Abstract: To effectively realize on-line control of the cutting deflection of thin-walled parts in side milling, a control strategy based on numerical model with finite element method (FEM) and feedrate optimization is proposed. According to the FE simulation results of cutting process, the numerical model among feedrate of machine tool, cutting force, and workpiece deflection is established, and the optimal control target of cutting force is determined. The function of force signal real-time filtering and the strategy of on-line feedrate optimization which based on Brent-Dekker are developed in the open modular architecture CNC system, and feedrate in the machining process could be adjusted to ensure optimum control of cutting force and on-line control of machining deflection through the filtered cutting force and corresponding optimization algorithm. Experimental results show that flank milling deflection of thin-walled workpiece could be maintained within a specified range in the machining process through on-line feedrate optimization, and cutting efficiency is improved.

Key words: cutting deflection, on-line control, on-line feedrate optimization, open modular architecture CNC system