Thermal error analysis and error prediction modeling on a machine tool

Thermal errors are the largest contributor to the dimensional errors of a workpiece in precision machining. It is very significant to study how to accurately simulate the spindle thermal errors. In this paper a novel concept of thermal error modes analysis is proposed to develop a better understanding of the thermal deformation on a machine tool. The basic thermal error modes for a structural element are the thermal expansion and bending mode. The selection of sensors location can be improved based on the thermal error modes analysis with finite elements analysis for reference. Through variables grouping and optimization approach, key temperature variables are identified, the number of thermal sensors has been reduced from 16 to 3. The thermal error prediction modeling based on the proposed method has been applied to a machine for verification, and the results show the thermal error prediction model is satisfying for thermal error compensation.