Process analysis for centerless feed-through loops using time and frequency discrete evaluation of the acoustic emission signal

• Applicant: Professor Dr.-Ing. Thomas Bergs
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569521597

In centerless grinding of rotationally symmetrical workpieces, the workpiece is guided and positioned in the grinding gap through contact with the grinding wheel, work rest and regulating wheel. The economic potential of the process for the production of large quantities is high due to the workpiece being supplied parallel to the machining process. However, process monitoring is complex, as force sensors cannot be integrated due to the lack of workpiece clamping. Consequently, it is not possible to investigate the cause-effect relationships between the process input variables and the wear-related changes in the contact conditions of the workpiece on the grinding wheel, regulating wheel and work rest using conventional measuring methods. The aim of this project is therefore to model the wear-related change in contact conditions on the grinding wheel, regulating wheel and work rest during centerless through-feed grinding in order to explain and predict changes in process results for adaptive, resource-saving process control. A data-driven empirical methodology is to be developed and used for this purpose. Preliminary work to check the plausibility of the methodology was successfully completed at the institute of the proposal author. They showed that a time- and frequency-discrete evaluation of acoustic emission signals is suitable for achieving the objective. First, in this research project, a measurement and evaluation methodology for recording the workpiece-related process state variables during centerless through-feed grinding will be developed and validated for a grinding process with systematically varied process parameters. This methodology is then further developed to identify the causes of wear-related process deviations by carrying out tests with discrete wear conditions. This makes it possible to assign a detected change in the structure-borne sound signal to the contact point causing it (workpiece-grinding wheel, workpiece regulating wheel and work rest). Finally, the model is qualified for simultaneous and time-continuous wear progression on the grinding wheel, regulating wheel and work rest. By combining the data-driven model which has been developed up to this point with existing empirical-analytical models, the variation of the component result variables is explained as a function of the wear-related changes in contact conditions. The aim of the follow-up project is to develop a design model by applying existing empirical-analytical process models of centerless grinding in combination with the data-driven methodology to be developed in phase 1 and the cause-effect relationships also identified in phase 1 for the targeted identification of suitable parameter combinations for the purpose of targeted generation of defined process results.

• DFG Programme: Research Grants