空间2自由度冗余驱动并联机构运动学性能分析

面向建筑机器人领域的高性能机械臂需求，提出了一种空间2旋转自由度的3-UPS&U冗余驱动并联机构。基于螺旋理论和修正的G-K公式对机构的整体自由度进行分析，确定了其围绕恰约束支链万向副旋转的运动特性。建立驱动参数与末端参数之间的映射关系，得到其工作空间模型。通过主驱动并联、从动约束串联的独立建模，构造了该并联机构完整的广义雅可比矩阵，进一步得到动平台末端中心点线速度与驱动关节速度之间的无量纲化雅可比矩阵，并据此建立了特定工作空间下机构的灵巧度、承载能力和刚度性能评价指标。最后结果表明，3-UPS&U冗余驱动并联机构进行较高频次上下摆动作业时，在约束支链所布置的对应转轴方向上，具有更佳的综合运动学性能，且能大大降低性能衰减的幅度。

Kinematic Performance Analysis of Spatial 2-DOF Redundantly Actuated Parallel Manipulator

Aiming at the demand of high-performance manipulators in the field of construction robots, a spatial 2 rotational DOF 3-UPS&U redundantly actuated parallel manipulator is proposed. Based on the screw theory and the modified G-K formula, the overall degree of freedom of the manipulator is analyzed, and the kinematic characteristics of the universal joint rotation around the proper-constraint branch chain are determined. The mapping relationship between the actuated parameters and the end-point parameters is established, and the workspace is obtained. Through independent modeling of the actuated legs and the passive leg, the complete generalized Jacobian matrix of the parallel manipulator is constructed, and the dimensionless Jacobian matrix of the linear velocity of the end center point and the actuator joints is further obtained. The dexterity, load-carrying capacity and stiffness performance evaluation indexes of the manipulator under a specific workspace are established. The final results show that when the 3-UPS&U redundantly actuated parallel manipulator swings up and down at a high frequency, it has better comprehensive kinematic performance in the direction of the corresponding axis of the constraint branch, and can greatly reduce the amplitude of performance degradation.