中文摘要：

将环路增量法应用于多环路并联机构的误差分析中，并提出环路选取原则。基于D—H参数，结合冗余驱动机构特点，采用环路增量法，建立兼顾位置和姿态两类误差的球面2-DOF冗余驱动并联机器人机构误差模型。该误差模型除包含机构的结构参数误差外，同时还将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考虑进来，更全面地反映了机构的工程实际情况。基于该误差模型进一步分析球面机构出现卡死现象的原因，预估了机构误差，为该机构样机的运动学标定研究奠定了理论基础。

英文摘要：

Loop circuit incremental method is applied to error analysis of multi-loop parallel mechanism, and presents the loop circuit selection principle. Based on D-H parameter and characteristics of mechanism with actuation redundancy, the error model of spherical 2-DOF parallel manipulator with actuation redundancy is established by virtue of loop circuit incremental method which includes both position error and posture error. In the error model, mechanical structural parameter error is considered, at the same time, considering the deviation between axis of each revolute joint and center of sphere from the reason of processing and assembling etc. These make the error model more close to actual project. Based on the error model, the reason of jammed phenomenon which spherical mechanism appears is further analyzed, and the mechanical error is estimated. This lays a theoretical foundation for kinematics calibration research of the prototype.