Qualification of function integrated feed units on the basis of compliant mechanisms in small machine tools for small work pieces

• Applicants: Professor Dr.-Ing. Rolf Lammering; Professor Dr. Thomas Schuster; Professor Dr.-Ing. Jens P. Wulfsberg
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 172887528

This project aims for a non-intuitive development of feed units based on compliant mechanisms for small modular high precision machine tools and its realization in a software-based process. High precision in motion and the absence of friction are the main advantages of compliant mechanisms qualifying them for the use in micro manufacturing.The design of compliant mechanisms turns out to be a complex task. Aspects of great importance are the position of flexure hinges and the stiff parts connecting them. Moreover, the geometry of flexure hinges and the connecting stiff parts are significant concerning the static and dynamic behavior of the entire mechanism. Methods based on structure optimization such as topology and geometry optimization shall be used to shape compliant mechanisms in a quick and non-intuitive way.Accurate modeling of compliant mechanisms is of essential importance for further investigations such as optimization, analysis and control. The derivation of efficient mathematical models is absolutely necessary for the use in mathematical trajectory optimization and real-time control. Directly related is the precise approximation of flexure hinges. Parasitic motion and mechanical properties need to be determined to ensure a high accuracy of the model. Based on the dynamic model, a mathematical description of the problem of trajectory optimization needs to be derived, analyzed and solved. The focus of mathematical research lies on an appropriate modeling considering the required high precision and modularity of the machine as well as the development and implementation of an efficient solver. The aim is to acquire software adjusted to the requirements of micro manufacturing which can be adapted for various feed units. This software shall be qualified for coupled feed units and integrated into the software of the whole process of development. A method of controlling the feed unit will be derived using the dynamical model. A challenging requirement is to ensure highly precise motion despite the presence of disturbances such as the forces of processing. A further task will be to assure the feed unit is quickly coupleable and ready for use in a modular machine tool. This shall be achieved by constructing and implementing control methods depending on the machine tool configuration. Experimental investigation will be carried out to quantify properties of feed units and to ensure their adaptability in micro manufacturing.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1476: Small Machine Tools for Small Work Pieces