Principle and Verification of a Structure Model Based Correction Approach

Structure model based correction is a new approach for the reduction of thermally induced positioning errors in machine tools. Herein axis-position dependent correction values are calculated in thermal real-time using thermal and thermo-elastic models. The correction values are used for the compensation of thermal errors. Necessary input data for the thermal model are captured in the control. This approach is verified at a 6-axis-machine using a camera based pose measuring system. The paper shows the principle of the correction approach and its verification by pose measurements. In conclusion the correction model meets the qualitative displacement in the workspace quite well.