INCREMENTAL VERSUS BEST LINE CURVE APPROXIMATION APPROACHES APPLIED TO THE GENERATION OF CNC TOOL PATH

Abstract

Minimization of machining time is one of the most important tasks in the modern manufacturing technology. This paper aims to compare between two different types of curves approximation techniques namely Best Line Curve Approximation (BLCA) technique and Incremental Line Curve Approximation (ILCA) technique. These two approaches are based on approximation of any curve segment by a sequence of linear segments. Throughout building robust mathematical model via computer iteration programs ILCA technique and using the simple iteration method as a numerical approximation tool to achieve these tasks. The “Best Line” is the tangent line that touches the maximum number of points, while the incremental line is a chord line that intersects the interior curve throughout a small interval so that the produced deviation is still within the required tolerance. The proposed approaches are applied to numerical example for the purpose of maneuverability. The results show that BLCA approach requires further modification to control the tool path, but it gives a wide reduction in the length of tool path compared with ILCA approach which tends to maximize the tool path length but it requires a very simple modification to control the tool.