A revised B spline interpolation algorithm of CNC machining

Abstract

In modern CNC machining, the interpolation of complex profile curve with high speed and high accuracy is required. Based on B spline curve theory, a revised algorithm of cubic B spline curve interpolation is presented in the paper. This proposed algorithm gives a new method which is based on pre-judgment of machining feedrate to calculate the tangent vectors of spline curve junction. The tangential vectors are used to establish the spline curve equations with time as a parameter. The trajectory and feedrate profile can be generated simultaneously with these equations. The simulation results show that the algorithm has high calculation efficiency and meet the demands of trajectory accuracy and feedrate smoothing.