JP3562208B2 - Passenger protection system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an occupant protection device such as an airbag device or a seatbelt device provided in a vehicle such as an automobile, and more particularly to an operation control of a passenger protection device for a passenger seat.
[0002]
[Prior art]
2. Description of the Related Art In the event of an accident such as a vehicle, an occupant protection device that prevents an occupant from hitting a structure inside the vehicle and protects the occupant has been put to practical use. Specifically, the occupant protection device includes an airbag device, a seat belt device, and the like. The airbag device deploys an airbag between the occupant and a structure inside the vehicle when the vehicle collides, which serves as a cushion to receive the occupant and prevent the occupant from colliding with the structure. Things. Further, the seat belt device fixes the occupant to the seat and prevents the occupant from colliding with the structure. In particular, in recent years, a seatbelt device with a pretensioner for retracting a seatbelt by a predetermined length at the time of a vehicle collision to more securely fix an occupant to a seat has been put to practical use. In addition, vehicles in which these occupant protection devices are provided not only in the driver's seat but also in the passenger seat are in practical use.
[0003]
Japanese Patent Application Laid-Open No. Hei 5-270351 discloses an airbag device. In particular, this device deploys an airbag at an optimal timing according to a seating position of an occupant. The seating position of the occupant is detected by providing a distance sensor on the dashboard in front of the occupant and measuring the distance from the sensor to the occupant.
[0004]
[Problems to be solved by the invention]
The conventional passenger seat occupant protection device actually operates at the time of a vehicle collision, even when the occupant is not seated here. This operation is meaningless operation, and when repairing it, it is necessary to replace not only the activated device but also parts such as the dashboard containing the passenger airbag, which increases the repair cost. was there.
[0005]
Like the device described in the above publication, even if an attempt is made to detect the presence of an occupant based on the distance from the dashboard to the occupant, there is a possibility that this may be erroneously detected as an occupant, such as when luggage is placed in the passenger seat. is there.
[0006]
The present invention has been made in order to solve the above-described problems, and has as its object to provide a passenger seat occupant protection device that operates properly according to the presence or absence of a passenger in a passenger seat.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, a passenger seat occupant protection device of the present invention includes a protection unit that protects an occupant from a collision with a vehicle internal structure under a predetermined condition, and detects a movement of a passenger seat occupant in a vehicle front-rear direction. Motion detection means, acceleration detection means for detecting acceleration of the vehicle, correlation value calculation means for calculating a correlation value between the movement of the passenger in the front passenger seat and the acceleration of the vehicle, and that the vehicle is being decelerated by the brake. determined, and the occupant presence determining means determines the presence or absence of the passenger on the basis of the detected value and the correlation value of the motion detecting means at this time, when the occupant there is determined by the occupant presence determining means previously has a operation controller which causes controlling the operation of said protective means passenger seat, the. The presence or absence of a passenger in the passenger seat may be determined when the detection value of the acceleration detection means indicates a deceleration equal to or greater than a first predetermined value, regardless of the braking operation.
[0008]
If acceleration occurs in the vehicle, the occupant moves due to the inertial force generated by the acceleration, and therefore, there is a correlation between the acceleration and the movement of the occupant. Based on this correlation, it can be determined whether or not the occupant is sitting in the passenger seat. If the occupant is not seated, the occupant protection means for the passenger seat is not operated so that the device does not operate when it is not necessary.
[0009]
The protection means performs a predetermined operation at the time of a vehicle collision, suppresses the movement of the occupant, and prevents the occupant from colliding with the internal structure of the vehicle. Specifically, in the event of a collision, the airbag device is deployed to the front of the occupant to prevent the occupant from colliding with the steering post or dashboard, and the seatbelt is retracted a predetermined length to firmly fix the occupant to the seat The protection means includes a seat belt device with a pretensioner. The present invention can be applied to an occupant protection device using a plurality of these protection means alone or to an occupant protection device using a combination of a plurality of types.
[0010]
The movement detecting means detects the movement of the passenger in the front passenger seat, particularly the movement in the front-rear direction of the vehicle. Specifically, it is provided at a predetermined position in the vehicle interior, and has a distance sensor that detects a distance to a passenger seat occupant, and a movement calculating unit that calculates the movement of the passenger seat occupant based on the change in the distance. be able to. Rather than simply determining the presence or absence of an occupant based on the distance detected by the distance sensor, the occupant can be distinguished from large luggage placed on the passenger seat, for example, by determining the change in distance, that is, the movement of the occupant. Can be.
[0011]
The correlation value calculating means calculates a correlation value between the vehicle acceleration and the movement of the occupant in the vehicle longitudinal direction. When acceleration occurs in the vehicle, an inertial force acts on an object inside the vehicle. For example, when a brake operation is performed, a negative acceleration (hereinafter, referred to as a deceleration) occurs in the vehicle traveling direction, and thereby an inertial force acts on the occupant in a forward direction. The occupant moves forward by this inertial force. As described above, since there is a correlation between the vehicle acceleration and the movement of the occupant, the presence or absence of the occupant can be determined by examining the characteristics of the correlation in advance. This determination is made by the occupant presence / absence determination means. As described above, when the occupant is seated, the occupant moves in accordance with the deceleration caused by the brake, for example, and when such a motion correlated with the deceleration is detected, It can be determined that the occupant is seated. When the occupant is not seated, the motion detecting means detects the motion of the seat. Since the seat is firmly fixed to the vehicle, no movement due to inertial force occurs. Therefore, there is no correlation with the deceleration due to the brake, and in such a case, it can be determined that the occupant is not seated.
[0012]
In particular, the correlation between the vehicle acceleration and the movement of the occupant is strong during deceleration due to the brake operation, and the correlation between the acceleration and the movement of the occupant is obtained when a predetermined amount of brake operation is performed or when the predetermined reduction is performed. It is also preferable to limit the time when the speed occurs.
[0013]
If the operation of the protection means is controlled based on the above determination, the operation will not be performed when there is no occupant to be protected.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter, referred to as embodiments) will be described with reference to the drawings.
[0015]
FIG. 1 is a schematic configuration diagram of the present embodiment. Inside a dashboard 14 facing the passenger seat 12 of the vehicle body 10, an airbag body 16 including an airbag and an inflator for deploying the airbag is provided. The deployment of the airbag is controlled by the airbag ECU 18. At the front end of the ceiling of the vehicle body 10, a distance sensor 22 for measuring a distance to an occupant 20 seated on the passenger seat 12 is provided. In the present embodiment, the distance sensor 22 irradiates the infrared beam 24 and detects the distance based on the time until the reflected light 26 from the measurement target reaches the sensor 22. In the case of such a sensor, its installation position needs to be provided at a position where the position of the occupant 20 in the front-rear direction of the vehicle can be detected, and is preferably provided within a plane passing through the center line of the passenger seat. This is because, as will be described later, the movement of the occupant is detected based on the change in the distance measured by the distance sensor 22. Is desirable in terms of accuracy. Therefore, in addition to the above-mentioned ceiling front end, it is also possible to provide it on the dashboard 14. The output of the distance sensor 22 is sent to the airbag ECU 18.
[0016]
The airbag ECU 18 is provided with an acceleration sensor 28 that detects the acceleration of the vehicle in the front-rear direction. Further, the airbag ECU 18 has a microcomputer 30 for operating the inflator in accordance with a program stored in advance based on the output of the distance sensor 22 and the output of the acceleration sensor 28, and deploying the airbag as shown by a dashed line in the figure. Provided.
[0017]
FIG. 2 is a block diagram showing the configuration of the airbag ECU 18 that controls the operation of the airbag. The airbag ECU 18 is provided with the acceleration sensor 28 as described above, and further provided with a microcomputer 30 which performs an operation described below according to a program stored in advance.
[0018]
The distance sensor 22 measures the distance to the occupant 20 at a predetermined sampling cycle, and sends the result to the motion calculation unit 32 of the microcomputer 30. The movement calculation unit 32 detects the amount of movement during this time, that is, the movement speed of the occupant, from the previous and current measurement results of the distance sensor 22. Therefore, the distance sensor 22 and the motion calculation unit 32 function as a motion detection unit that detects the front-back motion of the passenger in the front passenger seat.
[0019]
The output of the motion calculation unit 32 and the output of the acceleration sensor 28 are sent to a correlation value calculation unit 34, where a predetermined calculation is performed to calculate a correlation value. In the present embodiment, the correlation value is calculated as a product of the moving speed of the occupant calculated by the motion calculating unit 32 and the deceleration of the vehicle detected by the acceleration sensor 28.
[0020]
The occupant presence / absence determination unit 36 determines the presence / absence of an occupant based on the calculated correlation value and the calculation result of the motion calculation unit. If there is no occupant, the seat does not move, and the value calculated by the motion calculation unit 32 becomes 0. If this is detected continuously for a predetermined number of times, it is determined that there is no occupant. If the calculated motion value is not 0 and the calculated correlation value is equal to or greater than a predetermined value, it is determined that an occupant is present. Except in the above cases, the determination of the presence or absence of the occupant is suspended, and the result of the previous determination is maintained. In the present embodiment, this determination is made at the time of deceleration by a brake in which the correlation between the acceleration of the vehicle and the movement of the occupant appears relatively strong, thereby improving the detection accuracy. In order to determine that the vehicle is being decelerated by the brake, the determination can be made, for example, based on the lighting of a brake lamp. Alternatively, the determination can be made based on the fact that the master cylinder pressure of the brake has exceeded a predetermined value. It is preferable that the predetermined value of the master cylinder pressure is set to a sufficiently large value that shows a relatively strong correlation between the movement of the occupant and the deceleration by conducting an investigation in advance. Alternatively, the deceleration may be directly measured, and the above determination may be made when the deceleration is equal to or more than a predetermined value. This predetermined value is desirably set to a value that shows a relatively strong correlation between the deceleration and the movement of the occupant, as described above.
[0021]
The operation control unit 38 controls the deployment of the airbag based on the presence or absence of the occupant and the deceleration. That is, when the deceleration detected by the acceleration sensor 28 is equal to or more than a predetermined value and the presence or absence of the occupant is determined by the occupant presence / absence determination unit 36, the airbag main body 16 is instructed to deploy the airbag of the seat. . Based on this command, the airbag body 16 operates the inflator to deploy the airbag. Thus, when a large deceleration occurs at the time of a collision or the like, an occupant who is largely moved forward by the inertial force due to the deceleration can be received, and a collision with the windshield or the dashboard can be avoided.
[0022]
The above-described motion calculation unit 32, correlation value calculation unit 34, occupant presence / absence determination unit 36, and operation control unit 38 are actually the microcomputer 30 itself, and the function of each unit is in accordance with the program stored in the microcomputer 30 in advance. It is achieved by working.
[0023]
FIG. 3 shows a control flowchart of the present embodiment. When the electric components of the vehicle are turned on, an initial check is performed (S100). When the brake is operated by a predetermined amount, the distance S between the sensor 22 and the occupant transmitted from the distance sensor 22 is compared with the previous distance to determine whether or not the distance has changed (S104). If there is no change in the distance, it is determined whether this state of change has continued for a predetermined number of times (S106). If the change has continued for a predetermined number of times, an occupant presence flag indicating that there is an occupant in the passenger seat (P seat) is set. It is cleared (S108). On the other hand, if it is determined in step S106 that the number has not reached the predetermined number, the occupant presence flag is maintained at the previous state.
[0024]
If it is determined in step S104 that there is a change in the distance S, the product of the change amount ΔS of the distance and the acceleration α detected by the acceleration sensor is calculated as a correlation value X between the two amounts, and this is calculated as a predetermined value. It is compared with a threshold value _{X 0} (S110). If the correlation value X is a threshold X ₀ or more, it is determined that there are passenger in the passenger seat, to set the occupant state flag (S112). On the other hand, when the correlation value X is determined to be less than the threshold value X ₀ in step S110, to keep the occupant state flag in the state up to the last time.
[0025]
Subsequently, the acceleration α is compared with the threshold α ₀ (S114), and if the acceleration α is equal to or greater than the threshold α ₀ , first, a deployment command is issued to the airbag in the driver's seat (Seat D) (S116). Next, if the occupant presence flag in the passenger seat is set (S118), a deployment instruction is issued to the airbag in the passenger seat (S120). In step S114, the detected acceleration alpha is when it is determined to be less than the threshold value alpha _0, the process returns to step S102, the flow described above is performed again. If it is determined in step S118 that there is no occupant in the passenger seat, the process ends without deploying the airbag for the passenger seat.
[0026]
In the present embodiment, the airbag device that deploys to the front of the occupant as the occupant protection means has been described. However, the present invention is also applicable to a so-called side airbag device that deploys to the side of the occupant. Further, the present invention can be similarly applied to a seatbelt device with a pretensioner that retracts the seatbelt by a predetermined amount at the time of a vehicle collision and restrains the movement of the occupant.
[0027]
Further, in the present embodiment, the distance sensor that measures the distance based on the arrival time of the infrared ray is used as the occupant's movement detecting means, but another known distance sensor can be used. For example, one that measures distance based on the principle of triangulation can be used. Further, instead of the distance sensor, the movement of the occupant may be detected based on an image on the seat.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an airbag ECU that controls the airbag according to the embodiment.
FIG. 3 is a control flowchart of the embodiment.
[Explanation of symbols]
Reference Signs List 10 vehicle body, 12 passenger seat, 18 airbag ECU, 22 distance sensor, 28 acceleration sensor, 30 microcomputer, 32 movement calculation unit (microcomputer), 34 correlation value calculation unit (microcomputer), 36 occupant presence / absence judgment unit (micro Computer), 38 Operation control unit (microcomputer).

Claims (3)

Protection means for protecting the occupant from a collision with a vehicle internal structure under predetermined conditions;
Movement detection means for detecting the movement of a passenger in the front passenger seat in the front-rear direction of the vehicle;
Acceleration detection means for detecting the longitudinal acceleration of the vehicle,
Correlation value calculation means for calculating a correlation value between the movement of the passenger seat occupant and the acceleration of the vehicle,
Determining that the vehicle is being decelerated by the brake, occupant presence / absence determination means for determining the presence / absence of a passenger in the passenger seat based on the detected value of the motion detection means and the correlation value at this time ;
When the presence of an occupant is determined in advance by the occupant presence / absence determination means , when a deceleration equal to or more than a predetermined value is detected by the acceleration detection means, an operation control unit that activates the protection means in a passenger seat,
A passenger protection device having a passenger seat. Protection means for protecting the occupant from a collision with a vehicle internal structure under predetermined conditions;
Movement detection means for detecting the movement of a passenger in the front passenger seat in the front-rear direction of the vehicle;
Acceleration detection means for detecting the longitudinal acceleration of the vehicle,
Correlation value calculation means for calculating a correlation value between the movement of the passenger seat occupant and the acceleration of the vehicle,
It is determined that the vehicle is decelerating at a deceleration greater than or equal to a first predetermined value based on the acceleration detected by the acceleration detecting means, and a passenger in the passenger seat is determined based on the detected value of the motion detecting means and the correlation value at this time. Occupant presence / absence determination means for determining the presence / absence of
An actuation control unit that activates the protection means in the passenger seat when the acceleration detection means detects a deceleration equal to or greater than a second predetermined value when the presence of an occupant is determined in advance by the occupant presence / absence determination means; When,
A passenger protection device having a passenger seat. It is a passenger seat occupant protection device according to claim 1 or 2 ,
The movement detecting means is provided at a predetermined position in the vehicle interior, and has a distance sensor for detecting a distance to a passenger seat occupant, and a movement calculating unit for calculating the movement of the passenger seat occupant based on a change in the distance. Seat occupant protection device.

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