Cutter Workpiece Engagement Calculations for Five-axis Milling Using Composite Adaptively Sampled Distance Fields

Composite adaptively sampled distance fields are a new approach to shape representation that is well suited for Numerically Controlled (NC) milling simulation. In NC milling, as the milling tool moves along the tool path, it carves out a swept volume and a portion of the workpiece is removed. During the milling tool motion, it is in contact with the workpiece over an instantaneous common surface which is called Cutter Workpiece Engagement (CWE) surface. In order to model the process mechanics and dynamics accurately, it is important to have a precise geometric representation of the CWE surface. One of the fundamental difficulties has been the accurate and computationally efficient determination of this surface along the tool path for five-axis milling applications. In this paper, we provide a brief introduction to distance fields for swept volumes and describe a new method for determining the CWE surface for general and complex five-axis NC milling. The combination of high simulation speed, high accuracy and modest memory requirements provide significant improvements over existing approaches.