Les exosquelettes représentent des systèmes mécaniques portables qui ont reçu une grande attention de la part de la communauté scientifique ces derrières années, vues les possibilités qu'ils offrent.Ces possibilités concernent principalement les fonctions d'assistance et de réhabilitation des personnes en situation de handicape et personnes âgées, dans un objectif de leur permettre de recouvrir leur facultés motrices. Cependant, d'autres possibilités sont concernées comme permettre à des personnes paraplégiques de remarcher ou de permettre des opérations de manipulation excédent les capacités humaines.Pour permettre la réalisation des fonctions offertes par les robots portables, une connaissance fine de la dynamique du système est requise en relation avec les tâches à réaliser par les sujets. Par ailleurs, des approches de commande sûres qui prennent en compte la sécurité des usagers est nécessaire. Dans cet objectif, des techniques de commande bio-inspirées avec des techniques de commande par découplage non-linéaire sont considérées. Les dernières assurent que la loi de commande est stable et bornée en prenant en considération le domaine de saturation des actionneurs alors que les premières ont inspiré la conception de contrôleurs basés sur les oscillateurs locaux non-linéaires (Central Pattern Generators : CPG).Les CPGs sont modélisés par des réseaux de neurones qui peuvent être représentés par un ensemble d'oscillateurs non-linéaires situés dans la moelle épinière, avec des capacités de génération de signaux rythmiques multidimensionnels synchrones pour remplir des fonctions motrices sous le contrôle de simples signaux de commande. Ces signaux sont supposés être de nature périodique ou semi-périodique, dont la génération pour étudier les systèmes de locmotion humain reste un problème de recherche d'actualité.Dans la présente thèse, l'analyse, la simulation et la commandes des articulations d'un robot portable utilisé pour les membres inférieurs en utilisant, d'un côté les oscillateurs locaux non-linéaires et d'un autre côté des techniques de commande par découplage non-linéaire sont proposés, avec comme objectif final de permtre la mise en œuvre des approches proposées sur la plate-forme expérimentale développée au sein du FSATI (French South African Institute fo Technology).Pour atteindre l'objectif qui a été fixé par les travaux de recherche engagés, une étude de l'état de l'art sur les aspects liés à la connaissance de l'anatomie, la physiologie et l'analyse biomécanique de la marche humaine a été effectuée. Par ailleurs, une étude détaillée des oscillateurs locaux non-linéaires en parallèle avec les approches de commande directe et inverse, ont permis la proposition de stratégies de commande qui couplent les oscillateurs non-linéaires d'un côté et des techniques de découplage non-linéaire d'un autre côté ont été proposées et validées sur des systèmes de plusieurs degrés de liberté. Des simulations intensives ont été conduites afin de vérifier la capacité d'adaptation temps des approches de commandes mises en œuvre avec l'humain ans la boucle.Les contributions de la présente étude concerne deux approches de commande. La première approche concerne l'intégration d'une approche bio-inspirée, basée sur les oscillateurs locaux non-linéaires et la deuxième approche est basée sur les techniques de commande bornée par découplage non-linéaire / Wearable robotic system has become a well sought after mechanism in the field of biomechatronics engineering due to the the various possibilities it possess. These possibilities encompass the assistive and rehabilitative protocols rendered to disabled and elderly people, in order to enable them regain control of their limbs and of course increase the abilities of able-bodied persons. It therefore clearly drives the motive of bringing back paraplegics back on their feet as well as executing difficult task beyond human ability.Achieving the intended function of wearable robots requires the model dynamics of the physical system in relation to the tasks required to be performed by subjects. This demands a proper control measure which takes into account the safety of the wearer. For this purpose, bio-inspired control techniques and bounded nonlinear feedback controllers are considered. The latter control design ensures that the stipulated power required is not exceeded as well as the saturation of the actuator, while the former motivates the design of controllers based on the concept of Central Pattern Generators (CPG). CPGs are characterised as biological neural networks which can be represented by a set of coupled nonlinear oscillator situated in the spinal cord of mammals, having the capability of generating coordinated multidimensional rhythmic signals for the purpose of locomotion, under the control of simple input signals. These rhythmic signals are termed to be periodic or quasi-periodic in nature, hence performing this task in robotics and animal motor control has been a perpetual research problem. The movement of the lower limb of humans thus present a platform to investigate and address this difficulty.In this thesis, the analysis, simulation, and control of joints which relate to the human lower limbs via CPGs and feedback control techniques are investigated with an aim of practically implementing the control strategies using a lower limb exoskeleton is presented. To accomplish this goal, it is expedient to have comprehensive knowledge of the anatomy, physiology and the normal gait biomechanics of the human lower limbs. Understanding the theories, principles and mathematical background of nonlinear oscillators are also required. Control strategies using the inverse and the forward dynamics approach based on different types of coupled nonlinear oscillators and nonlinear feedback control techniques were considered for single/multiple degrees of freedom (DoF). Simulations and results were presented to verify the controller-human system ability to constantly and dynamically track and readapt its control parameters to maintain its desired motion dynamics, with reduced control torque values.This work basically deals with two distinct method of control systems; one which integrates bio-inspired methods with classical and nonlinear control techniques to govern the exoskeletons' joints with a human in the loop, and another which utilises bounded nonlinear feedback control techniques for same purpose

In this thesis, a passive exoskeleton spine was designed and evaluated by a series of biomechanics simulations. The design objectives were to reduce the human operator’s back muscle efforts and the intervertebral reaction torques during a full range sagittal plane spine flexion/extension. The biomechanics simulations were performed using the OpenSim modeling environment. To manipulate the simulations, a full body musculoskeletal model was created based on the OpenSim gait2354 and “lumbar spine” models. To support flexion and extension of the torso a “push-pull” strategy was proposed by applying external pushing and pulling forces on different locations on the torso. The external forces were optimized via simulations and then a physical exoskeleton prototype was built to evaluate the “push-pull” strategy in vivo. The prototype was tested on three different subjects where the sEMG and inertial data were collected to estimate the muscle force reduction and intervertebral torque reduction. The prototype assisted the users in sagittal plane flexion/extension and reduced the average muscle force and intervertebral reaction torque by an average of 371 N and 29 Nm, respectively.

Bakgrund: Stroke drabbar miljontals människor världen över varje år och medför ofta ensidiga motoriska nedsättningar som allvarligt reducerar förmågan till självständighet i vardagen. Fysioterapin efter stroke sker därför vanligen genom uppgiftsorienterad träning riktad mot att rehabilitera den motoriska förmågan på den affekterade sidan så att patienten kan återgå till ett självständigt liv. Men processen ställer stora krav på patienten som inte alltid kan förväntas uppnå bästa resultat med sin rehabilitering. Därför forskas det alltmer på innovativa teknologiska hjälpmedel med potential att assistera strokepatient såväl som fysioterapeut i rehabiliteringen. Exoskelett och hjärndatorgränssnitt (BCI) är två sådana hjälpmedel som undersöktes i denna studie. Syfte: Studien hade syftet att sammanställa det vetenskapliga stödet för tillämpning av BCI-styrda exoskelett (BCI-Exo) vid rehabilitering av motorisk arm- och handfunktion efter stroke i dess subakuta samt kroniska fas. Metod: Litteratursökningar utfördes i databaserna PEDRO, PUBMED, AMED och CINAHL vilket gav 22 träffar som efter granskning och sållning resulterade i att fyra artiklar inkluderades i studien. Resultat: Samtliga studier redovisade statistiskt signifikanta förbättringar av motorisk handfunktion i interventionsgruppen jämfört med kontrollgruppen utifrån de utfallsmått som tillämpades. Konklusion: Resultatet indikerade att BCI-Exo kan främja återhämtning och neuroplasticitet för strokepatienter oavsett vilken fas de infinner sig i. Dock är teknologin fortfarande relativt ny varvid fler studier behöver utföras för att bättre specificera och förstå för- och nackdelar jämfört med konventionella behandlingsmetoder. / Background: Stroke affects millions of people around the world each year and often results in unilateral motor impairments that severely reduce the ability for independence in everyday life. Physiotherapy after stroke is therefore usually performed through task-oriented training aimed at rehabilitating the motor functional ability of the affected side so that the patient can return to an independent life. But the process places great demands on the patient who cannot always be expected to achieve the best results from their rehabilitation. Therefore, innovative technologies are increasingly being researched with the potential to assist stroke patients as well as physical therapists in the rehabilitation process. Exoskeletons and brain-computer interfaces (BCI) are two such rehabilitative tools that were investigated in this study. Objective: The study aimed to compile the scientific support for the use of BCI-controlled exoskeletons (BCI-Exo) in motor functional arm and hand rehabilitation after stroke in its subacute and chronic phase. Method: Literature searches were conducted in the databases PEDRO, PUBMED, AMED and CINAHL, which resulted in 22 hits which, after review and screening, resulted in four articles being included in the study. Results: All studies reported statistically significant improvements regarding motor function in the hemiplegic hand in the intervention group compared to the control group based on the outcome measures used. Conclusion: The results indicated that BCI-Exo can promote recovery and neuroplasticity after stroke regardless of its phase. However, the technology is still in its early stages and more studies need to be performed to better specify and understand the advantages and disadvantages compared to conventional treatment methods.

Robotic exoskeleton technologies are one of the most active fields of robotics in recent years. Exoskeleton systems can give essential support for limb motions with enhanced strength and endurance, and they have a wide variety of therapeutic and supportive utility in life. These technologies have been extensively improved to be utilized for human power enhancement, worker injury prevention, human power assistance, and physical interface in augmented reality. Employees in the manufacturing and construction industries perform especially challenging duties, increasing their risk of health problems, disability, and medical leave, resulting in diminished job competitiveness and a shortage of qualified applicants. The usage of an exoskeleton might decrease muscular peak loads and lessen worker injury risks. This study includes a detailed analysis of employees wearing exoskeletons while doing various job-related duties. In this thesis, the tests assess the benefits of adopting exoskeletons in lowering human muscular activity and, as a result, weariness, and exhaustion. Unlike industrial robots, robotic exoskeleton technologies must be carefully built since they actually interact with actual users. The study used two widely available exoskeletons named Eksovest, an upper-body exoskeleton, and LegX, a lower-body exoskeleton. The study includes five applications: shoulder height weight-lifting, wall drilling, and roof drilling positions for the upper body Eksovest, and virtual chair and knee position for the lower body LegX. This application evaluated electromyography (EMG) signals which were collected using EMG sensors on the human body as supportive tools. Furthermore, the investigations compare the different volunteer’s body muscle data gathered by EMG sensors mounted on biceps, thigh, and calf muscles. The work also evaluates the accuracies of the data collecting procedures used in this study. Based on this study, it is discovered that by employing these exoskeletons may reduce muscular activity by up to 60%, hence enhancing the workforce's work life by reducing load and stresses on their body. This research will assist to raise the awareness by the outcomes of SMEs about the use of exoskeleton.

Although the level of automation in the automotive industry is currently high, real humans are still required for assembly tasks, for example, during overhead tasks. This type of work can cause injuries in workers in this sector, especially musculoskeletal disorders (MSDs), being a cause for the inability to work in developed countries and, in turn, becoming a significant health problem. There is an aim to reduce the risk for these type of injuries during the development processes of this type of assembly operations. Various options are currently being considered where technology and the human factor can be combined. Among them, we find the object of study for this project, an exoskeleton.The aim of this project is to study the biomechanical effects as well as the ergonomics of a passive exoskeleton called Paexo Shoulder, developed by the company Ottobock, with the aim of relieving tensions in the shoulder joints and upper part of the shoulders, during its use in assembly tasks. For this purpose, an experiment will be designed in which several participants will carry out a series of tasks both with and without the exoskeleton, in such a way that the effects of its use and how they affect the users of the product can be observed. For this purpose, an experiment was designed to evaluate the effects of the use or non-use of this exoskeleton on 10 participants when performing a task similar to an overhead task in an assembly line. For the evaluation of the product, the Xsens motion capture system, in particular the Awinda model, was used together with the ScaleFit software to evaluate the results obtained through the motion capture recordings. In addition, in order to improve Digital Human Modelling (DHM) tools, the same task was simulated with the IPS-IMMA software, where the results were later analysed and compared with the motion capture results through ScaleFit.The results showed relatively large improvements in the respective moment reduction at the shoulder joint when using the exoskeleton. However, it was also observed that due to the upward force exerted by the exoskeleton on the arms, participants spent less time in low-risk areas evaluated by ScaleFit and therefore, this effect needs to be studied further.

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Of the 795,000 people that suffer a stroke in the United States every year, 65% experience hemiparesis. Foot drop is a common gait pathology in people with lower-limb paresis and is often caused by neuropathy of the peroneal nerve that innervates the muscles responsible for ankle dorsiflexion. Foot drop can impede toe clearance and increase the risk of falling, the leading cause of injury among adults ≥65 years. Lower-limb robotic exoskeletons have been used for gait training and can aid with walking, but current devices on the market can be heavy, expensive, and constrained to in-clinic use. Soft wearable robotic devices offer a lightweight and cost-effective alternative to traditional lower-limb exoskeletons. In particular, soft pneumatic systems have the potential to provide a high power-to-weight ratio making them ideal for a wearable application. The soft pneumatic exosuit consists of a footplate to collect air, storage to temporarily house the collected air, and two pneumatic actuators to provide an assistive torque around the wearer’s ankle joint while walking. EMG and IMU sensors were integrated to control the opening and closing of solenoid valves so that assistive torques could be applied to the ankle joint at optimal moments during the gait cycle. Preliminary validation of the soft pneumatic exosuit on a healthy participant demonstrated that the system could successfully deliver the air required to contract the actuators when the EMG sensors detected an increase in muscle activity. These results demonstrate that the current soft pneumatic exosuit appears to be a promising alternative to current rehabilitation exoskeletons on the market while remaining portable and low-cost. / 2025-05-24T00:00:00Z

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