光学 精密工程, 2014, 22 (5): 1274, 网络出版: 2014-06-03
斜视航空相机的斜距离焦补偿
Oblique distance defocus compensation for oblique photographic airborne camera
航空相机 斜距离焦 凸轮 剩余离焦量 补偿 airborne camera oblique distance defocus cam mechanism residual defocus compensation
摘要
针对斜视航空相机成像时产生的离焦,设计了相应的调焦机构以补偿斜距离焦量。分析了斜距离焦原理,得出了斜距离焦补偿量的计算公式,并提出采用凸轮机构对斜距离焦量进行补偿。考虑传统的基于偏心凸轮的斜距调焦机构的理论模型具有数学近似的缺点,设计了理论模型没有进行数学近似的基于圆柱凸轮的斜距调焦机构。由于斜距调焦机构设计时是基于某一典型高度,当相机工作于其他高度时会产生剩余离焦量,文中分析了剩余离焦量产生的原因、处理方法和处理流程,从而使斜距离焦量在相机所有工作高度和扫描角范围内均得到补偿,为相机获得高质量图像提供了条件。最后,在实验室利用平行光管模拟了不同物距的成像,验证了提出的斜距调焦机构的有效性和准确性。
Abstract
For defocus generated during imaging from an oblique photographic airborne camera, a corresponding focusing mechanism was designed to compensate oblique distance defocus for high imaging quality. The principle of oblique distance defocus was analyzed, the formula of defocus compensation was obtained and a cam mechanism was proposed to compensate the defocus. A focusing mechanism based on a cylindrical cam was designed to replace the traditional focusing mechanism based on eccentric cam, in which the theoretically mode is exact instead of proximal. As the oblique distance defocus system was designed based on a typical height, the residual defocus would be emerged at other heights. The cause of residual defocus was analyzed. The process method and process flow were developed to eliminate the residual defocus. All amount of oblique distance defocus were compensated in all heights and scan angels. Camera imaging simulation with different objects in laboratory approves the validity and accuracy of the proposed focusing mechanism.
刘波, 贾继强, 丁亚林, 苏东风. 斜视航空相机的斜距离焦补偿[J]. 光学 精密工程, 2014, 22(5): 1274. LIU Bo, JIA Ji-Qiang, DING Ya-Lin, SU Dong-Feng. Oblique distance defocus compensation for oblique photographic airborne camera[J]. Optics and Precision Engineering, 2014, 22(5): 1274.