Comparison of NURBS trajectory interpolation algorithms for high-speed motion control systems

In state of the art computerized numerically controlled (CNC) machines toolpaths are often defined as polynomial Non-Uniform Rational B-Spline (NURBS) curves. This article investigates three main types of interpolation algorithms for NURBS toolpaths. These are Taylor series interpolation (TSI), predictor-corrector interpolation (PCI) and feedrate correction polynomial interpolation (FCPI). Interpolation accuracy of each method is investigated for an example NURBS toolpath. Interpolation computation time is also investigated for each method. Results are presented that compare the accuracy and computation efficiency of each method. It is shown that the Predictor-Corrector interpolation method achieves the best accuracy of the investigated methods without significant increase in computation time.