A Novel Joint Torque Estimation Method and Sensory System for Assistive Lower Limb Exoskeletons
A Novel Joint Torque Estimation Method and Sensory System for Assistive Lower Limb Exoskeletons
复制标题
一种新型的辅助下肢外骨骼关节扭矩估计方法和感知系统
DOI：
10.1109/iros.2018.8594250
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
N. Tsagarakis
中科院分区：
文献类型：
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作者：
L. Saccares;Ioannis Sarakoglou;N. Tsagarakis
这项工作提出了一种新的方法，用于在线估计用户的脚踝，膝盖和臀部的扭矩，其目标是为扭矩控制的下肢外骨骼生成参考信号。特别是，这种方法试图解决在真实的生活场景中出现的困难时，非循环运动活动，意外的地形或不可预测的与周围环境的相互作用发生。所提出的方法的优点在于，其不需要关于用户的上身（即，姿势、重量和质心位置）或关于用户的上身与环境的任何交互（即，有效载荷处理或推拉任务）的任何信息。通过经由新颖的传感器化鞋感测系统监测用户的脚与地面的相互作用，该方法对用户的下肢应用逆静态分析以真实的时间估计每个腿关节处的扭矩。该系统是完全可穿戴的，符合人体工程学和便携式的，并使用减少数量的身体姿势传感器。传感器鞋的设计允许跖屈，同时测量脚趾和脚跟方向以及相互作用载荷。这允许在不规则的地形上行走，并在不同的任务中保持自然的脚部姿势。在不同的任务和地形条件下进行了试验，以验证所提出的方法。最后，将该策略在线估计的膝关节力矩作为参考信号驱动iT-Knee双足系统完成辅助任务。
This work presents a novel method for estimating online the torques at the ankle, knee and hip of a user with the goal of generating reference signals for torque controlled lower limb exoskeletons. In particular, this approach attempts to address difficulties arising in real life scenarios when noncyclic locomotion activity, unexpected terrain or unpredicted interactions with the surroundings occur. An advantage of the proposed method is that it does not require any information on the user's upper body (i.e. pose, weight and center of mass location)or on any interaction of the user's upper body with the environment (i.e. payload handling or pushing and pulling task). By monitoring the interaction of the user's feet with the ground through a novel sensorized shoe sensing system, the method applies an inverse static analysis on the user's lower limbs to estimate in real time the torque at each leg joint. The system is fully wearable, ergonomic and portable and uses a reduced number of body posture sensors. The design of the sensorized shoes permits plantar flexion, while measuring the toe and heel orientation and the interaction loads. This allows walking on irregular terrains and natural feet postures in different tasks. Trials were performed to validate the proposed approach under different tasks and terrains. Finally, the knee torques estimated online by the proposed strategy were used as reference signals to drive the iT-Knee Bipedal System in an assistive task.