智能假肢膝关节的优化设计及运动学分析

Optimum design and dynamics analysis of intelligent prosthetic knee joint

智能假肢膝关节是一种代偿下肢缺失功能的机械电子装置,可以采用双摇杆机构实现对假肢膝关节运动特性的模拟。针对假肢膝关节行走过程中能量消耗过大、稳定性较差的问题,以假肢膝关节机构峰值驱动力矩最小为优化目标,建立了优化模型;在满足性能与结构的约束条件下,运用复合形法对该模型进行优化求解,得到了假肢膝关节机构的最佳结构参数;在此基础上,利用ADAMS软件进行了虚拟运动仿真。结果表明:优化后的智能假肢膝关节具有优良的仿生性能,其峰值驱动力矩相比优化前降低了40%,驱动力矩变化范围缩小36%,大大地提升了智能假肢膝关节的稳定性与续航能力。

Intelligent prosthetic knee joint is a mechanical and electronic device which compensates for the basic function of lower limb disability.The kinematic characteristics of knee joint can be simulated by using double rocker mechanism.The optimization model of the knee joint mechanism of the double rocker prosthesis was established to solve the problem of excessive energy consumption and poor stability in walking process of intelligent prosthetic knee joint mechanism.Constraints were established according to the performance and geometric boundary.The optimization model was solved numerically by complex method,and the optimal structural parameters of the prosthetic knee joint mechanism were obtained.On this basis,virtual motion simulation was carried out using ADAMS software.The results show that the optimized prosthetic knee joint mechanism has excellent bionic performance.The peak driving moment of the active rod was reduced by 40%and the variation range of driving moment was reduced by 36%,which effectively improved the endurance of the knee joint mechanism.