Integrated simulation, error assessment, and tool path correction for five-axis NC milling

Abstract

A system of algorithms is presented for material removal simulation, dimensional error assessment, and automated correction of five-axis numerically controlled (NC) milling tool paths. The methods are based on a spatial partitioning technique that incorporates incremental proximity calculations between milled and design surfaces. Hence, in addition to real-time animated five-axis milling simulation, milling errors are measured and displayed simultaneously. Using intermediate error assessment results, a reduction-of-intersection-volume algorithm is developed to eliminate gouges on the workpiece via tool path corrction. A similar technique is implemented for detection and elimination of unexpected collisions between the tool assembly and the workpiece. These combined algorithms provide efficient, accurate, and automatic assessment and correction of five-axis milling tool paths. Finally, the view dependency typical of previous spatial partitioning based NC simulation methods is overcome by a contour display technique that generates parallel planar contours to represent the workpiece, thus enabling dynamic viewing transformations without reconstruction of the entire data structure.