サイクリング支援用受動的外骨格型支援システム

要約のみTohoku University小菅一弘課

Solvent Evaporation-Assisted Three-Dimensional Printing of Piezoelectric Sensors from Polyvinylidene Fluoride and its Nanocomposites

RÉSUMÉ Les matériaux piézoélectriques sont connus pour générer des charges électriques lors de leur déformation. Leur capacité à transformer linéairement l'énergie mécanique en énergie électrique, et vice versa, est utilisée dans la détection, l'actionnement, la récupération et le stockage d'énergie. Ces appareils trouvent des applications dans les domaines de l'aérospatiale, de la biomédecine, des systèmes micro-électromécaniques, de la robotique et des sports, pour n'en nommer que quelques-uns. On retrouve la propriété de piézoélectricité dans certaines céramiques, roches, monocristaux et quelques polymères. Le poly(fluorure de vinylidène) (PVDF) est un polymère piézoélectrique qui présente un coefficient piézoélectrique très élevé par rapport aux céramiques, ce qui laisse présager des applications de détection et de récupération d'énergie. La facilité de fabrication, la flexibilité et la biocompatibilité du PVDF sont autant de qualité qui en font un très bon candidat pour ces applications. Les dispositifs actuels à base de PVDF commercial sont disponibles en films plats ou en fibres unidimensionnelles (1D). L'impression tridimensionnelle (3D) du PVDF peut amener à des sensibilités, souplesses et capacités de fabrication accrues des capteurs embarqués en cas d'impression multi-matériaux. Le PVDF est un polymère semi-cristallin possédant cinq polymorphes, dont la phase β polaire qui présente les meilleures propriétés piézoélectriques. Malheureusement, le PVDF, provenant de la fusion ou de la dissolution, cristallise en une phase α non polaire thermodynamiquement stable. Diverses transformations physiques telles que le recuit, l'addition de charge, l'étirement ou le polissage sont effectuées pour transformer la phase α en phase β. En raison de la cristallisation inhérente du PVDF dans la phase α, il y a eu très peu de tentatives de fabrication de structures 3D à partir du PVDF. L'électrofilage en champ proche et la Déposition de Filament Fondu ont permis de fabriquer certaines structures 3D couche par couche avec du PVDF, soit avec l'application de hautes tensions électriques, soit avec la fusion à haute température du polymère. Et les deux nécessitent un traitement de polarisation pour conférer la piézoélectricité aux structures imprimés. Pour fabriquer des capteurs incorporés ou conformes, sur des substrats donnés, il est essentiel de ne pas avoir d'effets négatifs sur les matériaux adjacents à cause de la polarisation pendant le processus d'impression. Ainsi, dans ce travail, nous avons développé un procédé d'impression 3D qui crée des structures PVDF principalement en phase β, à température ambiante et sans application de tension de polarisation.----------ABSTRACT Piezoelectric materials are known to generate electric charges upon deformation. Their ability to linearly transform mechanical energy into electrical energy and vice versa, is utilized in sensing, actuation, transducing, energy harvesting and storage. These devices find applications in aerospace, biomedicine, micro electromechanical systems, robotics and sports, to name a few. Piezoelectricity is found in some ceramics, rocks, single crystals and a few polymers. Polyvinylidene fluoride (PVDF) is a piezoelectric polymer that exhibits a very high piezoelectric stress coefficient as compared to the ceramics, making it the forerunner for sensing and energy harvesting applications. PVDF’s formability, flexibility and biocompatibility, further reinforce its candidature. Present commercial PVDF-based devices come in flat films or one-dimensional (1D) fibers. Three-dimensional (3D) printing of PVDF leads to higher sensitivity, better compliance, and ability to print embedded sensors in case of multi-material printing. PVDF is a semi-crystalline polymer possessing five polymorphs, of which the polar β-phase exhibits highest piezoelectric properties. Unfortunately, PVDF from melt or solution crystallizes into a thermodynamically stable non-polar α-phase. Various physical transformations like annealing, filler addition, stretching or poling are carried out to transform the α-phase into β-phase. Due to the inherent crystallization of PVDF into α-phase, there have been very few attempts in fabricating 3D structures from PVDF. Near-field electrospinning and fused deposition modelling have demonstrated some layer-by-layer 3D structures with PVDF, either with application of high electric voltages or high temperature melting of the polymer, respectively. Also, both these techniques require a poling treatment to impart the desired piezoelectricity to the printed features. To fabricate embedded or conformal sensors on given substrates, it is essential to not have any adverse effects on the adjacent or substrate materials due to poling during the printing process. Thus, in this work, we develop a 3D printing process, that creates PVDF structures that inherently crystallize in the piezoelectric oriented β-phase at room temperature without any applied voltages. Solvent-evaporation assisted 3D printing is employed to print 3D piezoelectric structures of PVDF based solutions. In this process, the polymer solution is filled into a syringe which is inserted into a pneumatic dispenser. The pneumatic dispenser is mounted on a robotic arm that is controlled via a computer program

Non-linear actuators and simulation tools for rehabilitation devices

Mención Internacional en el título de doctorRehabilitation robotics is a field of research that investigates the applications of robotics in motor function therapy for recovering the motor control and motor capability. In general, this type of rehabilitation has been found effective in therapy for persons suffering motor disorders, especially due to stroke or spinal cord injuries. This type of devices generally are well tolerated by the patients also being a motivation in rehabilitation therapy. In the last years the rehabilitation robotics has become more popular, capturing the attention at various research centers. They focused on the development more effective devices in rehabilitation therapy, with a higher acceptance factor of patients tacking into account: the financial cost, weight and comfort of the device. Among the rehabilitation devices, an important category is represented by the rehabilitation exoskeletons, which in addition to the human skeletons help to protect and support the external human body. This became more popular between the rehabilitation devices due to the easily adapting with the dynamics of human body, possibility to use them such as wearable devices and low weight and dimensions which permit easy transportation. Nowadays, in the development of any robotic device the simulation tools play an important role due to their capacity to analyse the expected performance of the system designed prior to manufacture. In the development of the rehabilitation devices, the biomechanical software which is capable to simulate the behaviour interaction between the human body and the robotics devices, play an important role. This helps to choose suitable actuators for the rehabilitation device, to evaluate possible mechanical designs, and to analyse the necessary controls algorithms before being tested in real systems. This thesis presents a research proposing an alternative solution for the current systems of actuation on the exoskeletons for robotic rehabilitation. The proposed solution, has a direct impact, improving issues like device weight, noise, fabrication costs, size an patient comfort. In order to reach the desired results, a biomechanical software based on Biomechanics of Bodies (BoB) simulator where the behaviour of the human body and the rehabilitation device with his actuators can be analysed, was developed. In the context of the main objective of this research, a series of actuators have been analysed, including solutions between the non-linear actuation systems. Between these systems, two solutions have been analysed in detail: ultrasonic motors and Shape Memory Alloy material. Due to the force - weight characteristics of each device (in simulation with the human body), the Shape Memory Alloy material was chosen as principal actuator candidate for rehabilitation devices. The proposed control algorithm for the actuators based on Shape Memory Alloy, was tested over various configurations of actuators design and analysed in terms of energy eficiency, cooling deformation and movement. For the bioinspirated movements, such as the muscular group's biceps-triceps, a control algorithm capable to control two Shape Memory Alloy based actuators in antagonistic movement, has been developed. A segmented exoskeleton based on Shape Memory Alloy actuators for the upper limb evaluation and rehabilitation therapy was proposed to demosntrate the eligibility of the actuation system. This is divided in individual rehabilitation devices for the shoulder, elbow and wrist. The results of this research was tested and validated in the real elbow exoskeleton with two degrees of freedom developed during this thesis.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Eduardo Rocón de Lima.- Secretario: Concepción Alicia Monje Micharet.- Vocal: Martin Stoele

Design and evaluation of a powered prosthetic foot with monoarticular and biarticular actuation

To overcome the limitations of passive prosthetic feet, powered prostheses have been developed, that can provide the range of motion and power of their human counterparts. These devices can equalize spatio-temporal gait parameters and improve the metabolic effort compared to passive prostheses, but asymmetries and compensatory motions between the healthy and impaired leg remain. Unlike their human counter part, existing powered prosthetic feet are fully monoarticular actuating only the prosthetic ankle joint, whereas in the biological counter part, ankle and knee joint are additionally coupled by the biarticular gastrocnemius muscle. The goal of this work is to investigate the benefits of a powered biarticular transtibial prosthesis comprising mono- and biarticular actuators similar to the human example. The contributions of the present work are as follows: A biarticular prosthesis prototype is methodically designed to match the capabilities of the monoarticular muscles at the human ankle joint as well as the biarticular gastrocnemius muscle during level walking. The prototype consists of an existing powered monoarticular prosthetic foot, which is extended with a knee orthoses and a stationary biarticular Bowden cable actuator. Both actuators are modeled as serial elastic actuators (SEA) and the identification of the model parameters is conducted. A model based torque control utilizing the measurements commonly available in SEAs, an impedance control law based on human ankle reference trajectories, and a high level control to enable steady walking in the lab are introduced. The proposed hardware setup and control structure can provide sagittal plane angles and torques similar to the mono- and biarticular muscles at the human ankle, with proper torque tracking performance and a freely adjustable allocation of torque between the monoarticular and biarticular actuator. The biarticular prosthesis is evaluated in the gait lab with three subjects with unilateral transtibial amputation utilizing a continuous sweep experimental protocol to investigate the metabolic effort and spatio-temporal gait parameters. All subjects show a tendency to reduced metabolic effort for medium activity of the artificial gastrocnemius, although noise level and time variation are large. In addition to the reduction in metabolic effort, the artificial gastrocnemius is able to influence spatio temporal gait parameters between the impaired and the intact side, but partially opposing effects are observed among the individual subjects. In conclusion, this thesis describes the implementation of an artificial gastrocnemius following the human example and the systematic investigation of metabolic effort and spatio-temporal gait parameters. It is shown that the addition of the artificial gastrocnemius to a monoarticular prosthesis can positively affect the investigated parameters. The meaningfulness of the results should be improved by increased clinical effort in future work

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Bio-Inspired Robotics

Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field

Órtese passiva com atuador elástico para ciclismo assistido por estimulação elétrica

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2021.A lesão medular é uma condição debilitante que gera diversas complicações para os indivíduos que as têm. Eles podem desenvolver não somente problemas motores, mas diversos outros associados em decorrência da lesão, como problemas circulatórios, urinários, intestinais e de pele. Para a reabilitação e auxílio de pessoas com lesão medular, a estimulação elétrica funcional (FES) é uma técnica bastante utilizada, pois promove ganhos de massa muscular e óssea e melhora a circulação sanguínea. A combinação do FES com ciclismo (FES cycling), em geral com bicicleta estacionária ou triciclo, é bastante difundida, porém ainda há desafios de eficiência, como a baixa cadência e forças produzidas e fadiga acelerada, levando a exercício de baixas duração e intensidade. Neste trabalho, exploramos o uso de órtese passiva com atuador elástico incorporados aos protocolos do FES cycling. Para tanto, usamos um ambiente de simulação para o FES \textit{cycling} e incorporamos elementos passivos para entender se isso poderia aumentar a cadência do ciclismo. As simulações mostraram ganhos aproximadamente 10\% na cadência. Tendo resultados positivos, projetamos e construímos protótipo para testar com indivíduo com lesão medular em treinos de FES cycling. Como resultado, observamos que, assim como nas simulações, os parâmetros de atuação do elemento elástico influenciam nos ganhos. Conseguimos resultados positivos (ganhos de 11% e 17%) assim como negativos (perdas de -1,8% e -11%) na cadência durante os treinamentos. Lesão medular pode afetar significativamente a qualidade de vida e a investigação de sistemas que contribuam para melhora da qualidade de vida são essenciais. Neste trabalho, buscamos uma maneira de melhorar o uso do FES cycling na reabilitação através do uso de órtese passiva.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Spinal cord injury is a debilitating condition that generates several complications for individuals. They can develop not only motor problems, but also several others associated with the injury, such as circulatory, urinary, intestinal and skin problems. For rehabilitation and assistance of people with spinal cord injury, functional electrical stimulation (FES) is a widely used technique, as it promotes gains in muscle and bone mass and improves blood circulation. The combination of FES with cycling (FES cycling), on a stationary bicycle or a tricycle, is widespread, but there are still efficiency challenges, such as low cadence, low forces production and early fatigue, leading to low duration and low intensity exercise. In this work, we explore the use of passive orthosis with elastic actuator into FES cycling protocols. For this, we use a simulation environment for FES cycling and incorporate passive elements to understand if it could increase cycling cadence. The simulations showed gains of approximately 10 \% in cadence. With positive results, we designed and built a prototype to test with an individual with spinal cord injury in FES cycling training. As result, we observed that the chosen parameters for the elastic actuator influence the results, as seen in the simulations. We achieved positive results (gains of 11 \% and 17 \%) as well as negative (losses of -1.8 \% and -11 \%) for cadence during traning days. Spinal cord injury can significantly affect quality of life and to investigate systems that contribute to improve quality of life are essential. In this work, we look for a way to improve the use of FES cycling in rehabilitation through the use of passive orthosis