DESIGN OF A NOVEL DEXTEROUS ROBOT HAND

In the robotic community more and more hands are developed. Based on theexperience of HIT Hand and DLR Hand II, a smaller and easier manufactured dexterous robot hand withmultisen-sory function and high integration is jointly developed. The prototype of the hand issuccessfully built. It has 4 fingers in total 13-DOFs (degree of freedom). Each finger has 3-DOFsand 4 joints, the last 2 joints are mechanically coupled by means of four-bar linkage mechanism. Italso has an additional DOF to realize motion of the thumb relative to the palm. The fingertip forcecan reach up to 10 N. Full integration of mechanical body, actuation system, multisensory system andelectronics is a significant feature. DSP based control system is implemented in PCI busarchitecture and the serial communication between the hand and DSP needs only 2 lines.

Cartesian impedance control of dexterous robot hand

Presents a novel compliant motion control for a robot hand using the Cartesian impedance approach based on fingertip force measurements. The fingertip can accurately track desired motion in free space and appear as mechanical impedance in constrained space. In the position based impedance control strategy, any switching mode in contact transition phase is not needed. The impedance parameters can be adjusted in a certain range according to various tasks. In this paper, the analysis of the finger’s kinematics and dynamics is given. Experimental results have shown the effectiveness of this control strategy.

Design and modeling for a kind of humanoid dexterous hand with elastic palm

With dexterous hands, robots can improve the work scope and work ability significantly. As palms of the existing multi-hand robots are made of steel plates that have small contact area, the robots cannot grab firmly. In this study, a new five-fingered dexterous robot hand is developed. Having flexible palm with 17 degree of freedoms （ DOFs）, the hand can grasp more stably and firm- ly. First, the forward kinematics and inverse kinematics of the fingers and the hand are calculated. Then, the connection between the force exerting on the end effectors and the torque exerting on the joint is set up, laying the foundation for the following control. Finally, through the analysis and sim- ulation of the position, velocity and acceleration, the trajectory planning has a better performance.

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.

MANIPULATION KINEMATICS ON DEXTEROUS HANDS CONSIDERING PURE ROLLING CONTACTS AS PASSIVE JOINTS

The manipulation and constraint equations are established by considering the pure rolling motion in a dexterous hand as two passive joints. According to mapping relation among the motion of the system, the differential kinematics and mobility are studied. The minimal structure for realizing the task motion of the object is obtained, and the conditions for dexterous manipulation are presented. Finally, some rolling manipulations are used as examples to demonstrate the applicability of approach proposed.

Optimal design and workspace analysis of tooth-arrangement three-fingered dexterous hand

Based on analysis of human hand grasp, the finger number and the kinematic pair pattern are decided. Aiming at the parameters of each finger, a multi-objective function for optimizing the structure of multi-fingered hand was proposed. Considering the peculiarity of tooth-arrangement and dexterous hand grasp, the constraints were established, and a satisfactory result was gained. Furthermore, the optimal results were analyzed, and a law of parameter optimal design was given. It is proved that this optimization method is effective to optimize the relation of each parameter and make it integrated optimum under each standard. At last, the practical workspace of this hand was analysed and simulated. And a new effective simulation method of workspace was proposed.

Design and control of integrated pneumatic dexterous robot finger

Based on flexible pneumatic actuator(FPA),bending joint and side-sway joint,a new kind of pneumatic dexterous robot finger was developed.The finger is equipped with one five-component force sensor and four contactless magnetic rotary encoders.Mechanical parts and FPAs are integrated,which reduces the overall size of the finger.Driven by FPA directly,the joint output torque is more accurate and the friction and vibration can be effectively reduced.An improved adaptive genetic algorithm(IAGA) was adopted to solve the inverse kinematics problem of the redundant finger.The statics of the finger was analyzed and the relation between fingertip force and joint torque was built.Finally,the finger force/position control principle was introduced.Tracking experiments of fingertip force/position were carried out.The experimental results show that the fingertip position tracking error is within ±1 mm and the fingertip force tracking error is within ±0.4 N.It is also concluded from the theoretical and experimental results that the finger can be controlled and it has a good application prospect.

An Adaptive Hand Exoskeleton for Teleoperation System

Teleoperation can assist people to complete various complex tasks in inaccessible or high-risk environments,in which a wearable hand exoskeleton is one of the key devices.Adequate adaptability would be available to enable the master hand exoskeleton to capture the motion of human fingers and reproduce the contact force between the slave hand and its object.This paper presents a novel finger exoskeleton based on the cascading four-link closed-loop kinematic chain.Each finger has an independent closed-loop kinematic chain,and the angle sensors are used to obtain the finger motion including the flexion/extension and the adduction/abduction.The cable tension is changed by the servo motor to transmit the contact force to the fingers in real time.Based on the finger exoskeleton,an adaptive hand exoskeleton is consequently developed.In addition,the hand exoskeleton is tested in a master-slave system.The experiment results show that the adaptive hand exoskeleton can be worn without any mechanical constraints,and the slave hand can follow the motions of each human finger.The accuracy and the real-time capability of the force reproduction are validated.The proposed adaptive hand exoskeleton can be employed as the master hand to remotely control the humanoid five-fingered dexterous slave hand,thus,enabling the teleoperation system to complete complex dexterous manipulation tasks.

机器人灵巧手研究综述

机器人灵巧手可以模仿人类动作,完成复杂场景下的多种任务。机器人灵巧手的研究是开发智能人形机器人的关键技术之一。以机器人灵巧手的研究历程为核心,阐述了多指灵巧手的研究现状,分析了灵巧手的演化过程和研究进展。从自由度数目、驱动方式、机械传动方式和传感技术等方面探讨了灵巧手分类和特征,展望了灵巧手未来的发展趋势。

HIT／DLR HandⅡ类人形五指灵巧手机构的研究

为了使灵巧手的外观和结构功能更加类人化,研制了新一代类人形机器人五指灵巧手——HIT/DLR HandⅡ.该灵巧手由一个独立的手掌和5个完全相同的具有4个关节3个自由度的模块化手指构成.机电集成的设计思想保证了所有驱动器,传动系统和电路系统都集成在手指和手掌的内部.钢丝耦合机构的采用,保证了手指末端关节在整个运动范围内都能够保证精确定1:1传动比.包装件同结构功能件融合的设计思想不但进一步缩减的灵巧手的外形尺寸,而且使灵巧手外形更加类人化.所有的创新型设计使灵巧手的手指外形尺寸仅是上一代手指的1/3.此外,为了提高灵巧手的多感知能力,重新设计的力/力拒传感器,位置传感器及温度传感器通巧妙的集成在手指的内部.试验表明,所设计的灵巧手不但达到了设计目标,也表现出了很强的抓握能力.

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1.5kg,手指的指尖输出力10N。

三指机器人手爪设计与抓取研究

传统的多指仿人灵巧手虽然已实现较高的灵巧性与仿人性,但存在设计制作繁琐或价格昂贵以及手指末端抓力偏弱的弊端。而三指机械手作为一种简化形式一般又存在灵巧性不高的问题。针对以上弊端设计了一款基于滑块-摇杆机构的三指机器人手爪。将该结构直接类比人手所设计的手指关节能够实现中节指骨与远节指骨的耦合运动,且指尖力会随手指弯曲程度的增加而增大,有利于对细小目标物进行指尖捏取;采取与传统偏航-俯仰型不同的翻滚-俯仰型掌指结构,在增加了沿掌根关节的旋转自由度的同时尽可能地丰富了手爪的抓取姿态,使其能够适应更多的目标物,增加了灵巧性。在MATLAB中建立手指运动学模型并求得手指末端工作空间。经由实验验证得出该手爪具备较大的抓取力与丰富的抓取姿态。

欠驱动灵巧手的优化设计及仿真分析

传统欠驱动机械手的运动空间相对固定、操作功能单一,对抓取物没有较强的自适应性,为此设计一种新的连杆式欠驱动灵巧手机构,并进行设计优化和仿真抓取实验。阐述了该灵巧手的整体机构设计及工作原理,其可实现包络和指尖两种抓取模式。根据手指的几何尺寸采用协同耦合方式设计手掌尺寸,利用可变手掌协同手指抓取,提高了灵巧手在抓取形状复杂和不同尺寸物体时的自适应性。基于虚功原理建立灵巧手单指各关节的接触力模型,针对抓取过程中存在的抓取力不足及抓取不稳等问题,使用NSGA-II优化算法对单指机构的杆长进行尺度综合。利用建立的虚拟样机进行仿真抓取实验,结果表明,该灵巧手具有较强的自适应性,能够稳定抓取多种形状和尺寸的物体。

可侧摆腱驱五指灵巧手的设计与仿真

为了实现五指灵巧手对多种物体稳定抓取的目的,针对灵巧手结构复杂、成本高等问题,提出了一种基于蜗轮蜗杆驱动的手指侧摆方案,设计了一种以腱绳作为传动方案的仿人型五指灵巧手,具有驱动简单、质量轻、成本低等优点;利用D-H法建立了灵巧手指的运动学模型;且利用MATLAB的机器人工具箱,分析了手指的工作空间;利用ADAMS软件创建五指灵巧手的虚拟模型,分析了此单腱欠驱动灵巧手设计的有效性和抓取可行性。

基于PSO算法优化模糊PID控制器的灵巧手抓取控制研究

随着仿生学的进展,机器人领域中五指灵巧手作为主要执行机构的重要性不断增强。然而,在抓取过程中,五指灵巧手常常面临内部作用复杂、速度缓慢和效率低等问题。为了应对这些挑战,该文提出了一种基于角度闭环模糊自适应控制算法。该算法采用模糊策略来推断灵巧手关节角度偏差与控制器参数之间的关系,并制定相应的模糊规则。通过实时调整控制器参数,该算法能够提高系统的稳定性和抓取效率。此外,通过建立ADAMS模型和相应的闭环控制系统,以提高实验过程的可视化程度。实验结果表明,通过采用粒子群算法(Particle Swarm Optimization Algorithm)优化模糊自适应PID算法并改进系统参数,相较于传统的PID算法,可以显著减少灵巧手在抓取过程中的关节抖动,并展现出更好的手指指尖接触力控制性能。

Design and fabrication of a gecko-inspired surface for improving the grasping ability of a humanoid dexterous hand

Many studies have examined the design,fabrication and characteristics of gecko-inspired adhesives,but applied research on gecko-inspired surfaces in humanoid dexterous hands is relatively scarce.Here,a wedged slanted structure with a curved substrate suitable for humanoid dexterous fingers was designed and manufactured via ultraprecision machining and replica molding.The adhesion and friction properties of the wedged slanted structure show obvious anisotropic characteristics in the gripping and releasing directions,and the influence of structural parameters and motion parameters on the adhesion and friction was systematically studied.The humanoid dexterous fingers with gecko-inspired surfaces greatly increased the grasping force limit(increase to 4.02 times)based on the grasping of measuring cups with different volumes of water and improved the grasping stability based on the picking up of smooth steel balls of different diameters.This study shows that this process,based on ultraprecision machining and replica molding,is a green,high-efficiency,and low-cost method to fabricate large-area biomimetic surfaces that has potential applications in dexterous humanoid hands to improve grasping ability,stability and adaptability.

椭球型果蔬柔性采摘灵巧手设计

为提高采摘灵巧手的作业通用性、减少采摘过程中夹取损伤现象,设计一种椭球型果蔬气动柔性采摘灵巧手。对手指部件进行有限元分析,对比手指尺寸和指尖推力间的关系,分析手指性能,并对该灵巧手进行硬件选型和电路设计,开发控制系统,制作气动采摘灵巧手样机,进行功能测试。灵巧手总重1 kg,小巧灵活,手指张开时间为2 s,40 kPa气压输入下夹爪闭合时间为3s。搭载试验平台,进行采摘试验。试验表明,三种椭球型果蔬进行采摘作业的采摘成功率在92.5%以上,采摘损伤率低于7.5%,该灵巧手具有一定的通用性,具有高成功率和低损伤特点。

低温环境下电热手套对医护人员手部灵活性的影响

为探究电热手套在低温环境下的御寒能力及其对医护人员户外采样时手部灵活性的影响,利用气候室提供的-20℃低温环境,对穿戴不同手套的受试者进行手部皮肤温度变化和抓取试验,并记录抓取试验中受试者手部主观热感。研究结果表明:在-20℃的低温环境下,与受试者手部初始平均温度相比,30 min内受试者穿戴加热状态的电热手套时手部皮肤平均温度提高7.275℃,穿戴医用采样手套时手部皮肤平均温度降低21.425℃;与医用采样手套相比,电热手套能够有效减小低温对手部灵活性的影响。从室温到低温环境,20 min内受试者穿戴电热手套时的工效提高4.3%,对手部灵活性的影响率从常温时的42.1%降至低温时的39.6%;穿戴医用采样手套时的工效下降19.2%。综合受试者手部主观热感,所研制的电热手套可在低温环境中长时间保证手部工作的灵活性。研究结果可为医护人员户外采样用电热手套的研制提供参考。

手指精细动作训练对脑卒中恢复期偏瘫手功能障碍患者手功能的影响

目的 探讨手指精细动作训练对脑卒中恢复期偏瘫手功能障碍患者手功能的影响。方法 60例脑卒中恢复期偏瘫手功能障碍患者,随机信封法分为对照组和试验组,每组30例。对照组给予常规康复治疗,试验组在对照组基础上加手指精细动作训练。在治疗前、20次训练后第2次(治疗7周后)、40次训练后第3次(治疗14周后)评估两组Brunnstrom运动功能分期、偏瘫手功能分级以及Lindmark腕手功能评分,并进行比较。结果 治疗7周后,两组Brunnstrom运动功能分期比较无显著差异(P>0.05);治疗14周后,试验组Brunnstrom运动功能分期高于对照组,组间比较有显著差异(P<0.05)。治疗7周后,两组偏瘫手功能分级组间比较无显著差异(P>0.05);治疗14周后,试验组偏瘫手功能分级显著高于对照组,组间比较有显著差异(P<0.05)。治疗7、14周后,试验组Lindmark腕手功能评分分别为(10.68±3.30)、(17.48±5.17)分,均高于对照组的(8.70±2.58)、(14.75±4.89)分,组间比较有显著差异(P<0.05)。结论 手指精细动作训练可以有效改善脑卒中恢复期偏瘫手功能障碍患者的手功能。

波形梁护栏安全抓取灵巧手设计

针对高速公路护栏板安装过程机械化的需求,设计一种气动-磁吸附联合作用的灵巧机械手。该装置由手指式夹持机构和提升翻转手腕两部分组成,通过优化配置磁吸附模块和气动执行机构,实现对护栏板的容差适应,在电磁铁将护栏板提起的同时,机械卡爪也将护栏板抓紧,达到双重保障,通过反复测试实验,验证了该手爪能够保障护栏板操作过程的抓取安全与运动灵活。