A Fast Light Distribution Test Method for Vehicle Lamp Based on Imaging Principle & Study on the Inf

Udo Krueger ¹  刘小波² 周开亮²   陈德李²

（1. TechnoTeam BV GmbH, Germany；2. 光傲科技股份有限公司，上海 201101）

中文摘要：汽车前灯的空间光强分布性能通常通过转角型分布式光度计，在规定距离，进行扫描测试。这种测试方法不仅需要较大的测试空间（通常为25米测试距离），而且需要花费大量的时间（从几十分钟到几个小时）。随着国家法规以及整车厂对灯具质量的要求提高，急需快速的配光性能测试方法。本方法采用高精度的成像式亮度、色度计，实现了在几秒时间内对车灯配光的快速测试，并同时获得色度分布信息。

在本研究方法中，将前灯的光束直接照射在投影幕墙上，投射到幕墙上的光通量在墙上产生一个照度值，这样通过图像解析的亮度计得到该墙面的亮度分布。通过对该墙面及房间参数进行严格限制，并对各种影响测试结果精度的因素进行精确的标定，实现从亮度图像计算得到相应的照度分布以及光强分布。除此之外，可以得到任意平面的照度分布图（如路面照度分布，10米远处的投影屏照度分布等），也 可以得到半球空间的照度分布（就像ECE规定的25米半径的前照灯照度分布）。

在该测试方法中，进行近光灯测试时，系统的杂散光对测试结果的影响非常大，个别情况下，个别区域的误差超过80%。本方法通过对各种杂散光进行分析，并开发出一种杂散光修整的图像处理技术，实现了对近光灯的高精度测量。本测试方法通过缩束技术，可以大大缩小测试空间，满足产线一般工位的测试要求。通过对本方法的研究以及实际测试研究，开发出了成熟的系统标定技术以及杂散光修整技术，不仅实现了快速配光的测试要求，而且测试精度可以达到传统的分布式光度计的测试精度要求。

Abstract:The spatial light intensity distribution of car headlights is usually measuredby the Angle distributed photometer. This test method requires not only a largetest space (usually 25 meters) but also a large amount of time (from a fewminutes to a few hours).With the national regulations and the requirement ofthe whole vehicle factory to improve the quality of lamps and lanterns, it isurgently needed to test the light performance test. This method uses highprecision imaging brightness and colorimeter, and realizes the quick test oflight distribution in a few seconds, and obtains the color distributioninformation at the same time.

In this research method,the headlight beam irradiation on the projection curtain wall directly,projected on the walls of luminous flux has a illuminance value, so brightnessdistribution is obtained by the image resolution meter. Through the wall androom parameters are strictly limited, and the various factors influencing theaccuracy of the test results are accurate calibration, from the brightness ofthe image the corresponding illuminance distribution and intensity distributionis calculated. In addition, arbitrary plane illuminance distribution (such asroad illumination distribution, 10 meters projection screen illuminationdistribution, etc.), and hemisphere space illumination distribution (like ECEregulations of 25 meters radius distribution of light intensity of illumination)couldbe obtained.

In the test method, thestray light of the system is very important to the test results. In some cases,the error of the individual region is more than 80%.This method is used toanalyze all kinds of stray light, and develop a kind of image processingtechnology which has a kind of miscellaneous light finishing, and the highprecision measurement of the near-light is realized. The test method cangreatly reduce the test space and meet the test requirements of the productionline. Through the study of this method and practical testing research,developed a mature system calibration technology and stray light dressingtechnology, not only meet the fast light distribution test requirements, butthe test precision can reach the traditional distributed photometric testaccuracy.