Predictive Force Model Based Variable Feedrate Scheduling for High-Efficiency NC Machining

Abstract

For improving machining efficiency, variable feedrate optimization instead of constant feedrate becomes very important under constraints of surface roughness and dynamic milling force. In this paper, a predictive force model is established for ball-end milling with considerations of cutter deflection and change of feedrate direction. The corresponding cutting force coefficients are regressed from the experimental data. Then the cutting force model is used for scheduling variable feedrate along the given toolpaths, and formulas of iterative optimization of feedrate are further given. The proposed feedrate scheduling strategy is tested under various machining conditions. Experimental results show that the proposed method can effectively reduce machining time while ensuring machining quality.