JP2005075261A - Occupant detecting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve image processing accuracy when detecting occupants on a plurality of seats by performing an image processing of images imaging the inside of a cabin. <P>SOLUTION: An imaging device 14 for imaging a driver's seat 12 and a front passenger seat 13 in the cabin is provided with a single imaging element 21 and a prism 23 in which the image of the driver's seat 12 is made incident to one surface, the image of the front passenger seat 13 is made incident to the other surface, and both of the images are reflected at the inside to be collected to the imaging element 21 side. A prescribed image processing is performed for the imaged video imaged by the imaging device 14, and the presence or absence of each occupant at each boarding position is judged based on the result of the image processing. The presence or absence of the occupants at two portions can be detected by the single imaging element 21. The imaged video can be imaged at a wide image range for an imaging effective region of the imaging element 21 and various kinds of image processing can be performed by the imaged video of high resolution. As a result, there is an advantage of improving judging accuracy of the presence or absence of the occupants. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an occupant detection system and related technology.

  As a method of detecting whether or not an occupant is on a vehicle, there is a method of mounting a seating sensor on a seat (seat) in a vehicle as disclosed in Patent Document 1, for example. In this method, a load on the seat surface is detected by a seating sensor (load detection sheet) installed on the seat, and when the load is detected by the seating sensor, it is determined that the seating is detected in the detection circuit unit.

JP 2001-133341 A

  In the above-mentioned patent document 1, since the seating sensor must be arranged directly under the seat surface, there is a problem that the manufacturing process of the seat becomes complicated.

  Therefore, for example, by installing an imaging device such as a CCD sensor on the instrument panel, imaging the interior of the vehicle, and performing various image processing such as contour extraction, feature extraction, and pattern recognition of the captured image, the presence or absence of passengers It is also possible to determine the above (proposed example). In this case, as compared with Patent Document 1, it is not necessary to arrange a seating sensor immediately below the seat surface, and the seat manufacturing process is simplified.

  However, when an imaging device having a general imaging angle of view is used, when only one CCD sensor is used for the purpose of cost reduction, for example, only the passenger in the passenger seat can be detected, which causes inconvenience. If it is desired to detect both passengers and passenger seats, at least two CCD sensors must be installed, which is inefficient.

  On the other hand, when a single CCD sensor 1 having a relatively large imaging angle of view is used as shown in FIG. 6, for example, the center 2 in the imaging direction is placed between the driver seat 3 and the passenger seat 4. By setting, both the driver's seat 3 and the passenger seat 4 can be imaged. In this case, it is only necessary to perform various image processing such as contour extraction, feature extraction, and pattern recognition on the image captured by the single CCD sensor 1, and passengers 5 and 6 in both the driver's seat 3 and the passenger seat 4. Can be detected.

  However, the image formed on the CCD sensor 1 in FIG. 6 is as indicated by reference numeral 7 in FIG. 7, and the space 8 between the driver's seat 3 and the passenger seat 4 appears as it is. When various image processes such as feature extraction and pattern recognition are performed to detect the occupants 5 and 6, the image processing target area 9 occupying the entire area of the image 7 is between the driver seat 3 and the passenger seat 4. The space is narrowed by the space 8, and the image processing accuracy is lowered accordingly.

  Therefore, the main feature of the present invention is to improve image processing accuracy when image processing is performed on an image of a passenger compartment to detect a plurality of seats.

  In order to solve the above-mentioned problem, the invention described in claim 1 is an occupant detection system that detects whether or not an occupant is present at two predetermined boarding positions in a vehicle interior of an automobile. An imaging device that captures the boarding position, and the presence / absence of an occupant that performs predetermined image processing on the captured image captured by the imaging device and determines the presence / absence of each occupant at each boarding position based on the result of the image processing Detecting means, wherein the imaging apparatus has a single imaging element, one image of the boarding position is incident on one surface, and the other image of the boarding position is incident on the other surface. And a prism that is reflected inside and focused on the image sensor side.

  The invention according to claim 2 is the occupant detection system according to claim 1, wherein the apex angle of the tip of the prism is such that an image incident on an imaging effective area of the imaging element is the position of each boarding position. The angle is set to limit the range of the image incident on each surface of the prism so as to be limited to an image.

  Invention of Claim 3 is an occupant detection system of Claim 1 or Claim 2, Comprising: The said one boarding position is a driver's seat, and the said other boarding position is a passenger seat, The imaging device is installed on an instrument panel in a vehicle interior.

  According to a fourth aspect of the present invention, in the occupant detection system according to the third aspect, the image pickup device is mounted on a mounting board on which each electrical component in the instrument panel is mounted.

  The invention according to claim 5 is the occupant detection system according to claim 3 or 4, wherein the occupant detection system is installed on the instrument panel, and an image of one of the boarding positions is displayed on the one of the prisms. A transparent window is formed to enter the surface and the image of the other boarding position to enter the other surface of the prism, and a cover for covering the image sensor and the prism to make it inconspicuous from the outside In addition.

  In the occupant detection system according to the first aspect of the present invention, an image pickup apparatus that picks up images of both boarding positions in a vehicle interior has a single image sensor and an image of one boarding position incident on one surface, and the other surface. The image of the other boarding position is incident on the prism, and both images are reflected internally and condensed on the image sensor side, and a predetermined image processing is performed on the captured image captured by the imaging device, Since the presence / absence of each occupant at each boarding position is determined based on the result of this image processing, the presence / absence of two occupants can be detected with a single image sensor.

  In the occupant detection system according to the first aspect of the present invention, for example, as described in the second aspect, the apex angle of the tip of the prism, and the image incident on the imaging effective area of the imaging element are The image of both boarding positions, which is the imaging target, is effectively condensed on the image sensor by the prism by setting the angle to limit the range of the image incident on each surface of the prism so that it is limited to the image of Therefore, it is possible to form images of both boarding positions over the entire imaging effective area of the imaging device. Therefore, compared with the case where not only both boarding positions but also the space between both boarding positions are imaged together to detect the presence or absence of an occupant only for the boarding position, the imaging effective area of the image sensor has a wider image range. Various image processing can be performed on the captured high-resolution captured video. Therefore, there is an advantage that the determination accuracy of the presence or absence of a passenger is improved.

  In the occupant detection system according to the third aspect of the present invention, when one boarding position is a driver's seat and the other boarding position is a passenger seat, the imaging device is installed on the instrument panel in the passenger compartment. Thus, the driver's seat and the passenger's seat that are imaging targets can be effectively imaged simultaneously.

  In the occupant detection system according to the fourth aspect of the invention, since the mounting board for mounting each electrical component in the instrument panel is also used as the board for mounting the image sensor, the mounting dedicated to the image sensor is separately provided. Compared with the case where only the board is used, the number of parts can be reduced, and connection to the occupant presence / absence detecting means can be easily performed through the mounting board.

  The occupant detection system according to the fifth aspect of the invention has an advantage that the image sensor and the prism can be made inconspicuous from the outside by the cover, and the aesthetic appearance can be improved.

  FIG. 1 is a view showing a passenger compartment of an automobile equipped with an occupant detection system 10 according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the occupant detection system 10.

  The occupant detection system 10 detects whether or not an occupant is in a car. As shown in FIG. 1, the occupant detection system 10 is positioned at an intermediate position between a driver seat 12 and a passenger seat 13 on an instrument panel 11 of the car. It is arranged at the opposite position.

  The occupant detection system 10 includes an image pickup device 14 for picking up an image of the driver's seat 12 and the passenger seat 13 in the passenger compartment from the front (instrument panel 11 side), and contour extraction for an image picked up by the image pickup device 14. An image processing unit 15 that performs various image processing such as feature extraction and pattern recognition, and a determination unit that determines the presence or absence of each occupant in the driver seat 12 and the passenger seat 13 based on the image processing result in the image processing unit 15 16.

  The imaging device 14 includes an imaging device 21 such as a CCD, a lens system 22 for condensing the imaging device 21, and light 30 a and 30 b taken from diagonally right and left, and internally reflects the lens system 22 once. And a prism (optical element) 23 that condenses on the side, and these are arranged on the inner surface side of a cover (acrylic plate) 24 having transparent windows 26a and 26b formed of transparent plastic or the like as shown in FIGS. And is installed inside the instrument panel 11. The cover 24 is located at the center of the instrument panel 11, for example, and covers the image sensor 21, the lens system 22, and the prism 23 so that the cover 24 is not conspicuous from the outside. 11a is fixed and installed.

  As shown in FIG. 2, the lens system 22 condenses the light from the prism 23 with respect to the effective imaging area of the imaging device 21. Specifically, a 74 ° convex lens is used. The optical axis L1 of the lens system 22 is arranged so as to coincide with the central axis of the image sensor 21.

  As shown in FIG. 2, the prism 23 is formed in a triangular prism shape having an isosceles triangle in plan view using a transparent body such as glass, and the optical axis L1 of the lens system 22 is set on the front side of the lens system 22. It is installed symmetrically in plan view as an axis. The prism 23 has light-transmitting surfaces on the viewing side surfaces 36a and 36b facing the transparent windows 26a and 26b (FIGS. 3 and 4) of the cover 24 and the back surface 36c facing the lens system 22.

  As a result, the images of the driver's seat 12 and the passenger seat 13 in the passenger compartment pass through the transparent windows 26a and 26b (FIGS. 3 and 4) of the cover 24 as light 30a and 30b, respectively, and the visual field side surfaces 36a and 36b of the prism 23. From the rear side 36c, and is emitted toward the lens system 22 from the rear side 36c. The image of the driver's seat 12 and the passenger's seat 13 in the passenger compartment that is incident on the left and right visual field side surfaces 36a and 36b of the prism 23 from the oblique direction is reflected once inside the prism 23. The image of the driver's seat 12 located on the left side when viewed from the side is emitted from the back surface 36c of the prism 23, passes through the lens system 22, and then enters the region 37 on the left side of FIG. The image of the passenger seat 13 positioned on the right side when viewed from 14 is emitted from the back surface 36 c of the prism 23, passes through the lens system 22, and then enters the region 38 on the right side in FIG. 2 of the image sensor 21. Therefore, the relative left-right relationship between the driver's seat 12 and the passenger seat 13 is equivalent to the actual left-right relationship as shown in FIG. However, since the respective images that have entered the field from the field side surfaces 36a and 36b of the prism 23 are captured by mirror image reversal by one-time reflection in the prism 23, the left and right areas of the image sensor 21 are captured. The left and right relations of the captured images 41 captured at 37 and 38 are opposite to the images of the driver's seat 12 and the passenger seat 13 in the actual vehicle interior.

  Here, in general, in order to detect the occupants of both the driver's seat 12 and the passenger seat 13, it is desired that the angle is about 45 ° to 82 ° from the horizontal, and a 74 ° convex lens is used as the lens system 22, for example, the material When the prism 23 of BK4 is used, a desired viewing range can be obtained by setting the apex angle of the prism 23 to 32 ° from the relationship between the glass refractive index of Snell's law and the incident angle.

  The image processing unit 15 performs contour extraction on the captured image 41 captured by the image sensor 21 of the imaging device 14, performs feature extraction and pattern recognition on the extracted contour, The degree of coincidence with the image is calculated.

  The determination unit 16 determines the presence or absence of an occupant for each of the driver seat 12 and the passenger seat 13 based on the degree of coincidence given from the image processing unit 15. The determination result here is transmitted to another in-vehicle electrical unit through a predetermined network such as an in-vehicle LAN (not shown), and is used, for example, for determining whether or not the airbag needs to be operated.

  Note that the image processing unit 15 and the determination unit 16 perform image processing on the captured video imaged by the imaging device 14, and determine the presence / absence of each passenger in the driver seat 12 and the passenger seat 13 based on the result of the image processing. Functions as an occupant presence / absence detection means.

  4 indicates a mounting board on which various electrical components in the instrument panel 11 are mounted. The image pickup device 21, the image processing unit 15, and the determination unit 16 of the occupant detection system 10. Etc. are implemented.

<How to use>
The usage method of the vehicle periphery visual recognition apparatus of the said structure is demonstrated. First, the images of the driver's seat 12 and the passenger seat 13 in the passenger compartment shown in FIG. 1 pass through the transparent windows 26a and 26b (FIGS. 3 and 4) of the cover 24 as the lights 30a and 30b. In this manner, the light enters the field side surfaces 36 a and 36 b of the prism 23, is reflected once by the opposite side surfaces 36 a and 36 b, and then enters the image sensor 21 from the back surface 36 c through the lens system 22. The image formed on the image sensor 21 at this time is as shown in FIG.

  As shown in FIG. 5, both the driver's seat 12 and the passenger seat 13 can be monitored simultaneously by using only a single image sensor 21.

  Here, as shown in FIG. 2, by setting the apex angle of the front end of the prism 23 (32 ° in the case of using the prism 23 made of BK4), it is reflected once in the prism 23 and passes through the lens system 22. An incident angle with respect to each of the visual field side surfaces 36 a and 36 b of the prism 23 effective for forming an image in an effective imaging area of the imaging device 21 is set as an angle range corresponding to the driver seat 12 and the passenger seat 13 when viewed from the prism 23. Therefore, the driver's seat 12 and the passenger's seat 13 are incident on the left and right regions 37 and 38 of the image sensor 21 with an image range as wide as possible.

  Therefore, when the captured image captured by the image sensor 21 is extracted by the image processing unit 15 and feature extraction and pattern recognition are performed on the extracted contour, the occupant detection system shown in FIG. The angle of light incident on the prism 23 is limited to the range of the images of the driver seat 12 and the passenger seat 13 and the image is incident on the effective imaging area of the image sensor 21 compared to the captured image (FIG. 7). Thus, the imaging field of view can be effectively used, and the above-described various image processing can be performed with the high-resolution captured image 41 obtained by capturing images of the driver seat 12 and the passenger seat 13 in a wide image range. Therefore, there is an advantage that the determination accuracy of the presence / absence of a passenger in the determination unit 16 is improved.

  Further, since the mounting substrate 42 for mounting various electrical components in the instrument panel 11 is also used as a substrate for mounting the image sensor 21, only the mounting substrate dedicated to the image sensor 21 is used separately. The number of components can be reduced as compared with the above, and the connection to the image processing unit 15 and the determination unit 16 that are occupant presence / absence detection means can be easily performed through the mounting board 42.

  Furthermore, the cover 24 can make the imaging device 21 and the prism 23 inconspicuous from the outside, and has an advantage that the aesthetic appearance can be improved.

  In the above-described embodiment, the occupant detection system that determines the presence or absence of occupants in the driver seat 12 and the passenger seat 13 has been described. However, the present invention may be applied to, for example, a device that detects the presence or absence of occupants in the rear seat. In this case, for example, the imaging device 14 may be installed on the ceiling of the passenger compartment to detect the presence or absence of an occupant in the two right and left seat areas of the rear seat.

  Further, not only the detection of the presence / absence of an occupant as described above, but also detection of the presence / absence of the occupant's seat belt, the detection of the driver's dozing operation, and the like may be performed together by image processing such as image recognition.

It is a figure which shows the compartment of the motor vehicle by which the passenger | crew detection system which concerns on one Embodiment of this invention is mounted. 1 is a schematic block diagram illustrating an occupant detection system according to an embodiment of the present invention. It is a front view which shows the instrument panel in which the passenger | crew detection system which concerns on one Embodiment of this invention was installed. It is sectional drawing which shows the instrument panel by which the imaging device of the passenger | crew detection system which concerns on one Embodiment of this invention is mounted. It is a figure which shows the image imaged by the image pick-up element of the passenger | crew detection system which concerns on one Embodiment of this invention. It is a figure which shows the compartment of the motor vehicle carrying the passenger | crew detection system of the proposal example. It is a figure which shows the image imaged on the image pick-up element of the passenger | crew detection system of a proposal example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Crew detection system 11 Instrument panel 11a Opening part 12 Driver's seat 13 Passenger's seat 14 Imaging device 15 Image processing part 16 Judgment part 21 Imaging element 22 Lens system 23 Prism 24 Cover 26a, 26b Transparent window 30a, 30b Light 36a, 36b Field of view side 36c Back side 41 Imaged image 1 Mounting board

Claims (5)

An occupant detection system for detecting whether or not an occupant is present at two predetermined boarding positions in a vehicle interior,
An imaging device for imaging both the boarding positions in the vehicle interior;
Occupant presence / absence detection means for performing predetermined image processing on the captured video imaged by the imaging device and determining the presence / absence of each occupant at each boarding position based on a result of the image processing,
The imaging device is
A single image sensor;
A prism in which an image of one of the boarding positions is incident on one surface, an image of the other boarding position is incident on the other surface, and both the images are reflected inside and condensed on the imaging element side. An occupant detection system. The occupant detection system according to claim 1,
The apex angle of the tip of the prism limits the range of the image incident on each surface of the prism so that the image incident on the imaging effective area of the imaging element is limited to the image at each boarding position. An occupant detection system set at an angle to perform. The occupant detection system according to claim 1 or 2,
The boarding position of the one is a driver's seat;
The other boarding position is a passenger seat;
An occupant detection system in which the imaging device is installed on an instrument panel in a vehicle cabin. The occupant detection system according to claim 3,
An occupant detection system in which the image sensor is mounted on a mounting board on which each electrical component in the instrument panel is mounted. The occupant detection system according to claim 3 or 4,
Transparent on which the image of one of the boarding positions is incident on the one surface of the prism and the other image of the boarding position is incident on the other surface of the prism. An occupant detection system further comprising a cover in which a window is formed to cover the imaging element and the prism so as not to be conspicuous from the outside.

Images