Free-from surfaces such as three-dimensional (3D) printing products play an important role in customized production of manufacturing. Despite its popularity, 3D printing products often suffer dimensional quality issues due to geometric deformation during the layer-by-layer printing process. Different from traditional production, 3D printing products are often customized and not for mass production, thus it is often difficult to designate tolerance profiles to assess the production quality. To address this challenge, we propose a statistics-guided approach to characterize the dimensional quality for free-form surfaces. The proposed approach can provide local quality measures based on the original customized design and the scanned profile of a printed product. It gives a unified scale of the quality assessment measurements to conveniently compare the quality of products from different customized designs. Case studies and simulation experiments show that, the proposed approach can provide effective quality assessment and characterization for 3D printing.

诸如三维（3D）打印产品之类的自由表面在定制制造中起着重要作用。尽管3D打印产品很受欢迎，但是由于在逐层打印过程中出现几何变形，因此3D打印产品经常会遇到尺寸质量问题。与传统生产不同，3D打印产品通常是定制的而不是用于批量生产的，因此通常很难指定公差曲线来评估生产质量。为了解决这一挑战，我们提出了一种统计指导方法来表征自由曲面的尺寸质量。所提出的方法可以基于原始定制设计和印刷产品的扫描轮廓提供本地质量度量。它提供了统一的质量评估度量标准，可以方便地比较来自不同定制设计的产品质量。案例研究和仿真实验表明，该方法可以为3D打印提供有效的质量评估和表征。