Abstract: A novel planar 3 degrees-of-freedom reconfigurable parallel mechanism with infinite symmetric positions was proposed.The inverse kinematics analysis and direct kinematics analysis were carried out by using loop-closure equation.Then by means of Monte-Carlo method， linkage optimization was presented by genetic algorithm with an objective function consisting of all the factor-workspace，condition numbers of the Jacobian matrix and fluctuation.Afterwards，the constant orientation workspaces were obtained by using a discrete boundary searching algorithm.The singularity of the mechanism was analyzed by the Jacobian matrix and how the reconfigurable mechanism to get rid of the singularity region was discussed.The rotation capability was verified with a newly presented evaluation index and the reachable workspaces under partial joints' stoppages were carried out.The results show the superiorities of the novel reconfigurable parallel mechanism.

Key words: parallel mechanism, reconfigurable, genetic algorithm, linkage optimization, rotation capability

摘要： 提出了一种新型的具有无穷对称位置的平面3自由度可重构并联机构。利用闭环矢量方程进行正逆运动学分析，借助蒙特卡罗方法，以综合工作空间、雅可比矩阵条件数及其波动程度的函数为目标通过遗传算法进行杆件优化，之后应用一种离散边界搜索算法计算了相应的定姿态工作空间。通过雅可比矩阵分析机构奇异性，并讨论了可重构机构如何规避位置奇异区域，提出了一种评价机构转动性能的指标并用其检验了机构的转动能力，分析了部分关节故障下的可达工作空间，对比结果验证了新型的可重构并联机构的优越性。

关键词: 并联机构, 可重构, 遗传算法, 杆件优化, 转动性能