Free-Form Surface Reconstruction And Tool Path Simulation Based On Interpolate Subdivision

This study is based on the summary and analysis on the current international and domestic research status and basic theory of subdivision surface and tool path calculation, focusing on the current status of tremendous data and inefficient calculation method in such calculations, and combining the subject "Tool path calculation based on arbitrary topological composite surface model" of Department of Education of Zhejiang Province. The work researches and studies the reconstruction of complicate free-form surface and the calculation of tool path. Following are the major works:Firstly, based on initial triangular mesh, a calculation method for recursive interpolation is presented with general meaning. It optimizes weighting coefficient for abnormal vertices, improves boundary interpolate calculation, and thus improves the modeling capacity of interpolate subdivision surface.Secondly, based on subdivision mesh structure, the section normal curvature is calculated by the interpolation of vertices normal vector, and the principal curvature and direction are determined via Euler's formula and least square method. The Boundary interpolate curves are constructed from the position of the vertices and the normal vector. Based on these, a new method calculating the cutter contact position is presented, improving the precision of tool path in NC machining.Thirdly, an application software is developed based on above theories. It can process the initial triangular mesh data with interpolate subdivision and calculate tool path, and output the resulted mesh and tool path file. Through a complicate free-form surface example, the calculation results are compared with the popular Catmull-Clark and Loop models, and the tolerance analysis is conducted based on the results.Finally, the output tool path file is post processed and virtually machined in a simulation software.The surface reconstruction method based on recursive interpolate subdivision theory is simple and highly efficient, and also has great applicability. It has the prospect of a wide application on many areas, such as reverse engineering, image manipulation, etc.