JP2007163149A - Elbow detection method in optical axis adjustment method of headlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable optical axis adjustment method of a headlight acquired by improving a technology developed already, capable of coping with an actual situation of a present optical axis adjustment method of the head lamp, and having higher accuracy. <P>SOLUTION: This method is characterized as follows: a horizontal line is determined from a balance position of a horizontal balancer and an inclined line is determined at a designated angle from a balance position of an inclined sensor as shown in figure 4 by a sensor system (figure 3) for performing optical axis adjustment so that three-spot sensors on designated coordinates are balanced; the intersection point thereof is used as a virtual elbow point, and the position of the virtual elbow point is defined as '0'; a light and shade boundary point is determined at a prescribed interval in the vertical direction by a set value of inclination of the light and shade boundary point; therefore an inclined cut line is determined in a range at a prescribed interval and a horizontal cut line is determined at a prescribed interval by a method for determining the light and shade boundary point (cut line) by an approximate expression (least-squares method); and an intersection point combined therefrom is determined to be an elbow point, and optical axis adjustment is performed so that the determined elbow point falls within a specification range. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, in the light distribution pattern image on the screen surface where light from a downward headlamp is projected, an intersection (called an elbow point) between a horizontal cut line and an oblique cut line that constitute a cut line that is a light / dark boundary point The present invention relates to a method for adjusting the optical axis of a downward headlight, in which the optical axis is adjusted depending on whether or not it falls within a predetermined inspection pass area.

Conventionally, in the method of adjusting the optical axis of the downward headlight, the pixel group in the image processing technique is replaced with three sensor positions as shown in FIG. 2, and the three pixel groups at each position are optically balanced. An optical axis adjustment method has been performed to determine whether or not the elbow point falls within a predetermined inspection pass area, with the horizontal line and the oblique line passing through the horizontal line as the horizontal cut line and the oblique cut line, and the intersection point thereof as the elbow point. For example, Patent Documents 1, 2, and 3.
Japanese Patent No. 2058841 Japanese Patent No. 2778850 JP 2000-146761 A

  However, in recent years, the headlamps themselves have changed with the times, and in particular, the angle of the oblique cut line is not only 15 degrees, but it can be, for example, 13 degrees, 17 degrees, Z type, HID lamps (xenon lamps, etc.) ) And LED lamps, etc., and the light axis adjustment method of the headlamp with higher accuracy has been demanded.

  Therefore, the present invention is based on the “headlight optical axis adjustment method” which is the invention of the Japanese Patent Application Laid-Open No. 2000-146761 (hereinafter referred to as a basic invention) developed by the applicant of the present invention. It is to further improve the basic invention and to develop a more accurate and stable headlight optical axis adjustment method that can cope with the actual situation of the optical axis adjustment method for modern headlamps.

In view of this, the present invention has developed the following two inventions by applying improvement means for the measurement part of the “headlight optical axis adjustment method” which is the basic invention.
One of them is that, in the adjustment method of the basic invention, according to claim 2 of the basic invention, “a standard range consisting of a predetermined rectangular area is set, and the elbow point (EP) is within this standard range. The optical axis adjustment method of the headlight according to claim 1, characterized in that the quality of the optical axis is determined according to whether or not the optical axis is good. On the other hand, the elbow point (EP) is used in the measurement method. Regarding the measuring means, the elbow point (EP) creation method described in “Claim 1” of the basic invention is improved, and it is intended to be solved by a new optical axis measurement and adjustment method that is more accurate and stable. is there.

  According to this invention, it corresponds to the light distribution specifications of various modern lamps, and eliminates the illusion of lights by oncoming vehicles in night driving of vehicles by measuring and adjusting the cut line detection of downward headlights with high accuracy. However, it has extremely beneficial effects such as how to minimize traffic accidents in society.

An embodiment of the present invention will be described in detail with reference to the drawings. A light distribution pattern using pixels (FIG. 3) corresponding to a sensor-type headlight tester that adjusts an optical axis so that three sensors at specified coordinates are balanced. In the image (Fig. 4), the horizontal balancer balance position is a horizontal line, the diagonal line is obtained at a specified angle from the balance position of the diagonal sensor, the intersection point of these is the virtual elbow point, the position of the virtual elbow point is "0", A light / dark boundary point is obtained at a predetermined interval in the vertical direction with a set value of the gradient of the light / dark boundary point, and a diagonal cut line within a predetermined interval by a method of obtaining a light / dark boundary point (cut line) by an approximate expression (least square method). The horizontal cut lines are obtained at predetermined intervals, and the intersection point connecting them is defined as the elbow point, and the obtained elbow point is within the standard range. An optical axis adjusting method of downward headlight and performing round so optical axis adjustment.

  When another embodiment of the present invention is described in detail with reference to the drawings, a light / dark boundary point is obtained with a set value of the light / dark boundary inclination of the light distribution at a predetermined horizontal direction centered on a specific position on the horizontal line from the camera center position. Two vertical intervals are set from the average value (A) in the vertical direction, which is the most stable in the horizontal direction than the center position between the intersections with the diagonal line or the approximate value (B) by the least square method The position (C) of a predetermined interval that is considered as the position is designated, and the average value of the light and dark boundary points at the predetermined interval or the approximate value by the least square method is set as the position (D) on the Y-axis of the elbow point. The half position of the obtained position (B) or the specified percentage (variable by setting the angle of the oblique line) is the elbow point X-axis position, and the elbow point position X-axis (B), Y-axis (D) The elbow point determined and within the standard range An optical axis adjusting method of downward headlight and performing round so optical axis adjustment.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flowchart showing an elbow point detection method in an optical axis adjustment method for a headlight according to the present invention, and this elbow point detection method includes first step S1 to sixth step S6.

In the first step S1, a commercially available sensor-type headlight tester is cross-checked in an image (on the image processing screen) obtained by capturing a light distribution pattern image on the screen surface projected with light from a downward headlamp. 3 so that the sensor position as shown in FIG. 3 corresponds to the pixel position (FIG. 4) and the sensor in the CCD camera system as shown in FIG.
Horizontal part (A−B) − (B−C) = 0,
Tilting part (DE)-(EF) + (GH)-(H-1) = 0
The digital arithmetic processing is performed so that each of the three positions [3 degrees R (R is a right meaning), 2 degrees L (L is a left meaning), 0.5 L), a horizontal line and a diagonal line passing therethrough Is the virtual elbow point, and this virtual elbow point is the “0” (origin) position.

  In the second step S2, in order to provide the virtual elbow point “0”, that is, the specified range in the horizontal direction to the right and the diagonal direction to the left from the camera center position (HV), for example, a position (X1 ) To a position (X2) of 1.5 degrees R at a predetermined interval in the vertical direction (for example, an interval of 2 degrees D (D means that it goes down) to 2 degrees U (where U means that it rises)). Set the boundary slope setting.

  In the third step S3, a predetermined interval in the vertical direction from the position (X1) of 3.5 degrees R (for example, an interval from 2 degrees D (D means lowering) to 2 degrees U (U means up)). ], A setting value (maximum point) of the gradient of the brightness brightness / dark boundary up to a position (X2) of 1.5 degrees R is obtained as the light / dark boundary point.

  In the fourth step S4, a light / dark boundary line is obtained from each horizontal pixel in the meantime by an approximate expression (least square method) to obtain a horizontal cut line (A1). (See Figure 4)

  Similarly, in the fifth step S5, the virtual elbow point “0” is set to (X3) 3.0 degrees L to 1.0 degrees L at a predetermined interval in the vertical direction (3 degrees D to 2 degrees U). The oblique cut line (A2) is obtained by the same method as that for the cut line (X4), and the intersection is defined as the elbow point (W1).

  In the sixth step S6, the optical axis is adjusted by the basic invention so that the elbow point (W1) falls within the standard range.

  Next, another preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a flowchart showing an elbow point detecting method in the optical axis adjusting method for a headlight according to the present invention. FIGS. 5 and 6 are elbow point detecting methods in the optical axis adjusting method for a headlight according to the present invention. This elbow point detection method is composed of the first step S1 to the tenth step S10.

  In the first step S1, as shown in FIG. 5 and FIG. 6, the set value of the gradient of the light / dark boundary of the light distribution at a predetermined horizontal direction (Y) centered on a specific position on the horizontal line from the camera center position (V). Find the light and dark boundary points.

  In the second step S2, the set value (maximum value) of the inclination of each cut illuminance curve is set as the light / dark boundary point at the horizontal direction designated pixel interval in the (Y) interval.

  In the third step S3, an average position in the horizontal direction of the light and dark points at the interval (Y) or an approximate value (A) by the least square method is obtained.

  In the fourth step S4, two designated points are obtained vertically upward from (A).

  In the fifth step S5, the obtained designated point is obtained in the left horizontal direction, and the point (X) that collides with the oblique illuminance curve is obtained.

  In the sixth step S6, the center position in the (X) interval or the approximate value (B) by the least square method is obtained.

  In the seventh step S7, (C) is obtained by a specified interval (setting variable depending on the angle of the oblique portion) that is considered to be most stable horizontally than (B).

  In an eighth step S8, an average value in the vertical (vertical) direction or an approximate value (D) by the least square method is obtained from the specified interval horizontally from (C), and this is used as the Y-axis coordinate of the elbow point.

  In the ninth step S9, the X-axis coordinate of the elbow point is set at a predetermined interval (variable by the angle of the oblique portion) that is considered to be most stable than (B).

  In the tenth step S10, the optical axis is adjusted so that the obtained elbow point falls within the standard range.

As described above, another embodiment of the optical axis adjusting method of the downward headlight according to the present invention will be described in detail with reference to the drawings. As shown in FIGS. A light / dark boundary point is obtained with a set value of the light / dark boundary inclination at a predetermined interval [e.g., horizontal reference point [y1, y2] having a width of ± 1 degree (1.5R to 3.5R) around the point (Y), The vertical average position (A) during this period is obtained. The intersection [x1, x2] between the two straight lines drawn at a predetermined interval (for example, 0.25 degrees and 0.5 degrees above) from (A) and the light-dark boundary point diagonal portion is obtained, and its left and right center position (B ) From the horizontal point [z1, z2] at a predetermined interval (for example, ± 1 degree in width) around the point (C) [see FIG. 6] at a predetermined interval in the right direction (for example, 3.5 degrees) ) To obtain the elbow point position in the Y-axis direction.
Further, the elbow point position in the X-axis direction is a position that is half the predetermined interval in the right direction of the obtained position (B) (for example, 3.5 degrees / 2 = 1.75 degrees above). The optical axis is adjusted so that the obtained elbow point falls within the standard range.

  Then, the optical axis adjusting device used in the optical axis adjusting method according to the present invention will be described. FIG. 7 shows the optical axis adjusting device according to the present invention. An imaging lens (1) provided on the axis C (lamp), a half mirror (2) disposed behind the imaging lens (1), and a screen (3) disposed behind the half mirror (2) ) And a photometric measurement substrate (4) arranged directly above the half mirror (2) and a CCD camera (5) for picking up a projected image of the screen (3) are installed inside the lens unit (6). .

  The present invention has industrial applicability by establishing and actually using the technique of the elbow point detection method of the optical axis adjustment method of the headlight.

It is a flowchart which shows one Example of the optical-axis adjustment method of the headlight of this invention. It is a flowchart which shows the other Example of the optical axis adjustment method of the headlight of this invention. It is an old type sensor layout explanatory drawing which shows the optical axis adjustment method used for this invention. It is a layout diagram in a CCD pixel showing an optical axis adjustment method used in the present invention. It is explanatory drawing which shows the other Example of this invention. It is explanatory drawing which shows the other Example of this invention. It is a schematic sectional drawing which shows the optical axis adjustment apparatus used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging lens 2 Half mirror 3 Screen 4 Photometric measurement board 5 CCD camera 6 Lens unit A Average value of an up-down direction B The center position between the intersections with an oblique line, or the approximate value by the least squares method C Most stable in a horizontal direction The position of the predetermined interval that is considered to be D

Claims (2)

  For the light distribution pattern image on the screen surface projected with the light from the downward headlamp, the horizontal and diagonal lines that make up the cut line that is the bright and dark boundary line are obtained, and these intersecting elbow points are within the specified standard range. This is a method for adjusting the optical axis of a headlight that checks and adjusts the optical axis depending on whether or not it fits, and corresponds to a sensor-type headlight tester that adjusts the optical axis so that the three sensors at the designated coordinates are balanced. In the light distribution pattern image, the horizontal balancer balance position is obtained from the horizontal line, the diagonal line is obtained from the balance position of the oblique sensor at a specified angle, and the intersection point of these is determined as a virtual elbow point. ”, And the light and dark boundary points are obtained at predetermined intervals in the vertical direction with the set value of the gradient of the light and dark boundary points. By calculating the light and dark boundary points, which are cut lines by multiplication, diagonal cut lines at a predetermined interval and horizontal cut lines at a predetermined interval are obtained, and the intersection point connecting them is specified as an elbow point, and the obtained elbow point is a standard. An elbow point detection method in an optical axis adjustment method for a headlight, wherein the optical axis adjustment is performed so as to be within a range.   For the light distribution pattern image on the screen surface projected with the light from the downward headlamp, the horizontal and diagonal lines that make up the cut line that is the bright and dark boundary line are obtained, and these intersecting elbow points are within the specified standard range. An optical axis adjustment method for a headlight that inspects and adjusts the optical axis according to whether or not it fits, and the inclination of the light / dark boundary of the light distribution at a predetermined horizontal direction centering on a specific position on the horizontal line from the camera center position. A light / dark boundary point is obtained with the set value, and two vertical intervals are set from the vertical average value (A), and the center position between the intersections with the diagonal line, or an approximate value (B ) Specify the position (C) at a predetermined interval that is considered to be the most stable in the horizontal direction, and use the average value of the light and dark boundary points at the predetermined interval or the approximate value by the least square method from the position as the Y axis of the elbow point. The elbow point X axis (B) is defined as the position (D) of the elbow point, and the specified ratio of the setting variable according to the half position of the obtained position (B) or the angle of the diagonal line. ), The Y-axis (D) is specified, and the optical axis adjustment is performed such that the obtained elbow point falls within the standard range.

Images