复杂曲面零件在线检测与误差补偿方法

复杂曲面零件的高精度加工与精密检测一直是数字化制造领域的研究热点。为提高复杂曲面零件的加工精度、检测精度，提出一种集数控机床在线检测、加工误差分解与补偿加工为一体的集成化方法。介绍集成化在线检测方法及补偿系统的基本原理，分析数控加工后曲面零件测点数据的误差组成，提出一种基于空间统计分析的加工误差分解方法，在建立基于B样条曲面的确定性曲面回归模型的基础上，对回归模型残差进行空间独立性分析，分解出系统误差和随机误差，进而通过数控代码的修改，实现零件加工过程的系统误差补偿。列举一个曲面零件的加工与检测实例，进行方法有效性验证。通过加工工件的在线检测、误差分解、代码修改及补偿加工等环节，实例零件的加工精度有了大幅提高，而该系统的检测精度也通过与三坐标测量机(Coordinate measuring machine, CMM)检验结果的对比，得到了有效验证。

On-line Inspection and Machining Error Compensation for Complex Surfaces

Precision machining and inspection of complex surfaces have been the focuses of digital manufacturing. In order to improve machining and inspection accuracy of complex surface components, an integrated methodology of on-line inspection and machining error decomposition-compensation on NC machine is proposed. The principle of the system integrated on-line inspection and error compensation is then presented. The machining errors of measured points are analyzed after the machined surface is machined. The method of machining error decomposition is put forward using the spatial statistical analysis. A deterministic surface is established based on bicubic B-spline surfaces. Through the spatial statistical analysis of the residual errors of a regression model, the machining errors are decomposed into systematic errors and random errors. According to the decomposed systematic errors, the numeric control codes are modified and the machining errors compensation can be conducted. A part with a complex surface is taken as the example to verify the effectiveness of the proposed methodology. After the on-line inspection, the error decomposition, the code modification and the error compensation for the part, the machining accuracy of the test surface is greatly improved. The inspection accuracy of the system is also verified by comparison of the inspection data with a coordinate measuring machine.