Spatial statistical analysis and compensation of machining errors for complex surfaces

In order to obtain high machining accuracy for free-form surface components, an on-line inspection system with error compensation is proposed in this paper. Once the component is machined, it can be measured by the probe inspection system. Based on these measurement data, a deterministic surface can be established based on a bicubic B-spline surface. Through the spatial statistical analysis of the residual errors of a regression model, the machining errors are decomposed into systematic errors and random errors. For the systematic errors, the numeric control program is modified and the compensation for the machining errors calculated can be conducted without altering the machining benchmarks. Therefore, the combination of the on-line inspection and the compensation of the machining errors is achieved successfully. Experiments were conducted to verify the effectiveness of the proposed methodology.

► The machining errors of complex surfaces were obtained by on-line inspection.
► The machining errors were subdivided into systematic errors and random errors.
► The machining accuracy was improved after the systematic errors were eliminated.