Force-sensitive rail guide systems based on directly-deposited component-individual sensors

• Applicants: Professor Dr.-Ing. Berend Denkena; Professor Dr.-Ing. Marc Christopher Wurz
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Synthesis and Properties of Functional Materials ; Microsystems ; Production Automation and Assembly Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 428561441

Forces are an important source of information for cutting process and condition monitoring in machine tools. Previous approaches of force measurement, however, have not been able to establish themselves in production because of high integration efforts and costs. Especially medium-sized machine manufacturers cannot afford such developments. If force measurement is carried out by commonly used machine components, such as profiled rail guides, force measurement is possible without complex adaptation of the machine structure. An extension of existing machines is also conceivable for the first time. So far, low strains and severe disturbances (e.g. rolling element circulation, reversal effects) have prevented force measurement in profiled rail guide systems. The aim of this project is to work together with the transfer partners Bosch Rexroth AG and Fooke GmbH to develop sensor technology and intelligent signal processing that enables force measurement by sensors integrated in the carriages of profiled rail guide systems. The sensors are based on a new, patented sensor manufacturing technology researched at the Institute of Micro Production Technology (IMPT) within the CRC 653. These sensors offer higher measuring accuracy and sensitivity by eliminating the need for adhesive and intermediate carrier layers. The sensor and the also directly deposited electrical supply lines are thinner than conventional strain gauges. Moreover, the sensor layout can be individually adapted to each component. Based on the existing knowledge, IMPT and Bosch Rexroth enhance the sensor manufacturing technology in such a way that the complex sensor layouts, required for carriages, can be manufactured economically and integrated into process chains. This includes methods for adjusting several bridge circuits simultaneously and during the deposition process. In addition, corresponding adjusting sequences and technologies for plant-integrated characterisation are investigated (IMPT). Based on the research work of the Institute of Production Engineering and Machine Tools (IFW), a method for automated and simulation-based generation of component-specific sensor layouts is researched and transferred into practice. Together with Bosch Rexroth and Fooke methods for model-based sensor fusion and signal processing for calculating the process and constraining forces from the sensor signals of the carriages are investigated. The application of integrated force measurement systems also requires methods for practical calibration. These are developed with Fooke using system redundancies. Prototypes of the sensory carriages will be integrated into a portal machining centre. Finally, the potentials and limits of force sensor profiled rail guides are validated.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: Bosch Rexroth AG; Werk Schweinfurt; FOOKE GmbH