基于正交实验的并联机构刚度回归模型求解分析

并联机构刚度是衡量机构性能的重要指标.以3-PRS型并联机构为例, 提出一种基于正交实验和回归分析的刚度求解分析方法.在建立机构运动学模型和有限元模型的基础上, 通过正交实验的方法, 建立关于3-PRS机构上平台半径与相关杆件结构参数为因素的正交设计表.利用ANSYS-Workbench对多组实验分别进行计算, 利用有限元刚度分析实验数据建立多种多项式回归模型, 根据剩余标准差越小回归函数拟合程度越好的原则选取最好的回归模型, 并应用MINITAB软件对回归函数进行验证分析.研究结果表明:该方法为并联机构的刚度性能提供了新的方法, 利用得到的刚度回归函数模型可获得不同因素对刚度的影响规律.

Solving Analysis of Stiffness Regression Model for Parallel Mechanism Based on Orthogonal Experiment

The stiffness of the parallel mechanism is an important indicator to judge the institutional performance. The 3-PRS parallel mechanism is taken as an example to propose a stiffness solving analysis method based on orthogonal experiment and regression analysis. An orthogonal array of the platform radius and rod structure parameters is established by orthogonal experiment method based on a kinematics model and finite element model. Multiple experiments are calculated using ANSYS-Workbench, then a variety of polynomial regression models are established according to the stiffness of the finite element analysis of experimental data, and the best regression model can be selected under the principle of the smaller the residual standard deviation is, the better the degree of the regression function fitting will be, and verified with the MINITAB software. The results furnish a new type of method for stiffness properties of parallel mechanism study and achieve the law of influence of different factors on the stiffness utilizing this stiffness regression function model.