Meattini Roberto, Palli Gianluca, Melchiorri Claudio
IEEE Int Conf Rehabil Robot. 2017 Jul;2017:140-145. doi: 10.1109/ICORR.2017.8009236.
In this work, a surface skin electromyography(sEMG)-based control solution for elbow wearable assistive devices during load lifting tasks is presented. The goal of the controller consists in limiting the user's muscle activity during the task execution, in such a way that the assistive device can partially compensate the load-related biceps muscle effort. Since sEMG-driven control strategies based on the estimation of the joint torques generally requires complex task- and subject-dependent training sessions for tuning the control algorithms, here a more direct control approach is proposed, based on a muscle activity error related proportional-integral action together with an double-threshold activation logic. The controller's parameters are easily set by means of a fast, online and automatic subject calibration procedure, ensuring a simple adjustability to different users. An experimental phase has been conducted in order to evaluate the sEMG-based control performance involving four healthy subjects, using as wearable assistive device a twisted string action module, which is particularly suitable for assistive applications because of its lightness and compactness. Results show that the control strategy is able to successfully limit the EMG activity of the subjects during the lifting tasks, providing preliminary outcomes and promising possibilities for the use of twisted string-based technologies to assist human joints and muscles.
在这项工作中，提出了一种基于表面皮肤肌电图（sEMG）的控制解决方案，用于在举重任务期间控制肘部可穿戴辅助设备。控制器的目标是在任务执行期间限制用户的肌肉活动，以便辅助设备能够部分补偿与负荷相关的肱二头肌用力。由于基于关节扭矩估计的sEMG驱动控制策略通常需要复杂的任务和受试者相关的训练课程来调整控制算法，因此这里提出了一种更直接的控制方法，该方法基于与肌肉活动误差相关的比例积分作用以及双阈值激活逻辑。控制器的参数可通过快速、在线和自动的受试者校准程序轻松设置，确保对不同用户具有简单的可调性。为了评估基于sEMG的控制性能，进行了一个实验阶段，涉及四名健康受试者，使用一种绞合线动作模块作为可穿戴辅助设备，该模块因其轻便和紧凑而特别适合辅助应用。结果表明，该控制策略能够在举重任务期间成功限制受试者的肌电图活动，为使用基于绞合线的技术辅助人体关节和肌肉提供了初步结果和有前景的可能性。
