上肢外骨骼机器人控制系统建模与设计

外骨骼机器人与军事和人们的日常生活联系日益紧密.首先在简要介绍外骨骼机器人的基础上,讨论了上肢外骨骼机器人控制系统的结构设计,以及基于力与位置的双闭环控制原理;进而,详细讨论了控制系统各环节的选型设计,给出了系统的各组成部分的工作原理.最后,讨论了外骨骼机器人控制系统数学模型的建立,并运用Matlab软件中的Simulink对上肢外骨骼机器人控制系统的数学模型进行仿真,分析了无刷直流电机的响应特性.研究结果表明,采用的力与位置控制能使系统快速、稳定地产生响应信号.     

士兵可穿戴下肢外骨骼机器人多元感知方法研究

下肢外骨骼机器人是一种可穿戴且融合了多种机器人技术的复杂人-机系统。它将人类的智慧与机器人强壮的能力有效地结合起来,最大限度地提高人体的机动力和耐力,这为提升单兵作战系统的能力创造了条件。鉴于下肢外骨骼机器人在作战、后勤保障时可能遇到的复杂地形、多变随机的任务等,仅通过基于既定的典型步态规划程序驱动执行已知的特定动作,难以保证人机间的耦合性和动作的高随意性切换。为此,模拟并提炼出士兵常见的六种下肢动作作为后续研究,然后分析了下肢外骨骼机器人的感知控制原理,并提出了基于脑电预判感知、肌电精确感知和光纤实时校正的多信息融合的感知方法,强调将人的智能参与到机器人控制中,以期推进士兵可穿戴下肢外骨骼机器人的实用化。     

Active torque-based gait adjustment multi-level control strategy for lower limb patient–exoskeleton coupling system in rehabilitation training

This paper proposes an active torque-based gait adjustment multi-level control strategy for lower limb patient–exoskeleton coupling system (LLPECS) in rehabilitation training. The proposed controller has three levels of high, middle, and low sub-controllers: gait adjustment layer (high-level), interaction torque design layer (middle-level), and trajectory tracking layer (low-level). The high-level sub-controller uses an adaptive central pattern generator (ACPG) to adjust the desired gait for rehabilitation training according to the patient’s active torque. In the middle-level sub-controller, the desired interaction torque is designed with neural networks and the estimated muscle torque by utilizing nonlinear disturbance observer (NDO). In the low-level sub-controller, a time delay estimation-based prescribed performance model free control is designed for the accurate tracking performance of the exoskeleton, so as to make the actual interaction torque track the desired value. An exoskeleton virtual prototype, which is developed in SolidWorks, has been imported to MATLAB/Simulink to conduct co-simulations in the SimMechanics environment. The results of co-simulations demonstrate the effectiveness of the proposed control strategy when the patient’s muscle torque is at different recovery degrees.     

工业装配抗振外骨骼的动力学仿真及试验研究

针对手传振动问题，设计出一种上肢穿戴式工业装配抗振外骨骼作为干预装备。采用ADAMS建立了参数化的人机耦合仿真模型；为优化外骨骼减振单元结构参数，对外骨骼减振单元结构进行了单因素振动响应分析，发现减振器阻尼系数及安装位置是影响外骨骼减振性能的关键因素，剪式减振结构的前后弹簧刚度差异化取值时的效果更佳，通过交互正交试验得到修正的最佳因素水平组合。以接触压力和计权振动值为指标，通过抗振性能试验来评估外骨骼样机的减振性能，发现外骨骼在铆接期可减小约39.9%的接触压力，在间歇期接触压力减小49.4%,穿戴外骨骼可减小15.1%的日接振值，单日铆接效率最大可提高18%;接触压力和接振值的变化证明外骨骼具有减振及工具支撑功能。     

An original mechatronic design of a kinaesthetic hand exoskeleton for virtual reality-based applications

Within the new industrial era, the interaction between humans and virtual reality is spreading across our lives. The development of exoskeleton designed to enhance the immersivity of virtual reality environments has a potentially considerable social impact and arises as a hot research topic. The presented work dwells well with the subject by describing the mechatronic design process of a kinaesthetic hand exoskeleton system meant to reproduce proprioceptive stimuli coming from the interaction with a virtual reality. The presented prototype is a modular device, equipped with force and pose sensors, and driven by a Bowden-cable-based remote actuation system. Unlike similar devices, the proposed exoskeleton is specifically thought for VR interaction and is designed to be reversible while exerting up to 15 N per finger. For a more accurate rendering of kinetostatic finger stimuli, a procedure for reconstructing HMI force as a function of measured force and position signals by employing a system’s kinematic and dynamic model is presented, detailed, and followed by some preliminary tests. The results showed that the model can trace forces back to the end-effector with a percentage error below 15%.     

Comment on S. Ahmed,H. Wang,and Y. Tian, “Robust adaptive fractional-order terminal sliding mode control for lower-limb exoskeleton,” Asian J. Control,vol. 21, no. 1, pp. 1–10 (2019)

In this comment, it is shown that there are some non-negligible big mistakes in the analyses and stability proof of the proposed controller in the quoted paper, which makes the main results of this paper to be incorrect. The main unavoidable mistakes in the stability analysis of the main theorem (Theorem 1) are stated and some remarks are also mentioned to fix some of them.     

下肢外骨骼膝关节模糊滑模位置控制器设计

针对下肢助力外骨骼膝关节位置伺服系统运动过程中伺服精度要求高、冲击力矩大、负载变化范围广等特点,提出了一种运用模糊规则调节的位置伺服系统滑模控制策略.该策略设计了一种新型带有积分项的滑模面模糊调节部分的结构为单输入双输出,选用模糊规则调节新型终端滑模型趋近率来抑制滑模抖振.仿真及实验表明,该控制策略稳定性和伺服跟踪性好,对负载干扰的鲁棒性强.     

脑瘫儿童康复助行外骨骼机器人研究与展望

脑瘫是造成儿童行走功能障碍的最常见疾病。 下肢外骨骼在成人脊髓损伤或中风患者康复助行方面已有成熟应用,但 针对脑瘫儿童步态改善与行走效率提高的研究相对较少。 为了从技术与临床角度促进研究人员对脑瘫儿童康复助行外骨骼的 理解,本文首先分析了脑瘫儿童外骨骼相比成人外骨骼研究面临的特殊问题;其次根据下肢驱动关节数量对脑瘫儿童康复助行 外骨骼进行分类并综述其研究现状,重点阐述了其机构特点、控制策略、临床表现,分析了单关节与多关节脑瘫儿童康复助行外 骨骼的优缺点;最后探讨了脑瘫儿童康复助行外骨骼的发展趋势及面临的挑战。