滚珠丝杠式惯容器非线性建模与参数辨识

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。

Nonlinear Modeling and Parameters Identification of Ball-Screw Inerter

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.