JPH10100854A - Expansion control method for air bag of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of accidents caused by expansion by controlling the expansion of an air bag, and thereby enhance both safety and reliability. SOLUTION: An occupant sensor 1 composed of divided photo receiving elements 11A and 11B and the like, is provided in the inside of an automobile, the cross sectional image of the waist of an occupant 2 is formed based on the aforesaid sensor, it is so designed that the presence or absence, and the attitude of the occupant can be detected by integrating the addition, subtraction and the ratio of the outputs of the paired photo receiving elements 11A and 11B, and it is tried to prevent the occurrence of accidents caused by the expansion of an air bag by controlling the expansion of the air bag in response to the result of the detection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for detecting deployment of an occupant, particularly an occupant of an automobile, using a light receiving element such as a photodiode (PD), and controlling deployment of an airbag.

[0002]

2. Description of the Related Art Recently, many vehicles equipped with an airbag as a safety device for instantaneously bulging at the time of a collision and relieving an impact are increasing. FIG. 3 shows the concept of a conventional example of airbag deployment control. In the figure, 30 is an airbag, 31 is an acceleration sensor, 32 is an AND gate, and 33 is a driving device. That is, an occupant obtained by providing a switch on the buckle of the seat belt and operating this switch when the occupant wears the seat belt, or by providing an infrared sensor near the dashboard of the automobile and using the output thereof Signal along with the accident signal detected by the acceleration sensor 31
2, the logical product of the two is calculated, and the airbag 30 is deployed when it is established. Note that the airbag 30 is stored by a solid line and deployed by a dotted line.

[0003]

As described above, since an airbag is always deployed when an accident occurs due to the presence of an occupant, an accident occurs due to the deployment of the airbag depending on the posture of the occupant. Is becoming a problem. A specific example is shown in FIG. FIG. 2A shows a state in which the occupant 2 is leaning forward with a seat, and FIG. 2B shows a state in which the infant 2A is placed on a child seat 5 having a direction opposite to the traveling direction of the automobile 3. In such a case, if a collision occurs and the airbag is deployed, the occupant 2 and the infant 2A are repelled by this deployment, and a large accident may occur. In addition,
FIG. 5 shows a normal and safe case, in which case even if the airbag is deployed, no accident will occur due to deployment. Therefore, an object of the present invention is to make it possible to avoid an accident due to deployment of an airbag and to improve safety.

[0004]

According to the present invention, there is provided a light source for irradiating a belt-like light beam traversing the waist of a vehicle occupant, a lens, and a light receiving element divided into at least two regions. And a processing device for performing a predetermined process based on the output of the light receiving element, the reflected light from the waist of the occupant irradiated with the band-like light, the light receiving element of the divided light receiving element through the lens An image is formed in the boundary area so that the direction of the boundary and the direction of the band-shaped light beam are in the same direction, and the processing device calculates the sum, difference, and ratio of the output of each of the divided light receiving elements. The presence or absence and posture of the occupant are detected by integrating the values, and the deployment of the airbag is controlled according to the result.

[0005]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. In the figure, 1 is a light receiving element 11A,
An occupant sensor 11B including an imaging lens 12 and a filter 13 and the like, 2 is an occupant, 4 is a projection light source, and 6 is a seat. The output of the occupant sensor 1 is guided to a processing unit (not shown), where predetermined processing and control are performed. That is, the projection light source 2 emits a band-like light beam that crosses the vicinity of the waist of the occupant 3. The occupant sensor 1 receives reflected light near the waist of the occupant 3 via the filter 13 and the imaging lens 12 by the light receiving elements 11A and 11B divided into two.

FIG. 2 shows an example of a judgment method according to the present invention.
That is, (a) is a normal posture, (b) is a forward lean,
(C) shows when the child seat is mounted in the reverse direction, and (d) shows when the vehicle is unmanned. In each of these cases, the output of the light receiving elements 11A and 11B or the output of the occupant sensor is SA, S
When the ratio (SA / SB), the sum (SA + SB), the difference (SA-SB), and the like are obtained as B, the result is as shown in FIG. That is, the ratio (SA / SB) in the normal posture of (a)
(B) and (d)
Since the ratio (SA / SB) cannot be determined only when the person is unattended, the sum (SA + SB) and the difference (SA-SB) are obtained.

[0007] In addition, when the child seat is mounted in reverse in (c), the ratio (SA / SB) is undefined. In this case, the sum (SA + SB) and the difference (SA-SB) are both smaller than in other cases. By utilizing this, it is determined that the child seat is mounted in reverse (or an occupant (infant) is in front of the seat). As described above, by comprehensively determining the sum, difference and ratio of the light receiving element outputs SA and SB for each case, it is possible to distinguish each case and to determine the airbag according to the result. The deployment can be controlled. For example, in FIGS. 2A and 2D, the airbags are deployed in the cases of FIGS.
In the case of (c), the airbag is not deployed. Although the light receiving element is divided into two in the above description, it can be generally divided into a plurality.

[0008]

According to the present invention, not only the presence or absence of an occupant but also the posture of the occupant can be detected by using an occupant sensor having a simple structure including a light receiving element, and the deployment of the airbag can be controlled accordingly. It is possible to eliminate accidents caused by deployment and to provide an advantage that safety and reliability can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of a method for detecting the presence / absence and posture of an occupant according to the present invention.

FIG. 3 is an explanatory diagram of a conventional example of airbag deployment control.

FIG. 4 is an explanatory view of a dangerous posture of an occupant when the airbag is deployed.

FIG. 5 is an explanatory diagram of a normal state of an occupant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Occupant sensor, 2, 2A ... Occupant, 3 ... Car, 4 ... Light source, 5 ... Child seat, 6 ... Seat seat, 11
A, 11B: light receiving element (PD), 12: imaging lens, 1
3. Filter.

Claims (1)

[Claims] 1. A light source for irradiating a band-like light beam traversing the waist of an automobile occupant, a lens, a light receiving element divided into at least two regions, and a processing device for performing predetermined processing based on the light receiving element output. The reflected light from the occupant's waist, which is irradiated with the band-shaped light beam, is applied to the boundary region of the divided light receiving elements via the lens, and the direction of the boundary and the direction of the band-shaped light beam are the same direction. The processing device calculates the sum, difference and ratio of the divided light receiving element outputs, and detects the presence or absence and posture of the occupant by integrating these values;
A method for controlling the deployment of an airbag for an automobile, comprising controlling the deployment of the airbag according to the result.