Design and Performance Analysis of Focusing and Image Motion Compensation Mechanism for Low Light Level Multispectral Imager
-
摘要: 根据某型号微光多谱段成像仪的整机结构特性和工作条件,设计了一种调焦及像移补偿一体化的设备,达到节约空间、保证成像质量以及实现低照度环境下成像的目的。其中调焦功能由丝杠螺母配合楔形滑块实现,像移补偿功能由音圈电机实现,且配合有动、静态两级锁紧装置,使机构的可靠性、抗冲击性显著提高。结构外形尺寸为349 mm×192 mm×174 mm,调焦范围为±2 mm,像移补偿量为3 mm,调焦分辨率为0.05 μm,实测的定位精度为±5.7 μm。扫频振动试验得出其一阶模态为225 Hz,与有限元仿真分析结果基本一致,正弦振动试验和随机振动试验结果良好,均在技术指标要求范围内,说明具有良好的动态刚度,可以有效地避免共振现象的发生。综上所述,该调焦及像移补偿机构具有体积小,结构强度高的特点,可以很好地满足微光相机的工作条件。Abstract: According to the structural characteristics and working conditions of a low light level multispectral imager, an integrated device of focusing and image motion compensation is designed to be smaller, better imaging quality and low illumination imaging. The focusing function is realized by the screw nut and the wedge slider. The realization of the motion compensation function depends on the voice coil motor, and with the dynamic and static two-stage locking device. The reliability and impact resistance of the mechanism are significantly improved. The overall dimension of the structure is 349 mm×192 mm×174 mm, the focusing range is ±2 mm, the image motion compensation is 3 mm, the focusing resolution is 0.05 μm, and the actual positioning accuracy is ±5.7 μm. The first order mode is 225 Hz, which is consistent with the result of finite element simulation. The results of the sine vibration test and random vibration test meet the requirements of the technical indicators. It shows that it has good dynamic stiffness and can effectively avoid the resonance phenomenon. The focusing and image motion compensation mechanism has small size and high structural strength, which meet the working conditions of low light level cameras.
-
表 1 调焦机构的前四阶模态
Table 1. The first four modes of the focusing mechanism
Order Frequency/Hz Mode of vibration 1 238.5 Vibration in Y direction 2 246.6 Vibration in X direction 3 266.9 vibration in Z direction 4 368.2 Rotation with X axis 表 2 振动试验前后码值对比
Table 2. Comparison of code value before and after vibration test
Direction Code value before vibration Code value after vibration Difference X 69905 69911 6 Y 69911 69903 -8 Z 69903 69913 10 -
[1] 张元涛. 空间高灵敏度大动态范围微光成像技术研究[D]. 上海: 中国科学院大学(中国科学院上海技术物理研究所), 2018.ZHANG Yuantao. Research on Low-light Level Imaging Technology with High Sensitivity and Large Dynamic Range[D]. Shanghai: University of Chinese Academy of Sciences (Shanghai Institute of Technical Physics, Chinese Academy of Sciences), 2018. [2] Hong Dae Gi, Hwang Jai Hyuk. Fabrication and performance test of small satellite camera with focus mechanism[J]. Journal of Aerospace System Engineering, 2019, 13(4): 26-36. [3] 杨永斌. 空间光学相机调焦技术研究[J]. 航天器工程, 2011, 20(2): 20-24. https://www.cnki.com.cn/Article/CJFDTOTAL-HTGC201102005.htmYANG Yongbin. Study on focusing technology of space optical camera[J]. Spacecraft Engineering, 2011, 20(2): 20-24. https://www.cnki.com.cn/Article/CJFDTOTAL-HTGC201102005.htm [4] 李永昌, 金龙旭, 李国宁, 等. 宽视场遥感相机像移速度模型及补偿策略[J]. 武汉大学学报: 信息科学版, 2018, 43(8): 1278-1286. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201808022.htmLI Yongchang, JIN Longxu, LI Guoning, et al. Image shift velocity model and compensation strategy of wide-field remote sensing camera[J]. Geomatics and Information Science of Wuhan University, 2018, 43(8): 1278-1286. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201808022.htm [5] 姜紫庆, 贾建军. 空间相机透镜调焦机构的设计与测试[J]. 光学精密工程, 2018, 26(12): 2956-2962. https://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201812012.htmJIANG Ziqing, JIA Jianjun. Design and test of lens focusing mechanism for space camera [J]. Optics and Precision Engineering, 2018, 26(12): 2956-2962. https://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201812012.htm [6] 柴方茂, 樊延超, 辛宏伟, 等. 焦面二维精密调整机构研究[J]. 光电工程, 2014, 41(1): 6-11. https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC201401003.htmCHAI Fangmao, FAN Yanchao, XIN Hongwei, et al. Research on two-dimensional precision adjustment mechanism of focal plane[J]. Opto-electronic Engineering, 2014, 41(1): 6-11. https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC201401003.htm [7] 唐金松. 简明机械设计手册: 3版[M]. 上海: 上海科学技术出版社, 2009.TANG Jinsong. Concise Mechanical Design Manual: 3rd Edition[M]. Shanghai: Shanghai Scientific and Technical Publishers, 2009. [8] 张洪伟, 徐钰蕾, 李全超, 等. 轻型双波段航空相机调焦机构的设计[J]. 激光与光电子学进展, 2016, 53(8): 252-258. https://www.cnki.com.cn/Article/CJFDTOTAL-JGDJ201608034.htmZHANG Hongwei, XU Yulei, LI Quanchao, et al. Design of focusing mechanism for lightweight dual-band aerial camera[J]. Laser & Optoelectronics Progress, 2016, 53(8): 252-258. https://www.cnki.com.cn/Article/CJFDTOTAL-JGDJ201608034.htm [9] 辛宏伟. 小型轻质长条反射镜挠性支撑方案研究[J]. 光机电信息, 2010, 27(7): 51-55. https://www.cnki.com.cn/Article/CJFDTOTAL-GJDX201007015.htmXIN Hongwei. Study on flexible support scheme of small lightweight strip mirror [J]. Opto-mechatronics Information, 2010, 27(7): 51-55. https://www.cnki.com.cn/Article/CJFDTOTAL-GJDX201007015.htm [10] 许志涛, 刘金国, 龙科慧, 等. 高分辨率空间相机调焦机构精度分析[J]. 光学学报, 2013(7): 284-289. https://www.cnki.com.cn/Article/CJFDTOTAL-GXXB201307047.htmXU Zhitao, LIU Jinguo, LONG Kehui, et al. Precision analysis of focusing mechanism of high resolution space camera[J]. Acta Optica Sinica, 2013(7): 284-289. https://www.cnki.com.cn/Article/CJFDTOTAL-GXXB201307047.htm [11] 刘建, 刘文金. 应用格罗布斯准则判定测量结果中的粗大误差[J]. 木工机床, 2006(2): 26-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MGJC200602005.htmLIU Jian, LIU Wenjin. Application of grobs criterion to determine the gross error in measurement results[J]. Woodworking Machine Tool, 2006(2): 26-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MGJC200602005.htm [12] 袁健, 沙巍, 陈长征, 等. 空间相机桁架式支撑结构的集成优化设计[J]. 红外与激光工程, 2015, 44(12): 3661-3666. https://www.cnki.com.cn/Article/CJFDTOTAL-HWYJ201512027.htmYUAN Jian, SHA Wei, CHEN Changzheng, et al. Integrated optimization design of truss support structure for space camera[J]. Infrared and Laser Engineering, 2015, 44(12): 3661-3666. https://www.cnki.com.cn/Article/CJFDTOTAL-HWYJ201512027.htm