Adaptive Robust Control with Leakage-Type Control Law for Trajectory Tracking of Exoskeleton Robots

This paper investigates the trajectory following problem of exoskeleton robots with numerous constraints. However, as a typical nonlinear system with variability and parameter uncertainty, it is difficult to accurately achieve the trajectory tracking control for exoskeletons. In this paper, we present a robust control of trajectory tracking control based on servo constraints. Firstly, we consider the uncertainties (e.g., modelling errors, initial condition deviations, structural vibrations, and other unknown external disturbances) in the exoskeleton system, which are time-varying and bounded. Secondly, we establish the dynamic model and formulate a close-loop connection between the dynamic model and the real world. Then, the trajectory tracking issue is regarded as a servo constraint problem, and an adaptive robust control with leakage-type adaptive law is proposed with the guaranteed Lyapunov stability. Finally, we conduct numerical simulations to verify the performance of the proposed controller.

An Investigation of Exoskeleton Robotic Systems in Assisting Construction Tasks*

Whilst industrial robots have been widely used in many industrial sectors, they are predominantly used in a structured factory environment. In recent years, off-site robotics have been investigated extensively and there are some promising candidates emerging. One such category of robots is exoskeleton robots and this paper provides an in-depth assessment of their suitability in assisting human operators in undertaking manual operations typically found in the construction industry. This work aims to objectively assess the advantages and disadvantages of these two suits and provide recommendations for further improvements of similar system designs. The paper focuses on the passive exoskeleton robotic suits which are commercially available. Three types of activities are designed and a mechatronic methodology has been designed and implemented to capture visual data in order to assess these systems in comparison with normal human operations. The study suggests that these passive suits do reduce the effort required by human operators to undertake the same construction tasks as evidenced by the results from one focused study, though a number of improvements could be made to improve their performance for wider adoption.

Acceleration Workspace of Cooperating Multi-Finger Robot Systems

We present a mathematical method for acceleration workspace analysis of cooperating multi-finger robot systems using a model of point-contact with friction. A new unified formulation from dynamic equations of cooperating multi-finger robots is derived considering the force and acceleration relationships between the fingers and the object to be handled. From the dynamic equation, maximum translational and rotational acceleration bounds of an object are calculated under given constraints of contact conditions, configurations of fingers, and bounds on the torques of joint actuators for each finger. Here, the rotational acceleration bounds can be applied as an important manipulability index when the multi-finger robot grasps an object. To verify the proposed method, we used a set of case studies with a simple multi-finger mechanism system. The achievable acceleration boundary in task space can be obtained successfully with the proposed method and the acceleration boundary depends on the configurations of fingers.

Intelligent Control of Multi-fingered Robot Hand

The dynamics properties of a kind of multi-fingered robot hand is analyzed. It is pointed out that the dynamics property of this kind of multifingered robot hand in the approaching process is quite different from that in the grasping process and,different control algorithm should be taken in the two process. A position-force hybrid control algorithm is proposed which is applied to the control system of the University of Science and Technology Beijing double-thumb robot hand successfully.

A Review on Lower Limb Rehabilitation Exoskeleton Robots

Lower limb rehabilitation exoskeleton robots integrate sensing, control, and other technologies and exhibit the characteristics of bionics, robotics, information and control science, medicine, and other interdisciplinary areas. In this review, the typical products and prototypes of lower limb exoskeleton rehabilitation robots are introduced and stateof-the-art techniques are analyzed and summarized. Because the goal of rehabilitation training is to recover patients’ sporting ability to the normal level, studying the human gait is the foundation of lower limb exoskeleton rehabilitation robot research. Therefore, this review critically evaluates research progress in human gait analysis and systematically summarizes developments in the mechanical design and control of lower limb rehabilitation exoskeleton robots. From the performance of typical prototypes, it can be deduced that these robots can be connected to human limbs as wearable forms;further, it is possible to control robot movement at each joint to simulate normal gait and drive the patient’s limb to realize robot-assisted rehabilitation training. Therefore human–robot integration is one of the most important research directions, and in this context, rigid-flexible-soft hybrid structure design, customized personalized gait generation, and multimodal information fusion are three key technologies.

Robotic exoskeletons: The current pros and cons

Robotic exoskeletons have emerged as rehabilitation tool that may ameliorate several of the existing healthrelated consequences after spinal cord injury(SCI).However,evidence to support its clinical application is still lacking considering their prohibitive cost.The current mini-review is written to highlight the main limitations and potential benefits of using exoskeletons in the rehabilitation of persons with SCI.We have recognized two main areas relevant to the design of exoskeletons and to their applications on major health consequences after SCI.The design prospective refers to safety concerns,fitting time and speed of exoskeletons.The health prospective refers to factors similar to body weight,physical activity,pressure injuries and bone health.Clinical trials are currently underway to address some of these limitations and to maximize the benefits in rehabilitation settings.Future directions highlight the need to use exoskeletons in conjunction with other existing and emerging technologies similar to functional electrical stimulation and brain-computer interface to address major limitations.Exoskeletons have the potential to revolutionize rehabilitation following SCI;however,it is still premature to make solid recommendations about their clinical use after SCI.

WALK-ASSISTING BALANCE SYSTEM OF THE EXOSKELETON ROBOT FOR DISABLED PEOPLE

A novel methodology for a walk-assisting balance system of the exoskeleton robot for dis-abled people is presented. The experiment on the walk-assisting balance system is implemented using amini-type ropewalker robot. The mechanism of the ropewalker robot is designed, its dynamic model isbuilt, and its control system based on PWM is developed. The emulations in Matlab and the results ofexperiments prove that this methodology is effective.

Technical Analysis of Exoskeleton Robot

Recently, the need for exoskeleton robots has been increased due to the advancement of robotic technologies and changes in the concept of how the robots can be utilized in direct contact with human bodies. The robots, once only used on the factory floor, are now becoming a part of human bodies, which provides the unprecedented level of muscle power boost and the increase of running speed. If used very carefully, the exoskeleton robots can be also used for patients’ rehabilitation. The exoskeleton robots have many potential application areas;?hence most advanced countries are currently developing various types of exoskeleton robots. Those robots can be classified into two major categories, namely the rigid type and the soft type. Each type has own advantages and disadvantages, while the carrying load capacity and the actuation speed can be quite different. There are also many technical difficulties in order to use the exoskeleton robots in the field. The aim of this study is, therefore, to introduce the trends of exoskeleton robot development in advanced countries, while providing the analysis on the technical merits and downside of robot types. The comparison chart also indicates the major technical directions, in which the future technology will be headed for, such as the improved robot response characteristics by employing advanced sensors and artificial intelligence. The robots are becoming smarter, lighter, and more powerful. It is foreseeable that the wearable robots can be a part of human life in the very near future.

下肢外骨骼康复机器人仿真和试验分析

目的为了帮助下肢运动障碍者进行有序康复训练,设计一种下肢外骨骼康复机器人,动力源驱动下肢交叉摆动模拟人类正常步态行走,实现双下肢协调运动,帮助下肢运动障碍者完成康复训练。方法建立外骨骼机器人三维模型、下肢外骨骼机器人D-H模型,对下肢外骨骼康复机器人进行正、逆运动学分析,并将模型导入ADAMS,创建运动副与驱动函数进行运动学仿真,在此基础上制作样机并进行动力学测试试验分析。结果正、逆运动学验证了外骨骼康复机器人空间运动的合理性,ADAMS运动仿真结果与理论计算具有良好一致性,从而保证设计的下肢外骨骼结构与穿戴者下肢同步协调。仿真分析发现理论计算和仿真的误差主要来源于驱动函数误差,动作误差最大为2.15 cm。试验验证髋关节、膝关节运动与参考输入运动具有一致性。但是运动存在误差,髋关节平均误差为5.57°,膝关节平均误差为5.45°,实验发现电机扭矩不足是引起运动误差的首要因素,其次是零件加工误差和装配误差。结论通过理论计算、仿真与试验分析验证了方案的可行性,发现驱动误差、零件加工精度和装配精度可带来误差。研究结果可为进一步完善机器人性能和研究康复机器人动力学影响因素提供基础和参数依据。

下肢外骨骼机器人步行训练对痉挛型双瘫脑性瘫痪患儿平衡功能的影响

目的:探讨下肢外骨骼机器人步行训练对痉挛型双瘫脑性瘫痪患儿平衡功能的影响。方法:纳入2022年7月至2022年12月间就诊于浙江大学医学院附属儿童医院康复科的痉挛型双瘫脑性瘫痪患儿20例为治疗组,采用配对设计,年龄、性别、功能状态匹配的20例作为对照组。两组均给予常规的运动康复训练(运动疗法、悬吊训练、等速肌力训练),治疗组在此基础上增加下肢外骨骼机器人步行训练。在治疗前、治疗8周后对两组患儿进行表面肌电(sEMG)测试、动态平衡反应位移测试、静态平衡评分测试和儿童平衡量表(PBS)测试。结果:治疗前两组患儿臀大肌、臀中肌、股四头肌和胫前肌RMS数值,动态平衡反应位移、静态平衡评分及PBS评分组间差异无显著性意义(P>0.05),两组患儿治疗后臀大肌、臀中肌、股四头肌和胫前肌RMS数值,动态平衡反应位移、静态平衡评分及PBS评分均增加,治疗前后组内比较具有显著性意义(P<0.05),治疗后较治疗前有所改善,组间比较两组患儿治疗前后臀大肌、臀中肌和股四头肌RMS数值差值(臀大肌P=0.021;臀中肌P=0.016;股四头肌P=0.004)、动态平衡反应位移差值(前侧P=0.014;左侧P=0.003;右侧P=0.003)、静态平衡评分差值(P=0.005)及PBS评分差值(P=0.004)具有显著性意义,治疗组差值大于对照组,治疗组改善效果优于对照组。结论:下肢外骨骼机器人结合常规康复治疗能更加有效地改善痉挛型双瘫脑性瘫痪患儿平衡功能。

肌电和足压信息融合的外骨骼步态识别

为解决基于单一信号识别步态相位不够精准的问题,开展了动态交互力激励下的人机协同行走的步态识别研究。设计了肌电和足压信息采集的多模态传感器检测硬件平台;分别对单一信号开展滤波降噪、特征提取与降维等预处理;将表征下肢生理信息的肌电信号与运动信息的足压信号相融合,构建了支持向量机-模糊C均值(support vector machine-fuzzy C-mean algorithm,SVM-FCM)多模信息融合的外骨骼助行步态识别算法;开展了人机协同助行实验,实验结果表明:信息融合后的人机步态相位平均识别率达到82.49%,优于使用单一信号的识别效果,验证了多模信息融合算法识别人机协同步态的有效性。本研究可用于下肢外骨骼机器人运动控制,为人机运动相融奠定基础。

基于改进涡流搜索算法的外骨骼迭代学习控制

为提升康复外骨骼机器人的步态跟踪性能,提出一种基于改进涡流搜索算法的迭代学习控制方法。首先针对传统迭代学习控制抗扰性差和控制信息缺失问题,引入PD控制器、自适应遗忘因子、误差过渡曲线和控制信息搜索等策略,改进迭代学习控制律;其次,基于多种策略对涡流搜索算法进行改进,提出了一种改进涡流搜索算法,改进后的算法可优化迭代学习控制的PD参数;最后进行行走实验,将提出的迭代学习控制方法与现有的同类算法进行仿真和数值比较,并测试了扰动情况下的跟踪性能。实验结果表明,所提方法的误差更小,跟踪性能更强。该算法改进了迭代学习控制的不足,具有较强的抗扰性能,保证了使用时的稳定性。

基于人机工程学的下肢外骨骼运动控制

为避免外骨骼机器人髋关节和膝关节尺寸影响患者正常行走功能的恢复,踝尺寸对脚落地姿态的影响,提出一种基于人机工程学的外骨骼机器人运动控制方法.首先利用人机工程学对人体的参数进行收集,并以此构建适合人体尺寸、具有舒适穿戴的外骨骼模型架构,使外骨骼机器人满足穿戴人群差异化的需求;然后所构建的下肢外骨骼架构,建立外骨骼下肢末端的位姿并构建单肢三自由度机械腿的正向运动学方程,通过对机器人的步行计划,外骨骼机器人的实际步行过程由ADAMS进行模拟,验证人体行走时两腿各关节扭矩的变化规律;最后为了验证该方法在关节速度控制中的优越性和有效性,选择模糊PID进行控制.

康复外骨骼机器人对脑卒中下肢运动功能障碍疗效的Meta分析

目的:运用Meta分析方法系统评价康复外骨骼机器人对脑卒中患者下肢运动功能的康复疗效,并比较不同下肢外骨骼机器人的疗效差异,为脑卒中下肢运动功能障碍患者选择适合的外骨骼机器人提供科学理论依据。方法:计算机检索Cochrane Library、PubMed、Web of Science、Embase、中国知网、维普和万方数据库的相关文献,收集从建库至2022年11月发表的关于探讨下肢康复外骨骼机器人改善脑卒中患者下肢运动功能的随机对照临床试验。由2名研究人员进行文献检索与筛选,使用Cochrane 5.1.0偏倚风险评估工具和Jadad量表对纳入文献进行质量评价。采用RevMan 5.4和Stata 17.0软件对结局指标进行Meta分析。结果:①最终纳入22篇文献,Jadad评分显示均为高质量文献,共865例患者,试验组436例、对照组429例。②Meta分析结果显示,与对照组相比,外骨骼机器人可显著提高脑卒中患者下肢运动功能(Fugl-Meyer Assessment of Lower Extremity,FMA-LE)评分(MD=2.63,95%CI:1.87-3.38,P<0.05)、平衡功能(Berg Balance Scale,BBS)评分(MD=3.62,95%CI:1.21-6.03,P<0.05)、站起-走测试量表(Timed Up and Go,TUG)评分(MD=-2.77,95%CI:-4.48至-1.05,P<0.05)和步频(MD=3.15,95%CI:1.57-4.72,P<0.05),但对功能性步行量表(Functional Ambulation Category Scale,FAC)评分(MD=0.30,95%CI:-0.01-0.61,P>0.05)和6 min步行测试(6-minute walk test,6MWT)评分(MD=3.77,95%CI:-6.60-14.14,P>0.05)的提高不明显。③网状Meta分析结果显示,FMA-LE评分:平地行走式外骨骼(MD=10.23,95%CI:3.81-27.49,P<0.05)和减重式外骨骼(MD=33.66,95%CI:11.49-98.54,P<0.05)与常规康复治疗相比均能改善FMA-LE评分,排序结果为减重式外骨骼>平地行走式外骨骼>常规康复治疗;BBS评分:减重式外骨骼(MD=79.86,95%CI:2.34-2725.99,P<0.05)与常规康复治疗相比能显著改善BBS评分,排序结果为减重式外骨骼>平地行走式外骨骼>常规康复治疗;FAC评分:平地行走式外骨骼(MD=1.38,95%CI:1.00-1.90,P<0.05)与常规康复治疗相比能显著改善FAC评分,排序结果为平地行走式外骨骼>减重式外骨骼>常规康复治疗;TUG评分:减重式外骨骼与常规康复治疗相比(MD=0.07,95%CI:0.01-0.51,P<0.05)能显著改善TUG评分,排序结果为平地行走式外骨骼>减重式外骨骼>常规康复治疗。结论:康复外骨骼机器人可以改善脑卒中患者平衡、步行以及日常生活活动能力,其中减重式外骨骼在提高下肢运动功能和平衡功能方面疗效更优,平地行走式外骨骼在提高功能性步行和转移能力方面疗效更佳。

外骨骼机器人辅助步行康复治疗脊髓损伤:研究热点的CiteSpace分析

背景:脊髓损伤危害严重,损伤后步行功能障碍最影响患者的日常生活能力,在该领域运用外骨骼机器人开展辅助步行康复研究日趋活跃。目的:应用CiteSpace可视化软件绘制脊髓损伤后外骨骼机器人辅助步行为主题的科学知识图谱,并探讨近10年该领域研究现状、热点及未来趋势,为该领域后续科学研究和临床运用提供借鉴。方法:利用Web of Science核心集数据库通过布尔逻辑运算符进行主题词检索,选择语种英语,检索策略:TS=“spinal cord injury OR SCI”AND“walk OR walking”AND“robot OR exoskeleton OR(exoskeleton-assisted walking)OR EAW”,利用知识图谱软件CiteSpace 6.2.R4对去重后获得的高质量文献进行发文量、国家/研究机构合作、高影响力作者/文献共被引、关键词共现/聚类/突现等主题热点、国际前沿趋势可视化分析,并绘制科学知识图谱。结果与结论:①共纳入544篇高质量文献,近10年该领域发文量、总被引频次呈增长趋势;②发文量排名前3的国家依次是美国、中国、意大利,发文量排名前3研究机构是美国退伍军人事务部、美国退伍军人健康管理局、瑞士联邦理工学院;③被引文献频次最高(167次)和中介中心性最高(0.13)的作者均为美国宾夕法尼亚Esquenazi A团队,在该领域具有较高影响力;④对被引频次、中介中心性前5共被引文献分析显示:目前针对脊髓损伤患者配备动力外骨骼设备步行康复研究重点包括在机构、家庭等真实环境中步行康复训练安全性判断、优势分析、个体化培训计划设计,动力外骨骼设备应用于胸椎及以下节段运动功能完全丧失脊髓损伤患者辅助步行效果优劣、影响因素及应用潜力等;⑤近年该领域研究热点集中于个体化(individuals)、步态(gait)、动力外骨骼(powered exoskeleton)、减重支持(body weight support)、功能性电刺激(functional electrical stimulation)、康复(rehabilitation)、辅助技术(assistive technology)、步行活动(ambulation)、恢复(recovery)等内容;⑥该领域研究早期多应用于脑卒中患者,前沿包括减重支持、往复式步态矫形器及功能性电刺激等技术手段,脊髓损伤外骨骼机器人辅助步行康复研究近年呈现上升趋势,关注点逐渐向以适应性控制为机制的医用下肢外骨骼设备研制、安全性提升、应用潜力挖掘等前沿方向转变,研究检测手段注重联合功能性近红外光谱成像等高端技术,而关注患者生活质量、提升运动训练能力及改善机体结构为该领域未来的研究热点。

下肢康复外骨骼机器人设计与性能分析

为了更好地辅助偏瘫患者的康复训练,设计了一种基于盘式电机驱动的下肢康复外骨骼机器人,并通过助力效果可视化研究与性能分析来验证其不同康复训练模式的有效性。首先,对下肢康复外骨骼机器人的结构进行了详细设计,并利用OpenSim软件进行了人机耦合的生物力学分析。然后,开展了基于位置跟踪控制的被动康复训练实验以及抗阻康复训练实验并采集表面肌电信号,验证了所设计下肢康复外骨骼机器人在不同模式下辅助患者康复训练的有效性。结果表明,穿戴下肢康复外骨骼机器人能使人体膝关节的力矩减小50%左右;在被动康复训练实验中,跟随误差为-4°~8°,且人体下肢目标肌群的肌肉激活度呈明显的周期性变化;在抗阻康复训练实验中,人体下肢目标肌群的肌肉激活度随负重的增加而提高。所设计的下肢康复外骨骼机器人具有良好的灵敏性和跟随性,其被动及抗阻康复训练模式均有助于偏瘫患者下肢的康复,具有广阔的应用前景。

下肢外骨骼机器人步行训练对痉挛型双瘫的脑性瘫痪患儿步行功能和步态的影响

目的:探索下肢外骨骼机器人步行训练对痉挛型双瘫患儿步行功能及步态的影响。方法:招募2022年8月至2023年1月间就诊于浙江大学医学院附属儿童医院康复科的痉挛型双瘫儿童21例作为治疗组,采用配对设计,年龄、性别、功能状态匹配的21例作为对照组。两组均给予8周,5次/周常规的运动康复训练(运动疗法、悬吊训练、等速肌力训练),治疗组在此基础上增加下肢外骨骼机器人步行训练。在治疗前、治疗8周后对两组患儿进行6min步行试验(6MWT)、粗大运动功能测试量表88项版本(GMFM-88)D区及E区测试,并采用IDEEA运动捕捉系统评估患儿步态,得到步速、步频、步幅、支撑相时间等步态参数。结果:治疗前两组患儿6min步行距离(6MWD)、GMFM-88 D区评分、E区评分、步速、步频、步幅、双侧支撑相占比均无显著差异(P>0.05),治疗后两组患儿6MWD、GMFM-88 D区评分、E区评分、步速、步频、步幅均增加,双侧支撑相占比降低。组间比较治疗后上述指标无显著性差异(P>0.05),组间比较两组患儿治疗前后6MWD差值(PP<0.01),GMFM-88 D区评分差值(P<0.01)、E区评分差值(P<0.01)、步速差值(P<0.05)、步幅差值(P<0.05)、双侧支撑相占比差值(P<0.01)均有显著性差异,治疗组改善优于对照组。结论:外骨骼机器人训练结合常规康复治疗能够有效改善痉挛型脑瘫患儿的步行功能和步态。

外骨骼机器人可穿戴性能的设计现状及发展趋势

通过文献调查法,梳理了外骨骼机器人与人体结构的匹配情况及其在活动工效方面的应用成果,介绍了外骨骼机器人的基本类型及特点,重点分析外骨骼机器人研发中涉及的可穿戴性能优化设计方法及成效,总结展望其可穿戴性能设计的发展途径。研究认为,可以从分体式结构设计、轻量化设计、柔性化设计以及可调整结构设计4个方面对外骨骼机器人进行深入探讨和开发,从而更好地提升其可穿戴性能。

肌电生物反馈疗法与脊髓损伤患者运动功能的恢复

背景:肌电生物反馈技术具有非侵入性、实时反馈、个性化治疗和促进神经可塑性等独特优势,加速了脊髓损伤患者的功能恢复。目的:综述肌电生物反馈联合运动疗法、外骨骼机器人以及虚拟现实技术在脊髓损伤运动功能恢复中的应用现状及治疗效果。方法:应用计算机检索中国知网、PubMed数据库建库至2024年5月期间的相关文献,英文检索词为“Spinal cord injury,EMG biofeedback,physical therapy,robotic exoskeleton,VR,motor function,exercise”,中文检索词为“脊髓损伤,肌电生物反馈,运动疗法,外骨骼机器人,虚拟现实,运动功能,运动”,最终纳入71篇文献进行综述。结果与结论:肌电生物反馈疗法促进脊髓损伤康复的机制包括促进神经可塑性变化、增强神经肌肉连接和改善运动模式。肌电生物反馈作为新兴的技术手段,通常与运动疗法、外骨骼机器人以及虚拟现实联合用于脊髓损伤后运动功能的恢复,综合治疗效果得到明显提升。然而目前仍存在一些问题和挑战,例如缺乏机制的详细解析、缺少为结合疗效提供有力证据的大规模试验、技术适应性有限等。未来的研究可以集中在这些方面:提高肌电生物反馈的个性化和精准性;可以探索将肌电生物反馈与更先进的技术或工学设备相结合开发新型康复设备,扩大应用领域;将肌电生物反馈应用到步态训练系统、呼吸训练系统以及四肢联动康复系统中,提高反馈的准确性和个性化治疗方案的效果,同时提高设备的易用性和舒适性。

穿戴式外骨骼康复机器人结合Bobath技术对脑卒中偏瘫患者的影响

目的探讨穿戴式外骨骼康复机器人结合Bobath技术对脑卒中偏瘫患者步态、平衡能力、下肢运动Fugl-Meyer功能量表(FMA)评分的影响。方法纳入2020年11月—2022年11月我院收治的78例脑卒中偏瘫患者,按照数字列表法随机分为观察组与对照组,每组39例,对照组予以Bobath技术训练,观察组在对照组基础上予以穿戴式外骨骼康复机器人训练,干预8周。比较两组干预前后的步态参数(步频、步速、跨步长比率)、平衡能力[Berg平衡量表(BBS)]、下肢运动功能FMA评分、日常生活活动能力[改良Barthel指数(MBI)]、下肢肌力恢复情况(屈髋肌力、伸膝肌力)。结果干预前,两组各指标差异无统计学意义(P>0.05);干预后,两组步频、步速、跨步长比率、BBS评分、下肢FMA评分、MBI评分、屈髋肌力、伸膝肌力较干预前显著升高(均P<0.05),观察组步频、步速、跨步长比率、BBS评分、下肢FMA评分、MBI评分、屈髋肌力、伸膝肌力高于对照组(均P<0.05)。结论穿戴式外骨骼康复机器人结合Bobath技术可改善脑卒中偏瘫患者步态和平衡能力,促进下肢运动功能恢复,提高日常生活活动能力,增强患者下肢肌力。