Design and experiment of precision focusing mechanism of space remote sensing camera with lightweight and miniaturization
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摘要: 空间遥感相机在发射过程中及其在轨运行时,由于大气压力、温度、力学环境等的变化,导致焦面离焦。为了满足成像质量要求,相机在空间投入使用之前必须对偏离的焦面进行校正。针对轻小型空间相机的使用特性及要求,设计了一套调焦范围3 mm的像面移动式调焦机构,质量仅为3.25 kg。利用蜗杆传动的自锁性,防止焦面组件在外力作用下发生窜动。选用微型精密级直线滚动导轨保证CMOS靶面的直线性精度。同时利用光电编码器(16位)实时反馈靶面的位置信息,以保证其定位精度。对调焦机构进行了理论分析、动力学分析及试验验证、精度测试及分析、焦面标定试验等。试验结果表明:调焦机构的一阶固有频率为182.7 Hz,可以有效地避免共振现象;CMOS靶面的直线性精度优于20,定位精度优于4.2 m,满足调焦精度要求;焦面标定试验验证了调焦机构设计的有效性,满足了空间遥感相机的成像质量要求。Abstract: Space remote sensing camera in the launch process and its in-orbit operation, due to environment change of atmospheric pressure, temperature, mechanics, results in focal plane defocus. In order to meet the requirements of imaging quality, the focal plane must be corrected before putting it into use. For meeting the features and imaging quality requirements of lightweight and miniaturization space camera, the focusing mechanism was designed, the motion displacement was in the range of 3 mm, and the weight was only 3.25 kg. The self-locking property of the worm drive mechanism was used to prevent the movement of focal plane in the external forces. Micro-precision linear rolling guideway was selected to ensure the linearity accuracy of CMOS target plane. At the same time, photoelectric encoder (16 bit) was used to real-time feedback the positioning information of target plane, forming a closed-loop control to ensure its positioning accuracy. And, the theoretical calculations, dynamic analysis and experimental verification, accuracy testing and analysis, calibration test of focal plane were worked out. Experimental results indicate that the first natural frequency of focusing mechanism is 182.7 Hz, it can effectively avoid the resonance phenomenon. And the linearity accuracy of CMOS target plane is better than 20, the positioning accuracy is better than 4.2 m, meeting the focusing accuracy. Simultaneously, calibration experiment of focal plane verifies the designed effectiveness of the focusing mechanism, meeting the imaging quality of space remote sensing camera.
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Key words:
- space camera /
- focusing mechanism /
- deviation of focal plane /
- dynamics /
- precision analysis
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[1] Ding Yalin, Tian Haiying, Wang Jiaqi. Design on the focusing mechanism of space remote-sensing camera[J]. Optics and Precision Engineering, 2001, 9(1):35-38. (in Chinese) [2] Jiang Hao. Research on ultra-light SiC mirrors and support techniques[D]. Changchun:Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 2016. (in Chinese) [3] Zhang Hongwen. Research on the auto-focusing technology for space camera[D]. Changchun:Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 2003. (in Chinese) [4] Lv Shiliang, Liu Jinguo, Jia Ping. Accuracy analysis of the focusing precision for multispectral CCD space camera[J]. Infrared and Laser Engineering, 2013, 42(2):392-397. (in Chinese) [5] Xu Zhitao, Liu Jinguo, Long Kehui, et al. Accuracy analysis of focusing mechanism of high resolution space camera[J]. Acta Optica Sinica, 2013, 33(7):0728001. (in Chinese) [6] Wang Shuxin, Li Jinglin, Liu Lei, et al. Accuracy analysis of focusing mechanism in space camera with long-focal-plane[J]. Optics and Precision Engineering, 2010, 18(10):2239-2243. (in Chinese) [7] San Bing, Li Jinglin. Focusing device design of the large aperture optics system[J]. Infrared and Laser Engineering, 2013, 42(S2):329-332. (in Chinese) [8] Wang Zhongshan, He Xin, Cui Yongpeng, et al. Analysis and validation of large size focal-plane focusing device for space camera[J]. Infrared and Laser Engineering, 2014, 43(4):1206-1209. (in Chinese) [9] Hui Shouwen. Study of automatic focusing technique for long focus oblique real-time aerial camera[D]. Changchun:Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 2003. (in Chinese) [10] Jia Xuezhi, Wang Dong, Zhang Lei, et al. Optimizing design and precision experiment of focusing mechanism in lightweight space camera[J]. Optics and Precision Engineering, 2011, 19(8):1824-1831. (in Chinese) [11] Liu Lei, Cao Guohua. Double cam focusing mechanism of space camera with wide field and long-focal-plane[J]. Optics and Precision Engineering, 2012, 20(9):1939-1944. (in Chinese) [12] Wang Zhi, Zhang Liping, Li Chaohui, et al. Design of focusing mechanism of space tridimensional mapping camera[J]. Optics and Precision Engineering, 2009, 17(5):1051-1056. (in Chinese) [13] Wang Xianjun. Errors and precision analysis of subdivision signals for photoelectric angle encoders[J]. Optics and Precision Engineering, 2012, 20(2):379-386. (in Chinese)
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