Position-independent thermal error compensation and evaluation based on linear correlation filtering technology

Compensation for position-independent thermal error on the spindle is necessary and economical. Considering the nonlinearity and time-dependent characteristics of the thermal error, classical methods always adopt complicated models for compensation, which are always impracticable without robustness and efficiency. This paper proposes a concise error model based on two linearity sensitive points (LSPs) which are identified by linear correlation filtering technology. The precision of double-LSP model is verified to be nearly stable with spindle speed variation through different data validation. The compensation strategy based on axes origin offset (AOO) function is implemented on commercial system, and the cutting experiment comparison is carried out on the horizontal machining center. A step-shaped cutting test workpiece is designed for evaluating the precision of PITE compensation. Result shows that up to 84.84% thermal deformation is effectively compensated, which indicates a valuable prospect in industry.