Modeling and Optimization of Machine Processes

Interactions between machine structures and manufacturing processes, such as vibrations due to unsteady cutting, limit the process flow. With a detailed prediction of these interactions it is possible to optimize operation charts, machine parameters, path parameters and further details. The goal of the project "`Parametric modeling, prediction and optimization of interaction between machining process and structure using multibody systems and implicit filtering"', a research project of the priority program 1180, financed by the DFG (German Research Foundation), is to build a simulation model of an existing turning lathe and to optimize the manufacturing process. The project is a collaboration with the Institute for Machine Tools and Industrial Management (iwb), Technische Universit√§t M√ľnchen.

 

The optimization is based on models of the machine and the cutting process. One task is to build a model of the machine and to formulate the coupling between the specific models of the machine and the process. The cutting model is formulated in a way that allows the separation of chisel and work piece during the work process. This is realized by a modified unilateral contact augmented by a cutting model from IWB. The cutting model is validated with machining experiments.

 

The developed simulation model is used to optimize the operation charts. The used optimization algorithm needs a goal function to rate the process. Therefore, different goal functions are developed and investigated during this project. The simulation results are used to calculate the new surface and its characteristics and assessment criteria of the machining quality are obtained by both of them. A facing process is chosen as a test operation for the optimization. The optimization tool detects ideal parameters for the operation with respect to the dynamic limits of the working machine. With physical experiments the results are verified.