JP2008150039A - Occupant sensing means - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant sensing means capable of sensing the position of an occupant seated in a vehicle seat by one camera. <P>SOLUTION: A control circuit 20 computes the position of a front passenger seat 16 in the longitudinal direction and the angle of inclination of a seatback 26 based on a signal from a seat slide sensor 22 and a signal from a seatback angle sensor 28 at the time when it is determined that an occupant head 19 is within a predetermined distance from a head rest 30 by a signal from a proximity sensor 32. In addition, the image pickup data by a camera 12 is stored at the reference dimension at the reference position of the occupant head 19. Further, the control circuit 20 computes the position of the occupant head 19 by comparing the reference dimension with the measured dimension of the occupant head 19 in the image pickup data by the camera 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an occupant detection device, and more particularly to an occupant detection device that detects the position of an occupant seated on a vehicle seat.

  Conventionally, an example of an occupant detection device that detects the position of an occupant seated on a vehicle seat has been disclosed (Patent Document 1).

As shown in FIG. 8, this occupant detection apparatus has a pair of cameras 102 and 104 that take a picture of an occupant seated on the front seat 100 and generate a first image and a second image. The distance from the cameras 102 and 104 to the occupant is measured by a distance measuring device to which the cameras 102 and 104 are connected.
Japanese Patent Laid-Open No. 11-15980

  However, since such an occupant detection device uses a pair of cameras 102 and 104, the positional relationship between the cameras 102 and 104, that is, the relative position between the optical axis of the camera 102 and the optical axis of the camera 104 is managed. Since the management of the positional relationship between the optical axes of the cameras 102 and 104 and the vehicle body affects the distance measurement performance, the installation of the cameras 102 and 104 on the vehicle becomes complicated and the manufacturing cost increases. In addition, since two expensive cameras are used as compared with other parts such as sensors, the cost is significantly increased in this respect.

  In view of the above fact, an object of the present invention is to obtain an occupant detection device that can detect the position of an occupant with a single camera.

  According to a first aspect of the present invention, there is provided an occupant detection device according to the present invention, a camera that captures a head of an occupant seated on a seat, a head detection unit that is provided on a headrest and detects the occupant head, and the head detection unit When it is determined that the occupant head is within a predetermined distance from the headrest, a reference dimension at the reference position of the occupant head is determined based on imaged data obtained by the camera. When it is determined that the occupant head is not within a predetermined distance from the headrest, the position of the occupant head is calculated from a comparison between the reference dimension and the dimension of the occupant head of the data captured by the camera. And a position calculating means.

  Therefore, the position calculation means is provided on the headrest, and when the head from the head detection means for detecting the head of the occupant determines that the occupant head is within a predetermined distance from the headrest, the occupant seated on the seat When determining the reference dimension at the reference position of the occupant head based on the imaging data obtained by photographing the head with the camera, and when determining that the occupant head is not within a predetermined distance from the headrest, The position of the occupant is calculated from a comparison between the image data captured by the camera and the dimensions of the occupant head. As a result, the position of the occupant can be detected by one camera, and the occupant head can be reliably detected even when the occupant head is not in contact with the headrest.

  According to a second aspect of the present invention, there is provided an occupant detection device according to a second aspect of the present invention, comprising: a camera for photographing a head of an occupant seated on a seat; And a head detecting means for detecting the head of the occupant provided on an upper portion or a headrest of the seat back, and a signal from the head detecting means, the occupant head is a predetermined distance from the head detecting means. A reference position of the occupant head is determined based on a detection result by the seat position detection means, and a reference dimension at the reference position of the occupant head is determined based on imaging data by the camera. In addition, when it is determined that the occupant head is not within a predetermined distance from the head detection means, the dimensions of the occupant head of the data captured by the camera , A position calculation means for calculating the position of the passenger's head from the difference between the reference dimension and characterized by comprising a.

  Therefore, the position calculation means determines that the occupant head is within a predetermined distance from the head detection means based on a signal from the head detection means that is provided on the upper portion of the seat back or on the headrest and detects the occupant's head. In this case, the reference position of the occupant head is obtained based on the detection result by the seat position detection means, the reference dimension at the reference position of the occupant head is determined based on the imaging data by the camera, and the occupant head is the head If it is determined that the distance is not within a predetermined distance from the detection means, the occupant's head position is calculated from the difference between the occupant head dimension of the image data captured by the camera and the reference dimension. As a result, the position of the occupant head can be detected by one camera, and the occupant head can be reliably detected even when the occupant head is not in contact with the headrest.

  According to a third aspect of the present invention, in the occupant detection device according to the first or second aspect, the head detection means detects whether or not the head of the occupant is within a predetermined distance. It is a sensor.

  Therefore, in addition to the contents described in claim 1 or claim 2, the proximity sensor for detecting whether or not the occupant's head is within a predetermined distance is used as the head detection means. Even when the head is not in contact with the head detection means, the head of the occupant can be reliably detected.

  According to a first aspect of the present invention, there is provided an occupant detection device according to the present invention, comprising: a camera that captures a head of an occupant seated on a seat; a head detection unit that is provided on a headrest; When it is determined from the signal that the occupant head is within a predetermined distance from the headrest, a reference dimension at the reference position of the occupant head is determined based on imaged data obtained by the camera, and the occupant head is separated from the headrest. Since it is provided with position calculation means for calculating the position of the occupant head from a comparison between the reference dimension and the dimension of the occupant head of the image data captured by the camera when it is determined that the distance is not within the predetermined distance, The camera can detect the position of the occupant and has an excellent effect that the occupant head can be reliably detected even when the occupant head is not in contact with the headrest.

  The occupant detection device of the present invention according to claim 2 is a camera for photographing the head of the occupant seated on the seat, a position in the front-rear direction of the seat, and a seat position detection means for detecting the angle of the seat back of the seat, When it is determined that the occupant's head is within a predetermined distance from the head detection means by means of a head detection means for detecting the occupant's head and a signal from the head detection means provided on the upper part of the seat back or on the headrest In addition, the reference position of the occupant head is obtained based on the detection result by the seat position detection means, the reference dimension at the reference position of the occupant head is determined based on the imaging data by the camera, and the occupant head is the head detection means Position calculating means for calculating the position of the occupant head from the difference between the dimension of the occupant head of the image data captured by the camera and the reference dimension, Because having a together with the can detect the position of the passenger's head in one camera, when the passenger's head is not in contact with the headrest also have excellent effect that can reliably detect the passenger's head.

  According to a third aspect of the present invention, in the occupant detection device according to the first or second aspect, the head detecting means is a proximity sensor that detects whether or not the occupant's head is within a predetermined distance. Therefore, in addition to the effect of Claim 1 or Claim 2, it has the outstanding effect that a passenger | crew's head can be detected reliably.

  1st Embodiment of the passenger | crew detection apparatus of this invention is described according to FIGS.

  In the figure, the arrow FR indicates the vehicle front direction, the arrow UP indicates the vehicle upward direction, and the arrow IN indicates the vehicle width inside direction.

  As shown in FIG. 1, the occupant detection device 10 of the present embodiment includes a single camera 12, and this camera 12 is disposed in front of the head 19 of the occupant 18 above the instrument panel 14. ing. The central angle K of view angle of the camera 12 is directed toward the head 19 of the occupant 18 seated on the passenger seat 16, and the camera 12 is connected to a control circuit 20 serving as position calculation means.

  The seat cushion frame 21 of the passenger seat 16 is provided with a seat slide sensor 22 that constitutes a seat position detecting means, and detects the position of the passenger seat 16 in the front-rear direction. Further, a seat back angle sensor 28 constituting a seat position detecting means is disposed at a connecting portion between the seat cushion 24 and the seat back 26 so as to detect an inclination angle of the seat back 26. Further, a proximity sensor 32 as a head detecting means is provided in the headrest 30 provided in the upper part of the seat back 26. The proximity sensor 32 is constituted by, for example, a capacitance sensor so that it can detect whether the occupant head 19 is in contact with or close to the headrest 30 within a predetermined distance, for example. It has become.

  The seat slide sensor 22, the seat back angle sensor 28, and the proximity sensor 32 are connected to the control circuit 20, and the control circuit 20 receives information from the camera 12, the seat slide sensor 22, the seat back angle sensor 28, and the proximity sensor 32. For example, the passenger seat airbag device 40 disposed on the instrument panel 14 is controlled.

  Next, the operation of this embodiment will be described.

  In this embodiment, when the control circuit 20 determines from the signal from the proximity sensor 32 that the occupant head 19 is in contact with or approaching the headrest 30 within a predetermined distance, for example, The front / rear direction position of the passenger seat 16 is calculated based on the signal from the seat slide sensor 22 and the tilt angle of the seat back 26 is calculated based on the signal from the seat back angle sensor 28. Further, the image data taken by the camera 12 at that time is stored as a reference dimension at the reference position of the occupant head 19.

  As shown in FIG. 3, the reference dimension D1 (pixel) at the reference position of the occupant head 19 is a circle that is the contour of the occupant head 19, particularly the face, in the imaging data S1 of the horizontal size W (pixel) of the screen. The shape is recognized as an image, and the length of the round shape in the vehicle width direction is set as the reference dimension D1.

  Further, the control circuit 20 calculates the position of the occupant head from the comparison between the reference dimension D1 and the dimension of the occupant head 19 of the image data captured by the camera 12.

  That is, as shown by a two-dot chain line in FIG. 1, the occupant 18 bends forward, and as shown in FIG. 4, the measurement dimension D2 (pixel) of the occupant head 19 of the image data S2 captured by the camera 12 becomes the reference dimension D1. On the other hand, when it changes, the control circuit 20 compares the reference dimension D1 with the measurement dimension D2.

At this time, the position of the occupant head 19 has moved from the reference position on the vehicle rear side indicated by the solid line in FIG. 2 to the measurement position on the vehicle front side indicated by the two-dot chain line. Between the distance L1 (mm) between the instrument panel 14 and the occupant head 19 when determining the reference dimension D1 and the distance L2 (mm) between the instrument panel 14 and the occupant head 19 when measuring the measurement dimension D2 Is
L2 = (D1 / W) / (D2 / W) · L1 = (D1 / D2) · L1
From this equation, the control circuit 20 calculates the distance L2 between the instrument panel 14 and the occupant head 19 when measuring the measurement dimension D2.

  When the distance L2 between the instrument panel 14 and the occupant head 19 at the time of measuring the measurement dimension D2 is shorter than a predetermined distance, that is, the passenger seat airbag device 40 disposed on the instrument panel 14 and the occupant When the head 19 is approaching, for example, the operation of the passenger seat airbag device 40 is prohibited.

  Therefore, in the present embodiment, the position of the occupant head 19 can be detected with one camera. Therefore, unlike the prior art using two cameras, it is not necessary to manage the optical axis between the cameras, the camera can be easily mounted on the vehicle, the manufacturing cost can be reduced, and other parts such as sensors In comparison with this, since only one expensive camera is sufficient, the cost can be greatly reduced in this respect.

  In the present embodiment, the proximity sensor 32 that detects whether or not the occupant's head is within a predetermined distance is used as the head detection means, and therefore the occupant head 19 is not in contact with the headrest 30. In this case, the occupant head 19 can be reliably detected.

  Further, in this embodiment, the reference dimension D1 at the reference position of the occupant head 19 is image-recognized by the occupant head 19, particularly the round shape that is the contour of the face, in the imaging data S1 of the horizontal size W of the screen. The length of the round shape in the vehicle width direction is the reference dimension D1. For this reason, the reference dimension D1 and the measurement dimension D2 can be accurately measured as compared with the length in the vehicle vertical direction in the contour of the face affected by the hair.

  Next, a second embodiment of an occupant detection device according to the present invention will be described with reference to FIGS.

  In addition, the same member as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description.

  As shown in FIG. 5, in this embodiment, the camera 12 is disposed from the center 14A in the vehicle width direction at the top of the instrument panel 14, and the occupant head 19 is photographed from the front in the oblique vehicle width direction. It is supposed to be.

  Next, the operation of this embodiment will be described.

  In the present embodiment, as in the first embodiment, the control circuit 20 determines that the occupant head 19 is in contact with the headrest 30 within a predetermined distance, for example, or approached by a signal from the proximity sensor 32. If it is determined that the seat back sensor 22 is present, the position in the front-rear direction of the passenger seat 16 is calculated based on the signal from the seat slide sensor 22 at that time, and the tilt angle of the seat back 26 is calculated based on the signal from the seat back angle sensor 28. Is calculated. Further, the image data taken by the camera 12 at that time is stored as a reference dimension at the reference position of the occupant head 19.

  As shown in FIG. 6, the reference dimension D3 (pixel) at the reference position of the occupant head 19 photographed from the front in the vehicle width direction by the camera 12 is the occupant in the imaging data S3 of the horizontal size W (pixel) of the screen. The head 19, in particular, a round shape that is the contour of the face is recognized as an image, and the length of the round shape in the vehicle width direction is set as a reference dimension D3.

  Further, the control circuit 20 calculates the position of the occupant head from the comparison between the reference dimension D3 and the dimension of the occupant head 19 of the image data captured by the camera 12.

  That is, as shown by a two-dot chain line in FIG. 5, the occupant head 19 moves forward, and as shown in FIG. 7, the measurement dimension D4 (pixel) of the occupant head 19 of the imaging data S4 by the camera 12 is the reference. When it changes with respect to the dimension D3, the control circuit 20 compares the reference dimension D3 with the measurement dimension D4.

At this time, since the position of the occupant head 19 has moved from the reference position on the vehicle rear side indicated by the solid line in FIG. 5 to the measurement position on the vehicle front side indicated by the two-dot chain line, the reference dimension D3 and the measurement dimension D4. The distance L3 (mm) between the instrument panel 14 and the occupant head 19 when determining the reference dimension D3, the distance L4 (mm) between the instrument panel 14 and the occupant head 19 when measuring the measurement dimension D4, and the reference dimension D3 The distance Y1 (mm) between the camera 12 and the occupant head 19 at the time of determination, the distance Y2 (mm) between the camera 12 and the occupant head 19 at the time of measuring the measurement dimension D4, and the vehicle front and rear of the central axis K of view angle of the camera 12 Between the inclination angle θ with respect to the direction and the distance B from the occupant head 19 at the time of measurement dimension D4 measurement to the camera's angle of view center axis K (the right side from the screen center is positive) (mm),
Y1 = L3 · cos θ
Y2 = (D3 / D4) · Y1
L4 = Y2 · cos θ−B · sin θ
= {(D3 / D4) · Y1} · cos θ−B · sin θ
From this equation, the control circuit 20 calculates the distance L4 between the instrument panel 14 and the occupant head 19 when measuring the measurement dimension D4.

  When the distance L4 between the instrument panel 14 and the occupant head 19 at the time of measuring the measurement dimension D4 is shorter than a predetermined distance, that is, the passenger seat airbag device 40 disposed on the instrument panel 14 and the occupant When the head 19 is approaching, for example, the operation of the passenger seat airbag device 40 is prohibited.

  Therefore, in the present embodiment, the position of the occupant head 19 can be detected with one camera. Therefore, unlike the prior art using two cameras, it is not necessary to manage the optical axis between the cameras, the camera can be easily mounted on the vehicle, the manufacturing cost can be reduced, and other parts such as sensors In comparison with this, since only one expensive camera is sufficient, the cost can be greatly reduced in this respect.

  In this embodiment, in addition to the effects of the first embodiment, the camera 12 is disposed from the center 14A in the vehicle width direction at the upper part of the instrument panel 14, and the occupant's head 19 is inclined. Since photographing is performed from the front in the width direction, even when the occupant 18 is reading a book or the like, the occupant head 19 can be photographed by the camera 12 without being disturbed by the book or the like.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, in each of the above embodiments, the proximity sensor 32 as the head detection means is configured by a capacitance sensor, but the head detection means is not limited to this configuration, and the occupant head 19 abuts against the headrest 30. It may be a touch switch that directly detects the load. Further, the position of the head detecting means may be disposed on the upper portion of the seat back 26 facing the child occupant's head instead of the headrest 30.

  Further, the position of the camera 12 is not limited to the position on the instrument panel 14, and the camera 12 is placed on other parts such as the front pillar 50, the inner mirror 52, and the overhead console 54 as shown by a two-dot chain line in FIG. It may be arranged. Further, if the device for adjusting the angle of view center axis K in conjunction with the change in the angle of the seat back 26 and preventing the deviation of the angle of view center axis K is provided, the camera 12 is mounted on the upper portion of the seat back 26 or the headrest 30. It can also be arranged.

1 is a schematic side view showing a part of a vehicle to which an occupant detection device according to a first embodiment of the present invention is applied. It is operation | movement explanatory drawing of the passenger | crew detection apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the imaging data in the reference | standard position of the passenger | crew head of the passenger | crew detection apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the imaging data in the measurement position of the passenger | crew head of the passenger | crew detection apparatus which concerns on 1st Embodiment of this invention. It is operation | movement explanatory drawing of the passenger | crew detection apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the imaging data in the reference | standard position of the passenger | crew head of the passenger | crew detection apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the imaging data in the measurement position of the passenger | crew head of the passenger | crew detection apparatus which concerns on 2nd Embodiment of this invention. It is a schematic plan view which shows a part of vehicle with which the passenger | crew detection apparatus of the prior art example was applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Crew detection device 12 Camera 14 Instrument panel 16 Passenger seat 19 Crew head 20 Control circuit (position calculation means)
22 Seat slide sensor (Seat position detection means)
26 seat back 28 seat back angle sensor (seat position detecting means)
30 Headrest 32 Proximity sensor (Head detection means)

Claims (3)

A camera that shoots the head of the passenger seated on the seat;
A head detecting means provided on the headrest for detecting the head of the passenger;
When it is determined by the signal from the head detection means that the occupant head is within a predetermined distance from the headrest, the reference dimension at the reference position of the occupant head based on the imaged data taken by the camera And determining that the occupant head is not within a predetermined distance from the headrest, the occupant head is compared with the reference dimension and the dimension of the occupant head of the data captured by the camera. Position calculating means for calculating the position of the part;
An occupant detection device comprising: A camera that shoots the head of the occupant seated on the seat;
A position of the seat in the front-rear direction and a seat position detecting means for detecting an angle of a seat back of the seat;
A head detecting means provided on an upper part or a headrest of the seat back and detecting the head of the passenger;
When it is determined by the signal from the head detection means that the occupant head is within a predetermined distance from the head detection means, the occupant head reference is based on the detection result by the seat position detection means. If the position is determined, the reference dimension at the reference position of the occupant head is determined based on the image data captured by the camera, and the occupant head is not within a predetermined distance from the head detection means An occupant detection device comprising: position calculation means for calculating the position of the occupant head from the difference between the dimension of the occupant head of the image data captured by the camera and the reference dimension.   The occupant detection device according to claim 1 or 2, wherein the head detection means is a proximity sensor that detects whether or not the occupant's head is within a predetermined distance.

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