Thermo-energetic design of machine tools

A systemic approach to solve the conflict between power efficiency, accuracy and productivity demonstrated at the example of machining production

The challenge of research in the CRC/TR 96 derives from the attempt to satisfy the conflicting goals of reducing energy consumption and increasing accuracy and productivity in machining. The solution approach pursued is based on measures that make it possible to guarantee process accuracy despite increasing power losses without additional energetic measures under thermal transient environmental conditions and under operating conditions characterized by individual and small series production. The scientists of the CRC/TR 96 are researching and developing effective correction and compensation solutions for the thermo-elastic machine behavior during the course of the project, which will enable precision machining under the future conditions of energy-efficient production.

The following subgoals are derived from this:

  • Development of modeling fundamentals for a comprehensive calculation capability of thermo-elastic deformations and the heat fluxes causing them, as well as for the mapping of structural variability due to relative movements and minimization of calculation time,
  • Implementation of a current data image as a digital representation of the thermo-elastic functional chain. This includes model data as well as parameters and provides for the possibility of a cyclic update.
  • Recording of the effects of heat sources and sinks on the thermal behaviour of machine tools as well as the description of the temporal behaviour. Tracking of locally and temporally fluctuating parameters by means of parameter identification procedures as a prerequisite for the design and operation of correction and compensation approaches,
  • Development of basic metrological approaches for the detecting of thermo-elastic failures in specified structural areas of machine tools and their use for correction and compensation solutions,
  • Development and implementation of solutions for the control-integrated correction of thermo-elastic failures under consideration of process-accompanying data analysis.
  • Development and integration of design and material property-supported approaches for the compensation of thermo-elastic effects by stabilisation of the temperature field and reduction and homogenisation of the heat energy input in the area of load-bearing structures,
  • Technical-economic evaluation of the measures developed in the SFB/TR 96 with regard to their impact on product quality, volume performance, energy consumption and costs.

In phase 3 (demonstration phase), the research work relates to the entire machine. On the basis of the research results on simple partial and overall models, correction and compensation approaches are transferred to the application for the entire machine under the conditions of real operation. This leads to new scientific challenges due to a multitude of uncertainties and parameter fluctuations. The models have to be further developed and new solutions for the control of variable operating conditions such as online identification have to be developed.