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。     

Modular design and control of an upper limb exoskeleton

In this paper, we use modular design method to construct an upper limb exoskeleton. This new design method is more simple and easy for exoskeletons than the other techniques, and it is facility to be extended into more joints robots. We also propose a novel admittance control, which works in task space. The admittance control has PID form, and does not need the inverse kinematic and the dynamic model of the exoskeleton. The experimental results show that both the design and the controller work well for the upper limb exoskeleton.

     

下肢外骨骼伺服电机驱动控制方案设计

介绍了可穿戴式下肢外骨骼运动总体控制方案。针对人体髋关节和膝关节运动机理,采用了盘式伺服电机驱动二自由度下肢外骨骼模拟人体下肢摆腿运动控制技术来提高关节运动的响应性能,同时利用4个三维力传感器分别测量人大腿和小腿与外骨骼相互作用力,可用于外骨骼“人主机辅”控制模式算法设计中。在外骨骼2个关节处利用编码器获得关节角度、角速度信息既可用于外骨骼拉格朗日模型参数辨识,也可以作为反馈控制信号用于外骨骼“机主人辅”控制模式中。下位机采用LabVIEW驱动NI主控器实现信号传输与控制,上位机采用MATLAB/Simulink环境设计反馈控制算法与下位机进行实时通信,保证可穿戴式下肢外骨骼能够完成两种运动控制模式的目标,同时提高试穿员的可穿戴舒适性。     

基于肩部协同运动特征的康复外骨骼设计与人机相容性分析

受盂肱关节浮动转动中心的生理运动学属性影响,在基于外骨骼的肩部康复中,人体与外骨骼的兼容性将直接影响康复的效果甚至危及患者的安全。通过分析肩部协同运动特征,提出一种结构紧凑的顺应性肩关节自对准机构,并能够实现独立的锁骨和肩胛骨协同驱动锻炼。基于建立的人机闭链系统,提出4种完整的外骨骼构型,以肩部外骨骼运动空间灵巧性为评价标准,确定了最佳构型,设计并开发肩部外骨骼原型样机。穿戴性能测试试验结果表明,前伸和外摆时人机耦合界面相互作用力从20 N和35 N降低至1 N以下,人体自主外展轨迹和外骨骼穿戴对应点外展轨迹具有良好的吻合性,所提出的顺应性肩部康复外骨骼具有良好的人机相容性。     

下肢外骨骼助力机器人关节驱动设计及试验分析

针对人体下肢关节特点与助行要求,设计了外骨骼机器人关节结构;通过ADAMS软件仿真,分析了外骨骼机器人水平助行过程中关节功率配置需求,根据关节需求设计了外骨骼电液伺服驱动系统;为满足外骨骼机器人对人体下肢关节助力及柔顺性要求,提出了基于关节误差估计的PID控制方法。详细介绍了外骨骼机器人下肢关节结构的运动形式与技术参数,优化配置了关节结构的运动范围与驱动行程,对该机器人进行了运动学分析并通过外骨骼的典型动作进行验证;划分了外骨骼助行过程中步态与关节驱动映射,给出误差估计与补偿PID控制的具体参数;分别从关节跟踪与助力功率的角度,量化分析、对比了基于关节误差估计与常规PID两种控制方法的助力指标参数。试验结果表明,所设计外骨骼关节与驱动系统可实现穿戴者助力行走;对比常规PID控制,抑制了关节驱动控制输出区间的不连续,改善了关节跟踪误差,提升了助力效果与柔顺性。     

Study of an upper arm exoskeleton for gravity balancing and minimization of transmitted forces

An upper-arm wearable exoskeleton has been designed for the assistance and functional training of humans. One of the goals of this design is to provide passive assistance to a user by gravity balancing, while keeping the transmitted forces to the shoulder joints at a minimum. Consistent with this goal, this paper discusses: analytical gravity balancing design conditions for the structure of the exoskeleton; a possible implementation of these conditions into practical designs; the minimization of transmitted joint forces to the shoulder while satisfying the gravity balancing conditions; the numerical optimization of the system for gravity balancing and minimization of transmitted forces; and the effect of parameter variation on joint moments and joint forces via numerical optimization. An implementation of the design was undertaken using zero-free-length springs. The design idea presented in this paper may be useful in relieving the actuators effort of exoskeletons to support the weight of the arm and therefore the possibility of using small actuators and making the system light and portable or even a stand-alone passive support device can be developed based on these gravity balancing conditions.     

An eight-degree-of-freedom upper extremity exoskeleton rehabilitation robot: design,optimization, and validation

Upper extremity exoskeleton rehabilitation robots can be used for the training of patients with upper extremity motor dysfunction. In most cases, the design of such robots focuses on the configuration and the human-machine compatibility. For patients, the use of an exoskeleton rehabilitation robot mainly aims to improve their movement ability, which depends on the range of movement of the upper extremity joints. This paper proposes an eight-degree-of-freedom (DOF) upper extremity exoskeleton rehabilitation robot to improve the movement range of the patient’s upper extremity joints. The structural parameters of the shoulder joint are optimized and analyzed by the kinematic equations of the mechanism and the cyclic iteration algorithm such that the movement range of the patient joint can be maximized. The movement space of the robot is then simulated. Finally, the movement range of the rehabilitation robot joints and the movement space of the rehabilitation robot were measured. Experimental results show that the upper extremity exoskeleton rehabilitation robot can meet the patient’s shoulder, elbow, and wrist movement range, and the overlap with the human upper extremity movement space is 97.1 % and 95.7 % in the coronal and sagittal planes, respectively.

     

外骨骼足端人机接触力测量装置研究

下肢外骨骼机器人系统中,足端接触力的测量是人机交互运动控制的基础,针对设计上面临的足地接触状态复杂、趾关节挠曲运动、重量及尺寸空间限制等问题,提出基于分布式传感器布局,以及刚柔结合的足端人机接触力测量装置结构方案。采用 6 自由度全约束的人机连接方案实现与人足的可靠连接,通过多传感器布置方式来应对复杂的足端受力状况,采用刚柔结合的双层结构,结合多个运动副,解决传感器之间内应力问题,并实现顺应趾关节弯曲的需求,设计了高精度的供电及信号放大电路,并建立力平衡方程实现力信号的合成,最后开展了与三维力台的对比实验,验证了功能指标和测量精度符合设计需求。     

面向助力机器人设计的人体负重楼梯行走下肢运动研究

利用Motion Analysis公司开发的步态分析系统对12名测试对象分别进行不同负重(0kg,10kg,20kg,30kg)的上楼梯行走实验,检测出上楼梯过程中,下肢关键点的三维坐标值及脚底与地面间的反作用力及力矩,通过建立人体下肢动力学模型,获得行走过程中下肢各关节的运动学及动力学行走数据,并分析出随着负重的增加,下肢各关节的运动变化特征。揭示了人体不同负重上楼梯过程中下肢各关节的运动机理,获得的运动学及动力学数据为下肢助力机器人的设计提供了重要的理论依据。     

负重型下肢外骨骼液压动力单元的研究

助力外骨骼是以人为控制主体,机械结构为动力主体,人机高度耦合的复杂力随动系统。为了实现助力外骨骼长时间稳定可靠运行的目的,必须解决其动力单元的部分问题。基于外骨骼系统整体结构,着重于助力外骨骼的液压动力单元部分的研究。介绍负重外骨骼机器人的工作原理及其液压系统的组成,对人体步态进行分析,研究液压动力单元并进行样机实验。结果表明,负重型下肢外骨骼系统采用阀控液压系统,能够满足在负载 60 kg下完成人类基本的下肢运动动作,并且具有较好的人机耦合性。     

Review of human–robot coordination control for rehabilitation based on motor function evaluation

As a wearable and intelligent system, a lower limb exoskeleton rehabilitation robot can provide auxiliary rehabilitation training for patients with lower limb walking impairment/loss and address the existing problem of insufficient medical resources. One of the main elements of such a human–robot coupling system is a control system to ensure human–robot coordination. This review aims to summarise the development of human–robot coordination control and the associated research achievements and provide insight into the research challenges in promoting innovative design in such control systems. The patients’ functional disorders and clinical rehabilitation needs regarding lower limbs are analysed in detail, forming the basis for the human–robot coordination of lower limb rehabilitation robots. Then, human–robot coordination is discussed in terms of three aspects: modelling, perception and control. Based on the reviewed research, the demand for robotic rehabilitation, modelling for human–robot coupling systems with new structures and assessment methods with different etiologies based on multi-mode sensors are discussed in detail, suggesting development directions of human–robot coordination and providing a reference for relevant research.     

负重外骨骼机器人的设计及其运动学动力学仿真

介绍了人体下肢骨骼结构以及人体步态数据,并在此基础上创建了下肢外骨骼机器人的零件模型及其装配体模型,然后将装配体模型导入到MSC.ADAMS软件中,进行运动学和动力学仿真。仿真结果表明:该外骨骼机器人结构合理,能够保证机构运动的灵活性与穿着舒适性;其次是动力学仿真结果反映了外骨骼机器人各关节处所受载荷的变化规律。     

Tracking control of time-varying knee exoskeleton disturbed by interaction torque

Knee exoskeletons have been increasingly applied as assistive devices to help lower-extremity impaired people to make their knee joints move through providing external movement compensation. Tracking control of knee exoskeletons guided by human intentions often encounters time-varying (time-dependent) issues and the disturbance interaction torque, which may dramatically put an influence up on their dynamic behaviors. Inertial and viscous parameters of knee exoskeletons can be estimated to be time-varying due to unexpected mechanical vibrations and contact interactions. Moreover, the interaction torque produced from knee joint of wearers has an evident disturbance effect on regular motions of knee exoskeleton. All of these points can increase difficultly of accurate control of knee exoskeletons to follow desired joint angle trajectories. This paper proposes a novel control strategy for controlling knee exoskeleton with time-varying inertial and viscous coefficients disturbed by interaction torque. Such designed controller is able to make the tracking error of joint angle of knee exoskeletons exponentially converge to zero. Meanwhile, the proposed approach is robust to guarantee the tracking error bounded when the interaction torque exists. Illustrative simulation and experiment results are presented to show efficiency of the proposed controller. Additionally, comparisons with gradient dynamic (GD) approach and other methods are also presented to demonstrate efficiency and superiority of the proposed control strategy for tracking joint angle of knee exoskeleton.     

搬运辅助外骨骼结构设计与实验

为了辅助工人安全轻便地完成搬运任务,针对传统外骨骼在工业领域应用不便的问题,设计了一款新型被动式搬运辅助外骨骼。借助Opensim人体建模软件建立了搬运过程的运动学模型,并对搬运过程进行了力学分析。参照设计要求完成了外骨骼总体设计和弹性蓄能模块设计。根据力学分析求出助力力矩,完成了蓄能模块凸轮、弹簧的参数选择,并对关键零部件进行了力学仿真。仿真结果表明,额定负载下机构能正常运行,不会发生损坏。使用外骨骼样机进行了模拟搬运对比实验,实验过程采集了肌电信号、耗氧量和Borg表数据。结果表明,该款外骨骼对腰部和胸背竖脊肌的助力效果为31.5%和18.7%,显著降低了受试者感知的劳累水平,不会引起耗氧量的显著差异。     

下肢外骨骼负载携行控制方法研究

对人自然行走的步态运动规律进行了5个步态相位划分,并通过人体动作捕获试验获得行走过程中下肢髋关节和膝关节角度变化规律。结合髋关节与膝关节姿态运动规律建立膝关节外骨骼运动数学模型,从理论上分析负载携行系统的运动特性,给出位姿随动控制时的液压缸动态负载参考值。利用伺服阀对液压缸位移进行伺服控制,设计液压缸位移反馈PID控制律,实现携行系统在不同负重、不同位姿变化条件下人机耦合助力随动控制需求。通过重载携行试验表明:外骨骼能够实现50 kg以上人机重载携行,试穿员具有明显的省力效果。     

A systematic graph-based method for the kinematic synthesis of non-anthropomorphic wearable robots for the lower limbs

The choice of non-anthropomorphic kinematic solutions for wearable robots is motivated both by the necessity of improving the ergonomics of physical Human-Robot Interaction and by the chance of exploiting the intrinsic dynamical properties of the robotic structure so to improve its performances. Under these aspects, this new class of robotic solutions is potentially advantageous over the one of anthropomorphic robotic orthoses. However, the process of kinematic synthesis of non-anthropomorphic wearable robots can be too complex to be solved uniquely by relying on conventional synthesis methods, due to the large number of open design parameters. A systematic approach can be useful for this purpose, since it allows to obtain the complete list of independent kinematic solutions with desired properties. In this perspective, this paper presents a method, which allows to generalize the problem of kinematic synthesis of a non-anthropomorphic wearable robot for the assistance of a specified set of contiguous body segments. The methodology also includes two novel tests, specifically devised to solve the problem of enumeration of kinematic structures of wearable robots: the HR-isomorphism and the HR-degeneracy tests. This method has been implemented to derive the atlas of independent kinematic solutions suitable to be used for the kinematic design of a planar wearable robot for the lower limbs.     

凸轮在下肢外骨骼驱动中的应用及分析

以功能设计为出发点,设计下肢外骨骼驱动机构,与从模拟人体腿部肌肉运动的角度出发设计下肢外骨骼驱动的思路有明显不同。由于下肢运动的复杂性,传统的驱动方式在控制上很好实现下肢的行走运动很困难且成本很高,而提出的用复杂的步态曲线来反求设计凸轮外轮廓并用其作为下肢助行器的驱动机构,巧妙的避开了下肢外骨骼中关于如何实现运动控制的难点问题。同时,针对其存在的不能适应步态实时调整的问题也进行了结构补偿,以使外骨骼机构能在一定范围内实现速度的变动。     

面向竞技训练的下肢外骨骼多模态交互系统研究

目前关注辅助下肢提升身体素质训练的可穿戴设备研究存在缺失,而外骨骼与虚拟现实的协同研究是近几年的新兴方向,多模态信息融合的外骨骼系统能有效优化训练效果和训练体验。因此,开发了一套面向竞技训练的下肢外骨骼多模态交互系统,不仅提供了丰富多样且标准规范的辅助训练,并且实现了多感官的沉浸体验。首先,设计一种多自由度分步动作规划方法,基于下肢运动动作点实现训练动作的复现。其次,提出下肢外骨骼多模态交互系统,通过虚拟现实竞技训练模拟器实现信息空间中规范动作的呈现与指示,构建动作数据集和下肢外骨骼机器人实现物理空间中基础训练的辅助与矫正。系统基于多模态交互执行策略,实时给予训练者视觉、听觉、触觉的多感官反馈,实现符合安全规范的沉浸体验。最后,通过系统功能与用户体验两项实验进行系统验证。功能性实验证明,与原有传统训练相比,该系统平均可提升动作准确率27.62%,且具有一定通用性。用户体验的实验结果表明,该系统功能符合设计预期,舒适性相对其他指标有待提高。     

主被动结合的上下肢一体化助力外骨骼机器人的设计与效能评估

针对上肢外骨骼机器人对使用者腰背产生过重负荷的问题,设计了一种主被动结合的上下肢一体化助力外骨骼机器人,利用无源下肢外骨骼来承担部分负荷。基于助力外骨骼应用场景和人体结构特征分析,建立外骨骼机器人的机械结构模型,完成运动学仿真分析,验证了模型的合理性。为解决外骨骼机器人效能评估问题,提出一种模糊综合评估模型,详细介绍了外骨骼机器人的效能评估方法,评估结果为性能良好。研制外骨骼机器人样机,搭建总体控制系统,开展助力性能和负重性能测试实验。实验结果表明,所设计的上下肢一体化助力外骨骼机器人可承受20 kg的负载且对穿戴者提供一定的助力效果。所提出的模糊综合评估模型,为外骨骼机器人的优化设计提供了方向和理论依据。     

Control and Implementation of 2-DOF Lower Limb Exoskeleton Experiment Platform

In this study,a humanoid prototype of 2-DOF(degrees of freedom)lower limb exoskeleton is introduced to evaluate the wearable comfortable effect between person and exoskeleton.To improve the detection accuracy of the human-robot interaction torque,a BPNN(backpropagation neural networks)is proposed to estimate this interaction force and to compensate for the measurement error of the 3D-force/torque sensor.Meanwhile,the backstepping controller is designed to realize the exoskeleton's passive position control,which means that the person passively adapts to the exoskeleton.On the other hand,a variable admittance controller is used to implement the exoskeleton's active follow-up control,which means that the person's motion is motivated by his/her intention and the exoskeleton control tries best to improve the human-robot wearable comfortable performance.To improve the wearable comfortable effect,serval regular gait tasks with different admittance parameters and step frequencies are statistically performed to obtain the optimal admittance control parameters.Finally,the BPNN compensation algorithm and two controllers are verified by the experimental exoskeleton prototype with human-robot cooperative motion.