复杂光学系统的全局优化

逃逸函数法是目前最为实用的光学系统全局优化算法之一。这种全局优化的运行由多个不加或加入逃逸函数的阻尼最小二乘法局部优化组成。探讨了提高其优化效率的方法,提出了两个搜索机制以便提高各个局部优化的效率。首先搜索最佳阻尼因子,从而确定多维结构变量空间中解向量的最优方向;再沿该方向搜索解向量的最优长度。此外,用实验方法确定了逃逸函数的控制参数的最佳缺省值。在此基础上成功地研制了实用化的复杂光学系统全局优化程序。     

光学系统设计中全局优化方法的实现

 把变尺度法用于光学优化设计中，同时使用了“逃逸函数”技术, 从而实现了光学系统设计的全局优化。在使用逃逸函数时，两个因子H和W的确定是能否“逃逸”优化“陷井”的关键。用这种技术借助于C语言开发的程序成功地设计了一典型的光学系统。     

在定域法中实现光学全局优化

把不等式法用于光学优化设计中,同时使用了“逃逸函数”技术,从而实现了光学系统设计的全局优化在使用逃逸函数时,两个因子H和W的确定是能否“逃逸”优化“陷阱”的关键用这种技术借助于C++开发的程序成功地设计了一些典型的光学系统.     

混入逃逸函数的实数编码遗传算法优化光学系统

为了得到超多参量光学系统的最佳设计,将标准遗传算法的二进制编码改为实数编码以提高算法的鲁棒性和计算效率,并在评价函数中混入逃逸函数避免优化过程陷入局部极值.用改进后的遗传算法和CODE V对鱼眼镜头光学系统和折反射全景成像系统的设计案例进行光学参量优化,并应用Zemax对两种优化结果进行光线追迹成像模拟.计算结果表明,应用改进遗传算法比混入逃逸函数的遗传算法或CODE V软件优化所得到光学系统的成像质量有明显提高,在优化超多参量光学系统时具有较为理想的鲁棒性和计算效率.     

红外系统冷屏形状的优化设计

一次成像的简化式红外光学系统冷屏与出瞳不能匹配,致使系统受到杂散光干扰。在此情况下,对冷屏的开孔形状进行合理优化设计对杂散光的抑制十分必要。利用数学中的最优化计算来解决冷屏形状的优化问题,建立了优化变量和优化目标函数的数学模型,提出了全局优化和局部优化相结合的方法,分别用区间穷举法和阻尼最小二乘法完成,以得到较优的冷屏开孔形状。利用本方法,对一个现有的简化式热像光学系统设计了冷屏开孔形状,解决了该系统中由冷屏与出瞳不匹配造成的杂散光干扰的问题,从而验证了提出的冷屏优化设计方法的正确性与实用性。     

精密确定SAWR等效参数的计算机辅助方法

本文提出了有约束的内点惩罚函数-阻尼最小二乘法,并通过“内点罚函数-Powell法”与“内点罚函数-阻尼最小二乘法”相结合的新尝试,精密地确定出了声表面波谐振器的七个等效参数.计算结果比已经报道过的更加精确,表明本算法是精密确定SAWR等效参数的有效方法.     

光学自动设计双优选阻尼最小二乘法

本文提出了象差极重匀化因子的概念,以解决阻尼最小二乘法光学自动设计中象差权重的自动给定和优化问题.象差极重匀化因子的自动调整还可使在优化过程中出现的价值函数局部极值自动脱出.本文对程序作了简要描述,还给出了计算实例.     

评价函数思想在适应法中的应用

本文提出一种见解,即在光学自动设计的适应法程序中运用阻尼最小二乘法的评价函数思想,以一个简洁的微机用程序将两种优化思想融合。提出一种实现这种构思的途径,达到了预期效果。     

OCAD光学设计软件包

OCAD光学设计软件包是应用双优选阻尼最小二乘法为自动优化方法的多功能通用性光学设计CAD软件包,适用于IBM-PC/XT及其他兼容机。详细地介绍双优选阻尼最小二乘法的数学模型及自动优化方法,还介绍了软件包的基本功能及在软件包编制中几个具有特色的技巧和处理方法。     

ADTF通用多功能光学设计程序

本文介绍一个实用多功能光学设计程序;提出在适应法程序中移植阻尼最小二乘法评价函数思想的观点,并创造一种新型优化指标实现了这种移值;对焦距缩放、光阑位置优化、节省几何光学传递函数(OTF)计算时间等提出了看法。     

Lens Design: An Attempt to Use ‘Escape Function’ as a Tool in Global Optimization

In designing lenses with the damped least squares method, the solution obtained by optimization routine is a local minimum of the merit function. To get out of this and seek a different solution, we propose to use an ‘escape function’ as an additional operand of the lens system, to be controlled. Experiments were made on simple models of merit function and the advantage of this technique was ascertained. We also planted this algorithm into OSLO SIX (lens design software by Sinclair Optics) by means of CCL (C-compatible language) and applied it to actual lens design. Experiments convinced us that the method would be an effective tool for global optimization.     

Global and local optimization for optical systems

Issues concerning the efficiency of the Global Explorer (GE) algorithm are studied. Global optimization with GE consists of many local optimization runs with or without the escape function using the damped-least-squares method. In order to improve the efficiency of the local optimization and the GE run, two search schemes are incorporated. The first one searches for the best damping factor which effectively determines the optimum direction of the solution vector in the multi-dimensional variable space, and the second search is conducted along that direction to find the optimum length of the solution vector. Experiments are also made to determine the optimum default values for the parameters of the escape function. The algorithm with the improvements is successfully implemented in the GOLD program developed by Beijing Institute of Technology. Design examples using the software are given, which show that the global optimization feature is practical and powerful.     

基于遗传算法的全息光栅逆向优化设计

光栅是单色仪的核心器件,光栅的像差校正能力对单色仪性能有着决定性作用.本文研究了基于光线追迹点列图数值分析的遗传算法实现,建立了针对全息光栅成像质量的评价函数,并利用遗传算法实现了全息光栅的优化设计.结果表明,利用遗传算法可以简化求解过程,降低最优参量的误差,并克服局部极值的问题,明显优于阻尼最小二乘法.     

基于遗传算法的全息光栅逆向优化设计

光栅是单色仪的核心器件,光栅的像差校正能力对单色仪性能有着决定性作用.本文研究了基于光线追迹点列图数值分析的遗传算法实现,建立了针对全息光栅成像质量的评价函数,并利用遗传算法实现了全息光栅的优化设计.结果表明,利用遗传算法可以简化求解过程,降低最优参量的误差,并克服局部极值的问题,明显优于阻尼最小二乘法.     

Chromatic aberration elimination for digital rear projection television L-type lens by genetic algorithms

Following the development of a digitalized image optics system, chromatic aberration has become increasingly important especially in lateral color aberration. For rear projection television L-type lens, chromatic aberration plays the significant role because it is easily seen when facing bright screen. Basically, the elimination of axial chromatic and lateral color aberration for an optical lens depends on the choice of optical glass. DLS (damped least squares), a Ray-tracing-based method, is limited, owing to its inability to identify an enhanced optical system configuration. Genetic algorithms were applied to so-called global optimization but unfortunately so far the results show little success. Additionally, L-type optics with aspherical surface might complicate optimization due to being nonlinear response during optimization. As an alternative, this research proposes a new feasible chromatic aberration optimization process by using algorithms involving theories of geometric optics in a lens, real encoding, multiple dynamic crossover and random gene mutation techniques. In this research, rear projection television lens with aspherical surface and L-type lens are mainly discussed. Results and conclusions show that attempts to eliminate difficult axial and lateral color aberration are successful.     

Formulation of an Automatic Lens Design Problem by Modification of Weighted Tchebycheff Norm Method

Automatic lens design is viewed as a multiobjective optimization problem and is resolved by a minimization of the weighted Tchebycheff norm of objective functions. It is analytically solved using the multiplier method and a solution vector is transformed into the same form as the normal equation of the least squares method. Some numerical examples are given to show the effectiveness of the proposed method. The resultant solutions can not be obtained using the damped least squares method.