present embodiment, it is possible to determine the collision from the similarity of the G signal to the reference pattern, so that it is relatively possible to start a collision such as a bumper collision or a pole collision. It is possible to detect a collision that starts from a waveform with a low level early and start the squib starter early.

Next, a second embodiment of the present invention will be described with reference to FIG. In the figure, 11 is a weighting unit, 12 is a threshold value holding unit that holds a threshold value serving as a reference for collision determination, and other symbols are the same as or equivalent to those in FIG.

The difference between this embodiment and the first embodiment is that dG / d is calculated based on the correlation value obtained by the correlation value calculation unit 6.
This is the point that the dG / dt value obtained by the t calculation unit is weighted, integrated by the integration unit 7, and compared with the threshold value held in the threshold value holding unit 12. ..

According to this embodiment, it is assumed that the waveform of the G signal at the time of a normal collision is the waveform a of FIG. 6 and the waveform of the collision starting from the bumper or the collision with the pole is the waveform b. Assuming that the reference pattern of a waveform such as a collision beginning with or a collision with a pole is the waveform c in the figure, the weight determination unit 11 determines a weight coefficient according to the correlation value.

When the weighting unit 12 receives the weighting coefficient from the weight determining unit 11, the weighting unit 12 multiplies the weighting coefficient by the dG / dt value sent from the dG / dt calculating unit 3. As a result, the waveform d in FIG. 6 is obtained from the weighting unit 12. As is clear from the figure, the weighted waveform d becomes almost the same as the G signal waveform a at the time of a normal collision, and by integrating this by the integrating unit 12, the collision is almost the same as at the time of a normal collision. Can be detected.

Therefore, also in this embodiment, the same effect as that of the first embodiment can be expected.

In the above embodiment, the reference pattern holding section 5 has one type of reference pattern for the sake of simplicity, but the present invention is not limited to this.
It may have a plurality of types of reference patterns. Further, the reference pattern holding unit 5, the correlation value calculation unit 6, the integration unit 7,
You may make it have several systems which consist of the comparison part 9, and connect these systems mutually in parallel.

[0027]

As is apparent from the above description, according to the present invention, it is possible to determine the collision of a specified collision such as a collision starting from a bumper or a collision with a pole by using one G sensor. You can Further, even for these specified collisions, it is possible to make an early collision determination as in a normal collision.

[Brief description of drawings]

FIG. 1 is a block diagram showing functions of an embodiment of the present invention.

FIG. 2 is a waveform diagram showing an example of a reference pattern.

FIG. 3 is a waveform diagram showing an example of a waveform of an acceleration signal detected by an acceleration sensor.

FIG. 4 is a diagram showing a method of obtaining a correlation value from a relative value.

FIG. 5 is a block diagram showing functions of a second embodiment of the present invention.

FIG. 6 is a waveform diagram showing an effect of the second embodiment.

[Explanation of symbols]

1 ... G sensor, 3 ... dG / dt calculation unit, 4 ... Time (t) measurement unit, 5 ... Reference pattern holding unit, 6 ... Correlation value calculation unit, 7 ...
Integrating unit, 8 ... Threshold value holding unit, 9 ... Comparison unit, 10 ... Squib activation device, 11 ... Weight determining unit, 12 ... Weighting unit

[Procedure amendment]

[Submission date] December 8, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art A conventional collision determination device integrates a G signal, which is an output of a G sensor, for a certain period of time, and when a value ΔV, which is the integrated value, which indicates a vehicle speed change amount , exceeds a predetermined reference value, a collision occurs. Then, the airbag drive device is started.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

However, the integral value ΔV indicating the amount of change in vehicle speed varies depending on the position of the axle on which the G sensor is installed. For this reason, conventionally, a plurality of G sensors are installed in each part of the vehicle, and ΔV is measured by the G signal in each part of the vehicle to determine a collision.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

As described above, in the conventional collision determination device, a plurality of G sensors are installed in each part of the vehicle , and ΔV in each part of the vehicle is measured to judge the collision. However, there is a problem that the collision determination algorithm becomes complicated and the system becomes expensive.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

FIG. 2 shows an example of the reference pattern held in the reference pattern holding section 5. The reference pattern holding unit 5 includes, for example, several frontal collisions with different speeds ,
Reference pattern collision of the pole is stored.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

As described above, according to the present embodiment, the collision determination can be performed based on the similarity of the G signal with respect to the reference pattern. Therefore, when a collision such as a collision with a relatively low speed or a collision with a pole is started, There is an effect that a collision starting from a waveform having a relatively low level can be detected early and the squib starter can be started early.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

According to this embodiment, the correction is performed at a relatively high speed.
The waveform of the G signal at the time of end collision is a waveform a in FIG. 6, a relatively
If the waveform of a collision with a low speed or a collision with a pole is the waveform b, and the reference pattern of the waveform of a collision starting from the bumper or a collision with the pole is the waveform c in the figure, the weight determining unit is assumed. 11 determines a weighting coefficient according to the correlation value.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

When the weighting unit 12 receives the weighting coefficient from the weight determining unit 11, the weighting unit 12 multiplies the weighting coefficient by the dG / dt value sent from the dG / dt calculating unit 3. As a result, the waveform d in FIG. 6 is obtained from the weighting unit 12. As is clear from the figure, the weighted waveform d becomes almost the same as the G signal waveform a at the time of a head-on collision , and the integrator 12 integrates the same to detect a head-on collision almost in the same manner. can do.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027]

As is apparent from the above description, according to the present invention, a single G sensor is used and the speed is relatively low.
There collision or can be a collision determination of the identified collision such as collision against the pole. Moreover, even for those identified collision, as with such collision frontal collision, it is possible to make the collision determination early.

Front Page Continuation (72) Inventor Toshio Asami, 1-4-1, Chuo, Wako, Saitama Stock Company Honda R & D Co., Ltd.

Claims (2)

[Claims] 1. A collision determination device configured to determine a collision using an acceleration sensor mounted on a vehicle, comprising: a dG / dt calculator for calculating a differential value of an acceleration signal detected by the acceleration sensor; A reference pattern holding unit that holds the reference pattern, a correlation value calculation unit that calculates the correlation value of the differential value and the reference pattern output from the dG / dt calculation unit, and an integration unit that integrates the correlation value, A collision determination device comprising: a comparison unit that compares an integrated value of the integration unit with a predetermined threshold value, and a squib is activated by an output signal from the comparison unit. 2. A collision determination device for determining a collision using an acceleration sensor mounted on a vehicle, comprising: a dG / dt calculator for calculating a differential value of an acceleration signal detected by the acceleration sensor; A reference pattern holding unit that holds the reference pattern, a correlation value calculation unit that calculates a correlation value between the differential value output from the dG / dt calculation unit and the reference pattern, and a weight is determined based on the correlation value. A weight determining unit; a weighting unit that weights the differential value by reflecting the weight on the differential value output from the dG / dt calculating unit; and an integrating unit that integrates the weighted differential value, A collision determination device comprising: a comparison unit that compares an integrated value of the integration unit with a predetermined threshold value, and a squib is activated by an output signal from the comparison unit.