2RPU+2UPR+RPR多冗余驱动并联机构运动学分析与优化

Kinematic Analysis and Dimension Optimization of Multi-redundantly Actuated Parallel Mechanism 2RPU+2UPR+RPR

提出一种RPR型多冗余驱动两转一移并联机构2RPU+2UPR+RPR。基于螺旋理论建立机构运动螺旋系与约束螺旋系,分析机构自由度性质;建立机构运动学模型,基于软件仿真结果验证理论模型正确性;推导机构传递螺旋系,建立机构局部性能指标与全域性能指标;基于优质工作空间和优质传递性能分布对机构进行尺度优化,获得机构优化尺度与传递性能图谱,分析关键尺度参数对机构传递性能的影响;基于雅可比矩阵和传递性能分布分析优化尺度下机构奇异特性,机构在优化空间内无奇异位形。

A RPR-type multi-redundantly actuated parallel mechanism 2RPU+2UPR+RPR with freedom of two-rotation-one-translation was proposed.It can be used to design a variety of robots used in heavy loads and precision occasions.Motion and constraint screws about the mechanism were analyzed based on the screw theory,and with that the number and properties of degrees of freedom were analyzed.Kinematic model of the mechanism was developed and validated by simulation results.Transfer screw system of the mechanism was derived,and motion/force transfer index of the mechanism were established,including local and global performance index.In addition,the distribution characteristics of the performance index was analyzed.Dimension of the mechanism was optimized based on the quality workspace and quality transfer performance,and the optimized dimension was obtained,as well as the transmission performance map at the optimized dimension.What's more,the influence of key dimension parameters on the mechanism transfer performance was analyzed.To verify the results of the dimension optimization,singular properties at the optimized dimension were analyzed based on Jacobian matrix and transmission performance maps.The research result would provide a reference for the theoretical research and application of this multi-redundantly actuated parallel mechanism.