2-UPS/RR并联髋关节助力机构及运动性能

为了帮助髋关节受损的患者完成行走运动,提出了一种适用于髋关节助力的2-UPS/RR并联机构.该机构不仅可以满足髋关节助力所需要的前屈/后伸、内收/外展、内旋/外旋运动,还可以保证机构的旋转中心与不同患者的髋关节旋转中心重合.计算了自由度,并应用解析法给出了机构的位置反解,建立了速度雅克比矩阵,通过对驱动参数的限定,求解了机构的工作空间.最后,基于雅克比矩阵,对比分析了分别驱动移动副和虎克副2根旋转轴时机构的运动学性能.结果表明:在规定的工作空间内驱动移动副时,机构具有良好的可操作性、运动灵活性和刚度特性.相比当前的髋关节助力机构,其结构简单,有效避免了支链间不必要的干涉,减小了整个机构的占用体积.设计的该机构适合髋关节助力训练.

2-UPS/RR Parallel Mechanism Used in Human Hip Joint Power Assist and Kinematic Performance

To help patients with impaired hip joint walking exercise, a 2-UPS/RR parallel mechanism was presented, which is suitable for hip joint assisting. It meets the requirements of hip movement for flexion/extension adduction/abduction, pronation/supination, and its mechanism centres of rotations accurately match different patient’s hip. The mobility of the mechanism was calculated, inverse kinematics was solved by using the analytical method, and the velocity Jacobian matrix was established. By demarcating the driving parameters, the work space of the mechanism was coped with. Finally, in view of the Jacobian matrix, the kinematics performance of the mechanism was analyzed when driving mobile deputy and two axes of Hooke deputy, respectively. Results show that the mechanism is of favourable operability, flexibility and stiffness characteristics within the specified workspace. Compared wtih some existing hip joint power assist robots, the mechanism in simple structure can effectively avoid unnecessary interference between branches and significantly reduce the occupancy volume of the entire unit, absolutely with more advantages. Therefore, the designed mechanism is suitable for hip assist training.