Development of an online-capable warning system for process instabilities on the basis of stability limits calculated in a process-parallel approach

• Applicant: Professor Dr.-Ing. Christian Brecher
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 467600151

Within the framework of the DFG transfer project, an industrially applicable, online-capable early warning system for process instabilities due to regenerative chatter vibrations is to be implemented. The stability limits are determined parallel to the process within a demand-oriented simulation, which provides a statement on the machine control system based on the current process parameters as to whether the running process is stable or unstable.The central problem of efficiently mapping the variable dynamics of the machine-tool-material system is solved by new findings in the field of substructure coupling. A one-time measured model of the machine tool is coupled with analytical tool model in order to reduce the experimental measurement efforts to a minimum. In addition to the machine dynamics, knowledge of the material's sectional stiffnesses is required for calculating the stability limits. In order to avoid costly machining tests, the cutting stiffnesses are determined parallel to the process on the basis of process forces measured in real time. For this purpose, additional sensor technology is integrated into the spindle. The early warning system provides an online functionality that warns during machining of potential process instabilities in the further course of machining. The assessment basis is based on data recorded parallel to the process. Based on the warning, the occurrence of process instabilities can be prevented by operator intervention. Due to thewarning system, it is possible to design the process close to the stability limits, which increases productivity.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: CHIRON Group SE