Numerical Control Milling Machine Toolpath Generation for Regions Bounded by Free Form Curves and Surfaces

The search for strategies and methods to automatically generate toolpaths for Numerical Control (NC) machines from mechanical parts modeled by computer aided solid design systems has met with only limited success to date, mainly in applications to simplified models. Problems that occur when the existing strategies are applied to more complex models include the need for extensive human interaction and decision making and the lack of automatic gouge avoidance.; This study concentrates on the geometric aspect of the toolpath generation process for regions bounded by free-form curves and sculptured surfaces. Problems and difficulties that arise in various phases of toolpath generation are investigated and discussed. Algorithms based on methods in computational geometry, computer graphics, differential geometry, and graph theory are developed for the two- and three-dimensional regions to perform roughing and finishing. These algorithms will reduce the amount of human interaction and at the same time produce efficient toolpaths.