2-UPR-RPU并联机器人的动力学建模与性能分析

Dynamic Modeling and Performance Analysis of a 2-UPR-RPU Parallel Manipulator

动力学建模和性能分析是并联机器人设计中的研究重点。以2-UPR-RPU三自由度并联机器人(U:虎克铰,P:移动副,R:转动副)为研究对象,采用螺旋理论对其进行动力学建模与性能分析。基于闭环矢量法建立2-UPR-RPU并联机器人的运动学逆解模型。采用螺旋理论分析2-UPR-RPU并联机器人分支中各个关节和杆件的速度和加速度,结合虚功原理计算2-UPR-RPU并联机器人运动时的驱动力,并通过ADAMS软件进行数值仿真验证。基于动力学模型分析2-UPR-RPU并联机器人的动态可操作度椭球指标,获得2-UPR-RPU并联机器人在不同操作高度下的转动和移动动态性能分布图谱,为机构的样机设计提供参考依据。2-UPR-RPU并联机器人的动力学建模和性能分析为实现机构在实际操作中的高效高精度控制提供了重要的基础保证。

Dynamic modeling and performance analysis of parallel manipulators are research priorities in the design stage. Based on the screw theory, a systemic dynamic modeling and performance evaluation of a 2-UPR-RPU three degrees of freedom parallel manipulator are presented, where U, P, and R denote universal, prismatic, and revolute joint, respectively. Firstly, the inverse kinematics of the 2-UPR-RPU parallel manipulator is presented. Next, through the screw theory, the velocity and acceleration analysis of joints and limbs in the 2-UPR-RPU parallel manipulator are discussed in detail, followed by the actuated force of three actuators are obtained based on the virtual work principle. A numerical simulation based on the ADAMS software is conducted to verify the correctness of the theoretical result. Then, the distributions of dynamic manipulability ellipsoid index are used to evaluate the dynamic translational and rotational performances of the 2-UPR-RPU parallel manipulator in different operation heights, which provide references for the design of prototype. The dynamic modeling and performance analysis provide a fundamental basis for the efficient and precise control of 2-UPR-RPU parallel manipulator in the actual machining manipulations.