平面结构冗余并联机构的误差敏感度分析

针对一种含闭环支链的平面结构冗余并联机构进行误差敏感度分析。分析了该机构的逆运动学和正运动学。基于矩阵法建立了机构的误差模型，并通过反解、正解结合的方法对该误差模型进行了验证。基于误差模型，得到了评价机构误差敏感度的指标，绘制了各指标在工作空间内的等值线图。基于误差敏感度指标，定义了低误差敏感性工作空间，绘制了低误差敏感性工作空间在工作空间中的分布图。与平面3-RRR并联机构进行了误差敏感度对比分析。结果表明，该机构的低误差敏感性工作空间占比较大，同时可以通过调节其冗余支链不断扩大低误差敏感性工作空间，使机构在大范围空间中保持低误差敏感性。

Sensitivity Analysis of a Planar Parallel Manipulator with Kinematic Redundancy

The error sensitivity of a planar kinematically redundant parallel manipulator which has a closed-loop chain is analysed. The inverse kinematics and forward kinematics of the manipulator are analysed. Based on the matrix method, the error model of the manipulator is established. The error model is verified by combining inverse kinematics with forward kinematics. Based on the error model, the index of error sensitivity of the manipulator is obtained, and the contour map of each index in the workspace is drawn. Based on the error sensitivity index, the low error sensitive workspace is defined and the distribution of the low error sensitive workspace in the workspace is drawn. The error sensitivity is compared with that of the planar 3-RRR parallel manipulator. The results show that the low error sensitive workspace of the planar kinematically redundant parallel manipulator is large, and the low error sensitive workspace can be continuously expanded by adjusting the kinematically redundant chain, so that the manipulator can maintain low error sensitivity in a large range of the workspace.