Automated fabrication of shape models of free-form objects with a sculpturing robot.

Abstract

This thesis has resulted from the research project \Rapid Prototyping using Virtual Reality and Robot Milling", which started in 1994 at the Faculty of Industrial Design Engineering of Delft University o f T echnology.The project aimed at the development of both virtual and physical shape modeling techniques to support conceptual shape design.The thesis focuses on the development of shape sculpturing as an advanced physical shape modeling technique using robot milling.The technique has been implemented, evaluated and applied on the Sculpturing Robot system at Delft University of Technology.Chapter 1 is a general introduction into the di erent disciplines the research is related to, namely industrial design engineering, physical shape modeling, and tool path generation for sculptured surface milling.Chapter 2 describes shape sculpturing as a robot motion planning problem.We discuss the capabilities of the sculpturing process with regard to the shapes that can be machined exactly as well as the complexity of the sculpturing process.We propose a decomposition of the sculpturing problem into the subproblem of extracting a limited number of tool access orientations from the geometry of a free-form object, and the subproblem of generating the milling paths given any xed tool access orientation.Chapter 3 presents a method to compute a limited numberof tool access orientations by accessibility analysis of the free-form object.Chapter 4 shows that for a xed tool orientation, spatial planning and Minkowski operations can beapplied to state the sculpturing problem, and to describe, implement and compare NC machining methods.Chapter 5 describes the Sculpturing Robot (SR) system and the Multiple Access Orientation Sculptor (MAOS) software package to implement the methods from Chapter 3 and 4 with the SR system.Chapter 6 evaluates the methods both from Chapter 3 and 4 separately, a s w ell as the sculpturing strategy implemented by the software package.Chapter 7 provides conclusions drawn based upon the research described in this thesis.Many of the results in this thesis have been published.The paper (Tangelder, Vergeest & Overmars 1996) describes the method to extract tool access orientations from the geometry of a free-form object.The papers (Tangelder, Vergeest & Overmars 1997a) and (Tangelder, Vergeest & Overmars 1998) discuss the application of spatial planning and Minkowski operation to NC machining.Finally, t h e p a p e r ( T angelder, Vergeest, van den Belt & O v ermars 1997b) summarizes this Ph.D. thesis.