滚珠丝杠进给系统滚动结合部径向动态特性参数辨识

摘要

针对滚珠丝杠进给系统滚动结合部径向动态特性参数难以确定的问题,提出了一种进给系统在整机状态下滚动结合部径向动态特性参数辨识方法.该方法将丝杠简化为欧拉 伯努利梁,以建立在简谐激振力作用下丝杠轴向上各截面的径向振动方程;设计实验以测量丝杠上测量点的径向振动位移,结合丝杠径向振动方程所计算的理论值建立优化目标函数,基于人工鱼群算法优化识别出滚动结合部的径向刚度及径向阻尼参数.以自行研制的滚珠丝杠进给实验台为研究对象,采用该方法对其导轨副、两端轴承组及滚珠丝杠副滚动结合部的径向刚度与径向阻尼参数进行识别.实验结果表明:以该方法辨识的结合部的参数所计算的丝杠上测量点的径向振动位移与实验测试值之间的误差在3.0%以内,验证了该方法的正确性和有效性.%In allusion to the problems that the radial dynamic characteristic parameters of rolling joints were difficult to determine in ball screw feeding systems,a method to identify the radial dynam-ic characteristic parameters of rolling joints in assembled feed systems was proposed.The screw was simplified as an Euler-Bernoulli beam to create its radial vibration equation under the excitation of har-monic vibration forces,the experiments were designed to obtain the measurement points'radial vibra-tion displacements of the ball screw,combining with the theoretical values calculated by the radial vi-bration equation of the ball screw to establish the optimization goal function,and then the radial stiff-nesses and the radial damping parameters of the rolling joints were identified by using AFSA.Taking a self-developed ball screw feed drive test bench as the research obj ect,the radial stiffnesses and radial damping parameters of its guide pair,the ends of bearings,and its rolling joints in ball screw assembly were identified by using the proposed method.The experimental results demonstrate that the maxi-mum errors of measurement point radial vibration displacements between the calculated values and the tested ones are as 3.0% based on the parameters of rolling joints calculated by the proposed method, and verify the correctness and validity of the proposed method.