JP2006284600A - Occupant detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant detector capable of detecting precisely an occupant. <P>SOLUTION: In this occupant detector for detecting a position and a posture of the occupant 1 in a vehicular cabin by an infrared camera 2, the infrared camera is installed to include the occupant within an area of a glass pane 5 serving as one part or the whole of a background of an imaging area imaged by the infrared camera, and an infrared image acquired from the infrared camera is binarized to detect the presence of the occupant in the cabin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an occupant detection device that detects a seating position of an occupant of a vehicle.

  It has been proposed to activate a desired vehicle device (such as an air conditioner system or an airbag system) by detecting an occupant seated in the passenger compartment using an infrared sensor or the like (see, for example, Patent Document 1). .

  However, when detecting an occupant using an infrared sensor, it is difficult to separate the occupant from the background because there are many things that can become heat sources, such as the occupant's arms, thighs, or seat backrest trim. There was a problem that it could not be detected well.

JP-A-11-201822

  An object of this invention is to provide the passenger | crew detection apparatus which can detect a passenger | crew accurately.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided an occupant detection device for detecting the position and posture of an occupant in a vehicle cabin with an infrared camera, wherein one of the backgrounds of an imaging region of the infrared camera is detected. The infrared camera is installed so that an occupant is included in the area of the window glass that is a part or the whole, and the infrared image data acquired from the infrared camera is binarized to detect the presence or absence of an occupant in the vehicle interior An occupant detection device is provided.

  According to a second aspect of the present invention, in an occupant detection device that detects an occupant's position and posture in a vehicle cabin with an infrared camera, the infrared camera sandwiches a vehicle center line that equally divides the vehicle left and right. The occupant detection device is provided on the side opposite to the occupant.

  In the invention according to the first aspect, since the background region of the infrared camera is a window glass having a property of not transmitting infrared rays and having a constant emissivity, a uniform display image surface with less noise can be obtained. This facilitates separation of the occupant and the background and increases the occupant detection accuracy.

  In addition, in the invention according to the second aspect, since a sufficient distance between the occupant and the infrared camera can be secured, the entire occupant's face enters the field of view of the infrared camera, and in addition to the detection accuracy of the occupant itself, the occupant position, etc. Can be detected with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a configuration diagram of an infrared camera according to a first embodiment of the present invention, FIG. 2 is a plan view of an interior of an occupant detection device according to an embodiment of the present invention, and FIG. 3 is an infrared ray according to an embodiment of the present invention. FIG. 3 is a view taken in the direction of an arrow III in FIG. 2 showing a camera mounting position.

  The infrared camera 2 of the present embodiment shown in FIG. 1 includes a condenser lens 41, an infrared sensor 42, a processing device 43, and a storage device 44. The incident infrared ray 45 is imaged on the infrared sensor 42 through the condenser lens 41. The The signal output from the infrared sensor 42 is sent to the processing device 43, and occupant detection processing is performed in the processing device 43. And the processing result by the processing apparatus 43 is output to the vehicle system 45, and is recorded in the memory | storage device 44 as needed.

The infrared camera 2 of this example is incorporated in a vehicle as shown in FIGS. FIG. 1 is a plan view mainly showing the front seat of the vehicle, and the left side in the drawing is the vehicle traveling direction 4. The infrared camera 2 of this example detects the occupant 1 seated in the driver's seat located on the upper side of the figure, and the passenger seat side located on the opposite side (lower side of the figure) of the center line 3 on the left and right sides of the vehicle. Are attached to the inner surface of the front pillar (A pillar) portion 10. FIG. 3 is a view taken in the direction of the arrow III in FIG. 2, and the infrared camera 2 shown in FIG. 3 is attached to the upper part of the front pillar 10, that is, in the vicinity of the connecting portion with the roof panel.

Further, the detection area 13 of the infrared camera 2 attached at this position is set so that the occupant 1 is detected as shown in FIG. 1 and most of the background is the window glass 5 (wind glass of the front door). Has been.

Thus, when most of the background by the infrared camera 2 is set to the window glass 5, since the emissivity of the window glass 5 is constant, the passenger | crew 1 and the background can be separated accurately.

Further, since the infrared camera 2 is provided on the inner surface of the front pillar 10 opposite to the occupant 1 across the center line 3 on the left and right sides of the vehicle, the distance between the occupant 1 and the infrared camera 2 can be increased. 12 can be captured. Thereby, a face (side profile) with large radiant energy can be captured, and the detection accuracy of the occupant is increased. Furthermore, since the background is the window glass 5, it is possible to detect passengers at different positions.

  Next, the operation will be described with reference to FIGS.

In step S <b> 1 of the operation flowchart of FIG. 4, infrared image data is acquired by the processing device 43 using the infrared camera 2. In the image acquired in this case, the window glass 5 is the background with the face 12 of the occupant 1 as the center as shown in FIG. In FIG. 5, reference numeral 13 denotes an imaging region.

Since the window glass 5 is made of glass, the window glass 5 does not transmit infrared light in the 8 μm to 14 μm band emitted from the passenger. Therefore, only infrared rays radiated from the surface of the window glass 5 are incident on the infrared camera 2, and information outside the window glass 5 does not enter unlike the visible camera. Further, since the surface of the window glass 5 is very smooth, the emissivity (= 0.94) is constant. Therefore, it is very suitable as a background having uniform radiant energy.

Thereafter, in step S2 of the operation flowchart of FIG. 4, the captured image data is binarized with a predetermined threshold value. The binarized situation is shown in FIG. Then, in step S3 in the figure, the position of the center of gravity of the binarized image data is calculated, and the value is set as the occupant position. Next, in step 4 in the figure, the result is output to a vehicle system such as an airbag or an air conditioner.

In addition, when continuing a process, it returns to step S1 from step S5 of the figure, and repeats step S1-S4.

  Incidentally, in step S3, the calculation of the occupant position is not limited to the above-described method based on the center of gravity position, but, for example, as shown in FIG. Can also be set as the occupant position. For example, in the arrangement configuration of the infrared camera shown in FIG. 1, the leading edge in the vehicle forward direction corresponds to the nose 21 of the occupant 1. Although the position of the nose 21 relative to the entire head exists at a substantially constant position although there are individual differences, the accurate head position, that is, the sitting height of the occupant 1 can be detected without being affected by hair or the like.

<< Second Embodiment >>
FIG. 8 is an in-vehicle plan view showing an occupant detection device according to the second embodiment of the present invention. The present embodiment is an example in which the focus position 73 of the infrared camera 2 shown in FIG. 1 is set in front of the position 72 where the occupant 1 exists, and the background is blurred to reduce the influence of the background.

In the first embodiment described above, the in-focus position of the infrared camera 2 is set at the position 72 where the occupant 1 as the subject is present. In the present embodiment, the in-focus position 73 is set in front. In the imaging optical system, there is only one surface to be focused on. However, in the infrared sensor 2 or the like, even if a blur of an allowable circle of confusion caused by the sensor resolution and the lens resolution occurs, the image is not affected. . This area is called the depth of field. In the present embodiment, the occupant 1 is set to the very depth of the rear side depth of field, and the occupant 1 accurately captures an image in a focused state while the background window glass 5 is blurred.

According to the present embodiment, even if the sunlight rises on a part of the window glass 5 and the temperature rises and the background changes, the pattern diffuses due to the blur, so the influence can be reduced.

<< Third Embodiment >>
9 and 10 are diagrams illustrating the operation of the occupant detection device according to the third embodiment of the present invention. In this embodiment, in addition to the configuration of the first embodiment, a low emissivity region 31 having a lower emissivity than the surroundings is formed in a part of the seat backrest 8 or the seat pillow 7.

Specifically, the low emissivity region 31 is provided with a member having a smooth metal surface such as aluminum Al, copper Cu, magnesium Mg, and iron Fe. The low emissivity region 31 has the same temperature as the surroundings, but since the emissivity is low, the emitted infrared energy is reduced. Therefore, when the image is picked up by the infrared camera 2, it is displayed in black as shown in FIGS.

Since this position 31 is fixed in advance to the seat backrest 8 and the seat pillow 7, it becomes a mark of the position, and the height direction of the face 12 of the occupant 1 can be known more accurately. Therefore, even if the optical axis of the infrared camera 2 is deviated, it can be corrected based on the low reflectance region 31.

Furthermore, there is an effect that the position of the seat backrest 8 whose position is difficult to measure can be accurately known.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the embodiment described above, the example of detecting the occupant 1 on the driver's seat side has been given, but the mounting position of the infrared camera 2 is changed so as to detect the occupant seated in the passenger seat and the occupant seated in the rear seat. Also good. An infrared camera is attached to the inner surface of the front pillar on the driver's seat to detect the passenger seated in the passenger seat, and the inner surface of the center pillar (B pillar) or rear pillar (C pillar) to detect the passenger seated in the rear seat An infrared camera can be attached to the.

It is a block diagram of the infrared camera which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an in-vehicle plan view showing an occupant detection device according to an embodiment of the present invention. It is the III arrow directional view of FIG. 2 which shows the attachment position of the infrared camera which concerns on the Example form of this invention. It is a flowchart which shows the operation | movement which concerns on embodiment of this invention. It is FIG. (1) explaining the effect | action of embodiment of this invention. It is FIG. (2) explaining the effect | action of embodiment of this invention. It is FIG. (3) explaining the effect | action of embodiment of this invention. It is a top view inside a vehicle showing an occupant detection device according to another embodiment of the present invention. It is FIG. (1) explaining the effect | action of the passenger | crew detection apparatus which concerns on further another Example form of this invention. It is FIG. (2) explaining the effect | action of the passenger | crew detection apparatus which concerns on further another Example form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Passenger 2 ... Infrared camera 3 ... Center line 4 on either side of vehicle ... Forward direction 5 ... Window glass 6 ... Seat cushion 7 ... Seat pillow 8 ... Seat backrest 9 ... Handle 10 ... Front pillar 11 ... Center pillar 12 ... Face 13 ... Detection area 14 ... Door mirror 15 ... Front windshield 21 ... Recognition position 31 corresponding to occupant's nose ... Low emissivity area

Claims (3)

An occupant detection device that detects an occupant's position and posture in a vehicle interior with an infrared camera, wherein the infrared is so included that the occupant is included in a window glass region that is part or all of the background of the imaging region of the infrared camera. An occupant detection device, wherein a camera is installed, infrared image data acquired from the infrared camera is binarized, and the presence or absence of an occupant in the vehicle compartment is detected. In an occupant detection device that detects the position and posture of an occupant in a vehicle cabin with an infrared camera, the infrared camera is installed on the opposite side of the occupant across a vehicle center line that equally divides the vehicle into left and right An occupant detection device. The occupant detection device according to claim 1, wherein a focus position of the infrared camera is set between the infrared camera and the occupant.

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