聚焦光场成像三维粒子场重建方法

发布时间：2018-07-09 18:10

本文选题：层析重建 + 粒子图像测速　；参考：《北京航空航天大学学报》2017年11期

【摘要】：层析重建是层析粒子图像测速(Tomo-PIV)技术实现三维粒子位置和强度信息(三维粒子场)重构的核心步骤。相比于多相机的Tomo-PIV技术,单聚焦光场相机通过一次成像能够同时采集示踪粒子的散射光的方向和位置信息。因此,提出一种单聚焦光场相机的层析重建技术用于重构流场中的三维粒子场信息。为了验证本文方法的可行性及准确性,利用几何光学建立了示踪粒子的光场成像模型,利用光线追迹技术计算了粒子在聚焦光场相机中的成像,对比了被测流场中位于不同深度位置的粒子在聚焦光场相机中的成像差异;建立了基于单聚焦光场相机的层析重建数学模型,利用乘法代数重构技术(MART)对模拟所得的光场图像进行反演计算,实现了三维粒子场的重构,并利用归一化互相关系数来表征粒子的重建质量。结果表明,单个粒子在Z轴方向上的位置精度为±0.35 mm,初步证明了基于聚焦光场成像理论的三维粒子场重建方法的可行性。
[Abstract]:Tomographic reconstruction is the core step of Tomo-PIV (Tomo-PIV) technology to reconstruct 3D particle position and intensity information (3D particle field). Compared with the Tomo-PIV technique of multiple cameras, single focus field camera can simultaneously collect the direction and position of scattered light of tracer particles by one time imaging. Therefore, a single focus field camera tomography reconstruction technique is proposed to reconstruct the three-dimensional particle field information in the flow field. In order to verify the feasibility and accuracy of this method, a light field imaging model of tracer particles is established by geometric optics, and the imaging of particles in a focused light field camera is calculated by ray tracing technique. The imaging differences of particles at different depths in the measured flow field in the focusing field camera are compared, and a mathematical model of tomography reconstruction based on the single focus field camera is established. Multiplicative algebraic reconstruction (Mart) is used to invert the simulated light field image to realize the reconstruction of 3D particle field, and the normalized correlation number is used to characterize the reconstruction quality of the particle. The results show that the position accuracy of single particle in Z axis is 卤0.35 mm, which proves the feasibility of 3D particle field reconstruction based on focused light field imaging theory.
【作者单位】：东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室;
【基金】：国家自然科学基金(51676044,51506030,51327803) 江苏省自然科学基金杰出青年基金(BK20150023)~~
【分类号】：TP391.41

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