JP5126673B2 - Headrest position control device - Google Patents

Description

  The present invention relates to a headrest position control device that controls the vertical position of a headrest of a vehicle, for example.

2. Description of the Related Art Conventionally, a headrest control device that controls the vertical position of a headrest disposed in a vehicle to an appropriate position is known. For example, two sensors incorporated in a headrest, a drive device that is mounted in a backrest and moves the headrest up and down, and a signal from the sensor detects the position of the driver's head, and the headrest is in an optimal position An automatic headrest adjustment device is disclosed that includes a control circuit that adjusts so as to be (see Patent Document 1).
Japanese Utility Model Publication No. 63-79757

  However, in the headrest automatic adjustment device described in Patent Document 1, since the upper end position of the driver's head is detected by a sensor such as a reflective optical sensor, depending on the driver's hairstyle, hat wearing, etc. Since the detected upper end position of the driver's head changes, it may be difficult to adjust to an appropriate position. Further, since it is necessary to provide a sensor for detecting the upper end position of the driver's head, the manufacturing cost increases.

  This invention is made in view of the said situation, Comprising: It is providing the headrest position control apparatus which can control the vertical direction position of a headrest to an appropriate position. It is another object of the present invention to provide a headrest position control device capable of controlling the vertical position of the headrest to an appropriate position with a simple configuration.

  In order to achieve the above object, the present invention has the following features. A first invention is a headrest position control device for controlling a vertical position of a headrest of a vehicle, and both left and right end portions of the headrest and a driver's driver via a camera arranged in front of the driver. An image generation means for generating an image including a head, a position determination means for determining whether or not the position of the headrest in the vertical direction is appropriate based on the image generated by the image generation means, and the position And a position changing means for moving the headrest up and down to an appropriate position when it is determined by the determining means to be inappropriate.

  According to a second aspect of the present invention, in the first aspect of the invention, the headrest detection unit detects a vertical position of the headrest from the image generated by the image generation unit, and the position determination unit includes the headrest detection unit. Based on the detected vertical position of the headrest, it is determined whether or not the vertical position of the headrest is appropriate.

  In a third aspect based on the second aspect, the headrest detection means sets a boundary line with respect to the shading of the image on the side farther from the center line in the lateral direction of the face than the both ends in the lateral direction of the driver's face. The vertical position of the headrest is detected by detecting the vertical line segment.

  In a fourth aspect based on the third aspect, the headrest detection means is configured such that the vertical line segment is separated by approximately the same distance on the right side and the left side with respect to the center line in the horizontal direction of the face. Only when it is detected in the above, the line segment in the vertical direction is determined to be the both end positions in the horizontal direction of the headrest.

  In a fifth aspect based on the third aspect, the headrest detection means detects the vertical position of the headrest based on at least one of an upper end position and a lower end position of the vertical line segment.

  In a sixth aspect based on the second aspect, at least one of eyebrows, eyes, nose, mouth, and ears, which are feature points of the driver's face, is generated from the image generated by the image generation means. Feature point detecting means for detecting a vertical position of one facial feature point, wherein the position determining means is based on the vertical position of the facial feature point detected by the feature point detecting means; It is determined whether or not the position in the vertical direction is appropriate.

  In a seventh aspect based on the sixth aspect, the camera is disposed obliquely upward or obliquely downward with respect to the driver's head, and the feature points detected by the feature point detection means Position correction means for correcting the vertical position of the headrest detected by the headrest detection means with respect to the vertical position to the vertical position when the camera is disposed in front of the driver's head. The position determination unit determines whether the vertical position of the headrest is appropriate based on the vertical position of the headrest corrected by the position correction unit.

  In an eighth aspect based on the seventh aspect, the camera is disposed on the column cover so that the elevation angle can be changed.

  In a ninth aspect based on the eighth aspect, the position correction means determines the vertical position of the headrest detected by the headrest detection means based on the tilt angle of the column cover and the elevation angle of the camera. to correct.

  In a tenth aspect based on the first aspect, the camera is disposed for the purpose of detecting at least one of a driver's looking-aside state and an eye-closed state.

  According to the first aspect of the present invention, the image including both the left and right end portions of the headrest and the driver's head is generated via the camera disposed in front of the driver, and based on the generated image. Then, it is determined whether or not the position of the headrest in the vertical direction is appropriate. And when it determines with it not being appropriate, since a headrest is moved to an appropriate position to an up-down direction, the up-down direction position of a headrest can be controlled to an appropriate position.

  That is, it is determined whether or not the position of the headrest in the vertical direction is appropriate based on the images including both the left and right ends of the headrest and the head of the driver. Since it is possible to accurately determine whether or not there is, the vertical position of the headrest can be controlled to an appropriate position.

  According to the second aspect, the vertical position of the headrest is detected from the generated image, and it is determined whether the vertical position of the headrest is appropriate based on the detected vertical position of the headrest. Therefore, the vertical position of the headrest can be controlled to a more appropriate position.

  That is, for example, even when the driver or the like moves the vertical position of the headrest, the vertical position of the headrest is detected from the generated image, so that the accurate vertical position of the headrest can be detected. It becomes possible.

  According to the third aspect of the present invention, the vertical line segments constituting the boundary line with respect to the density of the generated image are arranged on the side farther from the horizontal center line of the face than the both ends of the driver's face in the horizontal direction. By detecting, the position of the headrest in the vertical direction is detected, so the accurate vertical position of the headrest can be detected.

  That is, boundary lines are generated at the both ends of the headrest in the left-right direction with respect to the density of the generated image. For example, in the case of a dark headrest, the inner side of the headrest is black and the outer side thereof is relatively white compared to the inner side, so that a boundary line is generated with respect to shading. Therefore, the vertical position of the headrest is detected by detecting the vertical line segment that forms this boundary line, so that the accurate vertical position of the headrest can be detected.

  According to the fourth aspect of the present invention, only when the vertical line segment is detected at a position that is separated by substantially the same distance on the right and left sides with respect to the center line in the horizontal direction of the face, Since the line segment in the direction is determined to be the both end positions in the left-right direction of the headrest, a more accurate vertical position of the headrest can be detected.

  In other words, since the driver's face is generally at a substantially central position in the left-right direction with respect to the headrest, the boundary line (= line segment in the vertical direction) relating to the shading of the image corresponding to the left and right end positions of the headrest is With respect to the center line in the left and right direction, the right and left sides are detected at substantially the same distance. On the other hand, other border lines (= vertical line segments, for example, decorations hung in the car) relating to the shading of the image are on the right and left sides with respect to the center line in the horizontal direction of the face. It is hardly detected at a position separated by substantially the same distance.

  Therefore, it is possible to prevent other boundary lines (such as decorations suspended in the vehicle) relating to the shading of the image from being erroneously determined to be the left and right end positions of the headrest. As a result, a more accurate vertical position of the headrest can be detected.

  According to the fifth aspect, since the vertical position of the headrest is detected based on at least one of the upper end position and the lower end position of the vertical line segment, a more accurate vertical position of the headrest is detected. be able to.

  That is, since the vertical line segment corresponds to the both end positions of the headrest in the left-right direction, the upper end position and the lower end position of the vertical line segment correspond to the upper end position and the lower end position of the headrest, respectively. Therefore, by detecting the vertical position of the headrest based on at least one of the upper end position and the lower end position of the line segment in the vertical direction, a more accurate vertical position of the headrest can be detected.

  According to the sixth aspect of the invention, from the generated image, the vertical direction related to at least one of the facial feature points of the eyebrows, eyes, nose, mouth, and ears that are the facial feature points of the driver. The position of is detected. Then, since it is determined whether or not the vertical position of the headrest is appropriate based on the vertical position of the detected facial feature point, the vertical position of the headrest is further controlled to an appropriate position. Can do.

  That is, since it is determined whether or not the vertical position of the headrest is appropriate based on the vertical position of the detected facial feature point, the vertical position of the headrest is determined based on the driver's hairstyle and hat. Therefore, it can be controlled to a more appropriate position without being affected by the wearing of the wearer.

  According to the seventh aspect, the camera is disposed obliquely above or obliquely below the driver's head, and the detected headrest is positioned relative to the vertical position of the detected feature point. The vertical position is corrected to the vertical position when the camera is disposed in front of the driver's head. Since it is determined whether or not the vertical position of the headrest is appropriate based on the corrected vertical position of the headrest, the vertical position of the headrest can be further controlled to an appropriate position.

  That is, for example, when the camera is disposed obliquely below the driver's head, the headrest is located farther from the camera than the driver's head. The position of the headrest in the vertical direction is a position below the actual position (= the position viewed from the front) with reference to the detected facial feature point (see FIGS. 3 and 4). Therefore, the detected vertical position of the headrest is corrected to the vertical position when the camera is disposed in front of the driver's head, and based on the corrected vertical position of the headrest, By determining whether or not the vertical position of the headrest is appropriate, the vertical position of the headrest can be further controlled to an appropriate position.

  According to the eighth aspect of the invention, since the camera is disposed on the column cover so that the elevation angle can be changed, the headrest can be used even when the tilt angle of the column cover (= tilt angle of the steering wheel) is changed. It is possible to generate an image including both left and right ends of the vehicle and the driver's head.

  According to the ninth aspect, since the detected vertical position of the headrest is corrected based on the tilt angle of the column cover (= the tilt angle of the steering wheel) and the elevation angle of the camera, the vertical direction of the headrest The position can be further controlled to an appropriate position (see FIGS. 3 and 4).

  According to the tenth aspect of the invention, since the camera is arranged for the purpose of detecting at least one of the driver's looking-aside state and the closed-eye state, the vertical position of the headrest is controlled to an appropriate position with a simple configuration. can do.

  That is, since the camera is disposed for the purpose of detecting at least one of the driver's looking-aside state and the closed-eye state, it is not necessary to dispose the camera for the purpose of controlling the position of the headrest. Therefore, the manufacturing cost can be reduced.

  Hereinafter, embodiments of a headrest position control device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of a configuration of a headrest position control device according to the present invention. As shown in FIG. 1, a position control ECU (Electronic Control Unit) 1 (= corresponding to a part of a headrest position control device) according to the present invention communicates with an input device 2 and an output device 3 as peripheral devices. Connected as possible.

  Here, with reference to FIG. 1, the peripheral device of position control ECU1 is demonstrated. First, the input device 2 will be described. The input device 2 includes a camera 21, a tilt angle sensor 22, and an elevation angle sensor 23. Here, the camera 21 is composed of a CCD (Charge Coupled Device) camera or the like disposed on the column cover 24 shown in FIG. 3, and captures images including both the left and right ends of the headrest and the driver's head. Is. Here, since the camera 21 is disposed on the column cover 24 shown in FIG. 3, it is disposed obliquely downward with respect to the driver's head. The camera 21 outputs the generated image information to the position control ECU 1.

  Furthermore, as shown in FIG. 3, the camera 21 is arranged so that the elevation angle α (the elevation angles α1 and α2 in FIG. 3) can be changed. Thus, since the camera 21 is arranged on the column cover 24 so that the elevation angle α can be changed, even when the tilt angle θ of the column cover 24 (= the tilt angle θ of the steering wheel) is changed, By changing the elevation angle α, an image including both ends of the headrest 33 in the left-right direction and the head M of the driver can be generated.

  In addition, the camera 21 is provided here for the purpose of detecting the driver's looking-aside state and the closed-eye state. Thus, since the camera 21 is disposed for the purpose of detecting the driver's looking aside state and the closed eye state, it is not necessary to dispose the camera 21 for the purpose of controlling the position of the headrest 33 (see FIG. 3). Therefore, the manufacturing cost for disposing the camera 21 can be reduced.

  The tilt angle sensor 22 (corresponding to a part of the position correction means) is a sensor that detects the tilt angle of the steering column 24 shown in FIG. 3 (tilt angle θ of the steering wheel 25 shown in FIG. 3). The elevation sensor 23 (corresponding to a part of the position correction means) is an elevation angle α (in FIG. 3, the elevation angle α1 in FIG. 3) relative to the center line of the steering column 24 shown in FIG. 3 (the one-dot chain line shown in FIG. 3). , Α2).

  Next, the output device 3 will be described with reference to FIG. The output device 3 includes a headrest ECU 31 and a lifting motor 32. The headrest ECU 31 (corresponding to a part of the position changing means) determines the vertical position of the headrest 33 (see FIG. 3) via the lifting motor 32 in accordance with an instruction from the position control ECU (position changing unit 16 described later). It is ECU which controls. The elevating motor 32 (corresponding to a part of the position changing means) is a motor that drives the headrest 33 (see FIG. 3) in the vertical direction in accordance with an instruction from the headrest ECU 31.

  Next, the functional configuration of the position control ECU 1 will be described with reference to FIG. The position control ECU 1 functionally includes an image generation unit 11, a headrest detection unit 12, a position correction unit 13, a feature point detection unit 14, a position determination unit 15, and a position change unit 16.

  The position control ECU 1 causes a microcomputer disposed in a proper position of the position control ECU 1 to execute a control program stored in advance in a ROM (Read Only Memory) or the like disposed in a proper position of the position control ECU 1. The microcomputer is caused to function as functional units such as the image generation unit 11, the headrest detection unit 12, the position correction unit 13, the feature point detection unit 14, the position determination unit 15, and the position change unit 16.

  The image generation unit 11 (corresponding to a part of the image generation means) is connected to both ends of the headrest 33 (see FIG. 3) in the left-right direction and the driver's head via the camera 21 disposed in front of the driver. This is a functional unit that generates image information including the part M.

  The headrest detection unit 12 (corresponding to a headrest detection unit) is a functional unit that detects the vertical position of the headrest 33 (see FIG. 3) from the image information generated by the image generation unit 11. Here, an example of a method for detecting the vertical position of the headrest 33 by the headrest detector 12 will be described with reference to FIG. FIG. 2A is an explanatory diagram illustrating an example of a method for detecting the vertical position of the headrest 33 by the headrest detection unit 12. The image P1 shown in the figure includes an image H1 of the headrest 33 and an image M1 of the driver's head.

  First, the headrest detection unit 12 is a vertical line segment that forms a boundary line with respect to the density of the image on the side farther from the horizontal center line LM0 of the face than the left and right end positions LM1 and LM2 of the driver's face ( LH1 and LH2 (hereinafter referred to as “end line segment”) are detected.

  Then, the headrest detection unit 12 calculates distances L1 and L2 between the center line LM0 of the left and right direction of the face and the end line segments LH1 and LH2, respectively, and when the distance L1 and the distance L2 substantially match (here, Only when the absolute value of the difference between the distance L1 and the distance L2 is less than a preset threshold value ΔL (for example, 30 mm), the end line segments LH1 and LH2 are positioned at both end positions of the headrest 33 in the left-right direction. It is determined that

  Further, the headrest detection unit 12 detects the position of the headrest 33 in the vertical direction based on the upper end position and the lower end position of the end line segments LH1 and LH2. Here, for example, the headrest detection unit 12 detects that the average position of the midpoints of the end line segments LH1 and LH2 is the center position of the headrest 33.

  In this way, the end line segment LH1, which forms the boundary line with respect to the density of the generated image, on the side farther from the horizontal center line LM0 of the face than the left and right end positions LM1, LM2 of the driver's face. By detecting LH2, the vertical position of the headrest 33 is detected, so that the accurate vertical position of the headrest 33 can be detected.

  That is, boundary lines are generated at both ends in the left-right direction of the headrest 33 with respect to the density of the generated image. For example, in the case of the dark headrest 33, the inner side of the headrest 33 is black, and the outer side thereof is relatively white compared to the inner side, so that a boundary line is generated with respect to shading. Therefore, since the vertical position of the headrest 33 is detected by detecting the vertical line segments (= end line segments LH1, LH2) constituting this boundary line, the accurate vertical position of the headrest 33 is detected. Can be detected.

  Only when the end line segments LH1 and LH2 are detected at positions separated by the same distance on the right and left sides with respect to the center line LM0 in the horizontal direction of the face, the end line segments LH1 are detected. , LH2 is determined to be the left and right end positions of the headrest 33, so that a more accurate vertical position of the headrest 33 can be detected.

  That is, since the driver's face is generally at the substantially central position in the left-right direction with respect to the headrest 33, the border lines (= end line segments LH1, LH2) relating to the shading of the image corresponding to the both end positions in the left-right direction of the headrest 33 ) Is detected at positions that are separated by substantially the same distance on the right and left sides with respect to the center line LM0 in the horizontal direction of the face. On the other hand, other border lines (= vertical line segments, for example, decorations hung in the car) relating to the shading of the image are on the right and left sides with respect to the center line in the horizontal direction of the face. It is hardly detected at a position separated by substantially the same distance.

  Accordingly, it is erroneously determined that other boundary lines (= vertical line segments, for example, decorations hung in the vehicle) relating to the shading of the image are the left and right end positions of the headrest 33. Therefore, the position of the headrest 33 in the vertical direction can be detected more accurately.

  Furthermore, since the vertical position of the headrest 33 is detected based on at least one of the upper end position and the lower end position of the end line segments LH1, LH2, a more accurate vertical position of the headrest 33 can be detected. .

  That is, since the end line segments LH1 and LH2 correspond to both the left and right positions of the headrest 33, the upper end position and the lower end position of the end line segments LH1 and LH2 correspond to the upper end position and the lower end position of the headrest 33, respectively. doing. Therefore, by detecting the vertical position of the headrest 33 based on at least one of the upper end position and the lower end position of the end line segments LH1, LH2, a more accurate vertical position of the headrest 33 can be detected. It is.

  A feature point detection unit 14 (corresponding to a feature point detection unit) detects, from the image generated by the image generation unit 11, each of eyebrows, eyes, ears, nose, and mouth, which are feature points of the driver's face. Is a functional unit that detects positions LM3 to LM7 in the vertical direction (see FIG. 2B).

  The position correction unit 13 (corresponding to a part of the position correction unit) is a headrest detection unit 12 with respect to the vertical positions LM3 to LM7 of the feature points detected by the feature point detection unit 14 (see FIG. 2B). It is a functional unit that corrects the vertical position of the headrest 33 detected by the above to the vertical position when the camera 21 is disposed in front of the driver's head M.

  Here, an example of a correction method by the position correction unit 13 will be described with reference to FIGS. 3 and 4. FIG. 3 is a side view showing an example of the influence on the image when the elevation angle α of the camera 21 is changed. As described above, the camera 21 is disposed on the column cover 24 so that the elevation angle α can be changed. 3A and 3B, the tilt angle of the column cover 24 (= tilt angle of the steering wheel 25) is constant (angle θ), and the elevation angle α is from the elevation angle α1 (see FIG. 3A). The case where the elevation angle α2 decreases (see FIG. 3B) will be described. Here, the viewing angle of the camera 21 is an angle (2 × φ).

  In addition, for the sake of convenience, the positions of the eyebrows, eyes, ears, nose, and mouth in the front-rear direction (left-right direction in the figure) that are the facial feature points and the front side of the headrest 33 are separated by a distance LP. And FIG. 4 is an explanatory diagram showing an example of an image when the elevation angle α changes. 4 (a) is an image in the case of FIG. 3 (a), FIG. 4 (b) is an image in the case of FIG. 3 (b), and FIG. It is an image when arrange | positioned in front with respect to the head M of. With reference to the headrest position H0 in the image when the camera 21 is disposed in front of the driver's head M, the headrest position H1 in the case of FIGS. 4 (a) and 4 (b). , H2 are detected below the position H0 by distances LQ1, LQ2, respectively.

That is, the position correction unit 13 corrects the vertical position of the headrest 33 detected by the headrest detection unit 12 upward by the distances LQ1 and LQ2, so that the camera 21 is in front of the driver's head M. It can correct | amend to the vertical direction position in the case of being arrange | positioned. Here, the distances LQ1 and LQ2 are obtained by the following equations (1) and (2), respectively, with reference to FIG.
LQ1 = LP × sin (θ + α1) (1)
LQ2 = LP × sin (θ + α2) (2)

In other words, the position correcting unit 13 first substitutes the tilt angle θ and the elevation angle α detected via the tilt angle sensor 22 and the elevation angle sensor 23 shown in FIG. LQ is calculated. Then, the position correction unit 13 corrects the vertical position of the headrest 33 detected by the headrest detection unit 12 upward by the calculated distance LQ, so that the camera 21 is in front of the driver's head M. Is corrected to the vertical position.
LQ = LP × sin (θ + α) (3)

  In this manner, the vertical position of the headrest 33 detected by the headrest detector 12 is corrected based on the tilt angle θ of the column cover 24 (= tilt angle θ of the steering wheel 24) and the elevation angle α of the camera 21. Therefore, the vertical position of the headrest 33 can be controlled to a more appropriate position (see FIGS. 3 and 4).

  Returning to FIG. 1 again, the functional configuration of the position control ECU 1 will be described. The position determination unit 15 (corresponding to a position determination unit) is a functional unit that determines whether the vertical position of the headrest 33 is appropriate based on the image generated by the image generation unit 11. Specifically, the position determination unit 15 detects the vertical position of the headrest 33 detected by the headrest detection unit 12 and corrected by the position correction unit 13, and the facial feature points detected by the feature point detection unit 14. Based on the vertical positions LM3 to LM7 (see FIG. 2B), it is determined whether or not the vertical position of the headrest 33 is appropriate.

  FIG. 5 is an explanatory diagram illustrating an example of a determination method by the position determination unit 15 (a first method illustrated in (a) and a second method illustrated in (b)). The end line segments LH1 and LH2 indicate the vertical position of the headrest 33 detected by the headrest detection unit 12 and corrected by the position correction unit 13. Here, for convenience, the line segment connecting the upper end positions of the end line segments LH1 and LH2 is the upper end position of the headrest 33, and the line segment connecting the lower end positions of the end line segments LH1 and LH2 is the lower end position of the headrest 33. The case where it is is demonstrated. The vertical positions LM3 to LM7 are the vertical positions of the facial feature points detected by the feature point detection unit 14.

  As shown in FIG. 5A, in the first determination method, the vertical positions LM3 to LM7 are all below the upper end position of the headrest 33 and above the lower end position of the headrest 33. This is a judgment. That is, when all the vertical positions LM3 to LM7 are detected, the position determination unit 15 determines that the vertical position LM3 of the eyebrows is below the upper end position of the headrest 33 and the vertical position LM7 of the mouth. Is above the lower end position of the headrest 33. When it is determined that this condition is satisfied, the position determination unit 15 determines that the vertical position of the headrest 33 is appropriate, and when it is determined that this condition is not satisfied, the headrest 33 is determined. It is determined that the vertical position of is not appropriate. Here, the position determination unit 15 determines whether or not the position of the headrest 33 in the vertical direction is appropriate by the first method.

  As shown in FIG. 5B, in the second determination method, first, the position determination unit 15 obtains an average vertical position LM8 of the vertical position LM4 of the eye and the vertical position LM6 of the nose. Then, the position determination unit 15 has a position separated from the vertical position LM8 upward by a preset distance LA below the upper end position of the headrest 33, and in advance downward from the vertical position LM8. It is determined whether or not the position separated by the set distance LA is above the lower end position of the headrest 33. When it is determined that this condition is satisfied, the position determination unit 15 determines that the vertical position of the headrest 33 is appropriate, and when it is determined that this condition is not satisfied, the headrest 33 is determined. It is determined that the vertical position of is not appropriate.

  Returning to FIG. 1 again, the functional configuration of the position control ECU 1 will be described. The position changing unit 16 (corresponding to a part of the position changing means) moves the headrest 33 to an appropriate position via the headrest ECU 31 and the lifting motor 32 when the position determining unit 15 determines that the position is not appropriate. It is a functional unit that moves up and down.

  Specifically, when the position determination unit 15 determines that the vertical position LM3 of the eyebrows is above the upper end position of the headrest 33, the position changing unit 16 starts from the vertical position LM3 of the eyebrows to the headrest 33. The distance to the upper end position is obtained, and the headrest 33 is raised by that distance. On the other hand, when the position determination unit 15 determines that the vertical position LM7 of the mouth is below the lower end position of the headrest 33, the position changing unit 16 changes the vertical position LM7 of the mouth from the lower end position of the headrest 33. Until the headrest 33 is lowered by that distance.

  FIG. 6 is a flowchart showing an example of the operation of the position control ECU 1 shown in FIG. First, the image generation unit 11 generates image information including both left and right end portions of the headrest 33 and the driver's head M (S101). Then, the headrest detection unit 12 detects the vertical position of the headrest 33 (S103). Next, the position correction unit 13 acquires the tilt angle θ and the elevation angle α via the tilt angle sensor 22 and the elevation angle sensor 23 (S105). Next, the position correcting unit 13 corrects the vertical position of the headrest 33 detected in step S103 based on the tilt angle θ and the elevation angle α acquired in step S105 (S107).

  Then, the feature point detection unit 14 detects the vertical positions LM3 to LM7 of the eyebrows, eyes, ears, nose, and mouth, which are the feature points of the driver's face (S109). Then, the position determination unit 15 determines whether the vertical position LM3 of the eyebrows is below the upper end position of the headrest 33 (S111). If it is determined that the position is below the upper end position of the headrest 33 (Yes in S111), the process proceeds to step S115. If it is determined that the position is not below the upper end position of the headrest 33 (= above the upper end position) (No in S111), the position changing unit 16 changes the upper end position of the headrest 33 from the vertical position LM3 of the eyebrows. The headrest 33 is raised by the distance up to (S113), and the process is terminated.

  If Yes in step S111, the position determination unit 15 determines whether the vertical position LM7 of the mouth is above the lower end position of the headrest 33 (S115). When it is determined that the position is above the lower end position of the headrest 33 (Yes in S119), the position determination unit 15 determines that the vertical position of the headrest 33 is in an appropriate position (S119), and the process ends. Is done. When it is determined that the position is not above the lower end position of the headrest 33 (= below) (Yes in S119), the position changing unit 16 causes the distance from the lower end position of the headrest 33 to the vertical position LM7 of the mouth. Only the headrest 33 is lowered (S117), and the process is terminated.

  FIG. 7 is a detailed flowchart showing an example of the headrest position detection process executed in step S103 of the flowchart shown in FIG. The following processing is all executed by the headrest detection unit 12. First, the left and right end positions LM1, LM2 of the face are determined (S201). Then, the vertical line segment (= end line segment) that forms the boundary line with respect to the density of the image on the side farther from the horizontal center line LM0 of the face than the left and right end positions LM1 and LM2 obtained in step S201. ) LH1 and LH2 are detected (S203). Next, a distance L1 between the left end line segment LH1 obtained in step S203 and the center line LM0 in the left-right direction of the face is obtained (S205). Next, a distance L2 between the right end line segment LH2 obtained in step S203 and the center line LM0 in the horizontal direction of the face is obtained (S207).

  Then, it is determined whether or not the absolute value of the difference between the distance L1 and the distance L2 is less than a preset threshold value ΔL (S209). If it is determined that it is not less than the threshold value ΔL (No in S209), the process returns to step S201, and the processes after step S201 are repeatedly executed. When it is determined that it is less than the threshold value ΔL (Yes in S209), the average position of the midpoints of the end line segments LH1 and LH2 is obtained (S211). And the average position calculated | required by step S211 is detected as a center position of the headrest 33 (S213), and a process is returned to step S105 shown in FIG.

  In this way, an image including both the left and right ends of the headrest 33 and the driver's head is generated via the camera 21 disposed in front of the driver, and the headrest is based on the generated image. It is determined whether or not the vertical position of 33 is appropriate. When it is determined that the headrest 33 is not appropriate, the headrest 33 is moved in the vertical direction to an appropriate position, so that the vertical position of the headrest can be controlled to an appropriate position.

  That is, since it is determined whether or not the position of the headrest 33 in the vertical direction is appropriate based on the image including both the left and right ends of the headrest 33 and the driver's head, the vertical position of the headrest 33 is determined. Since it is possible to accurately determine whether or not it is appropriate, the vertical position of the headrest 33 can be controlled to an appropriate position.

  Further, the vertical position of the headrest 33 is detected from the generated image, and it is determined whether the vertical position of the headrest 33 is appropriate based on the detected vertical position of the headrest 33. The vertical position of the headrest 33 can be controlled to a more appropriate position.

  That is, for example, even when the driver or the like moves the vertical position of the headrest 33, the vertical position of the headrest 33 is detected from the generated image, so the accurate vertical position of the headrest 33 is detected. It becomes possible to do.

  In addition, vertical positions LM3 to LM7 of the eyebrows, eyes, nose, mouth, and ears, which are feature points of the driver's face, are detected from the generated image. Then, based on the detected vertical positions LM3 to LM7 of the facial feature points, it is determined whether or not the vertical position of the headrest 33 is appropriate. Therefore, the vertical position of the headrest 33 is more appropriate. The position can be controlled.

  That is, since it is determined whether or not the vertical position of the headrest 33 is appropriate based on the vertical position LM3 to LM7 of the detected facial feature points, the vertical position of the headrest 33 is determined by the driver. Therefore, it can be controlled to a more appropriate position without being affected by the hair style, the wearing of a hat, and the like.

  Further, the camera 21 is disposed obliquely downward with respect to the driver's head, and the detected vertical position of the headrest 33 relative to the detected vertical position of the feature point is determined by the camera 21. It is corrected to the vertical position when it is arranged in front of the driver's head. Then, since it is determined whether or not the vertical position of the headrest 33 is appropriate based on the corrected vertical position of the headrest 33, the vertical position of the headrest 33 is further controlled to an appropriate position. Can do.

  That is, when the camera 21 is disposed obliquely below the driver's head, the headrest 33 is located farther from the camera 21 than the driver's head. The detected vertical position of the headrest 33 is a position below the actual position (= position viewed from the front) with reference to the detected facial feature point (see FIGS. 3 and 4). Therefore, the detected vertical position of the headrest 33 is corrected to the vertical position when the camera 21 is disposed in front of the driver's head, and the corrected vertical position of the headrest 33 is corrected. Based on this, by determining whether or not the vertical position of the headrest 33 is appropriate, the vertical position of the headrest 33 can be further controlled to an appropriate position.

The headrest position control device according to the present invention is not limited to the position control ECU 1 according to the above-described embodiment, and may be in the following form.
(A) In the present embodiment, the case where the position control ECU 1 controls the lifting motor 32 via the headrest ECU 31 has been described. However, the position control ECU 1 directly controls the lifting motor 32 without going through the headrest ECU 31. The form to do is also good.

  (B) In this embodiment, the position control ECU 1 functionally includes an image generation unit 11, a headrest detection unit 12, a position correction unit 13, a feature point detection unit 14, a position determination unit 15, a position change unit 16, and the like. Although the case where it is provided has been described, at least one functional unit among the image generation unit 11, the headrest detection unit 12, the position correction unit 13, the feature point detection unit 14, the position determination unit 15, and the position change unit 16 is an electric It may be configured by hardware such as a circuit.

  (C) In the present embodiment, the case where the headrest detection unit 12 detects the end line segments LH1 and LH2 has been described. However, the headrest 33 is changed (or added) to the end line segments LH1 and LH2. Alternatively, the left and right line segments indicating at least one of the upper end position and the lower end position may be detected. In this case, it is necessary to detect a line segment in the left-right direction that constitutes a boundary line in the vertical direction of the image. In this case, the upper end position and the lower end position of the headrest 33 can be directly detected.

  (D) In the present embodiment, the feature point detection unit 14 detects the vertical positions LM3 to LM7 of the eyebrows, eyes, ears, nose, and mouth that are the feature points of the driver's face. Although the case has been described, the feature point detection unit 14 may be configured to detect the vertical position of at least one feature point among the eyebrows, eyes, ears, nose, and mouth. For example, the feature point detection unit 14 may detect the vertical positions LM3 and LM7 of the eyebrows and the mouth. In this case, the processing by the feature point detection unit 14 is simplified.

  (E) In the present embodiment, the case where the position correction unit 13 performs correction based on the tilt angle θ and the elevation angle α detected via the tilt angle sensor 22 and the elevation angle sensor 23 has been described. At least one of θ and elevation angle α may use an estimated value. For example, the elevation angle α is obtained by estimating from the detected tilt angle θ on the assumption that the driver adjusts in advance so that his / her face is positioned at the approximate center of the image, and the position correction unit 13 obtains the elevation angle α. The correction may be performed based on the detected elevation angle α and the detected tilt angle θ. In this case, it is not necessary to provide the elevation angle sensor 23, and the manufacturing cost can be reduced.

  (F) Although the case where the camera 21 is disposed on the column cover 24 has been described in the present embodiment, it is disposed at other places (for example, in a meter hood, a meter panel, etc.). Form may be sufficient. In the case of being arranged at a fixed location such as in the meter panel, the correction processing by the position correction unit 13 is simplified.

  (G) In the present embodiment, the case where the camera 21 is disposed for the purpose of detecting at least one of the driver's looking-aside state and the eye-closed state has been described. However, the camera 21 has other purposes (for example, It may be arranged for the purpose of observing the driver's facial expression, the purpose of determining the driver's fatigue, and the like.

  The present invention can be applied to, for example, a headrest position control device that controls the vertical position of a vehicle headrest.

The block diagram which shows an example of a structure of the headrest position control apparatus which concerns on this invention Explanatory drawing explaining an example of the method of detecting the vertical position of the headrest by the headrest detection unit, and the vertical positions of the eyebrows, eyes, ears, nose, and mouth, which are feature points of the driver's face Illustration showing an example Side view showing an example of the effect on the image when the elevation angle α of the camera is changed The image figure which shows an example of the influence on the image when changing the elevation angle α of the camera Explanatory drawing explaining an example of the determination method by a position determination part. The flowchart which shows an example of operation | movement of position control ECU shown in FIG. Detailed flowchart showing an example of the headrest position detection processing executed in step S103 of the flowchart shown in FIG.

Explanation of symbols

1 Position control ECU (part of the headrest position control device)
11 Image generator (part of image generator)
12 Headrest detector (part of headrest detector)
13 Position Correction Unit (Position Correction Unit Means)
14 Feature Point Detection Unit (Feature Point Detection Unit Means)
15 Position determination unit (position determination means)
16 Position change part (a part of position change means)
2 Input equipment 21 Camera 22 Tilt angle sensor (part of position correction means)
23 Elevation angle sensor (part of position correction means)
24 column cover 25 steering wheel 3 output device 31 headrest ECU (part of position changing means)
32 Lifting motor (part of position changing means)
33 Headrest

Claims (7)

A headrest position control device for controlling a vertical position of a headrest of a vehicle,
Image generating means for generating an image including both ends of the headrest in the left-right direction and the driver's head via a camera disposed in front of the driver;
Headrest detection means for detecting the vertical position of the headrest from the image generated by the image generation means;
Position determining means for determining whether the vertical position of the headrest is appropriate based on the vertical position of the headrest detected by the headrest detecting means ;
If it is determined not proper by the position determining means, Bei example and a position changing means for moving the headrest, in the vertical direction to a proper position,
The headrest detection means detects a vertical line segment constituting a boundary line with respect to the shading of the image on the side farther from the lateral centerline of the face than the both lateral positions of the driver's face. A headrest position control device for detecting a vertical position of the headrest. The headrest detection means is provided only when the vertical line segment is detected at a position separated by the same distance on the right side and the left side with respect to the center line in the horizontal direction of the face. It determines that a line segment, which is both end positions in the lateral direction of the headrest, the headrest position control device according to claim 1. 2. The headrest position control device according to claim 1 , wherein the headrest detection unit detects a vertical position of the headrest based on at least one of an upper end position and a lower end position of the vertical line segment. A headrest position control device for controlling a vertical position of a headrest of a vehicle,
An image including both the left and right ends of the headrest and the driver's head is generated via a camera arranged in front of the driver and obliquely above or below the driver's head. Image generating means;
Headrest detection means for detecting the vertical position of the headrest from the image generated by the image generation means;
From the image generated by the image generation means, the vertical position of at least one of the facial feature points of the eyebrows, eyes, nose, mouth, and ears that are the facial feature points of the driver is detected. Feature point detecting means for
The vertical position of the headrest detected by the headrest detection unit with respect to the vertical position of the feature point detected by the feature point detection unit is arranged in front of the driver's head. and position correcting means for correcting the vertical position when there,
Based on the vertical position of the headrest corrected by the position correction means and the vertical position of the feature point of the face detected by the feature point detection means, whether the vertical position of the headrest is appropriate or not is determined. Position determining means for determining;
A headrest position control device comprising: a position changing unit that moves the headrest up and down to an appropriate position when the position determination unit determines that the position is not appropriate . The headrest position control device according to claim 4 , wherein the camera is disposed on the column cover so that an elevation angle can be changed. 6. The headrest position control device according to claim 5 , wherein the position correction unit corrects the vertical position of the headrest detected by the headrest detection unit based on a tilt angle of the column cover and an elevation angle of the camera. The camera is arranged for the purpose of detecting at least one of the inattentive state and the closed-eye state of the driver, the headrest position control device according to claim 1 or 4.

Images