2-PrRS-PR(P)S并联变胞机构工作空间分析与优化

Analysis and Optimization on Workspace of 2-PrRS-PR(P)S Parallel Metamorphic Mechanism

根据变胞理论,提出一种新型可变转动副轴线的2-PrRS-PR(P)S并联变胞机构,通过机构两个分支转动副轴线角度的改变实现机构变胞。首先,分析得出机构两个工作构态的运动学反解;其次,分析机构各参数对不同构态工作空间的限制,采用三维扫描法求解机构两个工作构态的工作空间;最后,研究机构各参数变化对机构不同构态工作空间体积大小的影响,以工作空间体积最大化为目标,利用遗传算法和单一变量法优化机构的结构参数。

Based on the theory of metamorphic mechanism,a novel parallel metamorphic mechanism of 2-PrRS-PR(P)S is proposed.The revolute pair of two limbs in the proposed mechanism can change its rotation axis to achieve the metamorphic configuration.Firstly,the kinematics inverse solutions of the two working configura⁃tions of the 2PrRS-PR(P)S are obtained.Then,the constraints conditions of the mechanism are analyzed.By us⁃ing the three dimensional search method,the reachable workspace is solved.Finally,the relationship between each of parameters and the workspace in different configurations are analyzed.Aiming at the maximized work⁃space volume,the optimized structural parameters is obtained by Genetic Algorithm and single variable analysis.