Integration, Sensing, and Control of a Modular Soft-Rigid Pneumatic Lower Limb Exoskeleton
Integration, Sensing, and Control of a Modular Soft-Rigid Pneumatic Lower Limb Exoskeleton
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模块化软刚性气动下肢外骨骼的集成、传感和控制
DOI：
10.1089/soro.2019.0023
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发表时间：
2019-10-11
期刊：
影响因子：
7.9
通讯作者：
Chen, Weidong
中科院分区：
文献类型：
--
作者：
Wang, Jiangbei;Fei, Yanqiong;Chen, Weidong
介绍了一种新型模块化软-刚组合式气动外骨骼系统的系统集成、传感与控制。建议的外骨骼由三个软铰链(用于驱动髋关节、膝盖和脚踝关节)和四个刚性链接(与腰部、大腿、小腿和脚对齐)组成。每个软铰链由定制的双向卷曲气动人工肌肉(CPAM)组成并由其驱动，而链接则是三维打印的。每个刚性连杆与其下部柔性铰链(如果有)组合成一个独立的软-刚性模块，即腰部-臀部、大腿-膝盖、小腿-脚踝和脚模块。每个模块都集成了多个传感器，包括两个用于检测充气压力的压力传感器，以及两个柔性传感器和一个通过数据融合估计软铰链弯曲角度的惯性测量单元。通过对CPAM的角度-扭矩-压力关系进行数据拟合，估算出驱动力矩。此外，还研制了外置式电空控制系统。设计了由压力伺服和位置/力矩控制器组成的双闭环控制系统来控制外骨骼铰链的弯曲角和驱动力矩。实验表明，所提出的外骨骼在步态周期的运动范围内具有良好的运动可控性。
This article presents the system integration, sensing, and control of a novel modular soft-rigid pneumatic exoskeleton for lower limb. The proposed exoskeleton consists of three soft hinges (to drive the hip, knee, and ankle joints) and four rigid links (aligned with the waist, thigh, crus, and foot). Each soft hinge is made of and actuated by a customized bidirectional curl pneumatic artificial muscle (CPAM), whereas the links are three-dimensional printed. Each of the rigid links combined with its lower soft hinge (if any) is made into an independent soft-rigid module, that is, the waist-hip, thigh-knee, crus-ankle, and foot modules. With each of the modules are multiple sensors integrated, including two pressure sensors for detecting the inflating pressures, and two flex sensors and an inertia measurement unit for estimating the bending angles of the soft hinges via data fusion. Through a data-fitted angle-torque-pressure relationship of the CPAM, the actuation torque is estimated. An external electropneumatic control system is also developed. The double closed-loop control system consisting of pressure servos and position/torque controllers is designed to control the bending angles and actuation torques of the exoskeleton hinges. Experiment shows good motion controllability of the proposed exoskeleton in the range of motion of a gait cycle.