一种非对称Stewart机构的运动精度分析  

Motion Accuracy Analysis of an Asymmetric Stewart Mechanism

作　　者：刘晓飞[1] 郭孟涛 万波 陈冉 赵永生[1] LIU Xiaofei;GUO Mengtao;WAN Bo;CHEN Ran;ZHAO Yongsheng(Parallel Robot and Mechatronic System Laboratory of Hebei Province,Yanshan University,Qinhuangdao 066004)

机构地区：[1]燕山大学河北省并联机器人与机电系统实验室,秦皇岛066004

出　　处：《机械工程学报》2024年第23期63-75,共13页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(52105036)。

摘　　要：对一种4/2型Stewart机构的运动精度进行了分析。建立了考虑轴承游隙和驱动分支尺寸误差的机构误差模型,分析了动平台位姿误差的空间分布情况;基于误差模型进行了机构各误差项的灵敏度分析;给出了在满足动平台运动精度要求的条件下各关节精度的取值方法;还给出了分别基于灵敏度-蒙特卡洛法与基于遗传算法的两种精度综合方法;建立了机构的静刚度模型,结合工况综合考虑了各关节误差与结构形变带来的误差影响;并与常规Stewart机构进行了对比分析,证明了其在俯仰工况下的适用性。对今后并联机构精度综合方面的研究具有一定的借鉴意义。The motion accuracy of a 4/2 type Stewart mechanism has been analyzed.It establishes an error model for the mechanism that takes into account bearing clearance and dimensional errors in the driving branches.The spatial distribution of pose errors of the moving platform is investigated.Sensitivity analysis of various error components in the mechanism is carried out based on the error model.Methods for determining the precision of each joint while satisfying the motion accuracy requirements of the moving platform are provided.Additionally,two precision synthesis approaches,namely sensitivity-Monte Carlo method and genetic algorithm-based method,are presented.The paper develops a static stiffness model for the mechanism,considering the combined effects of joint errors and structural deformations under different operational conditions.Comparative analysis with conventional Stewart mechanisms demonstrates its suitability for pitch conditions.The findings have significant implications for future research in precision synthesis of parallel mechanisms.

关 键 词：误差模型 灵敏度 蒙特卡洛法 遗传算法 精度综合 刚度 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]