新型2-2PRUR并联机构运动学分析及工作空间优化

摘要

A novel 2-2PRUR parallel mechanism is proposed to fit the actual demand of industrial production line.Kinematics analysis and workspace optimization are performed based on scatter plot.A method is presented by splitting the moving platform into two parts and adding planetary gear train,which could solve the over-constraints of four degrees of freedom parallel mechanism and increase the turning angle.The constraint equations are obtained using the coordinate method.The inverse-forward solutions of the mechanism are worked out.And the workspace is obtained by using the scatter plot of inverse kinematic solutions.Meanwhile,reasonable structural parameters are obtained by optimizing workspace with the principle of maximizing scattered points based on genetic algorithm.This work would lay the foundation for the future research and application of this type of parallel mechanism.%基于工业生产线实际需求,设计了新型2-2PRUR并联机构,进行运动学分析的同时基于散点图对工作空间进行了优化.提出了通过拆分动平台为两部分并加装行星轮系以解决四自由度并联机构过约束及增大转动自由度转角的方法;运用坐标法写出机构约束方程并求解位置正反解;利用位置反解方程解的散点画出机构工作空间,同时以散点数最大为原则运用遗传算法对工作空间进行优化,获得了合理的结构参数.为此类并联机构的研究和应用奠定了基础.