Volume : III, Issue : VIII, August - 2014

Abstract :

It is a common method in numerical control machining field using arcs to fit ellipse. As many numerical control machines do not support ellipse interpolation, ellipse machining is usually realized by arc machining using fitting method. Thus mismachining tolerance depends on theoretical fitting precision. However, present fitting ellipse is not precise due to inaccurate error algorithm of four–center arcs for machining. This work derives analytical form of normal error and determines finite solution interval of four–center arcs method for fitting ellipse. The transcendental equation for getting the error is derived on the basis of graphics theory, and the equation is solved using dichotomy. The minimum error band of fourcenter arcs for fitting ellipse has been determined for a given normal error, and this is realized by Visual LISP language for programming under AutoCAD environment. The optimal solution of four–center arcs for fitting ellipse has been determined, and the accurate criterion is supplied to determine whether four–center arc is feasible to fit ellipse for a given form tolerance.

Article: Download PDF    DOI : https://www.doi.org/10.36106/paripex  

Cite This Article:

, PARIPEX-INDIAN JOURNAL OF RESEARCH : Volume-2 | Issue-3 | March-2013

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