In allusion to the problem that the existing methods for joint's parameters identification cannot accurately identify the dynamic characteristic parameters of rolling joints in assembled ball screw feed drive unit,a novel method to identify the axial stiffness and damping parameters of rolling joints was proposed.In the method,the screw was simplified as an elastic rod and the axial vibration equations of the feed drive unit under the excitation of harmonic force were derived,the identification model of the joints'axial stiffness and damping parameters was created,the identification equations were established based on measuring the distance between supporting points of the screw,the frequency and amplitude of harmonic exciting force,and the amplitude of axial vibration velocity at the screw end section,and then the axial stiffness and damping parameters of the rolling joints were identified by solving the identification equations using genetic algorithm.Taking a self-designed ball screw feed drive test bench as the research object,the axial stiffness and damping parameters of its ball screw assembly,and its left and right bearing groups were identified by using the proposed method,and the correctness of identified results was verified by experiments.The results demonstrate that the proposed method is correct and effective,and the absolute error of axial vibration velocity at screw end section between the calculated and tested values is within 7.7 μm /s,which achieves high identification accuracy.%针对现有结合部参数识别方法不能精确识别装配状态下数控机床进给单元滚动结合部动态特性参数问题，提出进给单元装配状态下滚动结合部轴向动态特性参数识别方法。将丝杠简化为弹性杆件以建立简谐力作用下丝杠及工作台的轴向振动方程，基于该方程建立结合部轴向刚度与阻尼参数识别模型；通过实验测量丝杠支撑点间距离、简谐激振力频率及幅值、丝杠轴端截面轴向振动速度幅值等参数建立识别方程组；基于遗传算法优化求解该方程组，识别出滚动结合部轴向动态特性参数。以自行研制的滚珠丝杠进给实验台为研究对象，基于该方法对其左、右端轴承组及滚珠丝杠副结合部轴向刚度、阻尼参数进行识别，并对识别结果的正确性进行实验验证。结果表明所提方法正确、有效，丝杠轴端截面轴向振动速度幅值的理论计算值与实验测试值绝对误差在7．7μm／s 以内，参数识别精度较高。
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