基于线性插值原理的三维发射层析重建技术研究

Reconstruction Technology for Three-Dimensional Emission Computerized Tomography Based on Linear Interpolation Theory

三维发射层析技术跨越了传统二维层析技术中的“切片”过程,将被测区域作为一个整体进行重建,投影方向及位置不局限在同一水平面内,可以解决实际燃烧场测试中探测器位置受限以及装配误差等问题,对燃烧场的三维成像及测试具有重要意义。针对已有三维发射层析技术中权重矩阵的计算存在数据量大、精度和效率低等问题,在三维空间相机成像投影数学模型的基础上,提出了一种基于线性插值原理的三维权重矩阵计算方法,并结合代数迭代算法实现层析重建。通过数值模拟验证了算法精度,建立了多相机发射层析系统并对燃烧火焰进行三维层析重建。研究结果对提高层析重建精度和效率具有重要的参考价值。

Three-dimensional(3D)emission computerized tomography(ECT)is superior to the“slicing”process of the traditional two-dimensional ECT technology and reconstructs the test zone as a whole.As the projections are not limited to the same horizontal plane,3D ECT can solve the problems of limited detection positions and assembly errors encountered during actual combustion tests,which is necessary for 3D combustion imaging and testing.In this study,a 3D weight matrix calculation algorithm was developed using a mathematical model of camera imaging in a 3D space and the linear interpolation theory to reduce the data amount and improve the calculation accuracy and efficiency of the weight matrix for 3D ECT.The accuracy of the algorithm was verified via numerical simulations using an algebraic reconstruction algorithm for tomography reconstruction.An ECT system with multiple cameras was established,and the proposed algorithm was used to reconstruct the combustion flame.The results have a significant reference value for improving the accuracy and efficiency of tomographic reconstruction.