三坐标测量机在反求工程中的研究

Research on reverse engineering in coordinate measuring machine

零件原型数字化就是通过特定的数字化测量工具来获得零件几何数据的过程。以某汽轮机叶片为基础,介绍了利用接触式三坐标测量机获取零件三维数据的步骤和方法,即通过装夹零件、标定测头测杆、工件坐标系的建立、测量打点、数据输出等步骤得到零件的几何三维数据。最后通过实例的操作,得到了叶片的点云数据,并分析了在手动打点过程中产生测量误差的原因及其改善措施。实例表明,确定合理的测量路径、建立合适的零件坐标系、确定合适的测点个数、均匀的测力及其操作经验,可以提高点云的精度。

The digitization of part prototype is a process that to get the geometry of the parts using a number of specific digital measuring tools.Based on a turbine blade,it discussed the steps and methods to obtain the three-dimensional data of the parts using a contact-type coordinate measuring machine（CMM）.Through the steps of clamping parts,calibrating the probes and measuring rods,establish the workpiece coordinate system,measure the points and output the final data,it could obtain the three-dimensional data of the parts.Through an example,it proved the usability of this method.At last,the paper analyzed the measuring errors generated in the process and discussed the improve methods.The example proves that the precision of point-cloud could be improved by determining a reasonable measuring path,establishing an appropriate part coordinate system,choosing the appropriate number of measuring points and using uniform measuring force.