一种1T2R并联动力头的运动学分析与优化设计  

Kinematic Analysis and Optimal Design of a 1T2R Parallel Manipulator

作　　者：宋轶民[1] 张嘉滕[1] 孙涛[1] 

机构地区：[1]天津大学机构理论与装备设计教育部重点实验室,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2014年第10期863-870,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51075295;51205278;51135008);高等学校博士学科点专项科研基金资助项目(2012003211003;2012003212003);天津市应用基础与前沿技术研究计划资助项目(11JCZDJC22700;13JCQNJC04600)

摘　　要：面向飞机等大型结构件高效加工的需求,提出了一种新型5坐标可重构作业单元执行机构(称之为1T2R并联动力头)的运动学分析与设计方法.首先,借助闭环矢量法构造该类3自由度并联动力头的位置逆解模型,推导量纲统一的速度雅可比矩阵.利用数值搜索法搜索该机构的可达空间,研究关键参数对工作空间的影响规律.然后,以动平台外接圆半径为参照归一化设计参数,利用量纲统一雅可比矩阵的条件数构造兼顾机构运动学性能平均水平与波动量的全域评价指标,将其作为目标函数.最后,依据工程需求及性能要求,结合工作空间分析,确定约束条件,利用灵敏度分析实现机构尺度参数的综合,并用MATLAB遗传算法工具箱予以验证.此研究成果可为该类1T2R并联动力头的详细机械设计奠定理论基础.This paper presents the kinematic analysis and optimal design of a parallel manipulator with three degrees of freedom associated with one translation and two rotations（1T2R）,which may be applied to the high-efficient manufacturing of large aircraft structures. Firstly,the closed-loop vector method was used to establish the inverse position model,and then the homogeneous dimensional Jacobian matrix of the 1T2R parallel manipulator was ob-tained. The reachable workspace was acquired by the numerical search method,and the effect of key dimensional parameters on the workspace was demonstrated. Furthermore,the design parameters were normalized with respect to the radius of the moving platform of the 1T2R parallel manipulator. By using the condition number of the homogene-ous dimensional Jacobian matrix,a global performance index was formulated taking into account the average and the standard deviation of kinematic performance in the prescribed workspace,whose combination can be chosen as the target function of dimensional synthesis. Finally,based on the engineering requirements and the workspace analysis results,the optimized design parameters were obtained through the sensitivity analysis after determining the con-straint equations,which were verified by the genetic algorithm toolbox of MATLAB software. The researches of this paper can lay a solid foundation for more specific design of the 1T2R parallel manipulator.

关 键 词：并联动力头 运动学 量纲统一的雅可比矩阵 尺度综合 

分 类 号：TH122[机械工程—机械设计及理论]