车灯线光源的优化设计

车灯的优化设计是求线光源的适当长度,使得亮区既有足够的亮度,又能照射到较大的区域,同时又能使得光源的功率极小.为此,本文采用了一种给定的设计规范,在此设计规范下,我们根据物理光学直射及反射原理,用逆光法,假设光线分别从B,C两点(在测试屏上的两个测试点)射出,经过灯罩反射后与线光源所在的线段相交,交点数记为NB,NC,其大小反映了该点光的亮度.为能求出适合的线光源长度L,将L从0开始以固定步长增大至30 mm(线光源的最大可能长度),分别计算NB和NC,由设计规范应有NB≥2NC.由此得L的取值范围3.11≤L≤3.94,并由功率的极小化求得L=3.94 mm.在L=3.94的情况下,我们绘出了反射光线在测试屏上的分布图.最后我们还对该设计规范的合理性作出了评价.

Line light of lamp turning excellent design

An actual problem of lamp design that we often met is described. According to the design norm that the subject gives, we convert it to a pure mathematics problem of searching the minimal value that has conditions, using the optical knowledge in physics and the knowledge of operation of vectors and algebra .Because the operation is so complicated, we make use of Matlab making program to search the minimal length of lamp in the actual solving progress. Then from the two dots in the minimal line light source's boundary, we can conform the outline of the reflection area in the testing screen, that is, the splicing area of the two dots reflecting on the revolving paraboloid of the reflector. According to the knowledge of the parameter equation of the revolving paraboloid and reflecting theorem in optics and so on, we can make use of Matlab drawing the outline of the reflecting edge.