NURBS Interpolator for Improved High Speed Machining using Minimum Time Method

Abstract

The need to achieve maximum productivity in high speed machining of parts with complex profiles designed by NURBS is increasing. For interpolating NURBS tool paths, different parametric interpolators are proposed and curvature dependent adaptive interpolator is more promising among them. Even though adaptive interpolation follows maximum feed-rate at larger times leading to better utilization of machine capability, problems with machine dynamics still exist. In this paper a new method using minimum travel time is proposed to compute a smooth trajectory satisfying both chord error and machine dynamics without the need of look-ahead algorithms. Simulation results compared with adaptive interpolator show feed rate profile satisfying velocity, acceleration and jerk limits and chord error with optimized time.