关键词: NURBS曲线, 自适应规划, 干涉预处理, 前瞻插补

Abstract: Since larger speed fluctuation might be caused by direct adaptive interpolation in the process of machining,and overruns of acceleration and jerk during the acceleration and deceleration process were created according to the maxima curvature points to piecewise interpolate the NURBS curve,a kind of NURBS curve look-ahead interpolation algorithm based on interference pretreatment was put forward.The kinematic parameters of adaptive interpolate points was first obtained by adaptive processing to the curve;then the points of which the acceleration and jerk overrun (the dangerous point) was found and the speed of these points was look-ahead controlled,and the information of the dangerous point and its control strategy which could be used to interpolate the curve was got according to the look-ahead control information to proceed with interference processing;the real-time interpolation was made at last according to the interference type between each dangerous point.Simulation results showed that the algorithm could guarantee the machining accuracy,realize smooth transition of the feed rate and satisfied with the machine tool's demands.

Key words: non-uniform rational B-Spline curve, adaptive planning, interference pretreatment, look-ahead interpolation