The conventional method for machining parts with complex curved profiles on CNC machines is to approximate curved profiles to small line segments (by CAM systems). However, this method has some significant drawbacks, such as the very large size of G-code files generated by CAM softwares, difficulties to track machining processes and feedrate fluctuation caused by acceleration / deceleration control of CNC controllers. In this paper, a method of real-time CNC interpolation is proposed for complex curved profiles described by NURBS (Non-Uniform Rational B-Spline) parametric equations. Simulation results on the Matlab/Simulink software show that the presented method is quite capable of interpolating analytic curves and also free-form curves.
