3RPS/UPS结构并联机器人设计与分析

为了满足踝关节康复训练对自由度、工作空间和刚度等性能的要求，本文设计了一种新型的三自由度高刚性3RPS/UPS结构并联机器人.此结构在传统的3RPS结构基础上加入了一条UPS结构的冗余驱动支链，在保证满足自由度要求的同时，又增强了结构的刚度性能，减少了操作平台的晃动和形变，提高了操作精度.通过对此结构进行逆运动学分析、工作空间分析和刚度分析，验证了3RPS/UPS结构可以应用于踝关节康复训练这类具有高负载、操作灵敏等特点的操作任务.最后对该3RPS/UPS结构并联机器人进行了运动学控制仿真，仿真结果表明系统具有较高的动态轨迹跟踪控制精度，适用于实际应用.
To meet the demand of ankle rehabilitation training in degree of freedom (DOF), workspace and stiffness, this paper proposed a three-DOF parallel mechanism with a novel 3RPS/UPS structure. By adding a redundant driving chain with UPS structure under the foundation of the conventional 3RPS mechanism, the proposed structure can meet the demand of DOF and enhance the stiffness simultaneously. Consequently, the shaking and deformation of the operating platform is decreased, and the operation accuracy is improved as well. In this paper, we conducted a systematic analysis on the aspect of inverse kinematics, workspace and stiffness, and then demonstrated the feasibility of the proposed 3RPS/UPS structure to ankle rehabilitation training with the characteristics of heavy-load, microoperation and so on. To verify the applicability in practical operation of the proposed 3RPS/UPS structure, we conducted kinematics control simulation and obtained a high accuracy in dynamic trajectory tracking.