Thermal Error Analysis and Optimal Partition Method Based Error Modeling for a Machine Tool

Thermally induced errors have been significant factors affecting machine tool accuracy. 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 element method for reference. Through optimal partition method and stepwise regression, key temperature variables are identified, the number of thermal sensors has been reduced from 16 to 3. The thermal error modeling based on the proposed method has been applied to a machine for verification, and the results show the thermal error model is satisfying for thermal error prediction.