Spatial error prediction method for precision machine tools considering the influence of repeatability error.

• The relationship between repeatability error and data confidence is established. • The spatial error prediction model based on confidence weighting is derived. • The simulation process based on statistics is designed. • A spatial error measurement scheme based on data fusion is proposed. • The accuracy and reliability are verified on a horizontal machining center prototype. A spatial error prediction method for precision machine tools considering the influence of repeatability errors is proposed in this paper. Firstly, the reciprocal of the repeatability error is used to evaluate the measurement data confidence to distinguish the difference of useful information contained in the measurement data of different positions. Secondly, the proposed confidence index is used to weight the measured values of PDGEs at different positions, so that the data containing more useful information can play a full role in the error prediction, and the predicted error is substituted into the error model to predict the spatial error. Then, the computer simulation based on statistical analysis is designed, the PDGEs and spatial error prediction accuracy of the weighted algorithm are verified by simulation. Finally, a multi-instrument fusion spatial error measurement scheme is proposed, and the accuracy and reliability of the model are verified on a horizontal machining center prototype. [ABSTRACT FROM AUTHOR]