Abstract: A method of constructing a digital twin physical field of a computer numerical control machine tool with double order reduction is provided. A physical field finite element simulation sample data set in a working state sampling space has an order preliminarily reduced to sparse grid node data via an improved K Nearest Neighbor (KNN) algorithm, so that the number of point sets is kept within the real-time rendering capability range of graphic rendering software. A digital twin physical field proxy model is trained using a radial basis function (RBF) to realize reconstruction of the physical field. The proxy model is iteratively optimized using a genetic algorithm to solve the problem of deviation between a proxy physical field model and a real physical model. Finally, the proxy model is deployed to a digital twin system, and the physical field distribution is solved in real time.

Abstract: An evolutionary compensation method for a spindle rotation error of a CNC grinding machine is provided. Feature points are determined at an edge of a central hole of a spindle of a CNC grinding machine, and a spindle rotation error in-situ measuring device is fixed on the grinding machine and aligned with the edge of the central hole; a trajectory image of the feature points is acquired by using the measuring device; a measured value of the spindle rotation error is obtained according to the trajectory image; features of the spindle rotation error are fused with the measured value of the spindle rotation error, a spindle rotation error compensation model is established, to output a spindle rotation error compensation value, thereby compensating the spindle rotation error. By continuously calibrating the error model using the measured value, accuracy of the error model has been continuously optimized.