下肢膝关节外骨骼仿生机构运动学研究

Study on kinematics of biomimetic mechanism of knee exoskeleton of lower extremity

针对人体下肢行走时可分为摆动相与承载相的运动承载特征,提出具有运动包容性与承载有效性的下肢膝关节外骨骼仿生欠驱动五杆机构研究原型,运用闭环矢量法对其构建系统运动学模型,在此基础上得到系统速度雅可比矩阵,进而提出一种评价该仿生机构的全局性工作空间灵巧度的新型综合评价指标,并以此为优化目标。在MATLAB 9.0平台上,开展基于运动学模型的系统结构参数数值优化仿真,并结合UG NX 12.0虚拟样机仿真平台,进行仿真结果数据比对,通过误差分析验证了运动学建模的正确性,进而进行数据深入分析,结果表明:优化后的仿生机构相对人体膝关节运动空间而言,具有良好的仿生灵巧包容性,亦表明基于新型综合评价指标下的结构参数优化方法的有效性。

Aiming at the motion bearing characteristics of human lower limbs, which can be divided into the swing phase and bearing phase, a research prototype of bionic under actuated five-bar mechanism of lower limb knee exoskeleton with the motion tolerance and bearing effectiveness is proposed. Using closed-loop vector method to build the kinematics model of the system, a new type of comprehensive evaluation index of an evaluation of the overall situation of the bionic organ based on the system velocity Jacobian matrix is put forward. In the MATLAB 9.0 platform, the numerical simulations of the system structure based on kinematics model parameters are carried out optimization. Combined with UG NX 12.0 virtual prototype simulation platform, the simulation results are compared and the accuracy of kinematics modeling is verified through error analyses. Further data analyses show that the optimized bionic mechanism has well bionic dexterity tolerance compared to the motion space of human knee joint. It also shows the effectiveness of the structural parameter optimization method based on the new comprehensive evaluation index.