JPH07329698A - Occupant protection device for vehicle collision - Google Patents

Abstract

PURPOSE:To protect an occupant against collision from unexpected directions by judging the presence or absence of collision based on output signals from paired acceleration sensors, the vector processing of which has been performed, selecting an air bag optimum for protecting the occupant out of plurality of air bag devices by a judging means, and actuating the air bag thereafter. CONSTITUTION:Paired acceleration sensors 1 and 2 are disposed in such a way acceleration detecting directions are perpendicularly intersected with each other. It is judges by a comparison means 5 whether or not collision takes place by comparing an output signal from a detection section having a processing means 3 which performs vector processing on output signals from the acceleration sensors 1 and 2, and regenerates the result of the processing into an acceleration signal, with a reference value 4 prepared by collision tests. An optimum device for protecting an occupant is then selected out of a plurality of air bags based on the output signal from the detection section by a selection means 6. The air bag 8 is then driven by a drive means 7 based on the selected output signal. By this constitution, the occupant can be protected against collision from unexpected directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for protecting an occupant in a vehicle collision.

[0002]

2. Description of the Related Art A conventional vehicle occupant protection system has, as disclosed in, for example, Japanese Patent Application Laid-Open No. 55-19627, a vehicle section having either one or both of an electric type and a mechanical type collision detecting section. When a certain amount of impact is received due to a collision,
An occupant protection device such as an airbag is activated.

[0003]

Since the conventional vehicle occupant protection system uses a single acceleration sensor to detect a collision, the vehicle occupant protection system reacts to the collision from the detection direction of the sensor (front of the vehicle). However, there is a drawback that collisions from diagonal, side and rear cannot be detected, and in the case of an actual collision accident, the occupants could not be sufficiently protected.

Further, when the problem is dealt with by the conventional method,
Since an acceleration sensor is required for each collision direction and the structure is complicated, it is necessary to devise a collision detection means.

[0005]

In order to solve the above problems, a collision detecting means which is independent of the collision direction is indispensable. To this end, two acceleration sensors are arranged so that the acceleration detection directions are orthogonal to each other, and the acceleration at the time of collision is decomposed into two orthogonal vectors and detected. Then, the acceleration at the time of collision is obtained by synthesizing the two vector signals. This acceleration is compared with a reference value in a collision experiment to determine whether or not a collision has occurred, and an optimum device is selected and activated from a plurality of airbags. By these means, it is possible to construct an occupant protection device that does not depend on the direction of collision.

[0006]

FIG. 1 is an explanatory view of the operation of the collision acceleration detecting section in the present invention. The two acceleration sensors 1 and 2 (here, semiconductor capacitance detection type) are arranged so that their detection directions are orthogonal to each other, and a potential difference V is present between the movable electrodes 1a and 2a and the fixed electrodes 1b and 1c and 2b and 2c. Is being applied. When the acceleration α occurs in the θ direction with respect to the X axis due to the collision, the accelerations αx (= αcos θ) and α are applied to the electrode 1a of the sensor 1.
y (= αsinθ) occurs, but αy cannot be detected because it is perpendicular to the detection direction. At this time, the electrode 1a leans toward the electrode 1c and moves away from the electrode 1b due to inertia. Therefore, capacitance changes + ΔC and −ΔC proportional to the magnitude of the acceleration αx occur between the electrode 1a and the electrodes 1c and 1b. The acceleration αx is obtained based on this capacitance change amount. Similarly, the acceleration αy is obtained from the sensor 2, and the acceleration α of the collision is obtained by subjecting these two values to vector calculation processing.

If the acceleration sensor of the detection section is arranged so that the acceleration detection directions are orthogonal to each other, the same effect can be obtained even if the piezoelectric effect is applied or the piezoresistive effect is applied.

[0008]

EXAMPLE FIG. 2 is a block diagram of an occupant protection system used in this example. A pair of acceleration sensors 1 and 2 arranged so that the acceleration detection directions are orthogonal to each other, and a detection section having a processing means 3 for vector-processing the detection signal from this sensor and reproducing the acceleration signal, and an output from the detection section It has a comparison means 5 for comparing the signal with a reference value 4 obtained by a collision experiment to determine whether or not there is a collision, and a means 6 for selecting an optimum device for protecting an occupant from a plurality of airbags according to an output signal. It is composed of a judging section, means 7 for activating the airbag in response to an output signal from the judging section, and an airbag group including the means 7 and a pair of airbags 8.

FIG. 3 is a side view of the experimental vehicle of this embodiment. A detection unit is installed under the seat of each occupant, and there is a determination unit and an airbag connected to the detection unit.

FIG. 4 is an explanatory diagram of an embodiment of the present invention. The occupant protection system shown in Fig. 2 is installed in the vehicle for a fixed number of passengers. The occupants are on the right side of the driver's seat and rear seats. Here, the condition of the collision was 40 km / h and no braking to the wall (concrete) from the direction of 45 degrees. At this time, each detection unit detected the acceleration α from the 45-degree direction with the traveling direction as 90 degrees.

An explanation will be given with reference to the judgment flow chart of FIG. First, the occupant's boarding check is performed and the power is turned on when boarding. Next, the acceleration signal {α, θ} is input from the detection unit and this is compared with the reference value. If a collision is determined here,
Further, the direction of acceleration is determined, and the activation signal of the selected airbag is output. In the case of the driver's seat, the steering and the airbags 10a and 10b on the right door are activated as indicated by arrows. Similarly, in the case of the rear seat, the airbags 11a and 11b of the front and right doors are activated. At the time of a collision, the occupant is thrown forward due to inertia, but each is protected by an airbag in front. At the next moment, the car body rotated clockwise around the point of collision and collided with the wall a few times and stopped. At this time, the occupant separates from the front airbag that was initially protected and is thrown counterclockwise as opposed to the rotation of the vehicle body, but the occupant in the driver's seat is protected by the airbag 10b, and the occupant in the rear seat is inflated. Protected by 11b. Of course, airbags associated with seats that are not in use will not activate.

This device not only activates the airbag,
It can also be used as a start signal for other occupant protection devices such as seat belt retractors.

[0013]

EFFECTS OF THE INVENTION By installing a collision acceleration detecting section under the seat of each occupant, even if the acceleration applied to each occupant is different when the vehicle body rotates due to a collision or multiple collision occurs,
An appropriate airbag can be selected and activated for each occupant. According to the present invention, it is possible to protect an occupant from a collision from an unpredictable direction such as an actual collision accident, and it is possible to minimize human damage caused by a traffic accident.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a collision detection method of the present invention.

FIG. 2 is a block diagram of a device configuration according to an embodiment of the present invention.

FIG. 3 is a side view of a vehicle according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of an embodiment of the present invention.

FIG. 5 is a flowchart of determination according to an embodiment of the present invention.

[Explanation of symbols]

1, 2 ... Acceleration sensor, 3 ... Processing means, 4 ... Reference value, 5
... determination means, 6 ... selection means, 7 ... starting means, 8 ... airbags.

Claims (3)

[Claims] 1. A detection means comprising a pair of acceleration sensors arranged so that acceleration detection directions are orthogonal to each other, and two detection signals from the acceleration sensor are vector-processed to be reproduced as an acceleration signal, and the detection means. Based on the output signal of
Determination means for determining the presence or absence of a collision, and for selecting an airbag device most suitable for occupant protection from a plurality of airbag devices, means for activating an airbag based on an output signal from the determination means, An occupant protection device at the time of a vehicle collision, which is configured by an airbag. 2. The vehicle occupant protection device for a vehicle collision according to claim 1, wherein the collision acceleration detection unit is arranged under the seat of each occupant and operates independently. 3. The vehicle occupant protection device for a vehicle collision according to claim 2, wherein the power is automatically turned on by a human body detection sensor or the like when the occupant gets on the vehicle.