Real-time NURBS command generators for CNC servo controllers

This study proposes a real-time Non-Uniform Rational B-Spline (NURBS) motion command generator for computer numerical control (CNC) machines to achieve the goal of high-speed and highly accurate machining. Different numerical algorithms for implementing the NURBS motion command generator are compared on the basis of both the computation time and the precision of geometric representation. In addition, to reduce the computation time such that the corresponding servo control laws can be executed in real time, both the NURBS motion command generator and the servo control laws are realized using a digital signal processor. Experimental results indicate that the proposed real-time NURBS command generator is able to provide a satisfactory performance.