基于螺旋理论的3-RRR并联机构设计与仿真

摘要

Degree of freedom and structural synthesis for a 3-RRR parallel mechanism were discussed according to the screw theory.By analyzing constraint screw systems of moving platform and each branch mechanism,3-RRR series branch mechanisms were constructed.Degree of freedom for the parallel mechanism was calculated according to a revised criterion.It could move only in three-rotation directions.The 3-RRR parallel mechanism virtual simulation model was created according to virtual prototyping technology.Throngh forward kinematics simulation and workspace analysis,the problem of the parallel mechanism was found.Therefore,it can ensure kinematics and dynamics analysis for lower-mobility parallel mechanisms.%基于螺旋理论分析了一种3-RRR并联机构的自由度和构型.通过分析动平台和各分支机构的约束螺旋系,构造3-RRR串联分支,运用修正Crübler-Kutabath公式计算出其自由度满足3个转动自由度.基于虚拟样机技术建立3-RRR并联机构虚拟仿真模型,进行正向运动学仿真和工作空间分析,从而找到该机构存在的缺陷,为少自由度并联机构运动学和动力学分析提供保证.