Prospects for using T-splines for the development of the STEP-NC-based manufacturing of freeform surfaces
- 137 Downloads
For successful development of the intelligent manufacturing of freeform surfaces using STEP-CNC with online toolpath generation capability, it is required to make a choice of the optimal representation of a 3D model which will be used for machining. Traditionally, most existing CAD-CAM systems use NURBS to design freeform surfaces and to perform toolpath generation in order to machine them. The introduction of T-splines to CAD systems and some reported results of using them in manufacturing makes it possible to consider T-splines, or more generally T-NURCCs (Non-Uniform Rational Catmull-Clark Surfaces with T-junctions), as a good solution for the development of the STEP-NC-based manufacturing of freeform surfaces because of their advantages over NURBS. Therefore, this paper gives an overview of the main arguments in favor of choosing the T-spline surface representation for integration within STEP-CNC systems. We examine the prospects for T-splines to become an integral part of modern manufacturing systems, and highlight some important properties of T-splines which are the most beneficial for manufacturing processes. The paper presents the results of the development of a complete T-spline-enabled STEP-CNC system which can strategically support online toolpath generation for three-axis ball end machining of simple T-spline surfaces using four different freeform strategies defined in ISO 14649-11. These results represent the implementation of the first stage of the development process of intelligent STEP-CNC systems, and in the future more research is needed in this direction.
KeywordsSTEP-NC STEP-CNC Toolpath generation Freeform machining strategy
Unable to display preview. Download preview PDF.
The authors appreciate BECKHOFF China for their kind support of the open-architecture TwinCAT-CNC platform. Special Program of Ministry of Industry and Information Technology, China.
- 8.Suh SH, Kang SK, Chung DH, Stroud I (2008) Theory and design of CNC systems, 1st edn. Springer, Berlin. ISBN 1848822111, 9781848822115Google Scholar
- 10.Zhou K, Wang GJ, Jin HZ, Tan ZY (2008) NURBS interpolation based on exponential smoothing forecasting. Int J Adv Manuf Technol 39(11):1190–1196Google Scholar
- 21.Sederberg MT, Sederberg TW (2010) T-splines: a technology for marine design with minimal control points. In: 2nd Chesapeake power boat symposium 2010Google Scholar
- 23.ISO 14649-11 (2004) Industrial automation systems and integration—physical device control - data model for computerized numerical controllers—part 11: process data for millingGoogle Scholar
- 34.Alliez P, Tayeb S, Wormser C (2018) 3D fast intersection and distance computation. In: CGAL user and reference manual, 4.13 edn. CGAL Editorial BoardGoogle Scholar
- 35.Powell MJD (2009) The BOBYQA algorithm for bound constrained optimization without derivatives. Tech. Rep. NA2009/06; Department of Applied Mathematics and Theoretical Physics; CambridgeGoogle Scholar
- 36.Johnson SG (2018) The NLopt nonlinear-optimization package. http://ab-initio.mit.edu/nlopt
- 38.Huan J, Jing Y, Xiao WL (2011) Industrial control programming language based on IEC61131-3 CNC system software design, 1st edn. Beijing University of Aeronautics and Astronautics Press, Beijing. ISBN 7512404859, 9787512404854Google Scholar