基于遗传算法的自由曲面优化设计  

Design of Freeform Surface Based on the Genetic Algorithm

作　　者：李登高[1,2] 殷松峰[1,2] 凌永顺[1,2] 杨华[1,2] 解震[1] 陶会锋[1,2] 

机构地区：[1]电子工程学院红外与低温等离子体安徽省重点实验室,合肥230037 [2]脉冲功率激光技术国家重点实验室,合肥230037

出　　处：《光子学报》2014年第11期73-79,共7页Acta Photonica Sinica

基　　金：安徽省优秀青年科技基金(No.1308085JGD05);教育部新世纪优秀人才支持计划(No.NCET-09-0322)资助

摘　　要：为解决传统点光源近似设计方法难以满足实际应用需求的问题,基于遗传算法提出了一种面向扩展光源的自由曲面优化设计方法.该方法以虚拟点光源的辐射分布函数、原点位置偏移量及目标面尺寸因子等参数作为优化对象,首先对种群中任意个体根据能量守恒定律及Snell定律建立并求解偏微分方程,得到对应于该组虚拟参数的自由曲面,然后以实际扩展光源进行光线追迹,并综合考虑目标面照度均匀度和系统传输效率得到个体适应度,据此对种群进行选择、交叉和变异,直至优化结果满足设计要求.设计了发散半角为10°的均匀照明系统,光源采用直径为30mm的圆盘朗伯源,在Trace/pro环境下与传统设计方法进行对比,结果表明:系统均匀度从58.3%提高到93.5%,辐射传输效率从61.8%提高到72.9%,且光束质量对目标面距离的变化具有很好的稳定性.该设计方法能较好地实现对扩展光源辐射在空间分布的调控,对扩展光源系统设计具有重要指导意义.To overcome the shortness of traditional algorithms relying on the point source assumption,a freeform surface optimization method for the extended source was proposed based on the genetic algorithm.The optimal objects involve the radiation distribution function,the offset of origin and the size factor of receiver about the virtual point source.For each individual the reflector can be calculated numerically by solving the partial differential equations established according to the energy conservation law and Snell′s law corresponding to the set of virtual parameters.The individual fitness concerning the uniformity of the object region and the transmission efficiency was obtained according to the simulation results with an actual extended source.The selection,crossover and mutation operations are implemented until the optimization results can meet the requirements.To verify the effectiveness of the proposed method,a uniform lighting system with cone angle of 10°was designed.The contrast experiments are carried out in Trace/Pro with a disc lambertian source with the size of 30 mm in diameter.The light tracing experiments show that the uniformity of the object region increases from 58.3% to 93.5%,and the transmission efficiency increases from 61.8%to 72.9%.Meanwhile,the optical quality has quite good stability at varying distances.The experimental results demonstrate that the method can achieve the adjustment of the spatial distribution of the extended source radiation which has significant guidance for the design of extended source system.

关 键 词：自由曲面 遗传算法 均匀照明 优化设计 扩展光源 

分 类 号：O439[机械工程—光学工程]