Kinematics Analysis and Performance Optimization of Low Coupling PRPaR/2CRR Parallel Mechanism
Zhang Li
Zhu Lei
Xu Dong
Abstract：The mechanism is improved by adding support chains to the parallelogram mechanism in re-sponse to the performance shortcomings of the 3CRR parallel mechanism.Based on the topological structure syn-thesis method,a batch of spatial triple translational parallel mechanisms were synthesized,and a PRPaR/2CRR parallel mechanism with spatial triple translational motion was optimized.Characteristics such as degrees of free-dom and coupling were analyzed based on the theory of directional feature sets,respectively.The nonlinear kine-matics equations were established by using the geometric position relation and the constraint of the rod length,and the expression of the inverse position solution was derived.The forward and inverse position solutions were verified by numerical examples.Then,the velocity Jacobian matrix was calculated,the singularity was studied,and the conditions for generating positional anomalies were obtained.In addition,the working space and dexteri-ty degree distribution of the mechanism were analyzed by the graphic method.What's more,a multi-objective optimization design model was established based on the comprehensive performance of the workspace volume,the global dexterity,and the global operability,and the optimal structural parameter size solution was calculated using the NSGA-Ⅱ algorithm.The research results show that the external boundary of the workspace of the PRPaR/2CRR parallel mechanism is smooth,with a semi tire shaped structure and local cavities.A conclusion can be drawn that compared with the 3CRR parallel mechanism,the PRPaR/2CRR parallel mechanism has bet-ter workspace V,global dexterity GCI,operability μ,and other performance.Research has shown that PRPaR/2CRR has good industrial application prospects.
Keywords：Parallel mechanismPosition and orientation characteristicsKinematicsWorkspaceNSGA-Ⅱ optimization algorithm
Publication Date：2024-10-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：13( 83-95 )