JPH10232243A - Method and system for deciding side collision of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide side collision of a vehicle from an oscillatory energy based on the acceleration. SOLUTION: An acceleration sensor 12 fixed to the side face of a vehicle detects detects an acceleration to be generated upon side collision. The detected acceleration is differentiated through a differentiation unit 21 in an oscillatory energy operating block 20 and the absolute value thereof is operated through an absolute value operating unit 22. Subsequently, it is subjected to sectional integration through a sectional integrator 24 for operating the oscillatory energy and a decision is made whether a side collision occurred or not by comparing the operated oscillatory energy with a threshold level Th1. According to the method, a decision can be made quickly and accurately whether a side collision inflicting an injury upon a passenger has occurred or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for judging a side collision of a vehicle for operating a protection device for protecting an occupant in the event of a side collision of the vehicle.

[0002]

2. Description of the Related Art An occupant protection device such as an airbag device or a pretensioner device has been used to reduce injuries to an occupant due to a vehicle collision, and various new functions have been provided to cope with various anticipated collision situations. And the introduction of a system for operating the added functions in an integrated manner is urgent. For example, in the case of an airbag,
In addition to the conventional frontal airbag that protects the occupant from the impact at the time of a frontal collision, the introduction of a side airbag that protects the occupant from the impact at the time of a side collision is urgent.

The basic operation of the side airbag system is almost the same as that of the frontal airbag system which has been implemented in the past, although there are some differences in the system configuration. In the case of a side airbag system, a side airbag is embedded in the door panel, seat side, etc., and an impact sensor that closes the contact point when the vehicle receives a side impact exceeding a certain limit due to a side collision issues a deployment signal, The airbag is deployed by applying an operating current to a detonating element called a squib. The deployed airbag is interposed between a door panel and an occupant to perform a cushioning function.

[0004] However, the factors governing the deployment time required for deployment of the airbag differ in many respects between the side airbag and the frontal airbag, and the side space is narrower in the side direction than in the front direction of the occupant. In the case of a frontal collision, the factor that narrows the space between the occupant and the vehicle interior structure at the time of the collision is mainly the movement of the occupant due to inertial force, whereas in the case of a side collision, the occupant moves due to the inertial force and the side of the vehicle. Because of the additional entry of structures into the car,
The side airbag needs to be deployed in a short time after the collision as compared with the frontal airbag, and a collision determination in a very short time of several ms is required at the time of a high-speed collision. Therefore, in order to respond to such a demand and perform a side collision determination at high speed, attempts have been made in the past, for example, to install a compression switch for mechanically closing a contact in a vehicle side structure to determine a side collision. Was.

[0005]

Attempts to arrange a compression switch for mechanically closing a contact in a vehicle side structure in order to speed up the determination of a side collision and to perform a collision determination have been made to a location other than the compression switch position. In the event of a collision, a collision determination may not be made even if an occupant is injured. In the case of a collision at the compression switch position, a malfunction may occur even in a light collision that does not injure the occupant. For this reason, a collision determination method based on the acceleration signal detected by the acceleration sensor has been tried for the side collision determination as well as the front collision determination.
However, the speed change amount obtained by integrating the acceleration signal, which is a calculation value effective for collision determination, over a certain interval is due to the translational motion of the vehicle when the acceleration sensor is installed at the center of the vehicle. Although it is obtained as a stable operation value that is relatively independent of the collision location, since the translational movement of the vehicle occurs later than the collision, the detection of the acceleration signal at the center of the vehicle is delayed, and as a result, within the required judgment time. However, there is a problem that the amount of information obtained tends to be insufficient, and the determination is delayed. On the other hand, if an acceleration sensor is installed on the side of the vehicle, the acceleration signal resulting from the vehicle deformation occurring immediately after the collision can be detected. Since the magnitude of the speed change amount depends on the magnitude of the vehicle, it is difficult to make a determination within the required determination time even if the occupant is injured in a collision to a place distant from the acceleration sensor, etc. There were challenges.

[0006] For example, Japanese Patent Application Laid-Open No. 7-2049 entitled "Occupant restraint device and occupant restraint method at the time of a side collision of an objective vehicle" discloses an airbag device 1 shown in FIG.
Is disclosed. In the airbag device 1, an airbag 3 is disposed in a vehicle door 2 adjacent to an occupant, an acceleration sensor 4 is attached to an inner panel 2a of the vehicle door 2, and a lateral speed is measured from an acceleration signal output. The controller 5 issues a deployment command to the airbag 3 when the lateral speed exceeds a preset threshold.

However, the airbag device 1 is
When the value having a functional relationship with the acceleration, that is, the acceleration and the acceleration integrated value exceed a predetermined value within a predetermined time, the airbag 3
Is applied, for example, when the acceleration integral value exceeds 154.8 cm / s when 15 ms elapses after the acceleration threshold value exceeds 120 G, for example. It relied on a simple collision determination algorithm such as making a collision determination. For this reason, there has been a problem that it is not easy to maintain the determination performance with respect to various collision modes that require the deployment of the airbag.

The present invention has been made in view of the above-mentioned conventional problems, and focuses on relatively high-frequency acceleration vibration detected independently of a collision location in a side collision where an occupant is injured. The acceleration generated in the side collision is detected by the acceleration sensor installed in the part, and the collision vibration of this acceleration is regarded as a wave excited from the collision from the steady state (0G), and the vibration energy of the wave is used as the parameter of the vibration energy of the wave. It is an object of the present invention to perform high-speed and high-precision collision determination on a collision that may injure an occupant during a side collision of a vehicle by determining the likelihood.

[0009]

In order to achieve the above object, a vehicle side collision judging device according to the present invention comprises an acceleration sensor for detecting acceleration applied to a side surface of a vehicle, and a differential for obtaining a time difference between outputs of the acceleration sensor. An absolute value calculator for calculating an absolute value of an output of the differentiator; a section integrator for calculating a vibration energy to a vehicle side surface by integrating the difference absolute value in a section; Determining means for determining a threshold value of the vibration energy output from the section integrator to determine a collision.

[0010] Further, a vehicle side collision determining apparatus according to the present invention includes an acceleration sensor for detecting an acceleration applied to a side surface of a vehicle, a difference device for obtaining a time difference between outputs of the acceleration sensor, and an absolute value of an output of the difference device. An absolute value calculator, a speed change amount calculating section integrator for calculating the speed change amount by section integrating the output of the acceleration sensor, and an output of the speed change calculating section integrator being a predetermined threshold value. A comparator that outputs an active signal when the output signal exceeds the threshold, gate means for passing the output of the absolute value calculator on condition that the comparator outputs an active signal, and interval integration of the output of the gate means. A vibration energy calculating section integrator for calculating vibration energy to the side of the vehicle; and a determining means for determining a collision by determining a threshold value of the vibration energy output from the vibration energy calculating section integrator. It is characterized in that it comprises.

Further, the apparatus for determining a side collision of a vehicle according to the present invention comprises: an acceleration sensor for detecting an acceleration applied to the side of the vehicle; a differentiator for obtaining a time difference between outputs of the acceleration sensor;
An absolute value calculator for obtaining an absolute value of an output of the differentiator; and a timed operation for outputting a one-shot pulse that is maintained for a predetermined time when the output of the acceleration sensor deviates between a predetermined upper limit frame and a lower limit frame. Means, a gate means for passing the output of the absolute value calculator under the condition that the timed operation means outputs a one-shot pulse, and an output of the gate means is integrated over a period to produce a large amplitude acceleration vibration. A vibration energy calculating section integrator for calculating energy; and a judging means for judging a collision by judging a threshold value of the vibration energy output from the vibration energy calculating section integrator. It is.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a circuit configuration diagram showing an embodiment of a vehicle side collision determination device according to the present invention, and FIG. 2 is a diagram for explaining collision determination based on vibration energy calculated by the determination circuit shown in FIG. It is.

A vehicle collision judging device 11 shown in FIG. 1 includes an acceleration signal detection system centered on an acceleration sensor 12, a vibration energy calculation block 20 for calculating vibration energy,
Condition decision block 30 for imposing conditions on calculation of vibration energy
And a comparator 16 for determining the threshold value of the vibration energy to generate a development signal. The acceleration signal detection system includes a cascade connection circuit of an acceleration sensor 12, an anti-aliasing filter 13, an on / off switch 14, and an AD converter 15.

As the acceleration sensor 12, a semiconductor acceleration sensor having a stress-strain gauge formed on a semiconductor is used. For example, a stress-strain gauge utilizing a change in the piezoresistance of the semiconductor when distorted by receiving a stress is applied to a vehicle. And the like are used in which the pressure receiving surface is oriented in parallel with the side surface direction. The location where the acceleration sensor 12 is attached may be any location as long as it is close to the occupant on the side of the vehicle, but a structure that covers a wide area on the side of the vehicle such that the impact due to the side collision is transmitted relatively uniformly in various types of collisions. It is preferable to attach to. As an example, if it is a door, it is good to attach it to the center part of the front door / inner panel or door beam, etc.In the case of B pillar, the center or lower part of B pillar is suitable, and in the case of side sill, An area corresponding to the center of the front door from the base of the B pillar is preferable.

An anti-aliasing filter 13 connected to the acceleration sensor 12 is a filter for eliminating the influence of aliasing distortion, and limits a band with a predetermined band before converting an acceleration signal into discrete value data. The open / close switch 14 performs an open / close operation in accordance with a sampling clock having a period capable of detecting relatively high-frequency acceleration vibration generated at the time of collision, for example, a short period of about 0.1 to 0.5 ms. The AD converter 15 converts the acceleration signal sampled by the open / close switch 14 into digital data G (k) with predetermined quantization bits. AD converter 1
5, the vibration energy calculation block 20 and the condition determination block 30 are connected in parallel, and the acceleration data G (k)
Is the vibration energy calculation block 20 and the condition determination block 3
0.

The vibration energy calculation block 20 includes a differentiator 21, an absolute value calculator 22, a multiplier 23, and a section integrator 24.
Are connected in tandem. The difference device 21 performs a difference operation on the acceleration data G (k) sent from the AD converter 15. Therefore, the difference between the discretely input acceleration data G (k) and the acceleration data G (k−1) input one sampling clock before is dG (k) = G (k) −G ( K-1) is obtained. The absolute value calculator 22 calculates the absolute value of the difference output dG (k) of the differentiator 21. That is, ΔE = | dG (k) | = | G (k) −G (k−1) |. The multiplier 23 multiplies the output ΔE of the absolute value calculator 22 by the output of a comparator 32 in a condition determination block 30 described later. The interval integrator 24 outputs the output ΔE ′ of the multiplier 23.
(K) is integrated over a predetermined integration interval t2 to t1, and the vibration energy E of acceleration accompanying a speed change is calculated.
Find (k). That is, Get. The integration interval t2 to t1 is preferably about 5 to 30 ms, and a plurality of different intervals may be used.

The condition judging block 30 includes an interval integrator 31
And a cascade connection circuit of comparators 32. Interval integrator 31
Is the acceleration data G sent from the AD converter 15.
(K) is added for a predetermined section in accordance with the sampling clock. Speed change amount ΔV obtained by this section integration
(K) It is. The integration section t3 to t1 is determined to be a short section to a long section of, for example, about 5 to 30 ms, and a past signal is discarded every time a new acceleration signal is input. Comparator 32
Determines the speed change amount ΔV (k) obtained from the speed change amount calculation section integrator 31 based on a predetermined threshold value Th2. That is, a comparison operation is performed to determine whether or not the relationship ΔV (k) ≧ Th2 is satisfied. If the relationship is satisfied, the active signal “1” is output. Otherwise, the non-active signal “0” is output. Output.

The multiplier 23 supplied with the binary signals "1" and "0" obtained from the condition determination block 30.
Multiplies the output of the absolute value calculator 22 by 1 only when the active signal “1” is supplied, and sends the result to the vibration energy calculating section integrator 24 at the subsequent stage. Therefore, the output ΔE ′ (k) of the multiplier 23 is extracted from the output ΔE (k) of the absolute value calculator 22 only when a predetermined speed change is involved. The output of the multiplier 23 is output to the interval integrator 2
4, the value obtained by performing the interval integration is the acceleration G (k)
Is a section integral value of the absolute value of the difference (time differential value), and the physical quantity E (k) thus obtained is a quantity representing vibration energy, and increases according to the amplitude and angular velocity of the acceleration signal. Therefore, the vibration energy E (k) of the acceleration with the speed change calculated under the condition with the predetermined speed change amount is:
By setting the threshold value Th2 of the comparator 32 to the amount of speed change that appears remarkably in a side collision, the vibration energy due to the acceleration vibration during a non-collision and the acceleration during a collision detected when the vehicle rides on a curb, for example. It is a physical quantity that clearly distinguishes from vibration energy due to vibration.

As is clear from the calculation result of the vibration energy shown in FIG. 2, it can be seen that the vibration energy of the acceleration under the condition accompanied by the speed change due to the collision has an amplitude characteristic corresponding to the magnitude of the collision. Therefore, the vibration energy calculation block 20
In the comparator 16 connected to the
By determining the vibration energy based on the threshold value, it is possible to make a collision determination with high accuracy. For a high-speed side collision, a collision determination can be made in about 5 ms. A collision determination can be made at a point slightly above. This is several milliseconds after a collision at the time of a high-speed collision that requires a collision determination in a short time after the collision.
, The vibration energy rapidly increases, so that the threshold value TH1
Similarly, the collision determination can be performed at a high speed. Similarly, for a medium-speed side collision that requires a collision determination of about 10 to 40 ms after the collision, the vibration energy gradually increases after the collision. This is because an accurate collision determination can be made.

As described above, according to the vehicle side collision judging device 11, the acceleration sensor 12 detects the acceleration generated due to the side collision, calculates the vibration energy applied to the side of the vehicle based on the acceleration, and calculates the vibration energy. Since the collision is determined by determining the threshold value of the energy, attention is paid to the vibration of the relatively high frequency acceleration detected independently of the collision place from the initial stage of the side collision, and this vibration of the acceleration is High-speed side collisions that require deployment in an extremely short time of 5 to 10 ms in order to determine a collision as a wave excited from a steady state (0G) due to collision and determine the vibration energy of the wave as a threshold value Sometimes, it is possible to make a collision determination at the early stage of a collision in which the inertial movement of the occupant hardly occurs,
In addition, even in the case of a middle-speed side collision where deployment in about 10 to 40 ms is required, accurate collision determination can be performed without depending on the collision location, and the vibration energy is the total amount of vibration energy of acceleration vibration within a certain time. , It is possible to clearly distinguish between sporadic vibrations such as abuse such as closing a strong door or collision of a small mass object, and continuous vibrations at the time of a collision. It is possible to make an accurate collision determination for an appropriate collision mode.

Further, the vibration energy is calculated as an integral value of the interval of the absolute value of the time differential value of the acceleration, and is replaced by an amount which increases according to the amplitude and the angular frequency of the wave without using the square operation. The processing capacity burden required for digital signal processing is greatly reduced.

In the above-described embodiment, the collision is determined when the vibration energy is accompanied by a predetermined speed change amount. However, the present invention is not limited to the above-described embodiment, but may be applied to various designs. Changes are possible. For example, a condition judging block 40 having a configuration different from that of the condition judging block 30 can be used, as in a vehicle side collision progress device 51 shown in FIG. In the present embodiment, the condition determination block 40 is configured by a cascade connection circuit of a comparator 41, a flip-flop 42, and a one-shot timer 43. The output of the acceleration sensor 12 in the first stage comparator 41 is the upper threshold value Th4. And a determination is made as to whether or not the value deviates from a predetermined band sandwiched by the lower threshold value Th5. Acceleration data G
If (k) deviates from the predetermined band, the flip-flop 42 of the next stage is set by the output of the comparator 41. Further, the one-shot timer 43 operates in a timed manner by the Q output output together with the setting of the flip-flop 42,
A one-shot pulse that continues for a predetermined time from the set point is output as a threshold determination signal. The one-shot pulse output from the one-shot timer 43 is sent to the multiplier 23 in the same manner as the active signal, and the output of the absolute value calculator 22 is multiplied by 1 only while the one-shot pulse is at a high level. Of the vibration energy calculating section integrator 24. That is, the output ΔE ′ (k) of the multiplier 23 is integrated over a certain period of time with respect to the large-amplitude acceleration signal detected at the time of the collision, and used for calculation of vibration energy. In this case, the collision area where the collision determination is made and the non-collision area where the collision determination is not made are distinguished by one setting of the threshold value Th3 which gives the threshold for determining the threshold of the vibration energy. Even if the line of the collision area and the line of the non-collision area are different depending on the arrangement position, it can be dealt with only by replacing the threshold value Th3, whereby a safe and reliable collision determination can be made.

[0023]

As described above, according to the present invention, the acceleration sensor detects acceleration caused by a side collision, calculates the vibration energy applied to the side of the vehicle based on the acceleration, and calculates the vibration energy. Since the threshold value is determined and the collision is determined, attention is paid to the vibration of the relatively high frequency acceleration detected from the initial stage of the side collision, and the vibration of the acceleration is excited from the steady state (0G) by the collision. In the event of a high-speed side collision that requires deployment in an extremely short time, such as 5 to 10 ms, the occupant's inertial movement almost occurs even if the collision is determined by judging the vibration energy of the wave as a threshold value. It is possible to make a collision determination at the early stage of a collision that has not yet occurred, and it is possible to make an accurate collision determination regardless of the collision location even during a medium-speed side collision where deployment in about 10 to 40 ms is required. In addition, since the vibration energy calculates the total amount of vibration energy of the acceleration vibration within a certain period of time, there are one-shot vibration such as abuse such as closing a strong door, collision of a small mass object, and continuous vibration during a collision. Can be clearly distinguished,
As a result, an excellent effect can be achieved such that an accurate collision determination can be made for various types of collisions that require deployment of the airbag.

Further, according to the present invention, the vibration energy is obtained by calculating the integral of the absolute value of the time differential value of the acceleration, so that the vibration energy can be calculated according to the wave amplitude and the angular frequency without using the square operation. Substitution with a larger amount can provide an effect that the processing capacity load required for digital signal processing can be greatly reduced.

Further, the vibration energy is section-integrated with the absolute value of the time differential value of the acceleration only when the speed change amount obtained from the section integral value of the acceleration exceeds a predetermined threshold value. Since it is determined as vibration energy under conditions involving changes, the impact force determined as the absolute value of the time derivative of acceleration is integrated over the interval only when the speed change exceeds a predetermined threshold. As in the case of a high-speed side collision where the speed change gradient increases sharply, it is possible to determine the collision by catching the salient features after the collision has occurred. Thus, an excellent effect is achieved such that a reliable collision determination can be made.

Further, the vibration energy is integrated over a certain period of time from the detection of the acceleration having an amplitude exceeding a predetermined area to the absolute value of the time differential value of the acceleration to obtain the vibration energy of the large amplitude acceleration. Since the collision area where the collision is determined and the non-collision area where the collision is not determined are distinguished by one setting of the threshold value that provides a threshold for determining the vibration energy, the vehicle type and the acceleration sensor are determined. Even if the delineation between the collision area and the non-collision area is different depending on the arrangement position, it can be dealt with only by replacing the threshold value, and an excellent effect such as safe and reliable collision determination can be achieved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of a vehicle side collision determination device of the present invention.

FIG. 2 is a diagram for explaining a collision determination based on vibration energy calculated by a determination circuit shown in FIG. 1;

FIG. 3 is a circuit diagram showing a modified example of the vehicle side collision determination device of the present invention.

FIG. 4 is a schematic configuration diagram illustrating an example of a conventional vehicle side collision determination device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Vehicle side collision determination apparatus 12 Acceleration sensor 13 Anti-aliasing filter 15 A / D converter 16 Comparator 20 Vibration energy calculation block 21 Difference device 22 Absolute value calculation unit 23 Multiplier 24 Vibration energy calculation section integrator 30 Condition determination block 31 Speed change calculation section integrator 32 Comparator 40 Condition judgment block 41 Comparator 42 Flip-flop 43 One-shot timer

Claims (7)

[Claims] An acceleration sensor detects acceleration generated in association with a side collision, calculates vibration energy applied to a side surface of the vehicle based on the acceleration, determines a threshold value of the vibration energy, and makes a collision determination. A method for determining a side collision of a vehicle. 2. The method according to claim 1, wherein the vibration energy is obtained by section integration of an absolute value of a time differential value of the acceleration. 3. The method according to claim 2, wherein the vibration energy is obtained by integrating the absolute value of the time differential value of the acceleration only when the speed change amount obtained from the integrated value of the acceleration exceeds a predetermined threshold value. 2. The method for determining a side collision of a vehicle according to claim 1, wherein the determination is performed as vibration energy under a condition involving a change. 4. The vibration energy of the large-amplitude acceleration is obtained by integrating the absolute value of the time differential value of the acceleration over a predetermined time from the detection of the acceleration having an amplitude exceeding a predetermined area. A method for determining a side collision of a vehicle, characterized in that: 5. An acceleration sensor for detecting an acceleration applied to a side surface of a vehicle, a differentiator for obtaining a time difference between outputs of the acceleration sensor, an absolute value calculator for obtaining an absolute value of an output of the differentiator, and the absolute difference calculator. A vibration energy calculating section integrator for calculating the vibration energy to the side of the vehicle by integrating the values in a section, and a collision determination based on the threshold value of the vibration energy output from the vibration energy calculating section integrator. Means for determining a side collision of a vehicle. 6. An acceleration sensor for detecting an acceleration applied to a side surface of a vehicle, a differentiator for obtaining a time difference between outputs of the acceleration sensor, an absolute value calculator for obtaining an absolute value of an output of the differentiator,
A speed change amount calculating section integrator for calculating the speed change amount by section integrating the output of the acceleration sensor, and an active signal when the output of the speed change calculating section integrator exceeds a predetermined threshold value. A comparator that outputs the signal; gate means for passing the output of the absolute value calculator on condition that the active signal is output from the comparator; and section integration of the output of the gate means for vibration to the side of the vehicle. A vehicle comprising: a vibration energy calculating section integrator for calculating energy; and a determination means for determining a threshold value of the vibration energy output from the vibration energy calculating section integrator to make a collision determination. Side collision determination device. 7. An acceleration sensor for detecting an acceleration applied to a side surface of a vehicle, a differentiator for obtaining a time difference between outputs of the acceleration sensor, an absolute value calculator for obtaining an absolute value of an output of the differentiator,
When the output of the acceleration sensor deviates between a predetermined upper limit frame and a lower limit frame, a timed operation means for outputting a one-shot pulse lasting a predetermined time, and the timed operation means outputs a one-shot pulse. A gate means for passing the output of the absolute value calculator under the condition that the output of the gate means is section integrated, and a vibration energy calculating section integrator for calculating vibration energy of a large amplitude acceleration; A determining means for determining a threshold value of vibration energy output from the calculating section integrator to determine a collision, and determining a side collision of the vehicle.