An adaptive approach to error compensation by on-machine measurement for precision machining of thin-walled blade

Blade which is one of the most important thin-walled parts is widely used in aviation, aerospace and automotive fields. At present, the manufacturing technology of blade has been developed towards a new direction of high efficiency, precision and multi-process composition. However, the production efficiency and machining precision of blade are greatly limited due to the elastic, residual stress deformation and other inevitable distortion from NC machining process. In this paper, an adaptive error compensation approach by on-machine measurement for precision machining of blade is proposed and developed. According to the analysis and comparison between the nominal model and the practical measurement result, the adaptive process geometric model is constructed, which accurately describes the composite error compensation for precision machining of thin-walled blade. Firstly, an adaptive error compensation system structure and solution by on-machine measurement is described. Secondly, the error displacement field and anti-deformation compensation quantity is constructed and calculated by statistical analysis of on-machine measurement data. Thirdly, different from the nominal model, the process geometric model is adaptively constructed to solve the part-to-part variation for the actual NC programing of blade with the curve fairing algorithm. Finally, based on the adaptive process model, tool paths used for NC machining process can then be adaptively generated to implement composite error compensation for precision machining of blade. Examples show that the adaptive error compensation approach by on-machine measurement for thin-walled blade is feasible and the result is with high efficiency and accuracy.