JP2005263096A - Occupant detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant detection system capable of determining physique of an occupant and presence or absence of mounting of a child seat. <P>SOLUTION: This occupant detection system 1 comprises a seat belt 4 for restraining the occupant on a seat, a seat belt pulled amount detection device 30 capable of detecting pulled amount of the seat belt 4, and an occupant detection ECU5 for determining an occupant state on the seat based on the seat belt pulled amount transmitted from the seat belt pulled amount detection device 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an occupant detection system that determines an occupant state on a seat and transmits a determination result to an occupant protection device such as an airbag device.

An automobile is equipped with an airbag for passenger protection. The airbag is designed on the assumption that an adult is seated in a normal posture wearing a seat belt. Therefore, for example, when a child is seated or an infant is seated using a child seat, the airbag deployment pressure can be reduced or the airbag deployed to prevent impact to the child or infant. It is necessary to perform control such as prohibition. In order to perform such airbag control, it is important to accurately detect the occupant state on the seat. As an occupant detection system that detects an occupant state on a seat, for example, a system is known in which a load sensor is disposed on a seat and the occupant state is determined based on load data detected by the load sensor. Patent Document 1 discloses a method for detecting the load pattern of the seat seat surface and the usage amount of the seat belt in order to determine whether or not the child seat is mounted.
JP 2002-255010 A

  As described in Patent Document 1, it is important to adjust the deployment / non-deployment of the airbag depending on whether or not the child seat is mounted. However, the impact received by the occupant when the airbag is deployed and the occupant protection effect of the airbag vary depending on whether the seat belt is worn or the occupant's physique. Therefore, in addition to whether or not the child seat is mounted, it is necessary to detect the occupant's body size, sitting height, and the like as accurately as possible, and to control the airbag deployment pressure, deployment speed, and the like according to the occupant.

  This invention is made | formed in view of such the actual condition, and makes it a subject to provide the passenger | crew detection system which can determine the presence or absence of mounting | wearing of a passenger | crew's physique and a child seat.

  (1) The occupant detection system of the present invention is transmitted from a seat belt that restrains the occupant to the seat, a seat belt pull-out amount detection device that can detect a pull-out amount of the seat belt, and the seat belt pull-out amount detection device And an occupant detection ECU that determines an occupant state on the seat based on the seat belt pull-out amount data.

  When seat belts are worn, the amount of seat belt withdrawal differs depending on the occupant's physique (body size, sitting height, etc.). Further, the amount of the seat belt withdrawn varies depending on whether or not the child seat is mounted. For this reason, by detecting the amount of withdrawal of the seat belt, in addition to whether or not the seat belt is worn, it is possible to determine the occupant state on the seat, that is, the physique of the seated occupant and whether or not the child seat is mounted. .

  The occupant detection system of the present invention determines the occupant state on the seat using the amount of the seat belt withdrawn. Therefore, the occupant's physique and the like can be easily determined. If the determination result of the occupant detection system of the present invention is used in, for example, an airbag device, the deployment pressure, the deployment speed, etc. when deploying can be flexibly changed according to the occupant's physique as well as whether the airbag is deployed. Can be controlled.

  (2) Preferably, an occupant detection sensor capable of detecting an occupant state on the seat is further provided, and the occupant detection ECU is based on the seat belt withdrawal amount data and the occupant data transmitted from the occupant detection sensor. The occupant state on the seat may be determined.

  In this configuration, the occupant state is determined using the occupant data from the occupant detection sensor in addition to the seat belt withdrawal amount data. Examples of the occupant detection sensor include a load sensor such as a strain sensor, a capacitance sensor, and a pressure-sensitive film sensor, and an imaging sensor such as a CCD camera. One of these may be used, or a plurality of types may be used in combination.

  Thus, in this structure, since the passenger | crew state is determined from several data, the determination precision of a passenger | crew state is high. Further, when any one of the seat belt pull-out amount detection device and the occupant detection sensor has a problem, the occupant detection system of the present invention is configured to perform occupant determination based on data obtained from the other. Redundancy can be improved.

  (3) In the configuration of (2) above, the occupant detection sensor may be an imaging sensor. By imaging the occupant on the seat with an imaging sensor, data such as the physique of the occupant can be easily detected with high accuracy.

  The occupant detection system of the present invention determines the occupant's physique and the like based on the amount of the seat belt pulled out. Using this determination result, whether or not the airbag can be deployed, the deployment pressure when deployed, the deployment speed, and the like can be flexibly controlled according to the occupant's physique. Further, by using the occupant detection sensor in combination, the determination accuracy of the occupant state and the redundancy of the present system are improved.

  Embodiments of the occupant detection system of the present invention will be described below. First, the configuration of the occupant detection system of the present embodiment will be described. In FIG. 1, the layout of the passenger | crew detection system of this embodiment is shown. FIG. 2 shows a block diagram of the passenger detection system.

  As shown in FIGS. 1 and 2, the occupant detection system 1 of the present embodiment includes a CCD camera 2, a seat belt retractor 3, a seat belt 4, and an occupant detection ECU 5.

  The CCD camera 2 is incorporated in the corner portion of the room mirror 11. The CCD camera 2 can capture an occupant seated on the seat 7 (passenger seat). The CCD camera 2 is included in an occupant detection sensor constituting the present invention.

  The seat belt retractor 3 is installed below the center pillar. One end of the seat belt 4 is wound around a reel (not shown) in the seat belt retractor 3. The seat belt retractor 3 has a rotary encoder 30. The rotary encoder 30 is attached to a reel shaft (not shown) in the seat belt retractor 3. The rotary encoder 30 detects the rotation angle of the reel that rotates when the seat belt 4 is pulled out. The detected rotation angle data is transmitted to an occupant detection ECU 5 described later as seat belt withdrawal amount data. The rotary encoder 30 is included in the seat belt pull-out amount detection device constituting the present invention.

  The occupant detection ECU 5 is disposed at the passenger seat side end of the instrument panel 12. The occupant detection ECU 5 includes a constant voltage power supply 50, a CPU (central processing unit) 51, and a communication I / F (interface) 52.

  The constant voltage power supply 50 is connected to the vehicle battery 9 by a power supply line L1. An ignition switch 90 is disposed on the power supply line L1. The ignition switch 90 is disposed in the vicinity of the root of the steering shaft of the handle 13 (indicated by a one-dot chain line in FIG. 1). The constant voltage power supply 50 transforms the high voltage of the vehicle battery 9 into a low voltage. The constant voltage power supply 50 is connected to the CPU 51 through the power supply line L2.

  The CPU 51 includes an A / D converter 510, a RAM 511, and a ROM 512. The A / D converter 510 is connected to the CCD camera 2 via the signal line S1 and to the rotary encoder 30 via the signal line S2. The A / D converter 510 converts analog data (occupant data, seat belt withdrawal amount data) input from the CCD camera 2 and the rotary encoder 30 into digital data. The RAM 511 temporarily stores the converted digital data. A program (not shown) for occupant detection processing is written in the ROM 512 in advance. The CPU 51 determines the occupant's physique and the like from the occupant data and the seat belt withdrawal amount data in accordance with the program in the ROM 512.

  The communication I / F 52 is connected to the CPU 51 through a signal line S3. The communication I / F 52 transmits the determination result of the CPU 51 to the airbag device 6 via the signal line S4. The airbag device 6 includes an airbag ECU 60 and an airbag 61. The airbag ECU 60 is disposed below the center cluster of the instrument panel 12. The airbag 61 is accommodated in the passenger seat side of the instrument panel 12. The airbag ECU 60 is connected to the airbag 61 by a signal line S5. The airbag ECU 60 issues an instruction to the airbag 61 based on the determination result transmitted from the communication I / F 52.

  Next, the operation of the occupant detection system of this embodiment will be described. When the ignition switch 90 is turned on, a high voltage is supplied from the vehicle battery 9 to the constant pressure power supply 50 via the power supply line L1. The transformed power supply voltage is supplied to the CPU 51 via the power supply line L2. Thus, the occupant detection system 1 is started.

  First, the occupant state of the seat 7 is imaged by the CCD camera 2. The captured image data is transmitted to the CPU 51 of the occupant detection ECU 5. On the other hand, when the occupant is seated on the seat 7 and the seat belt 4 is attached, the seat belt withdrawal amount data is transmitted from the rotary encoder 30 to the CPU 51.

  Next, based on the occupant data from the CCD camera 2 and the seat belt pull-out amount data from the rotary encoder 30, the CPU 51 determines whether the occupant is seated, whether a child seat is installed, and whether the occupant is seated. judge. The determination result of the occupant state is transmitted to the airbag ECU 60 of the airbag device 6 via the signal line S4. The airbag ECU 60 issues an instruction to the airbag 61 based on the transmitted determination result. Specifically, in the case of vacant seat determination or child seat mounting determination, the airbag 61 is not deployed. In the case of determining a small physique such as a child, only one of the two-stage inflators (not shown) of the airbag 61 is ignited. That is, the deployment pressure of the airbag 61 is reduced. In the case of an physique determination equivalent to an adult, all the two-stage inflators of the airbag 61 are ignited. That is, the deployment pressure of the airbag 61 is increased.

  Next, the effect of the occupant detection system of this embodiment will be described. In the occupant detection system 1 of the present embodiment, the occupant state on the seat 7 is determined using the seat belt withdrawal amount data detected by the rotary encoder 30. Therefore, the occupant state on the seat 7 such as the occupant's physique can be easily determined. Further, the occupant state on the seat 7 is imaged using the CCD camera 2. Determination accuracy is improved by obtaining occupant data by image recognition in addition to the seat belt withdrawal amount data. Then, by using the determination result of the occupant detection system 1 for the airbag device 6, whether or not the airbag 61 is deployed, the deployment pressure when deployed, the deployment speed, and the like are flexibly controlled according to the occupant's physique. be able to.

  The embodiment of the occupant detection system of the present invention has been described above. However, the passenger detection system of the present invention is not limited to the above embodiment. The occupant detection system of the present invention can be implemented in various forms that have been modified or improved by those skilled in the art without departing from the scope of the present invention.

  For example, in the above embodiment, a CCD camera is used as an occupant detection sensor. However, the type of occupant detection sensor is not particularly limited. A load sensor, a pressure sensor, a distance sensor, or the like may be used in addition to the imaging sensor as in the above embodiment. A plurality of these sensors may be used in combination. For example, by using an imaging sensor and a load sensor in combination, information on the physique and weight of the occupant can be acquired. Thus, the physique of the occupant can be determined more accurately. Moreover, you may comprise the passenger | crew detection system of this invention, without using a passenger | crew detection sensor.

  In the above embodiment, a rotary encoder is used as the seat belt pull-out amount detection device. However, the type of the seat belt pull-out amount detection device is not particularly limited. In addition to the device that detects the rotation angle of the reel, a device that detects the winding diameter of the seat belt wound around the reel may be used.

  In the said embodiment, the determination result of the passenger | crew state was utilized for the airbag apparatus. For example, when the seat belt retractor includes a pretensioner mechanism, the determination result of the occupant state may be transmitted to the seatbelt retractor and used when the pretensioner mechanism is activated.

  In the above embodiment, the passenger state in the passenger seat is determined. However, the occupant detection system of the present invention can be similarly applied to a driver's seat and a rear seat as well as a passenger seat.

1 is a layout diagram showing one embodiment of an occupant detection system of the present invention. It is a block diagram of the passenger detection system.

Explanation of symbols

1: Occupant detection system 2: CCD camera (occupant detection sensor)
3: Seat belt retractor 30: Rotary encoder (seat belt withdrawal amount detection device)
4: Seat belt 5: Occupant detection ECU 50: Constant voltage power supply 51: CPU 510: A / D converter 511: RAM 512: ROM 52: Communication I / F
6: Airbag device 60: Airbag ECU 61: Airbag 7: Seat 9: Vehicle battery 90: Ignition switch 11: Room mirror 12: Instrument panel 13: Handle

Claims (3)

A seat belt that restrains the occupant to the seat;
A seat belt withdrawal amount detection device capable of detecting the seat belt withdrawal amount;
An occupant detection ECU for determining an occupant state on the seat based on the seat belt withdrawal amount data transmitted from the seat belt withdrawal amount detection device;
An occupant detection system. Furthermore, an occupant detection sensor capable of detecting an occupant state on the seat is provided,
The occupant detection system according to claim 1, wherein the occupant detection ECU determines an occupant state on the seat based on the seat belt pull-out amount data and occupant data transmitted from the occupant detection sensor. The occupant detection system according to claim 2, wherein the occupant detection sensor is an imaging sensor.

Images