This study presents the experimental results that characterize a nastic sheet material’s performance. We defined nastic sheet as a McKibben muscle designed from a foundation that would be embedded as an array in an elastomer matrix. The goal is to be able to utilize the embedded McKibben sheets in the biomedical industry as an improvement to the synthetic devices and/or processes. One mechanism that might produce these improvements is to mimic the biological materials that form functional organs, biological structures, and active tissues. Linking human technology and natural structures is and will continue to be important to society for several reasons. It would improve: (1) the lifestyle of humans in regards to artificial parts that mimic human parts (which will allow us to live longer), (2) artificial limb functionality, and (3) comfort and aesthetics. The objective is focused on characterizing and evaluating McKibben muscles as an embedded muscle sheet by building McKibben muscles and testing them alone and in sheets with one, two, three, and five muscles. The sheets would be known as a single, double, triple and quintuple embedded sheet. Another objective is to determine the performance penalty that embedding puts on the material. The experiments performed used several different approaches, such as analytical models, tensile test analysis, and prototype construction of the specimens. All specimens were designed to have a constant final length of 120mm, being embedded in a polyurethane matrix. We characterized the fundamental performance of a McKibben muscle and each specific embedded sheet. We measured the specimens’ work-density and quantified the inactive matrix’s impact on work-density. Based on the results, several improvements were suggested on the fabrication of the specimens. The experiment shows positive potential outcome that could be utilized in the biomedical field, but the results would improve with the suggestions provided in the study. A sample of the results - the actual work-density for both the single and doubleembedded sheets showed an increase to 7.82% and 2.96% consecutively. Once the specimens are removed from the mold, the McKibben muscle automatically tries to retract to its initial state while the polyurethane matrix tries to stay at its initial state.

This paper reports the findings of conceptual design and application research for a novel use of irrigation fluid power to provide mobility to a legged autonomous, tethered irrigation robot. Systems already exist to convert fluid power to rotary motion to power various irrigation systems. The conceptual designs implement a McKibben actuator to generate linear motion with water as the process fluid and a compact 3DOF spherical joint to create a modular robot leg that can be used to create a legged ambulatory robot. A six-legged robot is proposed from the conceptual design of the modular leg. Irrigation was selected as the initial leading application, however, once deployed the devices provide a field-ready platform to facilitate a whole suite of agriculturally important activities; seeding, weed suppression, pest management, soil sensing, crop growth assessment, as well as creating a robust research platform. This work is the lead in research to provide a viable mechanism to facilitate control system and dynamic modelling ahead of full-scale prototyping and field testing. / Graduate / 2021-04-08

Arbetet undersökte möjligheterna att väva artificiella muskler och ämnade till att vara en förstudie till fortsatt forskning inom området. Rörelsehinder begränsar många människor i sin vardag och något som ca 15 % av jordens befolkning lever med. Dagens kommersiella rörelse-assisterande hjälpmedel är oftast bestående av hårda och stela material och möjligheten att utveckla mjuka och mer följsamma hjälpmedel utforskas ständigt. Syftet var att undersöka om en vävd artificiell muskel kunde efterlikna en däggdjurs muskel utifrån kraft och kontraktions egenskaper och vad textil kunde bidra med till konstruktionen. McKibben aktuatorer integrerades parallellt i en väv för att skapa en konstruktion. En litteraturstudie utfördes på ämnet muskler, aktuatorer och textil för att kunna dra rimliga slutsatser och analyser i arbetet. För att utvärdera egenskaperna hos en vävd muskel har olika kombinationer av vävda konstruktioner med integrerade McKibben aktuatorer undersökts. Konstruktionernas mått har varierats mellan hur hårt och hur tätt McKibben aktuatorerna integrerats i väven för att söka efter de optimala parametrarna. I rapporten kommer de att benämnas som kanaler och zoner. Sammanlagt har 10 olika vävprover skapats och testas. Testmetoderna som används i arbetet är framtagna specifikt för detta arbete och inga standardiserade metoder har använts. Testmetoderna som utformades är baserade på tidigare forskningsförsök samt kunskap om däggdjurs muskelns förmåga att kontrahera och utöva kraft. Kontraktionen testades genom att undersöka hur mycket den vävda muskeln drog ihop sig och styrkan mättes i kraft med hjälp av en dynamometer. Resultaten som gavs från testerna var att kanaler som begränsar McKibben aktuatorernas förmåga att expandera begränsar dess förmåga att kontrahera men att zonerna inte gav någon större påverkan på vare sig kraft eller kontraktion. Från på de vävda proverna som visade bäst resultat i testerna skapades en optimal artificiell muskel och en maskinvävd artificiell muskel. För den optimala artificiella muskeln integrerades fler McKibben aktuatorer. I syfte att undersöka ifall fler aktuatorer i konstruktionen visade på ökad kraft. Additivitet i kraft påvisades och textil bidrog till maximal kraft kunde uppnås. Den maskinvävda artificiella muskeln producerades för att undersöka potentiella produktionsmöjligheter och därmed skulle kunna användas till en tänkbar applikation. Arbetets resulterade i en optimerad vävd artificiell muskel och påvisar möjligheter för att skala upp en produktion av vävda artificiella muskler. Sammanfattningsvis kunde en vävd artificiell muskel påvisa goda kontraktions och kraftegenskaper likt en däggdjurs muskel. / The work investigated the possibilities of weaving artificial muscles and is intended to inspire further studies in the field. Disability affects many people in their daily lives and about 15 % of the world's population lives with some form of disability. Today´s commensally used rehabilitation and mobility assistance applications are usually made of hard and stiff materials. But the development of soft and more bodyc ompliant aids are constantly being explored. The purpose of this study was to investigate whether woven artificial muscles could show similarities with mammal's muscles based on their ability to exert force and contract. McKibben actuators were integrated in a woven structure creating a combined construction. The textile aspect was further investigated to examine if it could contribute to the construction by increasing these properties. A literature study was developed to increase the knowledge of subjects such as muscles, actuators and textiles. To investigate the properties of a woven muscle, various combinations of woven structures with integrated McKibben actuators have been created. The proportions of the woven structures have varied between how tight and how close the McKibben actuators could be integrated to the fabric. The purpose was to find the optimal parameters for the woven muscle. In the report, the parameters will be referred to as channels and zones. A total of 10 different constructions have been created and tested. The test methods used in the study were developed for this report and no established methods have been used. Test methods were designed and developed with the intention to investigate force and contraction properties for the weaved muscle based on information of mammal muscles. By measuring contraction length and force for each woven sample with integrated McKibben actuators. The results from the tests showed that a tight channel could limit the McKibben actuators' ability to contract, however the zones did not impact the contraction ability or force extraction. Based on the results the most optimal parameters were discovered and an optimal artificial muscle was created. For the optimal artificial muscle, more McKibben actuators were integrated. In order to investigate if the force could be increased. Additivity in force was found and the textile structure contributed to increased force. A machine-woven artificial muscle was produced to investigate potential production possibilities. Whether these woven artificial muscles could be used in further applications were discussed. The study resulted in an optimized woven artificial muscle. Industrial production opportunities were demonstrated by producing an artificial muscle in an industrial weaving machine. In conclusion, the weaved artificial muscle showed good contraction and force abilities similar to a mammalian muscle.

Mjuk robotik är ett område inom robotik där mjuka material används för att skapa robotar som kan användas i kontakt med människor samt anpassa sig till okända miljöer och uppgifter. För att kunna skapa mjuka robotar behövs mjuka material med förmåga att röra sig med många frihetsgrader. Det har i tidigare forskning visat sig möjligt att integrera McKibben aktuatorer i vävda textiliers väftriktning för att skapa en konstruktion med förmågan att röra sig med en frihetsgrad. Detta arbete ämnar undersöka hur McKibben aktuatorer kan integreras i en vävd textils varp- och väftriktning med syfte att uppnå ett så högt antal frihetsgrader och rörelser som möjligt. Arbetet syftar även till att kategorisera egenskaper hos den textila struktur som tas fram på ett sätt som underlättar användningen av textil inom mjuk robotik. En vävd konstruktion bestående av en dubbelvävd tuskaftsbindning designades med kanaler i väft-och varpriktning där McKibben aktuatorer kunde placeras. Flera konstruktioner med varierande väfttäthet och antal bindepunkter tillverkades sedan för att testa hur de påverkade konstruktionens E-modul, böjstyvhet och kraftgenerering. För att undersöka hur många frihetsgrader som konstruktionen kunde uppvisa testades olika rörelser. Här undersöktes om avståndet mellan McKibben aktuatorerna hade någon påverkan på dess förmåga att röra sig. Resultaten från testerna visade att E-modulen och böjstyvheten båda ökade med ökande väfttäthet. Väfttätheten anses alltså vara en effektiv parameter för att variera tygets flexibilitet och styvhet. Antalet bindepunkter hade ingen påverkan på E-modulen och ett tydligt samband till böjstyvheten kunde inte hittas. Testerna av konstruktionens förmåga att utöva kraft visade att konstruktionen kunde utöva en signifikant kraft mellan 15 – 20 Newton. När det kom till rörelse kunde konstruktionen uppvisa fyra frihetsgrader. Det framkom att zonstorleken hade en påverkan på de olika rörelsernas storlek. Om konstruktionen placerades i en bestämd form innan McKibben aktuatorerna aktiverades upptäcktes att den kunde bibehålla denna form självständigt under en längre tid. Det ansågs därmed intressant att i framtiden undersöka om denna egenskap skulle gå att kombinera med andra rörliga textila material, för att skapa en mjuk struktur med möjligheten att anta olika komplexa tredimensionella former för användning inom mjuk robotik. / Soft robotics is a category within robotics where soft materials are used to create robots for safe use in contact with humans or capable of adapting to their surroundings. To create soft robots, the materials must be able to move with several degrees of freedom where the movement is activated by some type of actuation. Previous research has already integrated McKibben actuators in woven textiles in weft direction, with the possibility to move in one degree of freedom. This work aims to integrate McKibben actuators in both warp and weft direction to achieve as many degrees of freedom as possible. The properties of the textile structure will also be characterized based on certain properties that could facilitate its use in soft robotics. To integrate the actuators, a double woven structure was created in plain weave with channels in warp and weft direction. The parameters weft density and number of binding points were then varied to investigate their effect on the textiles Young’s modulus, flexural rigidity and force generation. The degrees of freedom were tested by creating different movements where the distance between the actuators was varied to examine its effect on the movements. Results from the tests showed increasing Young’s modulus and flexural rigidity with an increasing weft density. Weft density is therefore an effective parameter to adapt the textiles flexibility and stiffness. The number of binding points had no effect on Young’s modulus and no distinct relationship could be seen with flexural rigidity. The force generation tests showed that the structure could exhibit a force between 15 – 20 N. With the movements tested, the textile construction could achieve four degrees of freedom and it was established that the distance between the actuators influence the size of the movements. If the textile was held in a certain position before actuation, it was discovered that it could independently hold that position for a long period of time. This type of memory effect could be interesting to investigate further to achieve more complex 3D movements in textiles for use in soft robotics.

Soft actuation methods are a developing field of robotics deemed suitable for physical human-robot interactions due to the adaptability of materials and compliant structures. Thermo-active soft actuators are a subset of these which convert thermal energy to mechanical work in the form of elongation, bending, or twisting to conform to the environment. This study is divided into three major studies that all use actuators with a working principle of phase-change fluid vaporizing for expansion with applied heat from a Peltier. The first study evaluates the bandwidth and efficiency between (i) traditional Joule heating, and (ii) Peltier heating, finding that Peltier heating can considerably improve the operational bandwidth of the actuator. The second study uses a thin membrane actuator placed in a braided mesh to form a McKibben muscle capable of lifting 5N, and formed into a gripper capable of manipulating objects within the environment. The third study uses actuators of a solid, hollow and flexible Peltier embedded silicone structure and are evaluated and optimized in order to increase actuation speed, finding that the embedded flexible Peltier design was able to elongate over 50% of its original height in 20 seconds. The overall aim of all of these studies was to improve bandwidth, efficiency, actuator lifetime, and create more symmetrical actuation and deactuation cycles.

No description available.

Conception, modélisation et contrôle des actionneurs intrinsèquement conformes avec une considération particulière sur la configuration anthropomorphe agoniste-antagoniste "La recherche vise à la conception, la modélisation et le contrôle des actionneurs intrinsèquement conformes pour les systèmes anthropomorphes.La première partie du travail se concentre sur l'étude de divers Existants et rechercher la possibilité d'autres actionneurs autres que les moteurs électriques conventionnels.Une attention particulière est accordée aux actionneurs souples à base de polymères élctroactifs qui ont un bon potentiel dans les futures applications robotiques. Parallèlement, on a synthétisé un modèle de la dynamique de l'actionneur et du contrôleur basé sur le modèle (MPC et contrôle optimal) pour un bras anthropomorphe 7 Dofs actionné par une paire antagoniste-agoniste de Muscles Artificiels Pneumatiques (PAM) à chaque articulation. Ce modèle et contrôleur est alors intégré dans l'environnement logiciel développé par l'équipe. En utilisant le bras manipulateur anthropomorphe basé sur PAM et le simulateur numérique, des tests sont effectués afin d'évaluer le potentiel de cet actionneur et de comparer avec les capacités du corps humain. / Design, modeling and control of inherently compliant actuators with a special consideration on agonist- antagonist anthropomorphic configuration" The research aims at the design, modeling and control of inherently compliant actuators for anthropomorphic systems. The first part of the work focuses on the study of various existing designs and look for the possibility of alternative actuators other than the conventional electric motors. Special attention is given to elctroactive polymer based soft actuators which have good potential in future robotic applications. In parallel, a model of the actuator dynamics and the model-based controller (MPC and optimal control) have been synthesized for an anthropomorphic 7 Dofs arm actuated by antagonist-agonist pair of Pneumatic Artificial Muscles (PAMs) at each joint. Such model and controller is then integrated within the software environment developed by the team. Using the PAMs based anthropomorphic manipulator arm and the numerical simulator, tests are done in order to evaluate the potential of this actuator and compare with the human body capabilities.

Animals exploit soft structures to move smoothly and effectively in complex natural environments. These capabilities have inspired robotic engineers to incorporate soft actuating technologies into their designs. Developing soft muscle-like actuation technology is one of the grand challenges in the creation of soft-body robots that can move, deform their body, and modulate body stiffness. This paper presents the development of smart pneumatic McKibben muscles woven and reinforced by using conductive insulated wires to equip the muscles with an inherent sensing capability, in which the deformation of the muscles can be effectively measured by calculating the change of wire inductance. Sensing performance of a variety of weaving angles is investigated. The ideal McKibben muscle models are used for analysing muscle performance and sensing accuracy. The experimental results show that the contraction of the muscles is proportional to the measured change of inductance. This relationship is applied to a PID control system to control the contraction of smart muscles in simulation, and good control performance is achieved. The creation of smart muscles with an inherent sensing capability and a good controllability is promising for operation of future soft robots.

No description available.

This work describes exceptional properties of McKibben pneumatical muscle and introduces its state-of-the-art model. The mathematical model is extended especially in a field of a thermodymical behavior. A new model applies a method used for describing of a thermodynamical behavior of pneumatic cylinders until now. This method is significantly upgraded to fit a muscle behavior, particularly by considering a heat generated by a muscle internal natural friction. The model is than verified and discussed with a real system. The haptic part introduces a development and design of a haptic glove interface for the use in robotics, especially in telepresence, or in VR. The force and touch feedback is provided by Pneumatic Muscles controlled by an open loop algorithm using the introduced mathematical model. The design is light and compact.