用于无运动部件变焦的变曲率反射镜技术研究

发布时间：2018-06-02 05:38

本文选题：无运动部件变焦 + 变形镜　；参考：《内蒙古大学》2015年硕士论文

【摘要】：无运动部件变焦(optical zoom without macroscopic moving elements)是指在没有光学部件宏观上相对位移的前提下实现光学变焦的过程。作为一种新型的光学变焦技术,宏观运动部件的消除不但可以使其应用到对空间、功耗或稳定性有苛刻要求的场合,而且能够提升变焦的时效性,因此极大地拓展了变焦技术的应用范围。目前,美国、德国、法国、中国等均已开展了将无运动部件变焦应用于天文望远镜及移动电子设备变焦成像等领域的研究。能够改变自身曲率半径的主动光学元件——变曲率反射镜是实现无运动部件变焦的关键。在特定的场合,比如小规模验证系统中,商用变形镜可以作为变曲率反射镜的替代来使用。然而,为了回避多点驱动变形镜控制复杂的问题,机理简单易于实现的功能经过简化的变曲率反射镜成为了一个研究分支。本文围绕变曲率反射镜技术开展研究工作,主要由以下几个部分组成：第一,系统地介绍了无运动部件变焦技术及关键器件——变曲率反射镜技术的国内外研究现状及发展趋势,并据此得出变曲率反射镜技术应用于无运动部件变焦成像领域时面临的难点。第二,从弹性薄板Roark应力应变定律出发,首先介绍了基于简支条件下的环形线负载机理的变曲率反射镜的曲率变化物理模型。其次,对单驱动点环形线负载驱动及多驱动点叠加环形线负载驱动这样两种能够实现环形线负载驱动机理的物理方式进行了性能上的对比分析,并以“最小驱动力实现最大中心形变”作为评价标准,通过分析确定了驱动环半径的最佳数值,同时分析了多驱动点叠加环形线负载驱动对于形变后的面形精度的调整控制能力。最后,通过比较不同基底材料、不同厚度对中心形变的影响及对驱动能力的要求,确定了变曲率反射镜原型样片的关键参数集合。第三,以优化后的多驱动点叠加环形线负载驱动实现反射镜曲率变化的物理模型出发,在考虑后续器件装配要求的前提下,对变曲率反射镜的整体结构形式进行了设计,并将其导入有限元软件中进行接近实际工况的有限元分析。分析表明,本文所建立的模型不但能够实现与曲率变化所对应的较大的中心形变,而且能够保证反射镜及其结构的使用安全。第四,介绍了变曲率反射镜原型镜片的加工、结构件的研制、驱动器的选择测试、实验平台的搭建以及最后的整体试验测试的详细描述,并对试验数据进行了分析,找出了实验过程中结构设计存在的问题,据此对变曲率反射镜的结构进行了改进。测试结果表明：100mmm口径,3mmm厚的铍青铜变曲率反射镜可以实现超过30个波长(波长632.8nm)的中心形变。此外,同等规格的K9玻璃变曲率反射镜能够实现的中心形变更大。
[Abstract]:Optical zoom without macroscopic moving elements) is the process of realizing optical zoom without the relative displacement of the optical component macroscopically. As a new type of optical zoom technology, the elimination of macroscopic moving parts can not only make it apply to the situation of demanding space, power consumption or stability, but also improve the timeliness of zoom. Therefore, the application of zoom technology is greatly expanded. At present, the United States, Germany, France, China and so on have carried out the research on the application of non-moving parts zoom in the field of telescope and mobile electronic device zoom imaging. Variable curvature reflector, an active optical element that can change its radius of curvature, is the key to realize zoom of moving parts. Commercial deformable mirrors can be used as an alternative to variable-curvature mirrors in specific situations, such as small scale verification systems. However, in order to avoid the complex problem of multi-point drive deformable mirror control, the simple and easy realization of the function of variable curvature mirror has become a branch of research. This paper focuses on the research of variable curvature mirror technology, which is mainly composed of the following parts: first, This paper systematically introduces the research status and development trend of zoom technology of moving parts and variable curvature reflector technology, which is the key device. Based on this, the difficulties in the application of variable curvature mirror technology in the field of zoom imaging without moving parts are obtained. Secondly, based on the Roark's stress-strain law of elastic thin plates, the physical model of curvature variation of variable curvature reflector based on simply supported toroidal load mechanism is first introduced. Secondly, the performance of single driving point ring line load drive and multi driving point superposition ring line load drive are compared and analyzed, which can realize the mechanism of ring line load drive. The optimum value of the radius of the driving ring is determined by using the "minimum driving force to realize the maximum central deformation" as the evaluation criterion. At the same time, the adjusting control ability of multi-point superposition ring line load drive on the deformation surface precision is analyzed. Finally, by comparing the effect of different substrate materials and thickness on the center deformation and the requirement of driving ability, the key parameter sets of the prototype sample of variable-curvature mirror are determined. Thirdly, based on the physical model of the curvature change of mirror realized by the optimized multi-drive point superposition ring line load drive, the integral structure of variable-curvature mirror is designed under the premise of considering the assembly requirements of subsequent devices. And it is introduced into the finite element software to carry on the finite element analysis which is close to the actual working condition. The analysis shows that the proposed model can not only realize the larger central deformation corresponding to the curvature change, but also ensure the safety of the mirror and its structure. Fourthly, the manufacture of the prototype lens of variable curvature mirror, the development of the structure, the choice and test of the driver, the construction of the experimental platform and the detailed description of the final whole test are introduced, and the test data are analyzed. The problems existing in the structural design during the experiment are found out, and the structure of the variable curvature mirror is improved accordingly. The results show that the Beryllium bronze reflector with 3mmm diameter of 100 mm diameter of beryllium bronze can achieve the center deformation of more than 30 wavelengths (632.8 nm). In addition, the K 9 glass mirror with the same size can achieve greater central deformation.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH74

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