JP2007253821A - Occupant imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant imaging device capable of eliminating the effect of the adjusting position of a steering column with a camera arranged thereon when imaging an occupant on a vehicle by using the camera. <P>SOLUTION: The occupant imaging device for imaging a driver of a vehicle seated in a driver's seat by a camera arranged on a position-adjustable steering column detects the adjusting position of the steering column, and detects the position of a headrest part of the driver's seat with the driver to be seated therein in the vehicle. The zooming ratio of the camera is changed, and its imaging range is changed according to the detected adjusting position of the steering column and the position of the headrest part in the vehicle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an occupant imaging apparatus, and more particularly to an occupant imaging apparatus suitable for imaging an occupant (especially a driver) riding in a vehicle with a camera disposed in a steering mechanism capable of adjusting the position.

2. Description of the Related Art Conventionally, there has been known an occupant imaging device in which a camera is disposed in a vehicle interior and an image of an occupant's face seated on a vehicle seat is captured by the camera (for example, see Patent Document 1). This imaging apparatus includes a seat position sensor that detects the position of a vehicle seat on which an occupant is seated, and measures the distance between the camera and the vehicle seat based on the output of the seat position sensor. Then, referring to a predetermined map, the zoom rate of the camera is set according to the distance between the distance-measured camera and the vehicle seat. Therefore, according to the conventional imaging device, the size of the occupant's face in the captured image captured by the camera can be kept constant regardless of the seating position of the occupant in the vehicle interior.
JP 2005-202786 A

  By the way, in the said conventional apparatus, a camera is a camera incorporated in the instrument panel, and is arrange | positioned in the position fixed beforehand in the vehicle interior. Therefore, the distance between the camera and the vehicle seat can be detected using only the seat position sensor that detects the position of the vehicle seat as described above.

  On the other hand, in a configuration in which the camera is disposed on a position adjustable steering column such as a tilt mechanism or a telescopic mechanism, the distance between the camera and the vehicle seat changes depending not only on the position of the vehicle seat but also on the position of the camera. To do. In this regard, in the configuration in which the distance between the camera and the vehicle seat is detected using only the seat position sensor for detecting the position of the vehicle seat as in the conventional device, the actual distance is the adjustment position of the steering column. Despite being affected, the detected value does not consider the effect, so the above distance may be erroneously detected, and as a result, the camera does not have the desired zoom rate, There may be a disadvantage that the size of the occupied occupant's face cannot be kept constant.

  The present invention has been made in view of the above points, and provides an occupant imaging device that eliminates the influence of the adjustment position of the steering column in which the camera is disposed when imaging a vehicle occupant using a camera. The purpose is to do.

  An object of the present invention is an occupant imaging device that images a vehicle occupant with a camera disposed in a position-adjustable steering mechanism, the steering mechanism position detecting means for detecting an adjustment position of the steering mechanism, and the steering mechanism position. This is achieved by an occupant imaging device comprising imaging range changing means for changing the imaging range of the camera in accordance with the adjustment position of the steering mechanism detected by the detecting means.

  In the invention of this aspect, the imaging range of the camera arranged in the position-adjustable steering mechanism is changed according to the adjustment position of the steering mechanism. In this case, it is possible to keep the size of the object displayed in the camera captured image constant regardless of the adjustment position of the steering mechanism in the image. Therefore, according to the present invention, when the vehicle occupant is imaged using the camera, the influence of the adjustment position of the steering mechanism in which the camera is disposed can be eliminated.

  The occupant imaging device described above further includes seat position detecting means for detecting the position of the vehicle seat on which the vehicle occupant is seated, and the imaging range changing means adjusts the steering mechanism detected by the steering mechanism position detecting means. If the imaging range of the camera is changed according to both the position and the position of the vehicle seat detected by the seat position detection means, both the adjustment position of the steering mechanism and the position of the vehicle seat Regardless of the size of the object projected on the camera image, it can be kept constant in the image. Therefore, when the vehicle occupant is imaged using the camera, the steering mechanism in which the camera is arranged is used. Both the influence of the adjustment position and the influence of the seat position of the vehicle occupant can be eliminated.

  In this case, the seat position detecting means detects the position of the headrest portion of the vehicle seat, and the imaging range changing means is the adjustment position of the steering mechanism detected by the steering mechanism position detecting means, and the seat position. What is necessary is just to change the imaging range of the said camera according to both the position of the said headrest part detected by a detection means.

  In the above occupant imaging device, the imaging range changing unit may change the zoom rate of the camera.

  In the above-described occupant imaging device, the imaging range changing unit may change an optical axis direction of the camera with respect to the steering mechanism.

  In the above-described occupant imaging device, the imaging range changing unit may change a range in which image processing is performed in the entire captured image captured by the camera.

  By the way, in the above-described occupant imaging device, the face direction of the vehicle occupant may be detected by processing a captured image captured by the camera.

  According to the present invention, when a vehicle occupant is imaged using a camera, the influence of the adjustment position of the steering mechanism in which the camera is disposed can be eliminated.

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

  FIG. 1 is a configuration diagram of a system including an occupant imaging device 10 mounted on a vehicle according to an embodiment of the present invention. FIG. 2 shows the mounting structure of the in-vehicle camera of this embodiment. 2A shows a view when viewed from the side of the vehicle, and FIG. 2B shows a view when viewed in the direction of arrow III shown in FIG. 2A. Show. FIG. 3 is a diagram schematically showing the position of the object whose position is detected in this embodiment.

  The occupant imaging device 10 of the present embodiment captures a vehicle driver seated on a vehicle seat with a single in-vehicle camera, and the system of the present embodiment processes an image captured by the in-vehicle camera to process the vehicle. This is a system that detects the direction in which the driver's face is facing and performs predetermined vehicle control based on the detection result. The occupant imaging device 10 includes a camera 12 for photographing mainly the head of a vehicle driver sitting on a driver seat in the vehicle. The camera 12 is disposed on a column upper cover 18 that covers a shaft portion of a steering column 16 having a steering wheel 14 on which a vehicle driver performs a steering operation.

  The camera 12 is a single unit together with an infrared projector associated with the camera 12 that enables the camera 12 to take a picture at night by irradiating the head of the vehicle driver sitting on the driver's seat with infrared light. It should just be stored in the case. The infrared projectors may be LED lamps that are provided in the camera case on the left and right sides of the camera 12 and project infrared light toward the vicinity of the vehicle driver's head. In this case, the same number of infrared projectors are provided on both the left and right sides of the camera 12 so that the illuminance by the infrared light on the face can be made equal to the left and right when the vehicle driver is facing the front (when not looking aside), As a result, it becomes easy to detect a characteristic part such as the driver's face width and face center line from the camera-captured image even at night, and the driver's face orientation angle can be accurately detected.

  The steering column 16 has a tilt mechanism for the vehicle driver to arbitrarily set the operation position of the steering wheel 14 in the vehicle in the vertical direction, and the operation position of the steering wheel 14 in the vehicle front-rear direction ( Specifically, it has a telescopic mechanism for setting arbitrarily in the axial direction of the shaft portion. The tilt mechanism has a vertical position of the steering wheel 14 around the fixed point O on the axis of the steering column 16, that is, an angle toward the shaft portion of the steering column 16 within a predetermined range (for example, 15 mm above and below from the neutral position). It is configured to be adjustable. Further, the telescopic mechanism is configured so that the position of the steering wheel 14 in the axial direction can be adjusted within a predetermined range (for example, 20 millimeters forward and backward from the neutral position).

  The part where the camera 12 is disposed on the column upper cover 18 is included in the movable range by the operation of the tilt mechanism and is included in the movable range by the operation of the telescopic mechanism. Further, the position of the camera 12 on the upper surface of the column upper cover 18 is as much as possible from the viewpoint of ensuring a clearance between the camera case and the surface of the combination meter 20 effective for absorbing shocks in the event of a vehicle collision. The wheel 14 side is desirable. The combination meter 20 is visible to a vehicle driver sitting on the driver's seat through an opening 14a that opens in a fan shape on the surface of the steering wheel 14. The vehicle driver operates the tilt mechanism and the telescopic mechanism so that the driving posture for gripping the steering wheel 14 is maintained in a desired state, and the combination meter 20 is visible through the opening 14a.

  The camera 12 is arranged such that the camera optical axis center is positioned on a vertical line passing through the center O of the steering wheel 14. The camera 12 has a camera angle of view that is directed obliquely upward from the installation position through the opening 14a on the surface of the steering wheel 14 so as to face the vehicle traveling direction and the driver's head (face) is present. In addition, it is possible to photograph the driver's face almost from the front. Further, the camera 12 has a zoom function for enlarging or reducing the captured image by changing the focal length continuously or stepwise by moving its constituent lens, and the zoom rate can be changed.

  A camera ECU 24 as a control device is connected to the camera 12. A captured image as a video signal captured by the camera 12 is supplied to the camera ECU 24. The camera ECU 24 is mainly composed of a computer, and as will be described in detail later, the driver's head or face (specifically, its line of sight) is in front by processing a captured image supplied from the camera 12. An angle from the direction (face orientation angle) is detected. Further, as will be described later, the camera ECU 24 changes the zoom rate of the camera 12 based on the linear distance between the camera 12 and the head of the vehicle driver.

  An inter-vehicle control ECU 26 mainly composed of a computer is communicatively connected to the camera ECU 24. The inter-vehicle control ECU 26 uses an obstacle sensor such as a millimeter wave radar or a laser radar disposed on a bumper or a front grill at the front end of the vehicle body, for example, to detect the vehicle existing in front of the host vehicle (especially on the course of the host vehicle). While detecting the presence or absence of a front obstacle that should be most carefully noted when the vehicle travels, when such a front obstacle exists, the distance between the host vehicle and the front obstacle, and the detected distance and a vehicle speed sensor are used. The relative speed between the two is detected based on the detected vehicle speed, and the collision between the host vehicle and the front obstacle is predicted based on the result.

  Information about the face direction angle of the vehicle driver described later detected by the camera ECU 24 is supplied to the inter-vehicle control ECU 26. The inter-vehicle control ECU 26 ascertains the face orientation angle θ, which is the direction in which the driver faces, based on the information on the driver's face orientation angle supplied from the camera ECU 24, and according to the face orientation angle θ. To correct the collision prediction between the vehicle and the obstacle ahead. The inter-vehicle control ECU 26 appropriately drives the display display and the buzzer according to the collision prediction result between the host vehicle and the front obstacle to alert the vehicle driver about the collision with the front obstacle, or warns the driver. The vehicle brake is activated to control the distance from the front obstacle (preceding vehicle).

  A tilt / telescopic position sensor 30, a first seat position sensor 32, a second seat position sensor 34, and a headrest position sensor 36 are connected to the inter-vehicle control ECU 26 via a CAN bus 28. The inter-vehicle control ECU 26 and the position sensors 30 to 36 each have a CAN communication device, and exchange information according to the communication protocol of the CAN bus 28 using the CAN communication device.

  The tilt / telescopic position sensor 30 is disposed on the steering column 16 whose position can be adjusted by a tilt mechanism and a telescopic mechanism. The tilt column and the telescopic position sensor 30 are adjusted positions of the steering column 16 in the vehicle, that is, operation positions around the axis of the steering wheel 14 (specifically, Outputs a signal corresponding to the front-rear-up / down-position on the XY plane. The first seat position sensor 32 is disposed between the driver's seat 38 and the rail of the vehicle interior floor, and outputs a signal corresponding to the position in the front-rear direction of the seat portion 38a of the driver seat 38 relative to the vehicle interior floor. The second seat position sensor 34 is disposed between the seat portion 38a and the backrest portion 38b of the driver's seat 38, and the angle of the backrest portion 38b with respect to the seat portion 38a (that is, front and rear at the upper end portion of the backrest portion 38b). A signal corresponding to the direction position is output. The headrest position sensor 36 is disposed between the backrest portion 38b and the headrest portion 38c of the driver seat 38, and the position of the headrest portion 38c with respect to the backrest portion 38b (specifically, its angle and height). A signal corresponding to both of the above is output. The output signals of the position sensors 30 to 36 are supplied to the inter-vehicle control ECU 26, respectively.

  The inter-vehicle control ECU 26 detects the adjustment position of the steering column 16 by the tilt mechanism and the telescopic mechanism based on the output signal of the tilt / telescopic position sensor 30 and determines the operation position (X1, Y1) in the vehicle at the center of the axis of the steering wheel 14. At the same time, based on the output signal of the first seat position sensor 32, the front-rear direction position X2 of the seat portion 38a of the driver's seat 38 with respect to the vehicle floor is detected. The inter-vehicle distance control ECU 26 also detects the position in the front-rear direction of the upper end portion of the backrest portion 38b with respect to the seat portion 38a based on the output signal of the second seat position sensor 34, and the detected value and the driver seat 38 described above. Based on the front-rear direction position X2, the front-rear direction position X3 at the upper end of the absolute backrest 38b in the vehicle is detected. The inter-vehicle control ECU 26 further detects the position of the headrest portion 38c relative to the backrest portion 38b based on the output signal of the headrest position sensor 36, and the detected value and the position X3 in the front-rear direction at the upper end portion of the backrest portion 38b described above. Based on this, the absolute position (X4, Y2) of the headrest portion 38c in the vehicle is detected. The inter-vehicle distance control ECU 26 transmits information on each detected position to the camera ECU 24.

  Next, the operation of the system of this embodiment will be described.

  In the system of this embodiment, the camera 12 disposed on the upper surface of the column upper cover 18 of the steering column 16 is oriented in the direction in which the face of the vehicle driver sitting on the driver seat 38 exists. Shoot. A captured image as a video signal captured by the camera 12 is supplied to the camera ECU 24.

  The camera ECU 24 performs image processing such as binarization processing and feature point extraction processing on the captured image input from the camera 12. Then, the vehicle driver's face width and face centerline are extracted from the captured image, and the left / right distance ratio of the driver's face projected on the captured image is calculated from those detection parameters, and the left / right distance ratio Then, the face orientation angle θ from the front direction is detected with reference to a cylindrical model prepared in advance. Information on the detected driver's face orientation angle θ is supplied from the camera ECU 24 to the inter-vehicle distance control ECU 26.

  The inter-vehicle control ECU 26 first detects a front obstacle that should be most noticed when the host vehicle travels using an obstacle sensor. When detecting the presence of a front obstacle, the vehicle is currently in front of the front obstacle based on the distance and relative speed with the front obstacle, the course of the host vehicle, the position of the front obstacle with respect to the course, and the like. Calculate the possibility of collision with. The shorter the time it takes for the host vehicle to collide with the front obstacle, the higher the possibility of the collision. Therefore, the possibility of collision calculated by the inter-vehicle control ECU 26 depends on the distance between the host vehicle and the front obstacle. The value corresponding to the time obtained by dividing by (collision prediction time) may be used. In this case, the value becomes larger as the collision prediction time is shorter. When the calculated possibility of collision reaches a predetermined level, a warning for avoiding collision is given from that point to at least the time of occurrence of a collision, or a forced vehicle brake is activated to obstruct the forward obstacle. Control the distance between vehicles.

  Each time the information on the driver's face orientation angle θ is supplied from the camera ECU 24, the inter-vehicle control ECU 26 compares the face orientation angle θ with the threshold value θ0. This threshold value θ is determined by the driver looking at the inner mirror, the outer mirror on the driver's seat or the passenger's seat, the display on the passenger compartment, or visually checking the outside of the vehicle for safety confirmation on the left and right sides of the vehicle. This is a boundary value of the face orientation angle for determining whether or not the side look is removed from the front direction, and is set to ± 15 °, for example.

  As a result of the comparison, when θ ≦ θ0 is established, it can be determined that the driver's face is substantially facing the front. Therefore, when the collision possibility between the host vehicle and the front obstacle is calculated, the collision Compare possibilities to normal baseline levels. In this case, when the own vehicle and the front obstacle have a relatively high possibility of collision, the above-described alarm and inter-vehicle distance control are performed. On the other hand, when [theta]> [theta] 0 is established, it can be determined that the driver's face is not facing the front direction, so that the possibility of a collision with a front obstacle should be reached when starting the above-described alarm or inter-vehicle control. Is reduced from the above reference level, and the collision probability between the host vehicle and the obstacle ahead is calculated, and the collision possibility is compared with the level reduced from the reference level. In this case, the above-described alarm and inter-vehicle distance control are performed even when the host vehicle and the front obstacle have a relatively low possibility of collision.

  As described above, according to the system of the present embodiment, it is possible to take an image of the vehicle driver sitting on the driver's seat 38 by the camera 12 disposed on the steering column 16 in the occupant imaging device 10. Further, before the vehicle collides with an obstacle ahead, in order to avoid a collision or reduce damage, a warning is given by a buzzer or a display, or a distance control is performed by forced braking. In the situation where it is determined that the driver's face is not facing the front as a result of the image processing of the captured image by the vehicle, it can be started earlier than the timing in the situation where the driver is determined to be facing the front .

  FIG. 4 is a diagram for explaining inconveniences that may occur when the camera 12 is disposed on the position-adjustable steering column 16. By the way, the camera 12 disposed on the steering column 16 whose position (in particular, the axial position of the shaft portion thereof can be adjusted by the telescopic mechanism) and the head (specifically, the face) of the vehicle driver as the subject. The relative distance varies depending not only on the position of the driver seat 38 in the vehicle but also on the adjustment position of the steering column 16, that is, the position of the camera 12 itself.

  If the zoom ratio of the camera 12 is fixed and the imaging range is fixed in advance, even when the vehicle driver is the same person, when the relative distance is relatively short (FIG. 4A). As shown in FIG. 4B, when the size of the face occupied in the camera-captured image is relatively large and the relative distance is relatively long (FIG. 4C), the face is shown in FIG. As described above, since the face size occupied in the camera-captured image is relatively small, the face size cannot be kept constant in the camera-captured image. In this regard, in such a configuration, when detecting the face direction angle θ of the vehicle driver from the camera captured image, the image processing must be performed independently regardless of the individual camera captured image, and the processing load increases. The angle may be difficult to detect.

  In order to solve such a problem, it is conceivable to detect the relative distance from the position of the driver's seat 38 in the vehicle and change the zoom ratio of the camera 12 according to the relative distance. However, in the configuration in which the relative distance is detected using only the position of the driver's seat 38, the relative distance is actually influenced by the adjustment position of the steering column 16 in which the camera 12 is disposed. Since the detection value does not consider the influence, a situation may occur in which the relative distance between the camera 12 and the head of the vehicle driver is erroneously detected. As a result, the zoom ratio of the camera 12 does not become a desired value. There is a possibility that the size of the driver's face in the camera captured image may not be kept constant.

  On the other hand, in the occupant imaging device 10 of the present embodiment, the relative distance between the camera 12 and the vehicle driver's head including the adjustment position of the steering column 16 is detected with high accuracy, and according to the relative distance. The imaging range is changed by changing the zoom rate of the camera 12. Hereinafter, the characteristic part of the present embodiment will be described with reference to FIGS. FIG. 5 is a diagram showing, as a map, the relationship between the linear distance L between the camera 12 and the vehicle driver's head and the zoom ratio Z of the camera used in the occupant imaging device 10 of the present embodiment. FIG. 6 shows a flowchart of an example of a control routine executed by the camera ECU 24 in the occupant imaging device 10 of the present embodiment.

  In the present embodiment, using the position sensors 30 to 36, the operation position (X1, Y1) of the steering wheel 14 in the vehicle, the longitudinal position X2 of the seat portion 38a of the driver seat 38 in the vehicle, the driver seat 38 A position X3 in the front-rear direction of the upper end portion of the backrest portion 38b and a position (X4, Y2) of the headrest portion 38c of the driver seat 38 are detected. These pieces of position information are transmitted to the camera ECU 24 via the inter-vehicle distance control ECU 26. The camera ECU 24 grasps each position described above based on the transmission information (step 100).

  The camera 12 is disposed at a predetermined position on the upper surface of the column upper cover 18 of the steering column 16. The camera ECU 24 stores in advance information defining the relative positional relationship between the axial center position of the steering wheel 14 and the position where the camera 12 is disposed (specifically, the position of the optical axis center). The camera ECU 24 refers to the relative positional relationship stored in this information, and based on the operation position (X1, Y1) of the steering wheel 14 in the vehicle as grasped as described above, the absolute position (XY plane) of the camera 12 in the vehicle. (Above) is calculated (step 102).

  In general, the head of the vehicle driver who sits on the driver's seat 38 is often present at a position predetermined with respect to the position of the headrest portion 38c of the driver's seat 38. The camera ECU 24 stores in advance position information of the head of the vehicle driver (specifically, the center of the face or the mouth) that is estimated to exist with respect to the position of the headrest portion 38c. In general, as the position of the seat portion 38a of the driver's seat 38 is closer to the rear of the vehicle, it can be determined that the driver has a larger physique, and a driver with a larger physique has a higher seat height. Can be judged. Further, as the backrest portion 38b of the driver seat 38 is tilted, the gap between the driver's head and the headrest portion 38c tends to increase. In view of this point, the position of the head of the vehicle driver with respect to the position of the headrest portion 38c stored in the camera ECU 24 is changed according to the position of the seat portion 38a in the vehicle, and the backrest is also changed. It is good also as changing according to the angle of the part 38b. Based on the position (X4, Y2) of the headrest portion 38c in the vehicle that has been grasped as described above, the camera ECU 24 refers to the positional relationship stored in this information, and the absolute position of the head of the vehicle driver in the vehicle ( (On the XY plane) is estimated (step 102).

  Based on the position of the camera 12 calculated as described above and the position of the head of the vehicle driver estimated as described above, the camera ECU 24 calculates a linear distance L between the two (step 104). In order to keep the face size of the same driver in the camera captured image constant regardless of the linear distance L, it is appropriate to increase the zoom ratio of the camera 12 as the linear distance increases. The camera ECU 24 stores in advance a map as shown in FIG. 5 that defines the relationship between the linear distance L between the camera 12 and the head of the vehicle driver and the zoom rate Z of the camera 12. This map is defined in such a relationship that the face size in the camera captured image is constant regardless of the linear distance between the camera 12 and the vehicle driver's head, and the longer the linear distance is, The zoom rate of the camera 12 is set to be large.

  The camera ECU 24 refers to the map shown in FIG. 5 above, and based on the linear distance L between the camera 12 and the position of the vehicle driver's head calculated as described above, the zoom rate Z of the camera 12 to be realized. Is set (step 106). When the zoom ratio Z is set in this way, an instruction is given to the camera 12 so that the zoom ratio Z is realized (step 108). When such an instruction is given from the camera ECU 24, the camera 12 subsequently performs imaging at the instructed zoom rate Z.

  Thus, in the occupant imaging device 10 of this embodiment, the adjustment position of the steering column 16 by the tilt mechanism and the telescopic mechanism in the vehicle, and the position of the driver seat 38 (specifically, the headrest portion 38c) in the vehicle Based on the above, the linear distance L between the camera 12 disposed on the steering column 16 and the head of the vehicle driver sitting on the driver seat 38 can be calculated. Then, according to the calculated linear distance L between the camera 12 and the vehicle driver's head, the camera angle of view can be adjusted by automatically changing the zoom rate of the camera 12.

  That is, according to both the adjustment position of the steering column 16 and the position of the driver's seat 38, the zoom ratio of the camera 12 can be automatically changed to change the imaging range. The shorter the linear distance L is, the more specifically, the more the steering column 16 is located in the vehicle rear side and the vehicle upper side in the vehicle by the tilt mechanism and the telescopic mechanism, or the driver seat 38 is in the vehicle front side than in the vehicle. The smaller the zoom rate, the smaller the zoom factor is set, and the captured image in which the subject reflected in the screen is reduced (expanded as the imaging range) can be acquired, and as the linear distance L is longer, Specifically, the zoom ratio increases as the steering column 16 is positioned further forward and lower in the vehicle or the driver seat 38 is positioned further rearward in the vehicle by the tilt mechanism and the telescopic mechanism. Set and obtain a captured image in which the subject displayed on the screen is enlarged (the imaging range is reduced) Door can be.

  According to such a configuration, the size of the face of the vehicle driver (particularly the face of the same driver) displayed in the camera-captured image is determined regardless of the linear distance between the camera 12 and the head of the vehicle driver in the image. That is, it can be kept constant regardless of the position of the driver's seat 38 (specifically, its headrest 38c) and regardless of the adjustment position of the steering column 16. Therefore, according to the occupant imaging device 10 of the present embodiment, it is possible to eliminate the influence of the adjustment position of the steering column 16 in which the camera 12 is disposed when imaging the vehicle driver using the camera 12. At the same time, it is possible to eliminate the influence of the seat position of the vehicle driver.

  Thus, if the size of the face of the vehicle driver projected on the camera captured image is kept constant in the image, each part of the face reflected on the captured image (face edge, above eyebrows, under the eyes, clefts, etc.) Therefore, in order to detect the face orientation angle θ of the vehicle driver from the camera-captured image, it is possible to perform image processing in association with each camera-captured image. For example, the image processing range of the camera-captured image when the camera ECU 24 extracts the edge of the face of the vehicle driver is reduced to the range where the face is expected to be projected according to the processing result of the previous camera-captured image. Or, using the face width of the vehicle driver extracted from the previous camera-captured image, it is possible to extract two edge lines whose distance is substantially the same as the face width as lines constituting the face edge. It becomes.

  Therefore, according to the present embodiment, it is possible to reduce the image processing load for detecting the face orientation angle θ of the vehicle driver from the camera captured image, and to improve the detection accuracy of the face orientation angle θ. It is possible.

  In the above-described embodiment, the steering column 16 is in the “steering mechanism” described in the claims, and the driver seat 38 on which the driver is seated is in the “vehicle seat” in the claims. The face orientation angle θ from the direction corresponds to the “face orientation direction” described in the claims, and the camera ECU 24 detects the adjustment position of the steering column 16 and describes the claims in the claims. The "steering mechanism position detecting means" detects the position (X4, Y2) in the vehicle of the headrest portion 38c of the driver's seat 38, so that the "seat position detecting means" described in the claims is According to the claims, the zoom ratio Z of the camera 12 is changed in accordance with the linear distance L to the head of the vehicle driver to change the imaging range. "Imaging range changing means" is realized, respectively.

  By the way, in the above embodiment, the linear distance between the camera 12 and the head of the driver of the vehicle changes depending on the adjustment position of the steering column 16 in the vehicle (particularly the position in the vehicle longitudinal direction by the telescopic mechanism) and the position of the driver seat. Then, in view of the possibility that the size of the driver's face reflected in the camera-captured image may not be kept constant, the adjustment position of the steering column 16 and the driver seat 38 are adjusted so that the size is kept constant. The imaging range for the interior of the vehicle is changed by changing the zoom rate of the camera 12 according to both the position and the camera angle of view.

  However, the present invention is not limited to this, and the imaging direction of the camera 12 in the vehicle changes depending on the adjustment position of the steering column 16 in the vehicle (particularly the vehicle vertical direction position by the tilt mechanism). Therefore, the direction of the optical axis of the camera 12 with respect to the steering column 16 is changed according to the adjustment position of the steering column 16 so that the face of the driver may not be reflected. The imaging range for the steering column 16 may be changed. According to such a modified example, the face of the vehicle driver who is the subject of the camera 12 can always be displayed near the center of the camera-captured image regardless of the adjustment position of the steering column 16. It is possible to eliminate the influence of the adjustment position of the steering column 16 in which the camera 12 is disposed when imaging the vehicle driver using the vehicle, and the vehicle from the camera-captured image resulting from the position adjustment of the steering column 16 can be eliminated. It is possible to prevent the undetected face of the driver.

  In the above embodiment, the angle of view of the camera 12 can be changed by changing the zoom ratio to change the imaging range in hardware. However, the method of changing the camera imaging range is limited to this. Instead, the angle of view of the camera 12 is fixed in advance, and the size and position of the image processing range is appropriately changed in the entire captured image to change the imaging range of the camera 12 in software. It may be obtained. Also in this modified example, it is possible to obtain the same effect as the above-described embodiment.

  In the above embodiment, the information on the vehicle driver's face orientation angle θ detected using the captured image of the camera 12 is used to correct the collision prediction between the host vehicle and the front obstacle. However, the present invention is not limited to this, and a system that issues an alarm simply according to the magnitude of the face orientation angle θ from the front direction, that is, when the face orientation angle θ is equal to or smaller than a predetermined angle. However, it may be used in a system that issues a warning to the vehicle driver when the face orientation angle θ exceeds a predetermined angle.

  In the above-described embodiment, the vehicle driver's face orientation angle θ is detected by performing image processing on the captured image of the camera 12, but the driver's state detected using the captured image of the camera 12 is the face orientation. It is not limited to the angle θ, and it may be one that detects a line-of-sight direction facing the eyes, a facial expression, blinking, lack of extension, dozing, etc. on the driver's face. Further, the vehicle user may be authenticated based on the state of each part of the driver's face.

  Further, in the above embodiment, the position sensors 30 to 36 are connected to the CAN bus 28 and the output signals thereof are supplied to the inter-vehicle distance control ECU 26 to detect the positions, and the information on the positions is obtained. The system for supplying the distance from the inter-vehicle control ECU 26 to the camera ECU 24 is used. However, the present invention is not limited to this, and the position sensors 30 to 36 are directly connected to the camera ECU 24 so that the information on each position is stored in each system. It may be supplied directly from the position sensors 30 to 36 to the camera ECU 24. Further, after forming one communication network with all the position sensors 30 to 36, the communication network and a communication network including the face-facing ECU 24 (may be via the inter-vehicle control ECU 26 as in this embodiment). The information may be supplied to the camera ECU 24 through the gateway by connecting via a gateway.

1 is a configuration diagram of a system including an occupant imaging device according to an embodiment of the present invention. It is a figure which shows the mounting structure of the vehicle-mounted camera which a present Example has. It is the figure which represented typically the position of the object by which a position is detected in a present Example. It is a figure for demonstrating the inconvenience which may arise when a camera is arrange | positioned at the steering column which can adjust a position. It is the figure which represented the relationship between the linear distance L of the camera and vehicle driver's head used in the passenger | crew imaging device of a present Example, and the zoom rate Z of a camera as a map. It is a flowchart of an example of the control routine performed in the passenger | crew imaging device of a present Example.

Explanation of symbols

10 occupant imaging device 12 camera 24 camera ECU
30 Tilt / Telescopic Position Sensor 32 First Seat Position Sensor 34 Second Seat Position Sensor 36 Headrest Position Sensor 38 Driver's Seat

Claims (7)

An occupant imaging device that images a vehicle occupant with a camera disposed in a position-adjustable steering mechanism,
Steering mechanism position detecting means for detecting an adjustment position of the steering mechanism;
An imaging range changing unit that changes an imaging range of the camera in accordance with an adjustment position of the steering mechanism detected by the steering mechanism position detecting unit;
An occupant imaging device comprising: A seat position detecting means for detecting the position of the vehicle seat on which the vehicle occupant is seated;
The imaging range changing unit is configured to capture an image of the camera in accordance with both the adjustment position of the steering mechanism detected by the steering mechanism position detection unit and the position of the vehicle seat detected by the seat position detection unit. The occupant imaging device according to claim 1, wherein the range is changed. The seat position detecting means detects a position of a headrest portion of the vehicle seat;
The imaging range changing unit is configured to capture an image of the camera in accordance with both the adjustment position of the steering mechanism detected by the steering mechanism position detection unit and the position of the headrest portion detected by the seat position detection unit. The occupant imaging device according to claim 2, wherein the range is changed.   The occupant imaging device according to any one of claims 1 to 3, wherein the imaging range changing unit changes a zoom rate of the camera.   5. The occupant imaging device according to claim 1, wherein the imaging range changing unit changes an optical axis direction of the camera with respect to the steering mechanism.   The occupant imaging device according to any one of claims 1 to 5, wherein the imaging range changing unit changes a range in which image processing is performed in the entire captured image captured by the camera.   The occupant imaging device according to any one of claims 1 to 6, wherein a direction in which a vehicle occupant faces is detected by processing a captured image captured by the camera.

Images