METHOD FOR DETECTION OF ELBOW POINTS IN A LIGHT AXIS ADJUSTING METHOD OF DOWNWARD HEADLIGHT

摘要

A method for detection of elbow points in a light axis adjusting method of a downward headlight is provided to accurately detect and adjust the cut line of the downward headlight according to various backlight specifications. A method for detection of elbow points in a light axis adjusting method of a downward headlight includes the steps of: calculating a predetermined horizontal interval with respect to a specific position on a horizon from a camera center position(S1); determining a set value of each cut illumination curve inclination as a brightness boundary point at an interval of a horizontal direction designated pixel in the interval(S2); calculating an approximate value in the horizontal direction average of a brightness point or according to a least squares method(S3); determining a point crossing an inclination brightness boundary line as an intersection point(S4); determining the inclination brightness boundary line and a horizontal brightness boundary line by a three point pixel group balance method in case that the intersection point exists(S5); vertically moving a point with determined up/down directions in case that the intersection point does not exist(S6); determining an intersection point and a new intersection point(S7); recognizing as z type downward light in case that the inclination of a cut line in a plurality of points is within a designated range(S8); determining a slope cut line and a horizontal cut line(S11); determining the slope cut line by the least squares method(S12); determining an intersection point and the horizontal cut line(S13); determining the intersection point of the slope cut line and the horizontal cut line as an elbow point(S14); and adjusting the light axis so that the elbow point is within a predetermined range(S15).