New ICA based thermal error compensation system

Thermal error of machine tools is one of the most significant considerations on machining errors. One of the difficult issues in thermal error compensation system is to select appropriate temperature variables and to obtain accurate thermal error model. In this paper, a new thermal error compensation method is proposed based on the independent component analysis (ICA). The proposed method extracts independent thermal error sources, namely virtual heat sources, using observed temperatures. A new thermal error modeling method using several significant sources among the extracted sources is also presented. The model has three submodels according to its operating condition. The proposed algorithm is tested using a used machining center. For the case of our machine tool, only one heat source is sufficient to model the thermal errors. The proposed model reduces the thermal errors to few microns and it corresponds to 1/10 of the original error.