基于初参数法的丝杠轴向支撑刚度辨识方法

Axial Stiffness Identification of Support Point for Ball Screw Based on Principle of Initial Parameter Method

针对丝杠轴向支撑刚度辨识问题,基于初参数解析方法建立丝杠的初参数矩阵方程,使用边界条件和内力平衡条件,求出矩阵方程中的初参数值。利用初参数值,建立丝杠两端支撑处和螺母处的轴向刚度辨识模型。测量丝杠振幅、简谐力幅值与频率、左轴承组右端面与螺母中间位置点的间距以及螺母中间位置点与右轴承组左端面的间距等参数,识别丝杠支撑点轴向刚度。实验研究表明:基于初参数解析方法建立的丝杠支撑点轴向刚度辨识模型简单,具有可行性。

A new method for evaluating the axial stiffness of ball screw at support point was proposed. Based on principle of initial parameter method, the initial parameter matrix equation was established for force and displacement of ball screw. The structural characters, including boundary condition, force balance and displacement compatibility at support point, were used to achieve initial parameter values. As a result, axial force and displacement of every point on ball screw could be obtained. The identification models of axial stiffness were built by analyzing the amplitude changes of ball screw under some load affection employing the knowledge of mechanical vibration and material mechanics. The research results are in good agreement with the results obtained by the available experiments.