A Combined Linear and Circular-Arc Approximation of Curves for Feedrate Smoothing of CNC Machining

This paper presents an estimation technique used to represent a parametric curve by a sequence of lines and circular arcs in CNC tool path generation. The advantage of this algorithm is that it can decrease the number of segments required for approximating the curve with the pre-defined tolerance value when compared to the common linearization process. A new combined algorithm also reduces a complexity of existing circular-arc approximation algorithms and can decrease computational time. The main contribution of this paper is a new algorithm provides with smoother feedrate of CNC machining controller due to the corner reduction. The experimental results are provided by the comparison of the original linearization method and this combined linear and circular-arc approximation method.