Mass Loss and Displacement Modeling for Multi-Axis Milling

arXiv (Cornell University)

Abstract

During the cutting process, material of the workpiece is continuously being removed by the cutting tool, which results in a reduction of mass as well as a displacement in the center of the workpiece mass. When using workpiece sided force sensors, such as table dynamometers, the total mass and the displacement of the center of mass affects the force measurement due to gravitational and inertial effects. The high flexibility of the milling process leads to a complex change of volume and mass and necessitates the consideration of the engagement conditions between tool and workpiece along the tool path in order to estimate changes in mass and center of mass. This paper proposes a method for estimating the mass loss and the displacement of the center of mass during multi-axis milling processes. In this method the tool gets numerically sliced along the tool axis and the workpiece removal for each slice along an arbitrary tool path gets calculated. To validate the mass loss model, experiments in both three-axis milling as well as multi-axis milling processes have been conducted. Since it is difficult to measure the center of mass, validation for the displacement of the center of mass was done by comparison with data extracted from CAD. The results show good agreement between the simulated and measured mass loss using the proposed approach.

Authors 6

1. Adrian Karl Rüppel
2. Patrick Ochudlo Aachen Institute of Automatic Control (IRT)

   RWTH Aachen University

   Affiliation as printed

   Institute of Automatic Control (IRT) , RWTH Aachen University , Campus-Boulevard 30 , 52074 Aachen , Germany

3. Mathias Bickel Aachen Laboratory for Machine Tools and Production Engineering (WZL)

   RWTH Aachen University

   Affiliation as printed

   Laboratory for Machine Tools and Production Engineering (WZL) , RWTH Aachen University , Campus-Boulevard 30 , 52074 Aachen , Germany

4. Sebastian Stemmler Aachen Institute of Automatic Control (IRT)

   RWTH Aachen University

   Affiliation as printed

   Institute of Automatic Control (IRT) , RWTH Aachen University , Campus-Boulevard 30 , 52074 Aachen , Germany

5. Thomas Bergs Aachen Fraunhofer Institute for Production Technology Laboratory for Machine Tools and Production Engineering (WZL)

   Fraunhofer Institute for Production Technology IPT · RWTH Aachen University

   Affiliation as printed

   Fraunhofer Institute for Production Technology (IPT) , Steinbachstraße 17 , 52074 Aachen , Germany

   Laboratory for Machine Tools and Production Engineering (WZL) , RWTH Aachen University , Campus-Boulevard 30 , 52074 Aachen , Germany

6. Dirk Abel Aachen Institute of Automatic Control (IRT)

   RWTH Aachen University

   Affiliation as printed

   Institute of Automatic Control (IRT) , RWTH Aachen University , Campus-Boulevard 30 , 52074 Aachen , Germany