基于频率灵敏度方法的宏微运动平台连接架结构优化

连接架与驱动设备频率相近而发生共振,将影响宏微运动平台的稳定工作和超精密定位的实现.为避免共振,本文以连接架为研究对象,搭建连接架固有频率有限元分析模型,并对有限元模型进行实验验证.然后,基于频率灵敏度方法对有限元模型结构参数进行摄动,通过分析刚度和第1阶固有频率对结构参数的灵敏度,进行设计变量选择,再以连接架质量为约束条件,将连接架第1阶固有频率倒数作为目标函数,对连接架优化模型进行优化并进行实验验证.通过优化,连接架第1阶固有频率得到了有效的提高,避免了连接架与音圈电机发生共振,从而为宏微运动平台稳定工作和超精密定位提供可靠依据.

Structure Optimization of Connection Frame in Macro/Micro Motion Platform Based on Frequency Sensitivity Analysis

Resonance usually results from similar frequency between connection frame and machine body, which will affect the realization of stability and ultra-precision positioning of macro/micro motion plat- form. In order to avoid resonance, this paper establishes a frequency model of connection frame using fi- nite element method which is verified experimentally. And then, based on sensitivity method, perturba- tion of structure parameters in the model was investigated to obtain structure parameter sensitivity of stiff- ness and the first order natural frequency respectively, and design variables were selected. At last, an optimization model of connection frame was built comprising the objective function which is reciprocal of natural frequency and is verified by experiment, constraint conditions which are the weight of connection frame, and design variables which are results of sensitivity of structural parameters. Through optimization of the connection frame, the first order natural frequency is improved effectively, avoiding resonance be- tween the connection frame and other parts. These results provide theoretical support for steady work and ultra-precision positioning of macro/micro motion platform.