一种结构解耦型变刚度驱动软体手抓握能力分析

为了实现变刚度驱动软体手的精确抓取,设计了一款结构解耦型的变刚度驱动(变刚度与变形驱动)软体手指。建立了软体手指的指尖力模型,并计算了手指指尖力,将实验测试的手指指尖力数据与计算结果进行比较,证明了手指指尖力模型在一定精度范围内能够预测手指的抓握行为。基于软体手指的指尖力模型对软体手的结构尺寸进行设计,并根据设计的软体手进一步研究指腹的抓握能力,通过仿真与实验的相互印证得到了软体手指腹抓取的抓握力模型。仿真和实验结果表明,软体手的抓握能力与手指的刚度、变形驱动能力以及软体手的抓握形态有关。     

3-DOF索杆桁架式欠驱动机械手运动控制

索杆桁架式机械手是将绳轮传动系统和平行四边形机构结合而提出的一种新型欠驱动机械手。绳索驱动力同时驱动手指关节耦合运动,而手指关节运动又会直接改变绳拉力在各指节单元的驱动力分布,导致索杆桁架式欠驱动系统具有强非线性和运动耦合特点。针对该问题,利用虚功原理,将绳轮传动系统等效为耦合的关节驱动力矩,并建立3-DOF手指准静态运动学模型。根据手指最大运动空间约束条件,确定关节弹簧配置分布并开展手指准静态运动空间分析。采用拉格朗日方程法建立手指一般动力学方程,并转换为"A-P"型等效动力学模型。在此基础上,开展预变形阶段运动控制研究。通过仿真分析和样机试验验证所提分析方法和运动控制策略的有效性。     

直线平夹自适应机器人手抓取分析与实验

传统机器人手在平夹模式下,其手指末端的运动轨迹为圆弧,难以精确捏持薄板物体。针对传统机器人手的不足,设计一种可实现直线平夹精确捏持和自适应包络通用抓取的机器人手,分析了该机器人手的工作原理,结构组成,并且对机器人手抓取模式、平夹抓取最大抓取质量和自适应包络抓取特性进行分析,为优化机器人手设计提供依据。研制了机器人手样机,并在手指表面安置了压力传感器实时监测抓取过程中的受力情况,开展了定性抓取实验和定量测试实验,通过对传感器反馈数据进行分析,得出了机器人手在不同抓取模式、抓取不同特性物体时的受力情况,验证了机器人手抓取性能。     

一种大负载搬运机械手的设计研究

大负载搬运机械手在装备制造、工业生产等领域有广泛的应用需求.本文设计了一种新型的具有自适应抓持能力的大负载搬运机械手,对机械手的方案选型、关键部件的强度校核进行了具体的分析和研究.     

FORCE FEEDBACK MODEL OF ELECTRO-HYDRAULIC SERVO TELE-OPERATION ROBOT BASED ON VELOCITY CONTROL

The tele-operation robotic system which consists of an excavator as the construction robot, and two joysticks for operating the robot from a safe place are useful for performing restoration in damaged areas. In order to accomplish a precise task, the operator needs to feel a realistic sense of task force brought about from a feedback force between the fork glove of slave robot and unfamiliar environment. A novel force feedback model is proposed based on velocity control of cylinder to determine environment force acting on fork glove. Namely, the feedback force is formed by the error of displacement of joystick with velocity and driving force of piston, and the gain is calculated by the driving force and threshold of driving force of hydraulic cylinder. Moreover, the variable gain improved algorithm is developed to overcome the defect for grasping soft object. Experimental results for fork glove freedom of robotic system are provided to demonstrate the developed algorithm is available for grasping soft object.     

刚软结合可穿戴手部康复装置设计

手部康复装置是用于手部功能恢复治疗的装置,刚性装置柔性不足、贴合性差,容易造成二次伤害;软体装置驱动力小,且复杂软体装置不易制作。为克服刚性装置与软体装置的缺点,提出了一种结合软体关节与刚性指节的可穿戴手部康复装置。分析人手的生物结构,设计软体关节结构并分析其弯曲特性,基于刚软结合设计气动手指执行器,并进行有限元应力与变形分析;完成软体硅胶关节模具和手部康复装置的制作;搭建气动手指执行器测试实验平台,测试刚软结合手指执行器的弯曲特性和指尖力,并进行手部康复装置对不同形状物体的抓取实验。结果表明所设计的刚软结合可穿戴手部康复装置可实现手部抓握等运动功能的康复训练。     

三指灵巧手结构设计与动态抓取研究

针对目前多自由度灵巧手存在的结构复杂、体积庞大等问题,设计了一种结构紧凑、质量轻盈的电机直驱式8自由度三指灵巧手.通过微型电机与齿轮减速器配合使用,实现了关节直驱方式,减少了驱动力损耗,手指驱动力得到有效提高.针对灵巧手在动态抓取模式下的不足,通过嵌入式超声波传感器、压力传感器和角度传感器的联合使用,对灵巧手的动态抓取...     

果蔬采摘欠驱动机械手爪设计及其力控制

为了实现果蔬的无损采摘,采用欠驱动原理设计出一种结构更简单、通用性更强的末端执行器。欠驱动机构是指驱动器数目少于机构本身自由度数目的机构,基于欠驱动原理设计的机械手结构简单可靠,抓取物体时具有形状自适应能力,手指可完全包络物体,可以通过最大接触力的闭环力反馈控制来实现无损采摘。基于这一设计思想设计出仅靠一个电动机驱动三个手指的机械手爪,通过理论分析、手爪机构设计与建模、结构参数优化,确定设计尺寸制出机械手爪,设计控制电路结合力反馈控制进行抓取试验。试验结果表明该手爪能实现期望的抓取与最大接触力控制功能,并具有控制简单可靠、抓取稳定、不损伤果实等特点。     

Maximum finger force prediction using a planar simulation of the middle finger

Maximum isometric finger-grip forces were predicted using a biomechanical model for plane motion of the middle finger. In the course of this study, mathematical representations of tendon displacement, the moment arm of tendon at the finger joints and muscle force-length relationship were investigated. The information gathered was applied to the model to estimate the maximum grip force of the middle finger gripping cylinders of different sizes. Muscle force per unit physiological cross-section area of 30 N/cm2 resulted in good agreement with measured force. However, for finger postures having an acute proximal interphalangeal joint angle, the estimated force was greater than that measured. Various joint angles were applied to the model to simulate the wrist and finger postures not limited to the cylinder grip. In general the finger force was greatest with the wrist in its extended position and at acute flexion of the proximal interphalangeal joint. The maximum finger force occurred at reduced metacarpophalangeal joint angles as the wrist joint changed from an extended position to a flexed one. It is also postulated that muscle force-length relationship is an important factor in muscle force predictions. The data obtained by this research are useful for the design of handles and the current model is applicable to the analysis of hand postures for workers using hand tools.     

Design of 3D-printed Cable Driven Humanoid Hand Based on Bidirectional Elastomeric Passive Transmission

Motion control of the human hand is the most complex part of the human body. It has always been a challenge for a good balance between the cost, weight, responding speed, grasping force, finger extension, and dexterity of prosthetic hand. To solve these issues, a 3D-printed cable driven humanoid hand based on bidirectional elastomeric passive transmission(BEPT) is designed in this paper. A semi-static model of BEPT is investigated based on energy conservation law to analyze the mechanical properties of BEPT and a dynamical simulation of finger grasping is conducted. For a good imitation of human hand and an excellent grasping performance, specific BEPT is selected according to human finger grasping experiments. The advantage of BEPT based humanoid hand is that a good balance between the price and performance of the humanoid hand is achieved. Experiments proved that the designed prosthetic hand's single fingertip force can reach 33 N and the fastest fingertip grasping speed realized 0.6 s/180°. It also has a good force compliance effect with only 430g's weight. It can not only grab fragile objects like raw eggs and paper cup, but also achieve strong grasping force to damage metal cans. This humanoid hand has considerable application prospects in artificial prosthesis, human-computer interaction, and robot operation.     

新型集成化仿人手指及其动力学分析

研究了一种新型的集成化仿人手指。这种手指有两个主要特点:采用微直线驱动器和腱传动相结合的方式驱动手指,实现了机械本体和驱动系统的集成;采用差动机构设计了轴线相交的2自由度基关节,手指末端的两个关节是机械耦合的。系统地分析了手指的运动学和动力学,为灵巧手的优化设计和控制奠定了基础。     

三自由度自适应抓持仿人手的设计研究

设计完成了用于仿人形机器人上的具有自动适应被抓持物体几何特征的三自由度仿人手。论文首先设计了具有自适应抓持能力的手指机构，进一步对该手指机构各关节之间的运动耦合关系进行了分析研究，并通过虚拟样机技术验证了所设计的仿人手机构传动系统的正确性和自适应抓持的可行性，最后提出了衡量仿人手抓持能力的指标，分析了所设计的仿人手的抓持能力。所有结果都表明手指机构是合理实用的，所设计完成的仿人手达到了设计要求。     

Function-oriented optimization design method for underactuated tendon-driven humanoid prosthetic hand

The loss of hand functions in upper limb amputees severely restricts their mobility in daily life. Wearing a humanoid prosthetic hand would be an effective way of restoring lost hand functions. In a prosthetic hand design, replicating the natural and dexterous grasping functions with a few actuators remains a big challenge. In this study, a function-oriented optimization design (FOD) method is proposed for the design of a tendon-driven humanoid prosthetic hand. An optimization function of different functional conditions of full-phalanx contact, total contact force, and force isotropy was constructed based on the kinetostatic model of a prosthetic finger for the evaluation of grasping performance. Using a genetic algorithm, the optimal geometric parameters of the prosthetic finger could be determined for specific functional requirements. Optimal results reveal that the structure of the prosthetic finger is significantly different when designed for different functional requirements and grasping target sizes. A prosthetic finger was fabricated and tested with grasping experiments. The mean absolute percentage error between the theoretical value and the experimental result is less than 10%, demonstrating that the kinetostatic model of the prosthetic finger is effective and makes the FOD method possible. This study suggests that the FOD method enables the systematic evaluation of grasping performance for prosthetic hands in the design stage, which could improve the design efficiency and help prosthetic hands meet the design requirements.     

欠驱动多指节机器人手的抓力分析

对欠驱动多指节机器人手的抓力进行了分析,给出了直指和曲指抓取物体时的抓力方程,并对手指抓力作了动态仿真。手指抓力分析为多指节手的机构与力控制设计提供了理论基础。     

五指仿人机器人灵巧手DLR/HIT Hand II

基于机电一体化设计思想和最新的驱动技术,研制DLR/HIT II仿人灵巧手。该灵巧手由5个相同结构的模块化手指和1个独立的手掌构成,每个手指有4个关节、3自由度,所有的驱动器和电路板均集成在手指或手掌内。采用新型的体积小输出力矩大的盘式无刷直流驱动电动机、质量轻的谐波减速器、齿形皮带等的驱动传动方案,使手指的体积和质量得到显著减小;采用钢丝耦合传动方案,实现手指末端两个关节的1:1耦合运动;手指具有位置、力/力矩、温度等多种感知功能。层次化的灵巧手硬件结构由手指电气系统、手掌电气系统和PCI总线控制卡等组成,灵巧手具有点对点串行通信、CAN以及网络等多种通信接口。在灵巧手的外观设计中,将外观设计与灵巧手的本体设计融为一体,实现灵巧手与人手相近的体积和外观。5指灵巧手的质量为1.5 kg,手指的指尖输出力10 N。     

A biomimetic hand employing a dual actuation scheme

This paper presents a biomimetic hand that employs a hybrid actuation scheme that provides large grasping forces and swift motion. This hybrid hand is made up of a red muscle actuator used for grasping and a white muscle actuator used for fast and accurate movement. A parallel structure utilizing fully back-drivable linear motors has been adopted for the white muscle actuators. The red muscle actuators employ a Micro Hydraulic Compressor Converter (MHCC), hydraulic cylinder, and a tendon. The tendon structure enables a passive shape adaptation during the act of grasping an object. Safety in regards to impact is achieved through the back-drivability. The hybrid hand is comprised of two fingers and a thumb. The fingers and the thumb all have 2 degrees of freedom. The hybrid actuation is only applied to the fingers. The experiment results indicate that a grasping force of 94N is generated through the red muscle actuator and a 3 Hz sinusoidal motion is obtained from the white muscle actuator.     

一种欠驱动多指杆机器人手

提出的欠驱动多指杆机器人手能用直指或曲指方式履行各种工业操作任务。本文描述了三指多指杆手的工作原理,手指位移与力分析,这种手抓取物体的适应性,稳定性,抓力都优于常规手爪,提出的手指结构能减少控制复杂性,重量和成本,并能实现多功能地抓取不同物体的能力。     

一种自适应拟人手指抓持力分析与结构优化

采用齿轮齿条传动机构，设计了一种新型自适应拟人手指。该手指自身不带驱动器，适合抓取不同形状、尺寸的物体，使机器人多指手以较少的驱动器驱动较多关节自由度。电机的数量大大减少使机器人手具有许多优点。另外，该手指与人的手指相似，适合用于拟人多指手。分析了该手指抓持力与其设计参数的关系，提出了该手指的结构优化设计原则。     

Analysis of suitable geometrical parameters for designing a tendon-driven under-actuated mechanical finger

This study aims to optimize the geometrical parameters of an under-actuated mechanical finger by conducting a theoretical analysis of these parameters. The finger is actuated by a flexion tendon and an extension tendon. The considered parameters are the tendon guide positions with respect to the hinges. By applying such an optimization, the correct kinematical and dynamical behavior of the closing cycle of the finger can be obtained. The results of this study are useful for avoiding the snapthrough and the single joint hyperflexion, which are the two breakdowns most frequently observed during experimentation on prototypes. Diagrams are established to identify the optimum values for the tendon guides position of a finger with specified dimensions. The findings of this study can serve as guide for future finger design.     

一种通用型负压软体机械手的设计与分析

由柔性材料制成的软体机械手不仅可以提高人机交互的安全性,而且对抓取对象也有一定的保护作用.设计了一种基于低成本3D打印技术的通用型负压软体机械手,该机械手主要由软体驱动器、手指和吸盘组成.软体驱动器提供动力,手指和吸盘用于抓取,且手指和吸盘既能独立又能组合工作.软体驱动器采用波纹管结构,并通过有限元仿真分析了不同结构参...