涡轮叶片叶面B-spline曲面层次化拟合方法

航空发动机涡轮叶片表面形状复杂,其三维重构是叶片成型精度分析以及质量控制的重要手段。涡轮叶片叶面是一个复杂的自由曲面,其拟合是重构涡轮叶片的关键步骤之一。本文以涡轮叶片叶面拟合为研究对象,提出一种B-spline曲面层次化拟合方法,该方法首先构建网格曲面的多分辨率模型,然后完成该多分辨率三角网格模型的参数化,最后在多分辨率三角网格的基础上通过粗略拟合、精确拟合以及最终拟合3个主要步骤完成曲面拟合。该方法可以完成高阶连续自由曲面的拟合,适用于海量测量数据的快速拟合,具有较高效率并且拟合结果精度高。

Hierarchical B-spline Surface Fitting of Turbine Blades

he turbine blades of an aero engine have complicated surfaces, the reconstruction of which is useful for accuracy analysis and quality control of blade formation. The leaf of a turbine blade is a complicated freeform surface and its fitting is an important step for the reconstruction of the blade. This article presents a B-spline surface hierarchical fitting approach, which includes three steps: constructing a progressive mesh of the surface, parameterizing the progressive mesh hierarchically, and then, fitting the surface based on the progressive mesh through rough fitting, fine fitting, and final fitting. The presented approach can result a higher order continuous freeform surface. Research shows that the approach is fast and accurate.