Abstract: A lot of design data are described in the form of curves in engineering design. Solubility curve is one of typical engineering curves and has the characteristics of engineering curves. Solubility curve was taken for an example. Methods of data sampling, data extraction, data sorting and storage of curves were put forward, and recognition of curves was realized during data extraction. Meanwhile, data sampling of curves were fitted by using Cardinal curve. Furthermore, digitizing of engineering curves was performed by using parabolic interpolation.

Key words: Engineering design, Engineering curves, Data fitting, Computer aided design, Spline curve

摘要： 工程设计中大量的设计资料是以曲线形式存在的，溶解度曲线是典型的工程曲线，具有工程曲线的特征。以溶解度曲线为例，提出曲线的数据点采样、数据提取以及数据点的排序与存储方法，并在数据提取过程中实现曲线的识别。同时利用Cardinal样条曲线对曲线上的采样点数据进行拟合，进一步通过抛物线插值法完成工程曲线的数字化。

关键词: 工程设计, 工程曲线, 数据拟合, 计算机辅助设计, 样条曲线