基于混合驱动仿生膝关节机构设计

Design of Bionic Knee Joint Mechanism Based on Hybrid Actuation

目的针对传统假肢关节机构与驱动系统的不足,设计并实现由磁流变阻尼器结合直流电机混合驱动,滚珠丝杠传动的多轴闭链仿生膝关节.方法通过多变量优化设计方法求解出膝关节机构参数、滚珠丝杠安装位置参数和电机的角速度及扭矩.基于虚拟样机技术构建了智能仿生腿的仿真平台并在其上进行了运动学仿真.结果仿生膝关节与人腿膝关节运动曲线接近,结合电机驱动可实现更大范围的步速调整.结论该优化方法得到的系统参数可使膝关节机构具有很高的仿生特性及良好的运动特性.

Corresponding to the deficiency of joint structure and actuation system for traditional prosthesis, multi-axis closed-chain bionic knee joint that is actuated by MR damper augmenting with DC motor and transmitted by ball screw is designed and implemented. By employing multi-variables optimization method, mechanism parameters of knee joint, installation position parameters of ball screw and angular velocity and torque of DC motor can be obtained. The simulation platform of intelligent bionic leg is then constructed by using virtual prototype technology and kinematics simulation is conducted. The movement curves of bionic knee joint are similar with that of human subjects. The mechanism can realize wider adjustment range of gait velocity by combining with DC motor actuation. Experimental results indicate that it can achieve high bionic characters and good motion performance for knee joint mechanism with the optimal parameters calculated by the proposed scheme.