四连杆仿生膝关节机构优化设计  

Structural Optimal Design of Four-bar Bionic Knee Joint

作　　者：张莉洁[1] 卢文涛[1] 曹学民[1] 

机构地区：[1]洛阳理工学院,河南洛阳471023

出　　处：《机床与液压》2015年第9期67-70,共4页Machine Tool & Hydraulics

基　　金：河南省科技厅项目(132300410253)

摘　　要：针对四连杆仿生膝关节能实现人腿自然步态的仿生特性要求,考虑摆动期灵活性,以踝关节中心点轨迹与实际人腿相应轨迹误差的均方根最小为优化目标,提出四连杆仿生膝关节尺寸参数的优化数学模型,采用二次规划方法对其进行优化设计,并通过MATLAB的中型算法来实现。通过运动仿真得到踝关节中心轨迹与实际轨迹吻合良好,能够获得自然人腿步态,并得到‘J’形膝关节瞬心轨迹,充分验证了其良好的运动仿生性能。最后,对支撑期速度瞬心位置进行分析,并针对支撑期稳定性提出采用智能磁流变阻尼器的承重自锁方案。In order to meet the requirements of four-bar bionic knee joint to realize characteristics of natural gait,considering the flexibility of leg swing phase,optimization mathematical model for size parameters of four-bar knee joint was presented with the goal of minimizing the root mean square error of the ankle joint center point trajectory and the target trajectory of a man. Parameters of the fourbar knee were optimized using Sequential Quadratic Programming method,which was realized by Medium-Scale Algorithms in Matlab.By kinematics simulation,it was verified that the center point trajectory curve of the optimized four-bar knee well matched with the target one,and natural gait of a man was able obtained. What＇s more,the‘J＇shape curve of the instantaneous center trajectory for this mechanism was plot,by which good motion bionic characteristics were fully verified. Finally position of the instantaneous center at support time is analyzed,and the scheme of loading self-locking structure of smart Magneto rheological（ MR） damper is suggested for its better stabilities by aimed at support time.

关 键 词：四连杆仿生膝关节 步态 二次规划 瞬心轨迹 承重自锁式结构 

分 类 号：TH112[机械工程—机械设计及理论]