基于轮廓特征的点阵尺寸可溯源测量

Traceable Dimensional Measurement for Lattices Based on Contour Features

工业计算机断层扫描(CT)是对点阵结构增材制件进行尺寸特征检测的有效选择,但目前缺少统一的工业CT尺寸测量误差评价方法,因此首先通过三坐标测量机和孔板标准器实现工业CT尺寸测量误差的评定,然后提出基于轮廓特征的点阵结构周期性尺寸测量方法,最后通过实例验证该方法的有效性。结果表明,该工业CT的最大允许误差(MPE)能够达到±(50+L/400)μm,满足当前检测要求。轮廓特征提取法能够实现点阵结构周期性尺寸特征的测量。

Industrial computed tomography(CT) is an effective tool for measuring the dimensional characteristics of lattice structures in additive manufacturing parts. However, currently there is no uniform method to evaluate the dimensional measurement errors of industrial CT. Therefore, in this paper, we first evaluate the dimensional measurement errors of industrial CT using a coordinate measuring machine and a hole plate standard;then, we propose a method for conducting the periodic dimensional measurements of the lattice structure based on contour features. Finally, the effectiveness of the method is verified via an example. The result shows that the maximum permissible error of the industrial CT can reach ±(50+L/400) μm, which meets the current testing requirements. The contour feature extraction method can be applied to measuring the periodic dimensional features of lattice structures.