JP4239031B2 - Elbow point detection method in the optical axis adjustment method of downward headlights - Google Patents

Description

  According to the present invention, in a light distribution pattern image on a screen surface projected with light from a downward headlight, an intersection (referred to as an elbow point) between a horizontal cut line and an oblique cut line constituting a cut line from a light / dark boundary point is predetermined. It is related with the optical axis adjustment method of a downward headlight which adjusts an optical axis according to whether it is settled in the inspection pass area | region.

  Conventionally, in the downward headlight optical axis adjustment method, the pixel group in the image processing technique is replaced with three sensor positions as shown in FIG. 3, and the three pixel groups at the respective positions are optically balanced. The horizontal and diagonal lines that pass through the position are horizontal cut lines and diagonal cut lines, and the intersection of these lines is the elbow point. .

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.
For example, Patent Documents 1, 2, and 3.
Japanese Patent No. 2058841 Japanese Patent No. 2778850 JP 2000-146761 A

  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. Although the basic invention was further improved and the invention of Japanese Patent Application No. 2005-355941 was developed, the optical axis adjustment method of the headlight with higher accuracy and stability that can correspond to the actual situation of the optical axis adjustment method of modern headlamps. Is to develop. In addition, for the recently developed Z-type lamp, a different criterion was added.

In view of this, the present invention has developed the following invention by improving 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 judged based on whether or not the optical axis is good. On the other hand, in the measurement method, the elbow point (EP) Improved the creation method. This is to be solved by a new optical axis measurement / adjustment method that is more accurate and stable.

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

The embodiment of the present invention will be described in detail with reference to FIGS. 2, 3, 4, and 5. The light distribution pattern image on the screen surface projected with the light from the downward headlight is a light / dark boundary line. A head that inspects and adjusts the optical axis depending on whether or not the intersecting elbow points are within a predetermined standard range by obtaining a horizontal light-dark boundary line (hereinafter referred to as a cut line) and an oblique cut line constituting the cut line. This is a light optical axis adjustment method in which the light intensity is set to the maximum value (set value) of the gradient of the light / dark boundary line of light distribution at a predetermined horizontal direction centering on a specific designated position in the horizontal cut line from the camera center position (V). Boundary points are obtained, and an average value or an approximate value is set to (A) from these light and dark boundary points, and an intersection (B) that intersects a horizontal oblique cut line from a position set in the vertical direction from the approximate value (A). Asking Or intersection (B) of when not retreive again, move the set position in the vertical direction up and down, 'find a new intersection (B)' intersection (B) to the intersection (B). A cut line is obtained from a light / dark boundary point at a plurality of points set from the intersection (B) in the same manner as a horizontal portion at a predetermined interval, and if the inclination is within a predetermined value, it is recognized as a Z-type downward ramp, In the case of a Z-type downward ramp, an oblique cut line is obtained by a method such as a least square method at a predetermined number of pixels on the oblique cut line from the intersection (B), and is set in the horizontal direction from the intersection (B). A horizontal cut line is obtained by a method such as a least square method at a predetermined interval of a specified number of pixels on the horizontal line around the intersection (D) intersecting with the horizontal cut line from (C), and the horizontal cut line and the diagonal obtained previously The “elbow point” is defined as the intersection of the cut lines, and the optical axis is adjusted so that the “elbow point” is within the standard range. It consists of over point "detection method.
However, if it is recognized that it is not a Z-shaped downward headlight (a light having a normal cut line), the diagonal cut line and the horizontal cut line are obtained by the variable three-point pixel group balance method in the designated pixel group. In the method of adjusting the optical axis of the downward headlight, the optical axis is adjusted so that the intersection point is the “elbow point” and the “elbow point” is within the standard range in the same manner as the Z-type downward light. This is a detection method of “point”.

  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 is composed of a first step (S1) to a fifteenth step (S15). ing.

  In the first step S1, as shown in FIG. 2, a predetermined horizontal interval (Y) centered on a specific position on the horizontal line is obtained from the camera center position (V).

  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, as shown in FIG. 2, the average value in the horizontal direction of the light and dark points at the interval (Y) or the approximate value (A) by the least square method is obtained.

  In the fourth step S4, an intersection that intersects the oblique bright / dark boundary line in the horizontal direction arbitrarily set in the vertical direction from the approximate value (A) is defined as (B).

  In the fifth step S5, if there is an intersection (B), the diagonal light / dark boundary line and the horizontal light / dark boundary line in the eighth step S8 are obtained by the three-point pixel group balance method at three positions as a normal downward ramp. For the Z-type downward lamp in which (B) may not be found, the process of the sixth step S6 is performed.

  In the sixth step S6, when the intersection (B) cannot be found, the point whose vertical direction is arbitrarily determined is moved up and down.

  In the seventh step S7, it is moved up and down, and the obtained intersection is obtained as (B) ′, which is newly designated as the intersection (B).

  In the eighth step S8, the ninth step 9, and the tenth step S10, if the inclination of the cut line is within a specified point at a plurality of points set at a predetermined interval from the intersection (B), it is recognized as a Z-type downward light.

  In the eleventh step S11, when a normal cut line light is used instead of a Z-type downward light, an oblique cut line and a horizontal cut line are obtained by a three-point pixel group balance method at three possible positions.

  In the twelfth step S12, when a Z-type downward light is recognized, an oblique cut line is obtained by a least square method or the like at a predetermined interval of the designated number of pixels on the oblique line from the intersection (B).

  In a thirteenth step S13, an intersection (D) intersecting the horizontal cut line is obtained from a position (C) set in the horizontal direction from the intersection (B), and the horizontal cut line is calculated by a least square method or the like from a predetermined pixel interval in the horizontal direction. Ask for.

  In the fourteenth step S14, an intersection point of the horizontal cut line and the previously obtained oblique cut line is set as an elbow point.

  In the fifteenth step S15, 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 adjustment method of the downward headlight according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 2, between 2.5 ° to 3.5 ° from the camera center position (y1 (Between and y2), a light / dark boundary point is obtained with a set value (maximum value) of the gradient of the light / dark boundary point, and an average value of this light / dark boundary point or an approximate value obtained by the least square method (at a position of 3.0 °) To obtain (A).

  The diagonal cut line is determined by the least-squares method with a maximum ± 0.5 ° variable width (between ± 32 dots) on the diagonal line from the point (B) where the diagonal line is cut horizontally from 0.5 ° on the position of (A). To do.

  However, if an oblique boundary line cannot be found, as shown in FIG. 1, 0.5 ° is lowered to 0.4 ° or 0.25 ° (set value) to obtain (B) ′ of the intersection (B) Let 'be a new intersection (B). Since the processing method of the Z-type downward lamp and the normal lamp is different, a plurality of points ((B) + 1.5 °, (B) + 2.0 °, (B ) + 2.5 °, (B) + 3.0 °) If the slope (a) of the light / dark boundary line is within the specified range (−2.8 ° ≦ (a) ≦ 2.8 °), the Z-shaped downward Let it be a light.

  (B) The horizontal cut line is determined by the least square method at intervals of ± 0.5 ° (± 32 dots) on the horizontal line from the point 4 ° in the horizontal direction from the point (C), and the intersection of the above oblique cut lines is the elbow. Let it be a point. The optical axis is adjusted so that the obtained elbow point falls within the standard range. However, in the case of a normal downward ramp due to the gradient of the light / dark boundary lines at a plurality of points, the oblique cut line and the horizontal cut line obtained by the three-point three-point pixel group balance method (variable width: 8.53 ° to 60 °). To determine the elbow point.

The down light measurement program is explained below. The processing routine for the down light measurement method is as follows.
(1) The maximum value (setting value) of the slope of each cutting illuminance curve at the horizontal direction designated pixel interval at ± 0.5 degree intervals [y1, y2] centered on a point 3 degrees to the right from the camera center position (V). Use a light / dark border. Let [A] be an approximate value obtained by a linear equation in the vertical direction of the bright and dark points between [y1, y2].
(2) A straight line is drawn in the horizontal direction at a position of 0.25 degrees above “A”, and the intersection with the oblique illuminance curve is set to “B”. Refer to FIG. 2. (3) The inclination “a” at positions of 1.5 degrees, 2 degrees, 2.5 degrees, and 3 degrees to the left from “B” is obtained. If a ≦ 2.8 degrees, it is determined that the Z beam light distribution. [FIG. 3] Reference <1> When it is determined that the light distribution is Z beam in (3).
1. The position 4 degrees to the right of “B” is taken as point C, and an approximate value “D” is calculated by a linear equation in the vertical direction of the light and dark points at an interval of ± 0.5 degrees to the left and right from point C. The intersection with the diagonal cut line is defined as the elbow point. Refer to [Figure 4]
<2> When it is determined in (3) that the light distribution is not Z beam distribution An oblique cut line is obtained from “B” by a least square method with a maximum ± 0.5 degree variable width, and its inclination b is calculated.
2. The values of the slope b are b <8.53 degrees, 8.53 degrees ≦ b <11.3 degrees, 11.3 degrees ≦ b <14.0 degrees, 14.0 degrees ≦ b <16.7 degrees, 16 .7 degrees ≦ b (which can be variably set) is determined, and the three points (G, H) on the left side of the diagonally cut portion of the balanced arrangement of the three-point pixel group at three positions that are variable according to the range , I) Change the position. See Fig. 5. Each pixel (5 × 5) while maintaining the image data position of 9 points of A, B, C, D, E, F, G, H, and I based on the determined sensor position of “G, H, I” The elbow point is obtained by detecting the point where the brightness of the minute total is the smallest in both left and right and top and bottom.
Left-right direction (DE)-(EF) + (GH)-(HI) = 0
Vertical direction (AB)-(BC) = 0
For a lamp such as a light distribution and a Z-beam light distribution in which the angle of the oblique part of the cut line greatly deviates from the standard 15 degrees, which cannot be supported by the conventional fixed three-position three-point pixel group balance method (FIG. 6), The above method is used as a measurement method that stably calculates equivalent measurement results.

  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) arranged behind the imaging lens (1), and a screen (3 arranged 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). .

About the downward light measurement program This invention has industrial applicability by establishing and actually using the technique of the elbow point detection method of the optical axis adjustment method of a headlight.

It is a flowchart which shows a processing routine. It is explanatory drawing which shows one Example of the optical-axis adjustment method of the headlight of this invention. It is explanatory drawing which shows one Example of the optical-axis adjustment method of the headlight of this invention. It is explanatory drawing which shows one Example of the optical-axis adjustment method of the headlight of this invention. It is explanatory drawing which shows one Example of this invention. It is explanatory drawing which shows the other Example of the usage method of this invention. (3-point balance system with 3 fixed positions) 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 Approximate value calculated | required by the average value or the least-squares method from the light-dark boundary point B A diagonal line in the horizontal direction from the position set up and down Intersection point B 'intersection point C Position set horizontally from the intersection point

Claims (2)

The light distribution pattern image on the screen surface projected with light from the downward headlight is a light / dark boundary line, and the cut line is a line that is averaged or approximated within a certain range of these light / dark boundary points. In the case of the horizontal direction, a horizontal light / dark boundary line, that is, a horizontal cut line, and in the case of the diagonal direction, a horizontal light / dark boundary line, that is, a diagonal cut line, is formed. This is a method for adjusting the optical axis of a headlight that checks and adjusts the optical axis based on whether or not these intersecting elbow points fall within a predetermined standard range, and is a horizontal cut from the camera center position (V). as the bright-dark limit point the contrast of the slope of the maximum value of the vertical light distribution (set value) in the horizontal direction by a predetermined distance range around the specified designated position in the line, which A plurality of light-dark boundary points determined at regular intervals in the range, and their average value or an approximate value point (A), in the horizontal direction from the position set in the upward direction from the point of near-cress (A) Find the intersection (B) that intersects the diagonal cut line, or if you cannot find the intersection (B), move the position set in the up direction again up and down to find the intersection (B) 'and find a new intersection (B ) ′ As the intersection (B), and a cut line is obtained from the light and dark boundary points at a plurality of points set from the intersection (B) in the same manner as the horizontal portion at a predetermined interval. In the case of a Z-type downward lamp, the diagonal cut line is obtained by the least square method at a predetermined interval of the designated number of pixels on the diagonal cut line from the intersection (B), and from the intersection (B). Set horizontally (C The intersection (D) that intersects the horizontal cut line is obtained by a method such as the least square method at a predetermined interval of the designated number of pixels on the horizontal line, and the intersection of the horizontal cut line and the previously obtained cut line is an elbow. An elbow point detection method in an optical axis adjustment method for a downward headlight, wherein the optical axis adjustment is performed so that the elbow point falls within a standard range. The light distribution pattern image on the screen surface projected with light from the downward headlight is a light / dark boundary line, and the cut line is a line that is averaged or approximated within a certain range of these light / dark boundary points. In the case of the horizontal direction, a horizontal light / dark boundary line, that is, a horizontal cut line, and in the case of the diagonal direction, a horizontal light / dark boundary line, that is, a diagonal cut line, is formed. This is a method for adjusting the optical axis of a headlight that checks and adjusts the optical axis based on whether or not these intersecting elbow points fall within a predetermined standard range, and is a horizontal cut from the camera center position (V). the maximum value of the brightness of the slope of the vertical light distribution in the horizontal direction by a predetermined interval around the specified designated position (setting value) as the light-dark boundary point in the line, these Average or approximated value (A) and to the near Nitinol intersection which intersects with the oblique cutoff line from (A) in the horizontal direction from the set position in the vertical direction from the plurality of light-dark boundary points determined at regular intervals in the circumference ( B), or if the intersection (B) cannot be found, the position set in the vertical direction is moved up and down again to find the intersection (B) ', and the new intersection (B)' is designated as the intersection (B) Then, a cut line is obtained from the light and dark boundary points at a plurality of points set from the intersection (B) in the same manner as the horizontal portion at a predetermined interval, and if the inclination is within a predetermined value, it is recognized as a Z-type downward ramp, and Z In the case of a mold downward ramp, an oblique cut line is obtained by a method of least squares at a predetermined interval of the designated number of pixels on the oblique cut line from the intersection (B), and the interval is set in the horizontal direction from the intersection (B). point than (C) Seeking new horizontal cut line by least square method the intersection (D) obtained new intersecting a horizontal cut line in the vertical direction at a predetermined interval specified number of pixels on the horizontal lines, diagonal obtained in the horizontal cut line in the previous If the intersection of the cut lines is an elbow point and the optical axis is adjusted so that the elbow point falls within the standard range, if it is recognized that the light has a normal cut line and is not a Z-type downward light The slant cut line and horizontal cut line are obtained by the three-point pixel group balance method that can be changed by setting in the designated pixel group, and the elbow point is within the standard range like the Z-type downward light with the intersection as the elbow point. The elbow point detection method in the optical axis adjustment method of the downward headlight, characterized in that the optical axis adjustment is performed so as to be within the range.

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