Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia.
PLoS One. 2018 Jul 12;13(7):e0200193. doi: 10.1371/journal.pone.0200193. eCollection 2018.
Prolong walking is a notable risk factor for work-related lower-limb disorders (WRLLD) in industries such as agriculture, construction, service profession, healthcare and retail works. It is one of the common causes of lower limb fatigue or muscular exhaustion leading to poor balance and fall. Exoskeleton technology is seen as a modern strategy to assist worker's in these professions to minimize or eliminate the risk of WRLLDs. Exoskeleton has potentials to benefit workers in prolong walking (amongst others) by augmenting their strength, increasing their endurance, and minimizing high muscular activation, resulting in overall work efficiency and productivity. Controlling exoskeleton to achieve this purpose for able-bodied personnel without impeding their natural movement is, however, challenging. In this study, we propose a control strategy that integrates a Dual Unscented Kalman Filter (DUKF) for trajectory generation/prediction of the spatio-temporal features of human walking (i.e. joint position, and velocity, and acceleration) and an impedance cum supervisory controller to enable the exoskeleton to follow this trajectory to synchronize with the human walking. Experiment is conducted with four subjects carrying a load and walking at their normal speed- a typical scenario in industries. EMG signals taken at two muscles: Right Vastus Intermedius (on the thigh) and Right Gastrocnemius (on the calf) indicated reduction in muscular activation during the experiment. The results also show the ability of the control system to predict spatio-temporal features of the pilots' walking and to enable the exoskeleton to move in concert with the pilot.
长时间行走是农业、建筑、服务业、医疗保健和零售业等行业中与工作相关的下肢疾病（WRLLD）的显著风险因素。它是导致下肢疲劳或肌肉衰竭、平衡能力差和跌倒的常见原因之一。外骨骼技术被视为一种帮助这些行业工人减少或消除 WRLLD 风险的现代策略。外骨骼通过增强工人的力量、提高耐力和最小化肌肉高度激活，从而提高整体工作效率和生产力，有潜力使长时间行走的工人受益（除其他外）。然而，控制外骨骼以实现这一目标而不阻碍其自然运动，对于健全人员来说是具有挑战性的。在这项研究中，我们提出了一种控制策略，该策略将双无迹卡尔曼滤波器（DUKF）集成到人体行走的时空特征的轨迹生成/预测（即关节位置、速度和加速度）中，并采用阻抗和监督控制器使外骨骼能够遵循该轨迹以与人类行走同步。实验是在四个受试者携带负载并以正常速度行走的情况下进行的，这是工业中典型的场景。在两个肌肉上采集的肌电图信号：右股中间肌（大腿上）和右比目鱼肌（小腿上），表明在实验过程中肌肉激活减少。结果还表明，控制系统能够预测飞行员行走的时空特征，并使外骨骼能够与飞行员协调移动。
