基于体标定追迹法的光场PIV权系数计算方法  

Volumetric-Calibration Ray Tracing-Based Calculation Method of Weight Coefficient in Light Field PIV

作　　者：吴治安 朱效宇 李健 张彪 许传龙 Wu Zhian;Zhu Xiaoyu;Li Jian;Zhang Biao;Xu Chuanlong(National Engineering Research Center of Turbo-Generator Vibration,School of Energy and Environment,Southeast University,Nanjing,Jiangsu 210096,China)

机构地区：[1]东南大学能源与环境学院火电机组振动国家工程研究中心,江苏南京210096

出　　处：《光学学报》2021年第20期25-35,共11页Acta Optica Sinica

基　　金：国家自然科学基金(51976038);江苏省重点研发计划(社会发展)(BE2020691);中央高校基本科研业务费专项资金(3203002101C3)。

摘　　要：针对光场粒子图像测速(PIV)技术中介质折射率变化及镜头畸变等因素而导致权系数计算误差较大的问题,提出一种基于体标定追迹技术的光场PIV权系数计算方法。该方法首先通过体标定方法建立空间物点与微透镜之间的映射关系,然后利用光线追迹技术计算控制体内的离散体素对像素的权系数,最后将该方法计算的权系数与直接追迹法计算的结果进行比较,并对标定板特征点的空间位置进行重建实验研究。实验结果表明,体标定追迹法计算出的权系数与直接追迹法的计算结果高度吻合;重建获得的标定板特征点在横向和深度方向上的位置误差分别小于0.002 mm和0.250 mm。Aiming at the problem of large calculation errors of weight coefficients caused by factors, such as medium refractive index changes and lens distortion in light field particle image velocimetry(PIV) technology, a method for calculating light field PIV weight coefficients based on volumetric calibration tracking technology is proposed. First, the mapping relationship between the spatial object points and the microlens is established by the volume calibration method. Second, the ray tracing technology is used to calculate the weight coefficient of the discrete voxel to pixel in the control body. Finally, the weight coefficient calculated by this method is compared with the direct tracking method, and the spatial positions of the feature points of the calibration plate are reconstructed experimentally. The experimental results show that the weight coefficient calculated by the volumetric calibration tracking method is highly consistent with the calculation results of the direct tracking method. The position errors of reconstructed calibration plate feature points in transverse and depth directions are less than 0.002 mm and 0.250 mm, respectively.

关 键 词：图像处理 体重建 光场PIV 体标定 权系数 

分 类 号：O359[理学—流体力学]