滚珠丝杠式惯容器非线性建模与参数辨识

Nonlinear Modeling and Parameters Identification of Ball-Screw Inerter

针对滚珠丝杠式惯容器存在的非线性力学特征,首先,分析了滚珠丝杠式惯容器的工作原理,对惯容器的主要部件进行了非线性力学分析,建立了考虑摩擦、间隙以及丝杠弹性力的惯容器非线性力学模型;然后,在数控液压伺服激振试验台上进行了惯容器的力学性能试验,得到了惯容器在不同惯容系数以及不同激振输入下的力学响应特性;最后,根据试验结果分析了摩擦和间隙对惯容器力学性能的影响,得到了便于参数辨识的惯容器力学模型结构,实现了惯容器输出力仿真与试验结果的分析和对比。结果显示,二者在一个周期内的均方根值误差不超过7%,非线性模型呈现出良好的拟合精度,证明了所述方法的可行性和有效性。

The working principle of a ball-screw inerter was analyzed regarding its nonlinear mechanics characteristics.A nonlinear mechanics model with friction,backlash and elastic force of screw was built based on the analysis of the major components of the ball-screw inerter.The mechanical responses of the ball-screw inerter were obtained by testing a ball-screw inerter with different inertances and excitation inputs using a CNC hydraulic servo exciting test-platform.Based on the testing results,the influence of friction and backlash on the mechanical performance of the ball-screw inerter was investigated,and a mechanics model with easily identifiable parameters was obtained with the simplification of friction and backlash.According to the experimental data,the parameters of the ball-screw inerter mechanics model were identified through the recursive least squares algorithm.Comparison of the simulation and experimental results of the ball-screw inerter output force showed that the root mean square value error of the output force in one period was less than 7%,which proves the efficiency of the proposed method.