Correction Algorithms and High-Dimensional Characteristic Diagrams

Abstract

The time-dependent consideration of the thermal situation in machine tools requires online-enabled methods for the correction of the tool position during the machining process. Higher-dimensional characteristic diagrams, which act as a lookup table for the prediction of the tool center point displacement from several temperature (or other) measurements, are well suited for this purpose. These characteristic diagrams are trained by finite element simulations. On the other hand, least-squares estimators together with reduced order models provide an alternative online-capable prediction technique for the tool displacement. In this context, optimal placement problems for the temperature sensors are described. In any case, the accuracy of simulations and estimation depends crucially on several parameters in the thermo-dynamic model. An approach that reveals the most relevant parameters using sensitivity analysis is also discussed.