Design and Development of a Hand Exoskeleton Robot for Active and Passive Rehabilitation

The present work, which describes the mechatronic design and development of a novel rehabilitation robotic exoskeleton hand, aims to present a solution for neuromusculoskeletal rehabilitation. It presents a full range of motion for all hand phalanges and was specifically designed to carry out position and force-position control for passive and active rehabilitation routines. System integration and preliminary clinical tests are also presented

ReHand - a portable assistive rehabilitation hand exoskeleton

This dissertation presents a synthesis of a novel underactuated exoskeleton (namely ReHand2) thought and designed for a task-oriented rehabilitation and/or for empower the human hand. The first part of this dissertation shows the current context about the robotic rehabilitation with a focus on hand pathologies, which influence the hand capability. The chapter is concluded with the presentation of ReHand2. The second chapter describes the human hand biomechanics. Starting from the definition of human hand anatomy, passing through anthropometric data, to taxonomy on hand grasps and finger constraints, both from static and dynamic point of view. In addition, some information about the hand capability are given. The third chapter analyze the current state of the art in hand exoskeleton for rehabilitation and empower tasks. In particular, the chapter presents exoskeleton technologies, from mechanisms to sensors, passing though transmission and actuators. Finally, the current state of the art in terms of prototype and commercial products is presented. The fourth chapter introduces the concepts of underactuation with the basic explanation and the classical notation used typically in the prosthetic field. In addition, the chapter describe also the most used differential elements in the prosthetic, follow by a statical analysis. Moreover typical transmission tree at inter-finger level as well as the intra- finger underactuation are explained . The fifth chapter presents the prototype called ReHand summarizing the device description and explanation of the working principle. It describes also the kinetostatic analysis for both, inter- and the intra-finger modules. in the last section preliminary results obtained with the exoskeleton are shown and discussed, attention is pointed out on prototype’s problems that have carry out at the second version of the device. The sixth chapter describes the evolution of ReHand, describing the kinematics and dynamics behaviors. In particular, for the mathematical description is introduced the notation used in order to analyze and optimize the geometry of the entire device. The introduced model is also implemented in Matlab Simulink environment. Finally, the chapter presents the new features. The seventh chapter describes the test bench and the methodologies used to evaluate the device statical, and dynamical performances. The chapter presents and discuss the experimental results and compare them with simulated one. Finally in the last chapter the conclusion about the ReHand project are proposed as well as the future development. In particular, the idea to test de device in relevant environments. In addition some preliminary considerations about the thumb and the wrist are introduced, exploiting the possibility to modify the entire layout of the device, for instance changing the actuator location

The development of artificial muscles using textile structures

The aim of this project was to investigate the use of textile structures as muscles to assist people with muscular deficiency or paralysis. Due to the average life expectancy continuing to increase, support for those needing assistance to move unaided is also increasing. The purpose of this project was to try to help a patient who would normally need assistance, to move their arm unaided. It could also help with rehabilitation of muscular injuries and increasing strength and reducing muscular fatigue of manual workers. The approach considered was to develop an extra corporal device for the upper limbs, providing the main required motions. Most devices currently available use motors and gearboxes to assist in limb movement. This study investigated a way of mimicking the contraction of biological skeletal muscles to create a motion that is as human as possible with a soft, flexible and lightweight construction. Electroactive polymers (EAPs) and pneumatic artificial muscles (PAMs) were investigated. It became clear that at present, the EAPs were unable to create the forces and speed of contraction required for this application. The use of pneumatics to create artificial muscles was developed upon. PAMs, like the McKibben muscle and the pleated pneumatic muscle mimic the natural contraction of skeletal muscle. These current PAMs were used as a basis to develop a new type of pneumatic artificial muscle in this project. A 90 mm ball-like structure was developed, produced from an air impermeable rubber coated cotton fabric. Joining three oval panels together created a 3-D spherical shape. Three of these structures were linked together, and when inflated, created an acceptable level of contraction and force. This method of producing artificial muscles created a soft, lightweight and flexible actuator with scope for different arrangements, sizes and positions of the muscle structure. The contraction process was mathematically modelled. This calculated the predicted rate and level of contraction of a 2-D muscle structure. These mathematical findings were able to be compared to the practical results, and produced similar contraction characteristics. The muscle structures were incorporated into a garment to form a type of muscle suit which could be worn to assist movement. This garment has an aluminium frame to protect the wearer's bones from stresses from the contracting muscles. This study has shown that the muscle suit developed can create movement for wearers that would normally need assistance, and also reduce muscle fatigue, which would be useful for manual workers. This is incorporated into a functional and wearable garment, which is easy to dress and more lightweight and aesthetically pleasing than current muscle suits.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modelling, Design Optimization, and Experimental Characterization of Miniaturized Pneumatic Artificial Muscles

Miniaturized pneumatic artificial muscles (MPAMs) are actuators designed to replicate the actuation behaviour of natural muscles. Their unique characteristics, including a high power-to- weight ratio, flexibility, compatibility with the human environment, and compact size, make them widely used in diverse applications. However, MPAMs face a significant challenge in terms of their low force output, which hinders their overall performance. Enhancing their force generation capability while maintaining their compact dimensions is crucial for improving their efficiency. The present thesis focuses on the design optimization, fabrication, and modelling of an MPAM to maximize its force output while ensuring compatibility with small-scale applications. To this end, a formal design optimization problem is formulated to determine the optimal sizes of MPAMs, with the objective of maximizing their blocked force under geometrical constraints. A comprehensive force model is derived, considering key parameters that influence the response behaviour of MPAMs, which serves as the objective function for maximization. To investigate the importance of various correction terms added to the simple force model of the MPAMs, two optimization formulations varying in their objective functions and vectors of design variables have been defined. One formulation considers the effects of energy stored in the braided sleeving and optimizes the parameters related to braid strands, while the other excludes these factors. To identify the optimal design, a hybrid optimization algorithm is employed, combining a stochastic-based algorithm with gradient-based algorithms. This approach allows for the identification of the global optimum while also examining the effects of different optimization algorithms on the results. Next, two MPAMs are fabricated using the dimensions obtained from the optimization procedure. The first sample utilizes Ecoflex-50 as the bladder material, while the second sample incorporates a mixture of PDMS and Ecoflex-30. The aim is to compare the performance of the MPAMs iii fabricated with different materials for their bladders. An experimental setup is subsequently designed to conduct quasi-static tests on each sample to measure their generated blocked force and contraction under various pressures as well as validate the theoretical results obtained from the optimization process. Finally, the hysteresis loops obtained from loading and unloading each sample under specific pressures are analyzed to derive correction terms that account for the nonlinear behaviour of MPAMs and the friction between their components. Different theoretical and empirical approaches are assessed to determine the most accurate correction terms. The resulting force model enables accurate predictions of force and contraction outputs under various inlet pressures. Overall, this study contributes significantly to the design optimization of MPAMs, offering potential applications in diverse fields, including soft robotics and medical devices. The combination of theoretical modelling, optimization techniques, fabrication, and experimental tests provides essential guide for the comprehensive understanding of MPAM’s performance and its potential for practical implementation

Kinematics and Robot Design IV, KaRD2021

This volume collects the papers published on the special issue “Kinematics and Robot Design IV, KaRD2021” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2021), which is the forth edition of the KaRD special-issue series, hosted by the open-access journal “MDPI Robotics”. KaRD series is an open environment where researchers can present their works and discuss all the topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”. KaRD2021, after the peer-review process, accepted 12 papers. The accepted papers cover some theoretical and many design/applicative aspects

Soft Robotics: Design for Simplicity, Performance, and Robustness of Robots for Interaction with Humans.

This thesis deals with the design possibilities concerning the next generation of advanced Robots. Aim of the work is to study, analyse and realise artificial systems that are essentially simple, performing and robust and can live and coexist with humans. The main design guideline followed in doing so is the Soft Robotics Approach, that implies the design of systems with intrinsic mechanical compliance in their architecture. The first part of the thesis addresses design of new soft robotics actuators, or robotic muscles. At the beginning are provided information about what a robotic muscle is and what is needed to realise it. A possible classification of these systems is analysed and some criteria useful for their comparison are explained. After, a set of functional specifications and parameters is identified and defined, to characterise a specific subset of this kind of actuators, called Variable Stiffness Actuators. The selected parameters converge in a data-sheet that easily defines performance and abilities of the robotic system. A complete strategy for the design and realisation of this kind of system is provided, which takes into account their me- chanical morphology and architecture. As consequence of this, some new actuators are developed, validated and employed in the execution of complex experimental tasks. In particular the actuator VSA-Cube and its add-on, a Variable Damper, are developed as the main com- ponents of a robotics low-cost platform, called VSA-CubeBot, that v can be used as an exploratory platform for multi degrees of freedom experiments. Experimental validations and mathematical models of the system employed in multi degrees of freedom tasks (bimanual as- sembly and drawing on an uneven surface), are reported. The second part of the thesis is about the design of multi fingered hands for robots. In this part of the work the Pisa-IIT SoftHand is introduced. It is a novel robot hand prototype designed with the purpose of being as easily usable, robust and simple as an industrial gripper, while exhibiting a level of grasping versatility and an aspect comparable to that of the human hand. In the thesis the main theo- retical tool used to enable such simplification, i.e. the neuroscience– based notion of soft synergies, are briefly reviewed. The approach proposed rests on ideas coming from underactuated hand design. A synthesis method to realize a desired set of soft synergies through the principled design of adaptive underactuated mechanisms, which is called the method of adaptive synergies, is discussed. This ap- proach leads to the design of hands accommodating in principle an arbitrary number of soft synergies, as demonstrated in grasping and manipulation simulations and experiments with a prototype. As a particular instance of application of the method of adaptive syner- gies, the Pisa–IIT SoftHand is then described in detail. The design and implementation of the prototype hand are shown and its effec- tiveness demonstrated through grasping experiments. Finally, control of the Pisa/IIT Hand is considered. Few different control strategies are adopted, including an experimental setup with the use of surface Electromyographic signals

Modelado de sensores piezoresistivos y uso de una interfaz basada en guantes de datos para el control de impedancia de manipuladores robóticos

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Arquitectura de Computadores y Automática, leída el 21-02-2014Sección Deptal. de Arquitectura de Computadores y Automática (Físicas)Fac. de Ciencias FísicasTRUEunpu