JP2007212429A - Elbow point detection method in optical axis adjustment method of headlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical axis adjustment method of a headlight that is improved from a prior invention, can respond to the actual condition of the optical axis adjustment method of a present head lamp, has higher accuracy, and is stable. <P>SOLUTION: In this elbow point detection method in the optical axis adjustment method of a downward-pointing headlight, light-dark boundary points are determined, based on a set value of the gradient of the light-dark boundary of light distribution in a horizontal predetermined interval from the camera center position to a specific position in a horizontal line as the center, an approximate value A is determined from these light-dark boundary points by the average value or least squares method, an intersection B is determined that crosses the oblique line horizontally from the position set vertically from A, the oblique line is determined by the least squares method at a predetermined interval of the specified number of pixels on the oblique line, the horizontal line is determined by the least squares method from a predetermined pixel interval on the horizontal line about the position C set horizontally from the intersection B, the intersection of the horizontal line and the previously determined oblique line, and the optical axis adjustment is performed so that the elbow point is within a standard 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. 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. Another object of the present invention is to develop an optical axis adjustment method for a Z-type lamp that has been developed in recent years, to which a criterion different from that of a conventional lamp is added.

In view of this, the present invention has been developed with the following measures taken 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 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 FIG. 1. With respect to a light distribution pattern image on a screen surface projected with light from a downward headlamp, a horizontal light / dark boundary line constituting a light / dark boundary line and an oblique line This is a headlight optical axis adjustment method that determines the light / dark boundary line and checks and adjusts the optical axis based on whether or not these intersecting elbow points fall within the specified standard range. A light / dark boundary point is obtained from the set value of the gradient of the light / dark boundary of the light distribution at a predetermined horizontal direction centered on a specific designated position on the line, and an approximate value (A If the intersection (B) that intersects the oblique light / dark boundary line in the horizontal direction from the position set in the vertical direction from the approximate value (A) is obtained, or if the intersection (B) cannot be found, Move the position set in the vertical direction up and down to find the intersection (B) ′, find the light and dark boundary point in the same way as the horizontal part at a predetermined interval from the intersection (B) ′, If the slope of the connected light / dark boundary is within a predetermined value, it is recognized as a Z-type light distribution, this recognition is used for Z-type display, and the intersection (B) ′ is set as a new Z-type intersection (B). If so, an oblique light / dark boundary line is obtained by a least square method at a predetermined interval of the designated number of pixels on the oblique line from the intersection (B), and the position (C) set in the horizontal direction from the intersection (B) is the center. Next, a horizontal light / dark boundary line is obtained by a least square method from a predetermined pixel interval on the horizontal line, and an intersection of the horizontal light / dark boundary line and the previously obtained diagonal light / dark boundary line is defined as an elbow point so that the elbow point falls within the standard range. Downward headlight characterized by optical axis adjustment The detection method of the elbow point in the optical axis adjusting method.

  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 eleventh step (S11). 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 position in the horizontal direction of the light and dark points in 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, when there is an intersection (B), the diagonal light / dark boundary line in the eighth step S8 is usually obtained as a downward ramp. In the Z-type downward ramp, the intersection (B) may not be found. The process of 6th 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, an oblique bright / dark boundary line is obtained by the least square method at a predetermined interval of the designated number of pixels on the oblique line from the intersection (B).

  In a ninth step S9, a horizontal light / dark boundary line is obtained by a least square method from a predetermined number of pixels in the horizontal direction around the position (C) set in the horizontal direction from the intersection (B), that is, an interval of 32 dots.

  In the tenth step S10, the intersection of the horizontal light / dark boundary line and the previously obtained diagonal light / dark boundary line is set as an elbow point.

  In an eleventh step S11, the optical axis is adjusted so that the obtained elbow point falls within the standard specification 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 FIG. The light / dark boundary point is determined with the set value (maximum value) of the gradient of the light / dark boundary point at the interval of y2), and the average value of the light / dark boundary point or the approximate value (at the position of 2.5 °) determined by the least square method. (A) is obtained.

  A diagonal light / dark boundary line (cut line) is determined by a least-squares method between ± 32 dots on the diagonal line from the point (B) at which the diagonal line is cut horizontally from 0.5 ° on the position (A).

  However, if a diagonal light / dark boundary line cannot be found, as shown in FIG. 3, 0.5 ° is lowered to 0.4 ° or 0.25 ° (set value) to obtain the intersection (B) ′ (B ) ′ Is a new intersection (B).

  (B) A horizontal light / dark boundary line is determined by a least-squares method at intervals of ± 32 dots on the horizontal line from the point (C) 4 ° in the horizontal direction from the point (C), and an intersection of the oblique light / dark boundary lines is defined as an elbow point. 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. 4 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 explanatory drawing which shows one Example of the usage method of this invention. It is explanatory drawing which shows the other Example of the usage method 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 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 Intersecting point B 'intersecting point C Position set horizontally from the intersecting point

Claims (1)

  For the light distribution pattern image on the screen surface projected with the light from the downward headlamp, the horizontal light and dark boundary lines and the diagonal light and dark boundary lines constituting the light and dark boundary lines are obtained, and these crossed elbow points are A headlight optical axis adjustment method that inspects and adjusts the optical axis depending on whether or not it falls within a predetermined standard range, at a predetermined horizontal direction centered on a specific designated position in a horizontal light / dark boundary line from the camera center position. The light / dark boundary point is obtained from the set value of the gradient of the light / dark boundary of the light distribution, and the average value or the approximate value (A) obtained from the light / dark boundary point by the least square method is set, and the vertical value is set from the approximate value (A). Find the intersection (B) that intersects the diagonal light / dark boundary line in the horizontal direction from the position or if you can not find the intersection (B), again move the position set in the vertical direction up and down again, A point (B) ′ is obtained, and a light / dark boundary point is obtained at a predetermined interval from the intersection (B) ′ by the same method as the horizontal portion, and the slope of the light / dark boundary line connecting the light / dark boundary points is within a predetermined value. If the recognition is used as a Z-type light distribution, this recognition is used for Z-type display, and the intersection (B) ′ is a new Z-type intersection (B). Otherwise, the designated pixel on the diagonal line from the intersection (B) An oblique bright / dark boundary line is obtained by a least square method at a predetermined interval of a number, and horizontal by a least square method from a predetermined pixel interval on the horizontal line with the position (C) set in the horizontal direction from the intersection (B) as a center. A downward headlight characterized in that a light / dark boundary line is obtained, an intersection of the horizontal light / dark boundary line and the previously obtained oblique light / dark boundary line is defined as an elbow point, and the optical axis is adjusted so that the elbow point falls within a standard range. Of elbow point in optical axis adjustment method

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