针对下肢外骨骼摆动过程中对操作者运动意图的识别和跟踪问题,首先提出了一种基于导纳原理的控制算法.该方法借鉴了物体运动过程中力和速度所具有的导纳特性,通过合理设计导纳参数将操作者与下肢外骨骼之间的交互力转化为外骨骼的期望运动轨迹.然后利用传统控制方法驱动外骨骼准确跟踪期望运动轨迹,最终实现操作者和外骨骼的协调运动.构建了包含交互力信息的人机系统模型,并在此基础上进行了仿真验证试验.仿真结果表明:相比于未驱动的外骨骼,正常摆动频率下操作者与外骨骼之间的交互力降低了约85%,并成功实现了对操作者运动的准确跟踪,误差在±0.3°以内.
To solve the problem of the pilot motion intent's identification and tracking during the swing motion of lower extremity exoskeleton,a control algorithm based on admittance method was proposed at first.This control method used the admittance characteristics between the force and velocity of moving object. And the interaction force between pilot and lower extremity exoskeleton was converted into the desired motion trajectories via the reasonable design of admittance parameters. Then the traditional control was employed to track these trajectories accurately. Finally the coordinated movement of pilot and exoskeleton was achieved. The human-machine system model including interaction force information was established and the simulations were conducted according to the system model. The results show that the interaction force between pilot and exoskeleton is reduced by 85% compared with the unpowered exoskeleton under the normal swing frequency,and the accurate tracking to pilot's motion trajectories is implemented successfully with the error ranged from-0. 3° to 0. 3°.