一种轻型仿人机械臂关节并联机构设计

Design of a Lightweight Humanoid Manipulator Joint Parallel Mechanism

基于人体上肢手臂结构特点与运动特性,提出一种轻型仿人绳驱动协作机械臂结构,完成了3-RRRR-(UPU)腕关节并联机构设计;弓形连杆铰链中心连线两两对角相交,交点随动平台相对静平台作球面纯滚动,形成椭圆运动轨迹。构建虚拟圆逼近椭圆误差模型,采集不同尺寸下并联机构运动误差数据进行插值优化处理,得出插值优化模型;在动、静平台分别建立动、静坐标系,构建并联机构运动学简图,完成正运动学分析。通过正运动学分析结果推演出绳索长度与并联机构末端动平台位姿关系,并通过逆运动学分析验证机构正运动学分析。

Based on the structural characteristics and motion characteristics of the upper limbs of human body,a lightweight humanoid rope-driven collaborative robotic arm structure was proposed and the 3-RRRR-(UPU)wrist parallel mechanism was designed.The center lines of the arcuate link hinge intersected on diagonals,and the intersection performed spherical pure rolling with the dynamic platform relative to the static platform,and an elliptical motion trajectory was formed.A virtual circle approximating ellipse error model was constructed,then the motion error data of the parallel mechanism under different sizes was processed with interpolation optimization treatment,finally the optimization model was obtained.The dynamic and static coordinate systems on the dynamic and static platforms were established respectively,a kinematics diagram of the parallel mechanism was constructed and the forward kinematics analysis was completed.Through the analysis of the forward kinematics,the relationship between the length of the rope and the position of the dynamic platform at the parallel mechanism end was deduced.Finally the correctness of the analysis result was verified by the verse kinematics.