This paper aims to solve the problem of free-form tubes’ machining errors which are caused by their complex geometries and material properties.,In this paper, the authors propose a multi-view vision-based method for measuring free-form tubes. The authors apply photogrammetry theory to construct the initial model and then optimize the model using an energy function. The energy function is based on the features of the image of the tube. Solving the energy function allows to use the gray features of the images to reconstruct centerline point clouds and thus obtain the pertinent geometric parameters.,According to the experiments, the measurement process takes less than 2 min and the precision of the proposed system is 0.2 mm. The authors used simple operations to carry out the measurements, and the process is fully automatic.,This paper proposes a method for measuring free-form tubes based on multi-view vision, which has not been attempted to the best of authors’ knowledge. This method differs from traditional multi-view vision measurement methods, because it does not rely on the data of the design model of the tube. The application of the energy function also avoids the problem of matching corresponding points and thus simplifying the calculation and improving its stability.

中文翻译：

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一种用于工业装配的基于多视图视觉的自由曲面管材测量方法

本文旨在解决自由曲面管材由于其复杂的几何形状和材料特性而导致的加工误差问题。在本文中，作者提出了一种基于多视图视觉的自由曲面管材测量方法。作者应用摄影测量理论构建初始模型，然后使用能量函数优化模型。能量函数是基于管子图像的特征。求解能量函数允许利用图像的灰度特征重建中心线点云，从而获得相关的几何参数。,根据实验，测量过程不到2分钟，所提出的系统精度为0.2毫米. 作者使用简单的操作来进行测量，并且该过程是全自动的。，本文提出了一种基于多视图视觉测量自由形状管的方法，据作者所知，该方法尚未尝试。这种方法不同于传统的多视图视觉测量方法，因为它不依赖于管子设计模型的数据。能量函数的应用也避免了对应点匹配的问题，从而简化了计算，提高了稳定性。