说明：  针对铣削过程建立的动力学方程，推导出可用以指导加工的稳定性叶瓣图，获得各主轴转速下对应的极限切深。
(According to the dynamic equation of milling process, the stable lobe diagram which can be used to guide machining is derived, and the corresponding limit cutting depth of each spindle speed is obtained.)