Abstract
- Thermal errors present a major hurdle in maintaining positioning accuracy in cutting machine tools. Model based compensation methods can predict the thermal error and reduce it via control-internal offsets. There are numerous such compensation models. For complex machine tool designs and under realistic working conditions, however, all of these methods still have not eliminated the thermal error reliably. The GeoComp project attempts to improve the accuracy of thermal error predictions by breaking down the error into individual assemblies along the kinematic chain and using the best suited compensation model for each error component. To demonstrate this on the DMU 80 evo, the kinematic chain for the z-direction of the column error was set up. Using three simulated load cases, the thermal error of this kinematic chain was examined and a compensation model for the dominant Z-slide error component was computed using a characteristic diagram. Once the training database has been extended, similar compensation models will be created for all assemblies and the resulting hybrid model will be tested and evaluated.