Image Processing Tools Used for PSP and Model Deformation Measurements
Image Processing Tools Used for PSP and Model Deformation Measurements
复制标题
用于 PSP 和模型变形测量的图像处理工具
DOI：
10.2514/6.2005-5007
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
M. Merienne
中科院分区：
文献类型：
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作者：
Y. Sant;A. Durand;M. Merienne
介绍了在风洞应用中使用图像处理工具如PSP（压敏涂料）和模型变形测量方面的最新进展。这些工具的输入是位于模型和风洞壁上的标记。评估它们的图像坐标是图像处理管道的第一步。开发了一种专用工具，并对其精度进行了详细讨论。然后给出了与已知世界坐标的真实标记物的匹配步骤。该算法是一种全新的算法，使用了RANSAC范式。它是3D的，用通常的针孔透镜模型来模拟透镜。同时解决了相机位姿问题和匹配问题。最后，可以用网格跟踪方法评估模型变形，即使只有一台相机也可以测量3D变形。从大量的PSP测试中了解到，残差来自于标记世界坐标的不确定性和光学畸变。我们开发了一种新的方法，通过在测试部分使用模型的几个视图来校准相机参数和测量标记坐标。该方法简便，准确度高。确定模型变形需要精确的现场摄像机标定，这在风洞试验中仍然是一个问题。提出了一种利用极极几何的方法，可以解决未知标记点的匹配问题。
Recent advances in using image processing tools for wind tunnel applications as PSP (Pressure Sensitive Paint) and model deformation measurements are presented. The input for these tools is markers located on the model as well as on the wind tunnel walls. Assessing their image coordinates is then the first step of the image processing pipe. A dedicated tool has been developed and its accuracy is discussed in detail. Then the matching step with real markers known by their world coordinates is presented. The algorithm is quite new and uses the RANSAC paradigm. It is 3D and models the l ens with the usual pinhole lens model. As a result, it solves also the camera pose problem together with the matching problem. Finally, model deformation can be assessed with a grid tracking method, which enables to measure 3D deformation even with only on e camera. It has been learned from a lot of PSP tests that the residual error comes uncertainties about marker world coordinates as well as from optical distortions. A new approach has been developed to calibrate the camera parameters and to measure the ma rker coordinates by using several views of the model in the test section. This method is simple and provides a high accuracy. Determining model deformation requires an accurate in situ camera calibration which is still a problem in wind tunnel testing. A s olution is proposed which used the epipolar geometry which solves the matching problem even for unknown markers.