Abstract: Aiming at low recursion-rate and poor approximation accuracy of polynomial-basis Hermite curve, which is commonly used in real-time interpolation of middle and top grade computer numerical control(CNC), a new kind of splines based on algebraic-exponential space, which takes full advantage of high recursion-rate and convergence-rate of exponential function e–t, is reconstructed. The experiment shows that the recursion rate of new curve is 1.7～2.1 times that of Hermite curve, and at the same time, the approximation precision is improved by one order of magnitude. The result indicates that the interpolation-algorithm based on new curve not only promotes machining precision of profile, but also improves machining efficiency simultaneously, thereby meeting the construction requirement of spline curve in middle and top grade CNC.

Key words: Algebraic-exponential spline basis, Computer numerical control, High speed and high precision, High-speed recursion, Spline interpolation