Abstract In the early days,designer emphasized that human-like robotic hands should have high degree of freedoms(DOFs) and fully simulate all motions of human hands.It makes the system to be too expensive and complex. In recent years, the performance of grasp is no longer depend on the DOFs only after the concept of underactuated is applied. In this article, we discussed the designs and mechanisms of robotic hands and the design principle of underactuated. The SYS-1 underactuated human-like robotic hand uses only six actuator to control ten DOFs, the fingers of SYS-1 consist of underactuated six-bar linkage that simulate human¡¦s fingers motion. The ejection effect is also well controlled. Every finger is an independent module and can be separate or deploy according to the needs. The conduit-tendon system let SYS-1 can work in the water or high temperature environment without any damage. We also analysis the motion characteristic and grasp performance of SYS-1 and compare to the other similar designs.

One of the greatest challenges in controlling robotic hands is grasping and manipulating objects in unstructured and uncertain environments. Robotic hands are typically too rigid to react against unexpected impacts and disturbances in order to prevent damage. The human hands have great versatility and robustness due, in part, to the passive compliance and damping. Designing mechanical elements that are inspired by the nonlinear joint compliance of human hands is a promising solution to achieve human-like grasping and manipulation. However, the exact role of biomechanical elements in realizing joint stiffness is unknown. We conducted a series of experiments to investigate nonlinear stiffness and damping of the metacarpophalangeal (MCP) joint at the index finger. We designed a custom-made mechanism to integrate electromyography sensors (EMGs) and a motion capture system to collect data from 19 subjects. We investigated the relative contributions of muscle-tendon units and the MCP capsule ligament complex to joint stiffness with subject-specific modeling. The results show that the muscle-tendon units provide limited contribution to the passive joint compliance. This findings indicate that the parallel compliance, in the form of the capsule-ligament complex, is significant in defining the passive properties of the hand. To identify the passive damping, we used the hysteresis loops to investigate the energy dissipation function. We used symbolic regression and principal component analysis to derive and interpret the damping models. The results show that the nonlinear viscous damping depends on the cyclic frequency, and fluid and structural types of damping also exist at the MCP joint. Inspired by the nonlinear stiffness of the MCP joint, we developed a miniaturized mechanism that uses pouring liquid plastic to design energy storing elements. The key innovations in this design are: a) a set of nonlinear elasticity of compliant materials, b) variable pulley configurations to tune the stiffness profile, and c) pretension mechanism to scale the stiffness profile. The design exhibits human-like passive compliance. By taking advantage of miniaturized joint size and additive manufacturing, we incorporated the novel joint design in a novel robotic manipulator with six series elastic actuators (SEA). The robotic manipulator has passive joint compliance with the intrinsic property of human hands. To validate the system, we investigated the Cartesian stiffness of grasping with low-level force control. The results show that that the overall system performs a great force tracking with position feedback. The parallel compliance decreases the motor efforts and can stabilize the system. / text

Grasping, the skill to hold objects and tools while doing in-hand manipulation, still is in many cases an unsolvable problem for robotics, but a natural act for humans. An efficient grasping requires not only human-like robotic hands with articulated fingers but also tactile, force, and kinesthetic sensors for the precise control of the forces and motions exerted during the manipulation. As a fully autonomous robotic dexterous manipulation is too difficult to develop for changing and unstructured environments, an alternative approach is to combine the low-level robot computer control with the higher-level perception and task planning abilities of a human operator equipped with an adequate human-computer interface (HCI). This thesis presents theoretical and experimental contributions to the development of an upgraded haptic-enabled anthropomorphic Ring Ada dexterous robotic hand and a biology-inspired synergistic real-time control system for teleoperated grasping of different objects using a CyberTouch HCI data glove. A fuzzy logic controller module was developed to efficiently control the underactuated Ring Ada’ robotic hand during grasping. A machine learning classification system was developed to recognize grasped objects. Experiments have convincingly demonstrated that our novel Ring Ada robotic hand equipped with kinematic position sensors and touch sensors is able to efficiently grasp different lightweight objects through teleoperation.

Hand impairments have a significant impact on quality of life and career performance. This effect is specially bold in the agricultural community, since farming activities involve continuously carrying and lifting heavy objects. Assistive robotic technologies hold considerable promise in alleviating such impairment issues. However, no portable assistive device is developed for farming applications, which requires additional considerations to ensure functionality of the device and its practicality in agricultural settings. In this work, a bi-layered structure for a robotic glove is presented, which consists of a passive extension and an active flexion layers. The former is responsible for extending the fingers, using a set of elastic bands. The flexion layer, which helps with flexing the fingers and grasping of objects, is a lightweight, self-contained, portable, cable-driven, and single-actuated robotic glove. The cable configuration is inspired from the human hand flexor tendons. Due to uncertainties associated with the fabric's flexibility and potential slippage between the cable and the glove, the designed mechanisms and sensory and control systems are initially implemented on a robotic hand. The rigid structure of the robotic hand provides a suitable proving ground for the design and control ideas. The novel power transmission system design enables the active layer to perform adaptive grasp of objects with unknown shapes, sizes, and material textures. The sensory system includes a bend sensor to detect the wearer's intention to perform grasp or release actions. Additionally, a PVDF-based sensor is developed for slip-detection, which is used as feedback to prevent further slipping of the grasped objects. Overall, the active flexion layer weighs 265 gr and can provide the maximum grasping force of 122 N, which is a noticeable improvement in comparison to the literature. / Doctor of Philosophy / Hand impairments have a significant impact on quality of life and career performance. This effect is specially bold in the agricultural community, since farming activities involve continuously carrying and lifting heavy objects. Assistive robotic technologies hold considerable promise in alleviating such impairment issues. However, no portable assistive device is developed for farming applications, which requires additional considerations to ensure functionality of the device and its practicality in agricultural settings. In this work, a bi-layered structure for a robotic glove is presented, which helps with grasping objects. The first layer is responsible for extending the fingers, using a set of elastic bands. The second layer, which helps with flexing the fingers, is a lightweight, self-contained, and portable robotic glove. A novel cable-driven power transmission system is designed to perform reliable grasps using only one actuator. The power transmission system design enables the robotic glove to grasp objects with unknown shapes, sizes, and material textures. The intention of the wearer for performing a grasp or releasing an object is detected using a bend sensor. Additionally, a vibration sensor is utilized for detecting the slip of the grasped object and preventing further slipping and dropping the object. The functionality of the developed robotic gloved is evaluated through experiments, where different geometry and weight of objects are grasped.

This work analyzes human-in-the-loop robotic systems to determine where human input can be most beneficial to a collaborative task. This is accomplished by implementing a pick-and-place task using a human-in-the-loop robotic system and determining which segments of the task, when replaced by human guidance, provide the most improvement to overall task performance and require the least cognitive effort. The first experiment entails implementing a pick and place task on a commercial robotic arm. Initially, we look at a pick-and-place task that is segmented into two main areas: coarse approach towards a goal object and fine pick motion. For the fine picking phase, we look at the importance of user guidance in terms of position and orientation of the end effector. Results from this initial experiment show that the most successful strategy for our human-in-the-loop system is the one in which the human specifies a general region for grasping, and the robotic system completes the remaining elements of the task. We extend this study to include a second experiment, utilizing a more complex robotic system and pick-and-place task to further analyze human impact in a human-in-the-loop system in a more realistic setting. In this experiment, we use a robotic system that utilizes an Xbox Kinect as a vision sensor, a more cluttered environment, and a pick-and-place task that we segment in a way similar to the first experiment. Results from the second experiment indicate that allowing the user to make fine tuned adjustments to the position and orientation of the robotic hand can improve task success in high noise situations in which the autonomous robotic system might otherwise fail. The experimental setups and procedures used in this thesis can be generalized and used to guide similar analysis of human impact in other human-in-the-loop systems performing other tasks.

The interest in the research and development of humanoid robots has been steadily growing in recent years. The application of such robotic systems are many and wide. In this bachelor’s thesis in mechatronics one such robotic system was built in the form of a hand. The aim was to investigate how well the robotic hand could imitate the movements of a user-worn controller glove as well as grip objects, both through wireless communication. The controller glove consisted of an Arduino Nano microcontroller, five flex sensors, an inertial measurement unit that detected the wrist rotation of the glove, a nRF24L01 transmitter as well as an external power source of 9 volts. The robotic hand consisted of three-dimensional printed parts from an open source library, an Arduino Uno microcontroller, a nRF24L01 receiver, two external power supplies of 9 volts and 5 volts and six servo motors, with one servo motor per finger and wrist. The finished robotic hand did well in imitating the motions of the controller glove with little to no observed delay and was able to grip onto objects of various sizes, shapes and weights up to 134 grams. The constructed robotic hand achieved the desired goals of the project. The results indicated that improvements can be made on the grip ability of objects with rigid surfaces as well as improving the imitation by implementing more degrees of freedom for the fingers of the robotic hand. / Intresset för forskning och utveckling av humanoida robotarhar under de senaste åren varit på ständig uppfart. Applikationerna av sådana robotsystem är många och breda. Idetta kandidatarbete inom mekatronik konstruerades ettsådant robotsystem i formen av en hand. Syftet var att undersöka hur väl robothanden kunde imitera rörelserna av enanvändarburen kontrollerhandske samt hur väl den kundegreppa tag om objekt med hjälp av trådlös kommunikation. Kontrollerhanskens komponenter bestod av en Arduino Nano mikrokontroller, fem flex sensorer, en tröghetsmätenhet som mätte rotationen av handleden, en nRF24L01sändarenhet samt en extern kraftkälla på 9 volt. Robothanden bestod av tredimensionellt utskrivna delar från ettopen source bibliotek, en Arduino Uno mikrokontroller, ennRF24L01 mottagarenhet, två externa kraftkällor på 9 voltrespektive 5 volt samt sex stycken servomotorer. Varje enskild finger samt handled var kopplad till en servomotorvar. Robothanden kunde imitera kontrollhandskens rörelser med liten försening och kunde greppa tag om objekt avolika storlekar, utformningar samt vikter upp till 134 gram.Den konstruerade robothanden åstadkom de önskade målensom sattes för projektet. Resultaten indikerade att robothandens greppförmåga om föremål med styva ytor och dessimitation kan förbättras.

Humans are social by nature, and the physical distancing due to COVID has converted many of our daily interactions into virtual ones. Among the negative consequences of this, we find the lack of an element that is essential to humans' well-being, which is the physical touch. With more interactions shifting towards the digital world of the metaverse, we want to provide individuals with the means to include the physical touch in their interactions. We explore the Digital Twin technology's prospect to support in reducing the impact of this on humans. We provide a definition of the concept of Robo Twin and explain its role in mediating human interactions. Besides, we survey research works related to Digital Twin's physical representation with a focus on under-actuated Digital Twin's robotic arms. In this thesis, we first provide findings from the literature, to support researchers' decisions in the adoption and use of designs and implementations of Digital Twin's robotic arms, and to inform future research on current challenges and gaps in existing research works. Subsequently, we design and implement two right-handed under-actuated Digital Twin's robotic arms to mediate the physical interaction between two individuals by allowing them to perform a handshake while they are physically distanced. This experiment served as a proof of concept for our proposed idea of Robo Twin. The findings are very promising as our evaluation shows that the participants are highly interested in using our system to make a handshake with their loved ones when they are physically separated. With this Robo Twin Arm system, we also find a correlation between the handshake characteristics and gender and/or personality traits of the participants from the quantitative handshake data collected during the experiment. Moreover, it is a step towards the design and development of Digital Twin's under-actuated robotic arms and ways to enhance the overall user experience with such a system.

Cette thèse présente la conception et la commande d’une main robotique légère et peu onéreuse pour un robot compagnon humanoïde. La main est conçue pour exprimer des émotions à travers des gestes et pour saisir de petits objets légers. Sa géométrie est définie à l’aide de données anthropométriques. Sa cinématique est simplifiée par rapport à la main humaine pour réduire le nombre d’actionneurs tout en respectant ses exigences fonctionnelles. La main préserve son anthropomorphisme grâce aux nombres et au placement de la base des doigts et à une bonne opposabilité du pouce. La mécatronique de la main repose sur un compromis entre des phalanges couplés, qui permettent de bien connaître la posture des doigts pendant les gestes, et des phalanges capable de s’adapter à la forme des objets pendant la saisie, réunis en une conception hybride unique. Ce compromis est rendu possible grâce à deux systèmes d’actionnement distincts placés en parallèle. Leur coexistence est garantie par une transmission compliante basée sur des barres en élastomère. La solution proposée réduit significativement le poids et la taille de la main en utilisant sept actionneurs de faible puissance pour les gestes et un seul moteur puissant pour la saisie. Le système est conçue pour être embarqué sur Romeo, un robot humanoïde de1.4 [m] produit par Aldebaran. Les systèmes d’actionnements sont dimensionnés pour ouvrir et fermer les doigts en moins de 1 [s] et pour saisir une canette pleine de soda. La main est réalisée et contrôlée pour garantir une interaction sûre avec l’homme mais aussi pour protéger l’intégrité de la mécanique. Un prototype (ALPHA) est réalisé pour valider la conception et ses capacités fonctionnelles. / This thesis presents the design and control of a low-cost and lightweight robotic hand for a social humanoid robot. The hand is designed to perform expressive hand gestures and to grasp small and light objects. Its geometry follows anthropometric data. Its kinematics simplifies the human hand structure to reduce the number of actuators while ensuring functional requirements. The hand preserves anthropomorphism by properly placing five fingers on the palm and by ensuring an equilibrated thumb opposability. Its mechanical system results from the compromise between fully-coupled phalanges and self-adaptable fingers in a unique hybrid design. This answers the need for known finger postures while gesturing and for finger adaptation to different object shapes while grasping. The design is based on two distinct actuation systems embodied in parallel within the palm and the fingers. Their coexistence is ensured by a compliant transmission based on elastomer bars. The proposed solution significantly reduces the weightand the size of the hand by using seven low-power actuators for gesturing and a single high-power motor for grasping. The overall system is conceived to be embedded on Romeo, a humanoid robot 1.4 [m] tall produced by Aldebaran. Actuation systems are dimensioned to open and close the fingers in less than1 [s] and to grasp a full soda can. The hand is realized and controlled to ensure safe human-robot interaction and to preserve mechanical integrity. A prototype(ALPHA) is realized to validate the design feasibility and its functional capabilities.

Le thème central de cette thèse est la conception d’actionneurs doux à partir de matériaux intelligents et d’une prothèse de main robotique souple. Notre approche prends en compte les différents points qui peuvent influer sur le développement d’une stratégie d’actionnement ou d’un muscle artificiel : i) Les mécanismes et la fonctionnalité de la main humaine afin d’identifier les exigences fonctionnelles pour une prothèse de main robotique en matière de préhension. ii) L’analyse et l’amélioration des mécanismes de la main robotique pour intégrer un comportement souple dans la prothèse. iii) L’évaluation expérimentale de la prothèse de main robotique afin d’identifier les spécifications du système d’actionnement nécessaire au fonctionnement cinématique et dynamique du robot. iv) Le développement et la modélisation d’une stratégie d’actionnement utilisant des matériaux intelligents.Ces points sont abordés successivement dans les 4 chapitres de cette thèse1. Analyse du mouvement de la main humaine pour l’identification des exigences technologiques pour la prothèse de main robotique.2. Conception et modélisation de la prothèse de main robotique à comportement souple.3. Evaluation mécatronique de la prothèse de main.4. Conception d’un muscle artificiel basé sur des matériaux intelligents. / In the field of robotic hand prosthesis, the use of smart and soft materials is helpful in improving flexibility, usability, and adaptability of the robots, which simplify daily living activities of prosthesis users. However, regarding the smart materials for artificial muscles, technologies are considered to be far from implementation in anthropomorphic robotic hands. Therefore, the target of this thesis dissertation is to reduce the gap between smart material technologies and robotic hand prosthesis. Five central axes address the problem: i)identification of useful grasping gestures and reformulation of the robotic hand mechanism, ii) analysis of human muscle behavior to mimic human grasping capabilities, iii) modeling robot using the hybrid model DHKK-SRQ for the kinematics and the virtual works principle for dynamics, iv) definition of actuation requirements considering the synergy between prehension conditions and robot mechanism, and v) development of a smart material based actuation system.This topics are addressed in four chapters:1. Human hand movement analysis toward the hand prosthesis requirements2. Design and modeling of the soft robotic hand ProMain-I3. Mechatronic assessment of Prosthetic hand4. Development of an artificial muscle based on smart materials

The aim of this work is to design a robotic hand, which will be controlled by wireless Wi-Fi, will be equipped with a camera and for easier operation will be designed control glove. The first part of the thesis is a theoretical analysis, various variants of sensors are described, which can be used for motion detection, each drive units and their control. Next chapters are focused on used electronic modules and microcontrollers. The second part is practical and is focused on the mechanical design of a five-finger robotic hand and fixing to a robotic arm. Also described is the control electronics of the entire robotic hand and the programmed firmware. Next, the design and implementation of the control glove is described. The last chapter describes the programmed application for the Android operating system.