Abstract:

Based on D-H transformation matrix,an error model of spherical 5R parallel manipulator was established firstly by virtue of loop circuit incremental method.Here,mechanical structural parameter errors
were considered,at the same time,considering the deviations among axes of  each revolute joint
and centers of sphere from the reason of processing and assembling etc.
These made the error models more close to actual projects.Secondly,the explicit function relationship among all follower movement parameter errors and axis-direction clearance quantity was obtained according to the error model.Finally,sensitivity of the manipulator was analyzed,contribution of each geometrical error component to the kinematics accuracy of the manipulator was researched.This lays a theoretical foundation for calibration,kinematics compensation and applications of the prototype.

Key words: 2-DOF, spherical manipulator, error modeling, D-H transformation matrix

摘要：

以D-H变换矩阵为建模工具，采用环路增量法,建立了包含杆件D-H参数的球面5R并联机构的误差模型，该模型不仅考虑了机构的结构参数误差，还考虑了由于加工和装配等原因出现的各转动副轴线和球心之间的偏差，使得误差模型更接近于工程实际;根据误差模型进一步计算得到了各从动件运动参数误差以及轴向间隙量的显式函数关系;最后对该机构进行灵敏度分析，研究了各几何误差源对该机构末端执行器位姿误差的影响程度。研究结果为该机构样机的标定、运动学补偿及应用提供了理论基础。


关键词: 2-DOF, 球面机构, 误差模型, D-H变换矩阵