Spline interpolation techniques for computer numerically controlled machining

Non-Uniform Rational B-Spline (NURBS) representation curves and surfaces are widely used in Computer Aided Design (CAD) of sculptured curves and surfaces. Currently, most NURBS curves or surfaces are machined by making piecewise linear approximations to the curves or surfaces and using linear interpolation techniques. To more accurately machine NURBS curves and surfaces, new interpolation techniques for Computer Numerically Controlled (CNC) machine tool controllers are required. Based on the previous work entitled "Spline interpolation algorithm for computer numerically controlled machining," this research work focuses on developing new spline interpolation techniques for high speed machining of sculptured surfaces.; Three major contributions have been made through this research work: (1) the ability to perform the tool radius offset inside the CNC controller and therefore the ability to use tool radius compensation for machining NURBS surfaces, (2) the ability to use spline interpolation for 4-axis and 5-axis contour machining, and (3) the ability to specify cutter axis orientation relative to the surface for 4-axis and 5-axis contour machining.