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。     

面向任务和基于几何特征的机器人多指手抓取模式规划

针对机器人多指手自身的特点,通过分析人手的抓取特性,对其可能具有的抓取模式进行分类。考虑被抓取物体的几何特征和任务要求,采用基函数为高斯核函数的RBF神经网络来表示被抓物体的样本特征和抓取模式之间的复杂非线性映射。将抓取模式分为10类,对于新的被抓物体,利用训练好的神经网络自动生成抓取模式,并利用VC++/OpenGL建立了可视化仿真平台,进行了抓取模式分类仿真实验,结果表明对于新的物体,机器人可以选择适当的抓取模式进行抓取。     

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。     

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。     

基于三维检测网络的机器人抓取方法

机器人抓取任务中面对的是不同形状和大小的物体,而散落在场景中的物体会有不同的姿态和位置,这对机器人抓取中计算物体位姿任务提出了较高的挑战。针对于此,本文设计了一种基于三维目标检测的机器人抓取方法,弥补了基于二维图像识别引导机器人抓取任务中对视角要求较高的缺陷。首先,设计了一种卷积神经网络在RGB图像中识别物体,并回归出物体三维包围盒、物体中心点;其次,提出一种计算机器人抓取物体最佳姿势的策略;最后,控制机器人进行抓取。在实际场景中,使用本文设计的三维检测网络,三维目标检测精度达到88%,抓取成功率达到94%。综上所述,本文设计的系统能有效找到机器人合适的抓取姿势,提高抓取成功率,满足更高的抓取任务要求。     

具有形状自适应的欠驱动拟人机器人手指

为了实现使用较少驱动器获得较多的自由度,从而在不增加控制难度的前提下,更好地抓取物体以及增加手的拟人化,需要研究欠驱动机械手指装置。提出了一种新的设计思想,以此为指导设计了一种机械手指装置,并对其主要设计参数进行了详细分析。试验证明,该装置可以作为机器人拟人手的一个手指或手指的一部分,用以实现机器人拟人手较少驱动器驱动较多的手指关节自由度,并具有抓取不同形状、尺寸的物体的自适应性,降低了装置对控制系统的要求。该装置外形与人手的手指相似,结构简单、可靠、易加工、体积小和重量轻。     

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...     

Development of Gesture-Changeable under-actuated Humanoid Robotic Finger

Robotic fingers, which are the key parts of robot hand, are divided into two main kinds: dexterous fingers and under-actuated fingers. Although dexterous fingers are agile, they are too expensive. Under-actuated fingers can grasp objects self-adaptively, which makes them easy to control and low cost, on the contrary, under-actuated function makes fingers feel hard to grasp things agilely enough and make many gestures. For the purpose of designing a new finger which can grasp things dexterously, perform many gestures and feel easy to control and maintain, a concept called "gesture-changeable under-actuated" (GCUA) function is put forward. The GCUA function combines the advantages of dexterous fingers and under-actuated fingers: a pre-bending function is embedded into the under-actuated finger. The GCUA finger can not only perform self-adaptive grasping function, but also actively bend the middle joint of the finger. On the basis of the concept, a GCUA finger with 2 joints is designed, which is realized by the coordination of screw-nut transmission mechanism, flexible drawstring constraint and pulley-belt under-actuated mechanism.Principle analyses of its grasping and the design optimization of the GCUA finger are given. An important problem of how to stably grasp an object which is easy to glide is discussed. The force analysis on gliding object in grasping process is introduced in detail. A GCUA finger with 3 joints is developed. Many experiments of grasping different objects by of the finger were carried out. The experimental results show that the GCUA finger can effectively realize functions of pre-bending and self-adaptive grasping, the grasping processes are stable. The GCUA finger excels under-actuated fingers in dexterity and gesture actions and it is easier to control and cheaper than dexterous hands, becomes the third kinds of finger.     

基于并联手指结构的多功能灵巧手的设计与研究

为满足工业生产对机器人末端夹持器灵巧性和承载能力的要求,设计了一种基于并联手指结构的多功能灵巧手。对手指机构的运动学、工作空间、奇异性进行了分析,对灵巧手的承载能力进行优化,并通过ADAMS仿真进行了验证。样机实验说明灵巧手具有理想的工作空间和较好的自适应性,可以实现对不同形状物体的随形抓取,适应柔性化工业生产的要求。     

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。     

拟人机器人手多指欠驱动机构研究

欠驱动机构具有增加抓取稳定性、降低控制难度等优点得到广泛研究.与实现单个手指的多关节动力传递的传统欠驱动机构设计思想不同,提出了一种新型多指欠驱动机构.该机构利用设置于关节轴上的扭簧实现了单个电机对多个手指根部的驱动.经分析,给出了该机构的主要参数设计原则.该机构可以作为拟人机器人手的食指、中指、无名指和小指的根部关节,使机器人手在抓取物体时,四个手指能够自动适应不同形状和尺寸的物体,产生适当的抓持力,抓取稳定性高,控制容易.     

基于套索传动的五指灵巧手设计与主从控制

为了使灵巧手更加轻质化、拟人化,设计了一种由舵机经套索驱动的19关节灵巧手。参照人手关节确定灵巧手的构型,通过套索传动实现了关节解耦与驱动后置,并分别对关节机构与驱动集成进行了设计。建立灵巧手多指运动学模型并对其工作空间进行了分析;基于弯曲传感器与主从映射算法实现了抓取的主从跟踪控制。搭建灵巧手样机并进行关节运动实验与抓取控制实验。实验结果表明,将套索传动应用于灵巧手具有可行性,基于主从控制可以实现灵巧手对多种物体的抓取。     

欠驱动两指多指杆机器人手的操作过程与抓力分析

欠驱动两指多指杆机器人手仅用一台驱动电机就能以直指或曲指方式履行各种工业操作任务。文中描述了欠驱动两指多指杆手的操作过程与手指的抓力分析 ,并对手指抓力作了动态仿真。与现有的欠驱动机器人手相比 ,这种多指杆机器人手的结构更为简单紧凑 ,且能减少控制的复杂性、重量和成本 ,并能实现多功能地抓取不同物体的能力     

Configuration Design of an Under-Actuated Robotic Hand Based on Maximum Grasping Space

Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.     

A dexterous robot hand with a bio-mimetic mechanism

This paper describes a development of bio-mimetic robot hand and its control scheme. This robot hand has four independently moving fingers, which are driven by four-coupled link mechanism with two linear actuators. By using the linear actuators, we make the hand similar to human hand in its structure and motion. The coupled link mechanism makes the hand compact in structure and efficient in power. The robot hand is designed considering the dexterity and the compact size suited for various tools and objects in daily life. The hand has tactile sensors mounted on the palm and the fingertips at each finger. With tactile sensor based feedback control and force closure method, the paper shows the control of the robot hand which is very stable in grasping and handling various objects.     

METHOD OF CLASSIFYING GRASPS BY ROBOT HANDS

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In-pipe inspection robot with active pipe-diameter adaptability and automatic tractive force adjusting

An in-pipe robot with active pipe-diameter adaptability and automatic tractive force adjusting is developed for long-distance inspection of main gas pipelines with different diameter series. Its physical design employs the scheme that three sets of parallelogram wheeled leg mechanism are circumferentially spaced out 120° apart symmetrically. This structural design makes it possible to realize the adaptation to pipe diameter and tractive force adjusting together. On the basis of analyzing the mechanical actions of the adaptation to pipe diameter and tractive force adjusting, the related mechanical models are established, and their control system structure and control strategy are discussed. To verify the pipe-diameter adaptability and tractive force adjusting of the robot, related field experiments are implemented in actual underground gas pipeline. The experimental results show that the theoretical analysis in this paper is valid and the prototype of this robot can work well in actual underground gas pipelines. Compared with other similar robots, this robot, which employs active mode for its adaptability to pipe diameter, can be adaptable to the wide range of gas pipeline diameters from 400 mm to 650 mm and automatically provide a stable and reliable tractive force with strong capacity of tractive force adjusting. As a mobile carrier for visual inspection and nondestructive testing to monitor block, corrosion, crack, defect, and wall thickness of main gas pipelines, its inspection range of one-time job in pipelines is extended beyond 1000 m.     

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.     

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.     

新型抓胎机械手结构优化及动作分析

针对目前传统抓胎机械手在取胎过程中易发生胎坯变形不对称和变形量大的问题,对抓胎机械手取胎过程中影响胎坯纵向和横向变形的主要因素进行了研究,提出了定位内撑一体的抓取方法;并结合实际工作要求,从抓胎机械手动力学参数设计角度出发,优化设计出了新型内撑抓胎机械手,利用动力学仿真分析软件ADAMS对新型机械手内撑机构工作位置的运动及动力学特性进行了仿真分析,通过有限元柔性体分析方法,对3种抓胎机械手取胎时轮胎胎坯变形量的大小及分布情况进行了对比、验证。研究结果表明:新型机械手能够实现胎坯定位、内撑取胎的功能,并且对取胎过程中胎坯存在的变形不对称和变形量大的问题均有明显改善。