Mghames Sariah, Laghi Marco, Della Santina Cosimo, Garabini Manolo, Catalano Manuel, Grioli Giorgio, Bicchi Antonio
IEEE Int Conf Rehabil Robot. 2017 Jul;2017:539-546. doi: 10.1109/ICORR.2017.8009304.
In this paper we present the design of a one degree of freedom assistive platform to augment the strength of upper limbs. The core element is a variable stiffness actuator, closely reproducing the behavior of a pair of antagonistic muscles. The novelty introduced by this device is the analogy of its control parameters with those of the human muscle system, the threshold lengths. The analogy can be obtained from a proper tuning of the mechanical system parameters. Based on this, the idea is to control inputs by directly mapping the estimation of the muscle activations, e.g. via ElectroMyoGraphic(EMG) sensors, on the exoskeleton. The control policy resulting from this mapping acts in feedforward in a way to exploit the muscle-like dynamics of the mechanical device. Thanks to the particular structure of the actuator, the exoskeleton joint stiffness naturally results from that mapping. The platform as well as the novel control idea have been experimentally validated and the results show a substantial reduction of the subject muscle effort.
在本文中，我们展示了一种用于增强上肢力量的单自由度辅助平台的设计。核心元件是一个可变刚度致动器，它紧密再现了一对拮抗肌的行为。该装置引入的新颖之处在于其控制参数与人体肌肉系统的阈值长度参数具有相似性。这种相似性可通过对机械系统参数进行适当调整来实现。基于此，思路是通过将肌肉激活估计值（例如通过肌电图（EMG）传感器）直接映射到外骨骼上来控制输入。这种映射产生的控制策略以前馈方式起作用，以利用机械设备类似肌肉的动力学特性。由于致动器的特殊结构，外骨骼关节刚度自然地由该映射产生。该平台以及新颖的控制理念已通过实验验证，结果表明受试者的肌肉努力显著降低。
