一种踝关节行走助力外骨骼的设计

An ankle exoskeleton for walking assist

设计了一种可穿戴的踝关节外骨骼.在跖屈驱动相,外骨骼帮助抬升脚后跟,增加蹬地力量,实现行走助力.外骨骼由电机提供转矩,经滚珠丝杆减速,输出直线运动.结构设计的带宽为9 Hz,满足正常行走的频率要求.外骨骼控制由转矩环、阻抗环和位置环3个底层控制环构成;单个步态周期中,由一个有限状态控制器来管理底层控制环的运行和切换.在传动装置设计中,使用了串联弹性驱动器技术,使得外骨骼具有反向可驱动性.控制实验表明:人为反向推动外骨骼,电机可以快速回退做出响应.

A wearable ankle exoskeleton was presented in this paper.The exoskeleton helped to lift the heel in the powered plantarflexion phase,strengthen the push off the ground and assist walking. A motor provided the torque,and a ball screwed as a reducer outputs linear movements.The struc-ture of the exoskeleton has a band width of 9 Hz,which met the demand of walking frequencies.The exoskeleton consisted of three basic control loops:torque loop,impedance loop and position loop.A finite state controller managed the running and switching of the control loops in a walking cycle.A novel technique,series elastic actuator,was used to design the transmission device and make the exo-skeleton to be backdriveable.A simple experiment indicates that the motor can quickly rollback in case that an external force is imposed on the exoskeleton.