Method of 5-axis Spline Interpolation and Realization in CNC System

An interpolation method using Non-Uniform Rational B-Spline (NURBS) technology in the CAD field is proposed and realized in a 5-axis Computer Numerically Controlled (CNC) system. In this method, the tool path is represented to two NURBS curves, tool-tip and tool-orientation spline curve, based on the same knot vector. CL data is firstly calculated and then transformed to five motion commands of 5 axes of machine through the real-time post-procession algorithm. The acceleration/deceleration controlling method is also presented to avoid the impact of machine. The proposed 5-axis spline interpolation method is realized in our developing 5-axis machine tool and the result of machining shows that the method is feasible.