A novel design process of low cost 3D printed ambidextrous finger designed for an ambidextrous robotic hand

This paper presents the novel mechanical design of an ambidextrous finger specifically designed for an ambidextrous anthropomorphic robotic hand actuated by pneumatic artificial muscles. The ambidextrous nature of design allows fingers to perform both left and right hand movements. The aim of our design is to reduce the number of actuators, increase the range of movements with best possible range ideally greater than a common human finger. Four prototypes are discussed in this paper; first prototype is focused on the choice of material and to consider the possible ways to reduce friction. Second prototype is designed to investigate the tendons routing configurations. Aim of third and fourth prototype is to improve the overall performance and to maximize the grasping force. Finally, a unified design (Final design) is presented in great detail. Comparison of all prototypes is done from different angles to evaluate the best design. The kinematic features of intermediate mode have been analysed to optimize both the flexibility and the robustness of the system, as well as to minimize the number of pneumatic muscles. The final design of an ambidextrous finger has developed, tested and 3D printed

A Methodology for the Design of Robotic Hands with Multiple Fingers

This paper presents a methodology that has been applied for a design process of anthropomorphic hands with multiple fingers. Biomechanical characteristics of human hand have been analysed so that ergonomic and anthropometric aspects have been used as fundamental references for obtaining grasping mechanisms. A kinematic analysis has been proposed to define the requirements for designing grasping functions. Selection of materials and actuators has been discussed too. This topic has been based on previous experiences with prototypes that have been developed at the Laboratory of Robotics and Mechatronics (LARM) of the University of Cassino. An example of the application of the proposed method has been presented for the design of a first prototype of LARM Hand

Performance Comparison Between FEDERICA Hand and LARM Hand

This paper describes two robotic hands that have been developed at University Federico II of Naples and at the University of Cassino. FEDERICA Hand and LARM Hand are described in terms of design and operational features. In particular, careful attention is paid to the differences between the above-mentioned hands in terms of transmission systems. FEDERICA Hand uses tendons and pulleys to drive phalanxes, while LARM Hand uses cross four-bar linkages. Results of experimental tests are reported to show how key design issues affect each robotic hand’s performance

An optimal design of driving mechanism in a 1 degree of freedom d.o.f. anthropomorphic finger

Mechanisms can be used in finger design to obtain suitable actuation systems and to give stiff robust behavior in grasping tasks. The design of driving mechanisms for fingers has been attached at LARM in Cassino with the aim to obtain one degree of freedom actuation for an anthropomorphic finger. The dimensional design of a finger-driving mechanism has been formulated as a multi-objective optimization problem by using evaluation criteria for fundamental characteristics regarding with finger motion, grasping equilibrium and force transmission. The feasibility of the herein proposed optimum design procedure for a finger-driving mechanism has been tested by numerical examples that have been also used to enhance a prototype previously built at LARM in Cassino

Innovative robot hand designs of reduced complexity for dexterous manipulation

This thesis investigates the mechanical design of robot hands to sensibly reduce the system complexity in terms of the number of actuators and sensors, and control needs for performing grasping and in-hand manipulations of unknown objects. Human hands are known to be the most complex, versatile, dexterous manipulators in nature, from being able to operate sophisticated surgery to carry out a wide variety of daily activity tasks (e.g. preparing food, changing cloths, playing instruments, to name some). However, the understanding of why human hands can perform such fascinating tasks still eludes complete comprehension. Since at least the end of the sixteenth century, scientists and engineers have tried to match the sensory and motor functions of the human hand. As a result, many contemporary humanoid and anthropomorphic robot hands have been developed to closely replicate the appearance and dexterity of human hands, in many cases using sophisticated designs that integrate multiple sensors and actuators---which make them prone to error and difficult to operate and control, particularly under uncertainty. In recent years, several simplification approaches and solutions have been proposed to develop more effective and reliable dexterous robot hands. These techniques, which have been based on using underactuated mechanical designs, kinematic synergies, or compliant materials, to name some, have opened up new ways to integrate hardware enhancements to facilitate grasping and dexterous manipulation control and improve reliability and robustness. Following this line of thought, this thesis studies four robot hand hardware aspects for enhancing grasping and manipulation, with a particular focus on dexterous in-hand manipulation. Namely: i) the use of passive soft fingertips; ii) the use of rigid and soft active surfaces in robot fingers; iii) the use of robot hand topologies to create particular in-hand manipulation trajectories; and iv) the decoupling of grasping and in-hand manipulation by introducing a reconfigurable palm. In summary, the findings from this thesis provide important notions for understanding the significance of mechanical and hardware elements in the performance and control of human manipulation. These findings show great potential in developing robust, easily programmable, and economically viable robot hands capable of performing dexterous manipulations under uncertainty, while exhibiting a valuable subset of functions of the human hand.Open Acces

Design and Simulation of a Mechanical Hand

A variety of mechanical hand designs have been developed in the past few decades. The majority of the designs were made with the sole purpose of imitating the human hand and its capabilities; however, none of these designs have been equipped with all the motions and sensory capabilities of the human hand. The primary goal of this thesis project was to design a robotic hand with the required amount of degrees-of-freedom and necessary constraints to achieve all the motions of the human hand. Demonstration of the American Sign Language (ASL) alphabet, using a virtual design and controls platform, was used as a means of proving the dexterity of the designed hand. The objectives of the thesis were accomplished using a combination of computerized 3-D modeling, kinematic modeling, and LabView programming. A mechanical hand model was designed using SolidWorks. Actuation methods were incorporated into the design based on the structure of the connecting tendons in the human hand. To analyze the motions of the mechanical hand model, finger assemblies were manufactured at two different scales (full and ¼ size) using rapid prototyping. These finger assemblies were used to study the developed forces within the joints prone to failure when subjected to actuation and spring forces. A free body diagram and an Ansys model were created to quantify the force and stress concentrations at the contact point of the pin joint in the distal interphalangeal joint, a location of failure in the rapid prototype assembly. A complete kinematic model was then developed for the mechanical hand using the Denavit-Hartenberg principle to map all the joints of the hand and finger tips in a universal frame of reference. A program was developed using LabView and Matlab software tools to incorporate the developed kinematic model of the designed hand and plot the 3-D locations of all joints in the universal frame of reference for each letter of the ASL alphabet. The program was then interfaced with the SolidWorks hand assembly to virtually control the motions of the designed assembly and to optimize the hand motions. In summary, a mechanical human hand model and interacting software platform were developed to simulate the dexterity of a designed human hand and to implement virtual controls, based on kinematic modeling, to achieve the optimum motion patterns needed to demonstrate the ASL alphabet. The designed hand was capable of performing all the static gestures of the ASL alphabet

Design, modelling, and control of an ambidextrous robot arm

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThis thesis presents the novel design of an ambidextrous robot arm that offers double range of motion as compared to dexterous arms. The proposed arm is unique in terms of design (ambidextrous feature), actuation (use of two different actuators simultaneously: Pneumatic Artificial Muscle (PAM) & Electric Motor)) and control (combined use of Proportional Integral Derivative (PID) with Neural Network (NN) for the hand and modified Multiple Adaptive Neuro-fuzzy Inference System (MANFIS) controller for the arm). The primary challenge of the project was to achieve ambidextrous behavior of the arm. Thus, a feasibility analysis was carried out to evaluate possible mechanical designs. The secondary aim was to deal with control issues associated with the ambidextrous design. Due to the ambidextrous nature of the design, the stability of such a device becomes a challenging task. Conventional controllers and artificial intelligence-based controllers were explored to find the most suitable one. Performances of all these controllers have been compared through experiments, and combined use of PID with NN was found to be the most accurate controller to drive the ambidextrous robot hand. In terms of ambidextrous robot arm control, a solution based on forward kinematic and inverse kinematic approach is presented, and results are verified using the derived equation in MATLAB. Since solving inverse kinematics analytically is difficult, Adaptive Neuro-Fuzzy Inference system (ANFIS) is developed using ANFIS MATLAB toolbox. When generic ANFIS failed to produce satisfactory results, modified MANFIS is proposed. The efficiency of the ambidextrous arm has been tested by comparing its performance with a conventional robot arm. The results obtained from experiments proved the efficiency of the ambidextrous arm when compared with a conventional arm in terms of power consumption and stability

Parametric mechanical design and optimisation of the Canterbury Hand.

As part of worldwide research humanoid robots have been developed for household, industrial and exploratory applications. If such robots are to interact with people and human created environments they will require human-like hands. The objective of this thesis was the parametric design and optimisation of a dexterous, and anthropomorphic robotic end effector. Known as the ‘Canterbury Hand’ it has 11 degree of freedoms with four fingers and a thumb. The hand has applications for dexterous teleoperation and object manipulation in industrial, hazardous or uncertain environments such as orbital robotics. The human hand was analysed so that the Canterbury Hand could copy its motions, appearance and grasp types. An analysis of the current literature on experimental prosthetic and robotic hands was also carried out. A disadvantage of many of these hand designs was that they were remotely powered using large, heavy actuator packs. The advantage of the Canterbury Hand is that it has been designed to hold the motors, wires, and circuit boards entirely within itself; although a belt carried battery pack is required. The hand was modelled using a parametric 3D computer aided design (CAD) program. Two different configurations of the hand were created in the model. One configuration, as a dexterous robot hand, used Ø13mm 3 Watt DC motors, while the other used Ø10mm, 0.5 Watt DC motors (although this hand is still slightly too large for a general prosthesis). The parts within the hand were modelled to permit changes to the geometry. This was necessary for the optimisation process. The bearing geometry of the finger and thumb linkages, as well as the thumb rotation axis was optimised for anthropomorphic motion, appearance and increased force output. A design table within a spreadsheet was created to interact with the CAD models of the hand to quickly implement the optimised geometry. The work reported in this thesis has shown the possibilities for parametric design and optimisation of an anthropomorphic, dexterous robotic hand

Parametric mechanical design and optimisation of the Canterbury Hand.

As part of worldwide research humanoid robots have been developed for household, industrial and exploratory applications. If such robots are to interact with people and human created environments they will require human-like hands. The objective of this thesis was the parametric design and optimisation of a dexterous, and anthropomorphic robotic end effector. Known as the ‘Canterbury Hand’ it has 11 degree of freedoms with four fingers and a thumb. The hand has applications for dexterous teleoperation and object manipulation in industrial, hazardous or uncertain environments such as orbital robotics. The human hand was analysed so that the Canterbury Hand could copy its motions, appearance and grasp types. An analysis of the current literature on experimental prosthetic and robotic hands was also carried out. A disadvantage of many of these hand designs was that they were remotely powered using large, heavy actuator packs. The advantage of the Canterbury Hand is that it has been designed to hold the motors, wires, and circuit boards entirely within itself; although a belt carried battery pack is required. The hand was modelled using a parametric 3D computer aided design (CAD) program. Two different configurations of the hand were created in the model. One configuration, as a dexterous robot hand, used Ø13mm 3 Watt DC motors, while the other used Ø10mm, 0.5 Watt DC motors (although this hand is still slightly too large for a general prosthesis). The parts within the hand were modelled to permit changes to the geometry. This was necessary for the optimisation process. The bearing geometry of the finger and thumb linkages, as well as the thumb rotation axis was optimised for anthropomorphic motion, appearance and increased force output. A design table within a spreadsheet was created to interact with the CAD models of the hand to quickly implement the optimised geometry. The work reported in this thesis has shown the possibilities for parametric design and optimisation of an anthropomorphic, dexterous robotic hand

Wire-driven mechanism and highly efficient propulsion in water.

自然生物的杰出表现往往令人们叹为观止。正因为如此，在机器人研究中对自然界动植物的模仿从未间断。本文受动物肌肉骨骼系统（尤其是蛇的脊柱以及章鱼手臂的肌肉分布）的启发，设计了一种新型的仿生拉线机构。该机构由柔性骨架以及成对拉线组成。柔性骨架提供支撑，拉线模拟肌肉将驱动器的运动和力传递给骨架，并控制骨架运动。从骨架结构分，拉线机构可分为蛇形拉线机构以及连续型拉线机构；从骨架分段来看，拉线机构可分为单段式拉线机构以及多段式拉线机构，其中每段由一或两对拉线控制。拉线机构的主要性能特征包括：大柔性，高度欠驱动，杠杆效应，以及远程传力。机构的柔性使得它可以产生很大的弯曲变形；欠驱动设计极大地减少了驱动器的数目，简化了系统结构；在杠杆效应下，骨架末端速度、加速度与拉线的速度、加速度相比得到数十倍放大；通过拉线将驱动器的运动和力远程传递给执行机构，使得拉线机构结构简单紧凑。基于以上特征，拉线机构不仅适合工作于狭窄空间，同时也适合于摆动推进，尤其是水下推进。论文系统地介绍了拉线机构的设计，运动学，工作空间，静力学以及动力学模型。在常曲率假设下分别建立了蛇形拉线机构以及连续型拉线机构的运动学模型，在此基础上建立了一个通用运动学模型，以及工作空间模型。与传统避障相反，本文提出了一种利用现有障碍或主动布置约束来拓展工作空间的新方法。通过牛顿-欧拉法以及拉格朗日方程建立了蛇形拉线机构的静力学模型以及动力学模型。在非线性欧拉-伯努利梁理论下结合汉密尔顿原理建立了连续型拉线机构的静力学模型以及动力学模型。论文中利用拉线机构设计了一系列新型水下推进器。与传统机器鱼推进器设计方法（单关节，多关节以及基于智能材料的连续型设计）相比，基于拉线机构的水下推进器的优点在于：所需驱动器少，能更好地模拟鱼的游动，易于控制，推进效率高，以及容易衍生新型推进器。设计制作了四条拉线驱动机器鱼，以此为平台验证了拉线推进器的性能以及优点。实验结果表明，基于蛇形拉线机构的推进器可以提供较大推力；基于连续型拉线机构设计的推进器受摩擦影响较小；基于单段式拉线机构的推进器可以模仿鱼类摆动式推进，具有很好的转弯性能；基于多段式拉线机构的推进器可以同时模仿摆动式推进和波动式推进，具有更好的稳定性以及游速。此外，基于拉线机构制造了一种新型矢量推进器。该推进器可以提供任意方向的推力，从而提高机器鱼的机动性能。实验中，在两个额定功率为1瓦的电机驱动下，机器鱼的最大游速为0.67 体长/秒；最小转弯半径为0.24倍体长；转弯速度为51.4 度/秒；最高推进效率为92.85%。最后，采用拉线推进器制作了一个室内空中移动机器人，取名为Flying Octopus。它由一个氦气球提供浮力悬停在空中，通过四个独立控制的拉线扑翼驱动可在三维空间自由运动。Attracted by the outstanding performance of natural creatures, researchers have been mimicking animals and plants to develop their robots. Inspired by animals’ musculoskeletal system, especially the skeletal structure of snakes and octopus arm muscle arrangement, in this thesis, a novel wire-driven mechanism (WDM) is designed. It is composed of a flexible backbone and a number of controlling wire groups. The flexible backbone provides support, while the wire groups transmit motion and force from the actuators, mimicking the muscles. According to its backbone structure, the WDM is categorized as serpentine WDM and continuum WDM. Depending on the backbone segmentation, WDM is divided into single segment WDM and multi-segment WDM. Each segment is controlled by one or two wire groups. Features of WDM include: flexible, highly under-actuated, leverage effect, and long range force and motion transmission. The flexibility enables the WDM making large deformation, while the under-actuation greatly reduces th number of actuators, simplifying the system. With the leverage effect, WDM distal end velocity and acceleration is greatly amplified from that of wire. Also, in the WDM, the actuators and the backbone are serperated. Actuator’s motion is transmitted by the wires. This makes the WDM very compact. With these features, the WDM is not only well suited to confined space, but also flapping propulsion, especially in water.In the thesis, the design, kinematics, workspace, static and dynamic models of the WDM are explored systematically. Under the constant curvature assumption, the kinematic model of serpentine WDM and continuum WDM are established. A generalized model is also developed. Workspace model is built from the forward kinematic model. Rather than avoiding obstacles, a novel idea of employing obstacles or actively deploying constraints to expand workspace is also discussed for WDM-based flexible manipulators. The static model and dynamic model of serpentine WDM is developed using the Newton-Euler method and the Lagrange Equation, while that of continuum WDM is built under the non-linear Euler-Bernoulli Beam theory and the extended Hamilton’s principle.In the thesis, a number of novel WDM based underwater propulsors are developed. Compared with existing fish-like propulsor designs, including single joint design, multi-joint design, and smart material based continuum design, the proposed WDM-based propulsors have advantages in several aspects, such as employing less actuators, better resembling the fish swimming body curve, ease of control, and more importantly, being highly efficient. Also, brand new propulsors can be easily developed using the WDM. To demonstrate the features as well as the advantages of WDM propulsors, four robot fish prototypes are developed. Experiments show that the serpentine WDM-based propulsor could provide large flapping force while the continuum WDM-based propulsor is less affected by joint friction. On the other hand, single segment WDM propulsor can make oscillatory swim while multi- segment WDM propulsor can make both oscillatory and undulatory swims. The undulatory swimming outperforms the oscillatory swimming in stability and speed, but is inferior in turning around. In addition, a novel robot fish with vector propulsion capability is also developed. It can provide thrust in arbitrary directions, hence, improving the maneuverability of the robot fish. In the experiments, with the power limit of two watts, the maximum forward speed of the WDM robot fishes can reach 0.67 BL (Body Length)/s. The minimum turning radius is 0.24 BL, and the turning speed is 51.4°/s. The maximum Froude efficiency of the WDM robot fishes is 92.85%. Finally, the WDM-based propulsor is used to build an indoor Lighter-than-Air- Vehicle (LTAV), named Flying Octopus. It is suspended in the air by a helium balloon and actuated by four independently controlled wire-driven flapping wings. With the wing propulsion, it can move in 3D space effectively.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Li, Zheng.Thesis (Ph.D.)--Chinese University of Hong Kong, 2013.Includes bibliographical references (leaves 205-214).Abstracts also in Chinese.Abstracth --- p.i摘要 --- p.iiiAcknowledgement --- p.vList of Figures --- p.xiList of Tables --- p.xviiChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Background --- p.1Chapter 1.2 --- Related Research --- p.2Chapter 1.2.1 --- Flexible Manipulator --- p.2Chapter 1.2.2 --- Robot Fish --- p.10Chapter 1.3 --- Motivation of the Dissertation --- p.13Chapter 1.4 --- Organization of the Dissertation --- p.14Chapter Chapter 2 --- Biomimetic Wire-Driven Mechanism --- p.16Chapter 2.1 --- Inspiration from Nature --- p.16Chapter 2.1.1 --- Snake Skeleton --- p.18Chapter 2.1.2 --- Octopus Arm --- p.19Chapter 2.2 --- Wire-Driven Mechanism Design --- p.20Chapter 2.2.1 --- Flexible Backbone --- p.20Chapter 2.2.2 --- Backbone Segmentation --- p.26Chapter 2.2.3 --- Wire Configuration --- p.28Chapter 2.3 --- Wire-Driven Mechanism Categorization --- p.31Chapter 2.4 --- Summary --- p.32Chapter Chapter 3 --- Kinematics and Workspace of the Wire-Driven Mechanism --- p.33Chapter 3.1 --- Kinematic Model of Single Segment WDM --- p.33Chapter 3.1.1 --- Kinematic Model of the Serpentine WDM --- p.34Chapter 3.1.2 --- Kinematic Model of the Continuum WDM --- p.39Chapter 3.1.3 --- A Generalized Kinematic Model --- p.43Chapter 3.2 --- Kinematic Model of Multi-Segment WDM --- p.47Chapter 3.2.1 --- Forward Kinematics --- p.47Chapter 3.2.2 --- Inverse Kinematics --- p.51Chapter 3.3 --- Workspace --- p.52Chapter 3.3.1 --- Workspace of Single Segment WDM --- p.52Chapter 3.3.2 --- Workspace of Multi-Segment WDM --- p.53Chapter 3.4 --- Employing Obstacles to Expand WDM Workspace --- p.55Chapter 3.4.1 --- Constrained Kinematics Model of WDM --- p.55Chapter 3.4.2 --- WDM Workspace with Constraints --- p.61Chapter 3.5 --- Model Validation via Experiment --- p.64Chapter 3.5.1 --- Single Segment WDM Kinematic Model Validation --- p.64Chapter 3.5.2 --- Multi-Segment WDM Kinematic Model Validation --- p.66Chapter 3.5.3 --- Constrained Kinematic Model Validation --- p.70Chapter 3.6 --- Summary --- p.73Chapter Chapter 4 --- Statics and Dynamics of the Wire-Driven Mechanism --- p.75Chapter 4.1 --- Static Model of the Wire-Driven Mechanism --- p.75Chapter 4.1.1 --- Static Model of SPSP WDM --- p.75Chapter 4.1.2 --- Static Model of SPCP WDM --- p.81Chapter 4.2 --- Dynamic Model of the Wire-Driven Mechanism --- p.88Chapter 4.2.1 --- Dynamic Model of SPSP WDM --- p.88Chapter 4.2.2 --- Dynamic Model of SPCP WDM --- p.92Chapter 4.3 --- Summary --- p.94Chapter Chapter 5 --- Application I - Wire-Driven Robot Fish --- p.95Chapter 5.1 --- Fish Swimming Introduction --- p.95Chapter 5.1.1 --- Fish Swimming Categories --- p.95Chapter 5.1.2 --- Body Curve Function --- p.96Chapter 5.1.3 --- Fish Swimming Hydrodynamics --- p.101Chapter 5.1.4 --- Fish Swimming Data --- p.103Chapter 5.2 --- Oscillatory Wire-Driven Robot Fish --- p.104Chapter 5.2.1 --- Serpentine Oscillatory Wire-Driven Robot Fish Design --- p.105Chapter 5.2.2 --- Continuum Oscillatory Wire-Driven Robot Fish Design --- p.110Chapter 5.2.3 --- Oscillatory Robot Fish Propulsion Model --- p.114Chapter 5.2.4 --- Robot Fish Swimming Control --- p.116Chapter 5.2.5 --- Swimming Experiments --- p.118Chapter 5.3 --- Undulatory Wire-Driven Robot Fish --- p.125Chapter 5.3.1 --- Undulatory Wire-Driven Robot Fish Design --- p.125Chapter 5.3.2 --- Undulatory Wire-Driven Robot Fish Propulsion Model --- p.130Chapter 5.3.3 --- Swimming Experiments --- p.131Chapter 5.4 --- Vector Propelled Wire-Driven Robot Fish --- p.136Chapter 5.4.1 --- Vector Propelled Wire-Driven Robot Fish Design --- p.136Chapter 5.4.2 --- Tail Motion Analysis --- p.140Chapter 5.4.3 --- Swimming Experiments --- p.142Chapter 5.5 --- Wire-Driven Robot Fish Performance and Discussion --- p.144Chapter 5.5.1 --- Performance --- p.144Chapter 5.5.2 --- Discussion --- p.147Chapter 5.6 --- Summary --- p.149Chapter Chapter 6 --- Aplication II - Wire-Driven LTAV - Flying Octopus --- p.151Chapter 6.1 --- Introduction --- p.151Chapter 6.2 --- Flying Octopus Design --- p.152Chapter 6.2.1 --- Flying Octopus Body Design --- p.152Chapter 6.2.2 --- Wire-Driven Flapping Wing Design --- p.153Chapter 6.3 --- Flying Octopus Motion Control --- p.156Chapter 6.3.1 --- Propulsion Model --- p.156Chapter 6.3.2 --- Motion Control Strategy --- p.157Chapter 6.3.3 --- Motion Simulation --- p.159Chapter 6.4 --- Prototype and Indoor Experiments --- p.161Chapter 6.4.1 --- Flying Octopus Prototype --- p.161Chapter 6.4.2 --- Indoor Experiments --- p.163Chapter 6.4.3 --- Discussion --- p.165Chapter 6.5 --- Summary --- p.166Chapter Chapter 7 --- Conclusions and Future Work --- p.167Chapter Appendix A - --- Publication Record --- p.170Chapter Appendix B - --- Derivation --- p.172Chapter Appendix C --- Matlab Programs --- p.176References --- p.20