Orientador: Aparecido Augusto de Carvalho / Resumo: O pé é o órgão base da sustentação do corpo humano que está constantemente submetido a esforços para garantir a estabilidade deste. Analisando-se a distribuição de força na região plantar de indivíduos, pode-se inferir a respeito de patologias nos pés, problemas posturais e de equilíbrio. O estudo da distribuição de força na região plantar é feito com o baropodômetro, um equipamento composto por sistemas de hardware e software. Neste trabalho é apresentado o desenvolvimento de um baropodômetro implementado no Laboratório de Instrumentação e Engenharia Biomédica do Departamento de Engenharia Elétrica, UNESP – Campus Ilha Solteira, constituído por 120 sensores resistivos, tipo Force Sensing Resistor (FSR), dispostos matricialmente em duas plataformas, e por circuitos de aquisição de dados, comunicação e interfaceamento. Com as informações obtidas, por meio do software é possível identificar deformidades na região plantar e locais desta região submetidos a forças elevadas. Foram feitos testes em um grupo de 30 voluntários com diferentes faixas etárias e diferentes graus de escoliose. Inicialmente os voluntários foram divididos em dois grupos, sendo que o grupo G2 (45-78 anos) apresentou valores de estabiliometria maiores quando comparados com o G1 (13-30 anos). De forma similar, foi segmentada a mesma população (N=30) em dois grupos, segundo o grau de escoliose, GrA (0-9°) e GrB (10-32°). O grupo GrB mostrou maiores valores de estabiliometria do que o GrA e foi possível determi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The foot is the main support organ of the human body that is constantly subjected to efforts to ensure the stability of the body. Analyzing the distribution of force in the plantar region of individuals, it is possible to infer about feet pathologies, postural and balance problems, among others. The study of foot force distribution is made with the baropodometer, an equipment composed by hardware and software systems. This work describes the baropodometer developed at the Instrumentation and Biomedical Engineering Laboratory at the Department of Electrical Engineering, UNESP – Ilha Solteira, composed of 120 resistive sensors (Force Sensing Resistor - FSR) arranged in matrix on two platforms. Furthermore, acquisition and communication boards and software made in LabVIEW were developed. With the information obtained, with the software it is possible to identify deformities in the plantar region and sites of this region subjected to high forces. Tests in 30 volunteers with different ages and different scoliosis angles were made. Firstly, the volunteers were divided into two groups according to ages. The second group G2 (45-78 years old) had higher stabilometry values than first group G1 (13-30 years old). Secondly, the 30 volunteers were divided in two groups according scoliosis angles, GrA (0-9°) e GrB (10-32°). The GrB group showed higher stabilometry values than the GrA group, and it was possible to determine that the higher the degree of scoliosis the lower the dependency of... (Complete abstract click electronic access below) / Mestre

The longitudinal forces generated from the Friction Stir Welding process are substantial. An understanding of these forces is critical to proper tool design. This study describes a technique to measure the longitudinal force distribution on a friction stir weld pin tool. Total longitudinal forces were recorded on a dynamometer while welding 6061 aluminum with non-threaded pins that varied in length and diameter. A model was developed that characterizes pin force as a function of pin length and diameter. Results suggest that force generally increases with pin length, while forces remain relatively constant with pin diameter. Unexpected force variation was found at large pin lengths, which yielded several possible models of the force distribution. All of the modeled force distributions proved to be non-uniform and increase linearly with pin length, which produces a pin force that increases with the square of the pin length.

Lors des interventions humaines pendant les arrêts de tranche des installations nucléaires d’EDF, on remarque une remise en suspension de certains radionucléides sous forme d’aérosols (1 µm < dp < 10 µm). Dans le cadre d’une augmentation des interventions effectuées de façon simultanée en bâtiment réacteur, il devient important de mieux comprendre la remise en suspension due à l’activité des opérateurs pour adapter leur radioprotection. Le but des travaux de cette thèse est de quantifier la remise en suspension des particules suite à la marche des opérateurs sur un sol faiblement contaminé. Pour cela, la démarche suivie consiste à coupler un modèle de remise en suspension aéraulique avec des calculs numériques d’écoulement sous une chaussure, puis à caractériser expérimentalement certains paramètres d’entrée du modèle (diamètre de particule, forces d’adhésion, mouvement de la chaussure).Le modèle de remise en suspension Rock’n’Roll proposé par Reeks et Hall (2001) a été choisi car il décrit de manière physique ce mécanisme et est basé sur le moment des forces appliquées à une particule. Il nécessite la maîtrise de paramètres d’entrée tels que la vitesse de frottement de l’air, la distribution des forces d’adhésion et le diamètre des particules.Concernant le premier paramètre, des simulations numériques d’écoulement ont été réalisées, à l’aide du code de calcul ANSYS CFX, sous une chaussure de sécurité en mouvement (numérisée par CAO 3D) ; les cartographies des vitesses de frottement obtenues donnent des valeurs de l’ordre de 1 m.s⁻ ¹ pour une vitesse angulaire moyenne de 200 °.s⁻ ¹ .Concernant le deuxième paramètre, des mesures AFM (Atomic Force Microscope) ont été réalisées avec des particules d’alumine ainsi que des particules d’oxyde de cobalt en contact avec des surfaces en époxy représentatives de celles rencontrées dans les installations d’EDF. L’AFM permet d’obtenir la distribution des forces d’adhésion et révèle une valeur moyenne bien plus faible que ce qui peut être calculé de façon théorique en utilisant par exemple le modèle JKR proposé par Johnson et al. (1971). De plus, cette technique, tenant compte des rugosités de surface, montre que plus la taille de la particule augmente, plus la moyenne des forces d’adhésion diminue. Enfin, l’analyse des mesures AFM a permis d’obtenir une corrélation liant la distribution des forces d’adhésion au diamètre des particules, remplaçant celle de Biasi et al. (2001) initialement utilisée dans le modèle Rock’n’Roll et permettant ainsi d’adapter le modèle aux particules et aux revêtements de sol étudiés. Le couplage, effectué dans le code de calcul ANSYS CFX, entre les calculs de vitesses de frottement et le modèle de remise en suspension, a permis de déterminer des taux de remise en suspension théoriques pour le cas d’un cycle unique de marche. Ce couplage a été dans un premier temps validé par une comparaison à l’expérience pour le cas simple d’une plaque en rotation dans un volume contrôlé. En complément, des expériences à l’échelle d’un local ventilé de 30 m³ ont été réalisées en marchant sur un revêtement époxy ensemencé en particules de tailles calibrées (1,1 µm et 3,3 µm). Ces expériences ont permis de mettre en évidence les paramètres influant la remise en suspension des particules, tels que la fréquence de pas et la taille des particules. / In nuclear facilities, during normal operations in controlled areas, workers could be exposed to radioactive aerosols (1 µm < dp < 10 µm). One of the airborne contamination sources is particles that are initially seeded on the floor and could be removed by workers while they are walking. During the outage of EDF nuclear facilities, there is a resuspension of some radionuclides in aerosol form (1 µm < dp < 10 µm). Since the number of co-activity will increase in reactors buildings of EDF, it becomes important to understand particle resuspension due to the activity of the operators to reduce their radiation exposure. The purpose of this Ph.D thesis is to quantify the resuspension of particles due to the progress of operators on a contaminated soil. Thus, the approach is to combine an aerodynamic resuspension model with numerical calculations of flow under a shoe, and then to characterize experimentally some input parameters of the model (particle diameter, adhesion forces, shoes motion).The resuspension model Rock'n'Roll proposed by Reeks and Hall (2001) was chosen because it describes physically the resuspension mechanism and because it is based on the moment of forces applied to a particle. This model requires two input parameters such as friction velocity and adhesion forces distribution applied on each particle.Regarding the first argument, numerical simulations were carried on using the ANSYS CFX software applied to a safety shoe in motion (digitized by 3D CAO); the mapping of friction velocity shows values of about 1 m.s⁻ ¹ for an angular average velocity of 200 °.s⁻ ¹ . As regards the second parameter, AFM (Atomic Force Microscopy) measurements were carried out with alumina and cobalt oxide particles in contact with epoxy surfaces representative of those encountered in EDF power plants. AFM provides the distribution of adhesion forces and reveals a much lower value than what can be calculated theoretically using JKR model (Johnson et al. (1971)). Moreover, this technique, taking into account the surface roughness, shows that adhesion forces decrease while particle diameter increase. Finally, the analysis of AFM measurements gives a correlation linking the distribution of adhesion forces to the particle diameter, replacing the one given by Biasi et al. (2001) originally used in the Rock'n'Roll model and thereby adapt the model to particles and flooring studied in our case.Coupling, performed in ANSYS CFX software, between the calculations of friction velocity and model of particle resuspension, gives theoretical resuspension rate during shoe motion. This coupling was initially validated by comparison to the experience for the simple case of a rotating plate in a controlled volume. Secondly, experiments at the scale of a ventilated room of 30 m³ were performed by walking on an epoxy coating initially seeded by calibrated particle size (1,1 µm and 3,3 µm). These experiments highlight the parameters influencing the suspension of particles, such as step frequency and particle size.

Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-30Bitstream added on 2014-06-13T20:47:51Z : No. of bitstreams: 1 freitas_rlb_me_ilha.pdf: 2701208 bytes, checksum: 5ab311e644d8a3837fea549fd3136b7e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho, descreve-se um sistema eletrônico informatizado implementado com o objetivo de medir a distribuição do peso corporal na região plantar de pacientes, visando relacioná-la diretamente à tipologia e deformidades dos pés e associando-a, indiretamente, a eventuais deformidades dos membros inferiores, coluna vertebral, algias músculoesqueléticas e instabilidades da postura humana. O sistema é constituído por células de carga com extensômetros, montadas em uma base metálica, circuito de condicionamento de sinais, circuito de interfaceamento e um display de cristal líquido. Foi construída uma plataforma piloto com 4 células de carga, mas o projeto do sistema prevê a construção de duas plataformas com 45 células de cargas, cada uma. As células de carga apresentaram resposta linear, precisão superior a 2%, resolução inferior a 0,5 N e histerese desprezível. São apresentados os resultados de medições, efetuadas com o sistema, para medir a distribuição de forças nas quatro células de carga, quando se aplicou sobre elas um peso conhecido. As informações foram apresentadas em um display de cristal líquido e posteriormente serão apresentadas na tela de um computador, por meio de um programa desenvolvido em Delphi, facilitando a visualização para especialistas da área, principalmente médicos, fisioterapeutas e terapeutas ocupacionais. Com o equipamento proposto será possível investigar, clinicamente, patologias estudadas pela Podologia, Posturologia e Podoposturologia, viabilizando, com as informações captadas pelo sistema, metodologias mais adequadas de tratamentos. / In this work we describe an electrical system implemented with the purpose of measuring the distribution of body weight in plantar region of patients, aiming to relate it directly to the typology and deformities of the feet and involving it, indirectly, to any deformities of the lower limbs, skeletal spine, muscle-skeletal pains and human posture instability. The system consists of load cells with strain gages within a metal base, signal conditioning circuit, interfacing circuit, and a liquid crystal display. A prototype platform with 4 load cells was built, but the system will have two platforms with 45 loads of cells, each one. The load cells presented linear response, precision better than 2%, resolution less than 0.5 N, and low hysteresis. We show the results of the force distribution when a know weight is applied over the four load cells. The informations have been presented in a liquid crystal display, but later they will be presented in the screen of a computer, facilitating the visualization for specialists, mainly doctors, physiotherapists and occupational therapists. With the proposed equipment it will be possible to investigate, clinically, pathologies studied by Podology, Posturology and Podoposturology making feasible, with the information obtained with the system, more appropriate methodologies of treatment.

Orientador: Aparecido Augusto de Carvalho / Banca: Nobuo Oki / Banca: Josivaldo Godoy da Silva / Resumo: Neste trabalho, descreve-se um sistema eletrônico informatizado implementado com o objetivo de medir a distribuição do peso corporal na região plantar de pacientes, visando relacioná-la diretamente à tipologia e deformidades dos pés e associando-a, indiretamente, a eventuais deformidades dos membros inferiores, coluna vertebral, algias músculoesqueléticas e instabilidades da postura humana. O sistema é constituído por células de carga com extensômetros, montadas em uma base metálica, circuito de condicionamento de sinais, circuito de interfaceamento e um display de cristal líquido. Foi construída uma plataforma piloto com 4 células de carga, mas o projeto do sistema prevê a construção de duas plataformas com 45 células de cargas, cada uma. As células de carga apresentaram resposta linear, precisão superior a 2%, resolução inferior a 0,5 N e histerese desprezível. São apresentados os resultados de medições, efetuadas com o sistema, para medir a distribuição de forças nas quatro células de carga, quando se aplicou sobre elas um peso conhecido. As informações foram apresentadas em um display de cristal líquido e posteriormente serão apresentadas na tela de um computador, por meio de um programa desenvolvido em Delphi, facilitando a visualização para especialistas da área, principalmente médicos, fisioterapeutas e terapeutas ocupacionais. Com o equipamento proposto será possível investigar, clinicamente, patologias estudadas pela Podologia, Posturologia e Podoposturologia, viabilizando, com as informações captadas pelo sistema, metodologias mais adequadas de tratamentos. / Abstract: In this work we describe an electrical system implemented with the purpose of measuring the distribution of body weight in plantar region of patients, aiming to relate it directly to the typology and deformities of the feet and involving it, indirectly, to any deformities of the lower limbs, skeletal spine, muscle-skeletal pains and human posture instability. The system consists of load cells with strain gages within a metal base, signal conditioning circuit, interfacing circuit, and a liquid crystal display. A prototype platform with 4 load cells was built, but the system will have two platforms with 45 loads of cells, each one. The load cells presented linear response, precision better than 2%, resolution less than 0.5 N, and low hysteresis. We show the results of the force distribution when a know weight is applied over the four load cells. The informations have been presented in a liquid crystal display, but later they will be presented in the screen of a computer, facilitating the visualization for specialists, mainly doctors, physiotherapists and occupational therapists. With the proposed equipment it will be possible to investigate, clinically, pathologies studied by Podology, Posturology and Podoposturology making feasible, with the information obtained with the system, more appropriate methodologies of treatment. / Mestre

All living organisms utilize thousands of molecular building blocks to perform mechanical tasks. These building blocks are mostly proteins, and their mechanical properties define the way they can be utilized by the cell. The spectrum ranges from rope like structures that give hold and stability to our bodies to microscopic engines helping us to perform or sense mechanical work. An increasing number of biological processes are revealed to be driven by force and well-directed distribution of strain is the very base of many of these mechanisms. We need to be able to observe the distribution of strain within bio-molecules if we want to gain detailed insight into the function of these highly complex nano-machines. Only by theoretical understanding and prediction of mechanical processes on the molecular level will we be able to rationally tailor proteins to mimic specific biological functions. This thesis aims at understanding the molecular mechanics of a wide range of biological molecules, such as the muscle protein titin or silk fibers. We introduce Force Distribution Analysis (FDA), a new approach to directly study the forces driving molecular processes, instead of indirectly observing them by means of coordinate changes.

This thesis project is a comprehensive practice to improve a research concept vehicle in both hardware and software aspects. The hardware of the friction brake system is improved to have higher stability and accuracy. The brake force distribution function is implemented to optimize the brake control system. A fault tolerant function based on the Pseudo-inverse control allocation strategy is designed, implemented, and tested to compensate for sudden fault in wheels when driving. / Detta examensarbete är ett omfattande arbete att förbättra ett forskningsfordon som heter Research Concept Vehicle (RCV) gällande både hårdvara och mjukvara. Hårdvaran i bromssystemet har förbättrats för bättre stabilitet och noggranhet. Bromskraftsfördelningsfuktionen har implementerats för att optimera bromssystemets reglering. En feltolerant funktion baserad på pseudo-invers reglering har också implementerats och testats för att kunna kompensera plötsliga felfall i hjul under körning.

The work presented in this thesis aims to make contribution to the understanding and application of six-legged statically stable walking machines in both theoretical and practical levels. In this thesis five pieces of work, performed with and for the three-joint six-legged Robot-EA308, are presented: 1) Standard gaits, which include the well-known wave gaits, are defined and a stability analysis, in the sense of static stable walking, is performed on an analytical level. Various definitions are given / theorems are stated and proved. 2) A free gait generation algorithm with reinforcement learning is developed. Its facilities of stability improvement, smooth speed changes, and adaptation in case of a rear-leg deficiency with learning of five-legged walking are experimented in real-time on the Robot-EA308. 3) Trajectory optimization and controller design is performed for the protraction movement of a three-joint leg. The trajectory generated by the controller is demonstrated with the Robot-EA308. 4) The full kinematic-dynamic formulation of a three-joint six-legged robot is performed with the joint-torques being the primary variables. It is demonstrated that the proposed torque distribution scheme, rather than the conventional force distribution, results in an efficient distribution of required forces and moments to the supporting legs. 5) An analysis of energy efficiency is performed for wave gaits. The established strategies for determination of gait parameters for an efficient walk are justified using the Robot-EA308.

L’industrie offshore, pétrolière et gazière est le principal utilisateur des robots sous-marins, plus particulièrement de véhicules télé-opérés (ou ROV, Remotely Operated Vehicle). L'inspection, la construction et la maintenance de diverses installations sous-marines font parties des applications habituelles des ROVs dans l’industrie offshore. La capacité à maintenir un positionnement stable du véhicule ainsi qu’à soulever et déplacer des charges lourdes est essentielle pour certaines de ces applications. Les capacités de levage des ROVs sont cependant limitées par la puissance de leur propulsion. Dans ce contexte, cette thèse présente un nouveau concept d’actionnement hybride constitué de câbles et de propulseurs. Le concept vise à exploiter les fortes capacités de levage des câbles, actionnés par exemple depuis des navires de surfaces, afin de compléter l’actionnement d’un robot sous-marin. Plusieurs problèmes sont soulevés par la nature hybride (câbles et propulseurs) de ce système d'actionnement. En particulier, nous étudions l’effet de l'actionnement supplémentaire des câbles par rapport à un actionnement exploitant uniquement des propulseurs et nous tâchons de minimiser les efforts exercés par ces derniers. Ces deux objectifs sont les principales contributions de cette thèse. Dans un premier temps, nous modélisons la cinématique et la dynamique d'un robot sous-marin actionné à la fois par des propulseurs et des câbles et équipé d'un bras manipulateur. Un tel système possède une redondance cinématique et d'actionnement.. L'étude théorique sur l'influence de l'actionnement supplémentaire par câbles est appuyée par une étude en simulation, comparant les capacités de force d'un système hybride (câbles et propulseurs) à celles d'un système actionné uniquement par des propulseurs. L'évaluation des capacités est basée sur la détermination de l'ensemble des forces disponibles, en considérant les limites des forces d'actionnement. Une nouvelle méthode de calcul est proposée, pour déterminer l'ensemble des forces disponibles. Cette méthode est basée sur le calcul de la projection orthogonale de polytopes et son coût calculatoire est analysé et comparé à celui d'une méthode de l’état de l’art. Nous proposons également une nouvelle méthode pour le calcul de la distribution des forces d'actionnement, permettant d'affecter une priorité supérieure au sous-système d'actionnement par câbles afin de minimiser les efforts exercés par les propulseurs. Plusieurs cas d'études sont proposés pour appuyer les méthodes proposées. / The offshore industry for oil and gas applications is the main user of underwater robots, particularly, remotely operated vehicles (ROVs). Inspection, construction and maintenance of different subsea structures are among the applications of ROVs in this industry. The capability to keep a steady positioning as well as to lift and deploy heavy payloads are both essential for most of these applications. However, these capabilities are often limited by the available on-board vehicle propulsion power. In this context, this thesis introduces the novel concept of Hybrid Cable-Thruster (HCT)-actuated Underwater Vehicle-Manipulator Systems (UVMS) which aims to leverage the heavy payload lifting capabilities of cables as a supplementary actuation for ROVs. These cables are attached to the vehicle in a setting similar to Cable-Driven Parallel Robots (CDPR). Several issues are raised by the hybrid vehicle actuation system of thrusters and cables. The thesis aims at studying the impact of the supplementary cable actuation on the capabilities of the system. The thesis also investigate how to minimize the forces exerted by thrusters. These two objectives are the main contributions of the thesis. Kinematic, actuation and dynamic modeling of HCT-actuated UVMSs are first presented. The system is characterized not only by kinematic redundancy with respect to its end-effector, but also by actuation redundancy of the vehicle. Evaluation of forces capabilities with these redundancies is not straightforward and a method is presented to deal with such an issue. The impact of the supplementary cable actuation is validated through a comparative study to evaluate the force capabilities of an HCT-actuated UVMS with respect to its conventional UVMS counterpart. Evaluation of these capabilities is based on the determination of the available forces, taking into account the limits on actuation forces. A new method is proposed to determine the available force set. This method is based on the orthogonal projection of polytopes. Moreover, its computational cost is analyzed and compared with a standard method. Finally, a novel force resolution methodology is introduced. It assigns a higher priority to the cable actuation subsystem, so that the forces exerted by thrusters are minimized. Case studies are presented to illustrate the methodologies presented in this thesis.

Cette thèse contribue à l'analyse des raideurs statique et dynamique des robots parallèles à câbles dans un objectif d'amélioration de la précision de positionnement statique et de la précision de suivi de trajectoire. Les modélisations statique et dynamique proposées des câbles considèrent l'effet du poids du câble sur son profil et l'effet de masse du câble sur la dynamique de ce dernier. Sur la base du modèle statique de câble proposé, l'erreur de pose statique au niveau de l'organe terminal du robot est définie et sa variation en fonction de la charge externe appliquée est utilisée pour évaluer la raideur statique globale de la structure. Un nouveau modèle dynamique vibratoire de robots à câbles est proposé en considérant le couplage de la dynamique des câbles avec les vibrations de l'organe terminal. Des validations expérimentales sont réalisées sur des prototypes de robots à câbles. Une série d'expériences de statique, d'analyses modales, d'analyses en régime libre et de suivi de trajectoire sont réalisées. Les modèles statiques et dynamiques proposés sont confirmés. Les dynamiques des câbles et du robot ainsi que leur couplage sont discutées montrant la pertinence des modèles développés pour l’amélioration des performances des robots à câbles en termes de design et le contrôle. Outre l'analyse des raideurs statique et dynamique, les modèles proposés sont appliqués dans l'amélioration du calcul de la distribution des efforts dans les câbles des robots redondants. Une nouvelle méthode de calcul de la distribution des efforts dans les câbles basée sur la détermination de la limite inférieure des forces dans les câbles est présentée. La prise en compte de la dépendance à la position dans l'espace de travail permet de limiter les efforts dans les câbles et ainsi d'améliorer l'efficience des robots d'un point de vue énergétique. / This thesis contributes to the analysis of the static and dynamic stiffness of cable-driven parallel robots (CDPRs) aiming to improve the static positioning accuracy and the trajectory tracking accuracy. The proposed static and dynamic cable modeling considers the effect of cable weight on the cable profile and the effect of cable mass on the cable dynamics. Based on the static cable model, the static pose error of the end-effector is defined and the variation of the end-effector pose error with the external load is used to evaluate the static stiffness of CDPRs. A new dynamic model of CDPRs is proposed with considering the coupling of the cable dynamics and the end-effector vibrations. Experimental validations are carried out on CDPR prototypes. Static experiments, modal experiments, free vibration experiments and trajectory experiments are performed. The proposed static and dynamic models are verified. Cable dynamics, robot dynamics and their coupling are discussed. Results show the relevance of the proposed models on improving the performances of CDPRs in terms of design and control. Besides stiffness analysis, the proposed models are applied on the force distribution of redundant actuated CDPRs. A new method on the calculation of the cable forces is proposed, where the determination of the lower-boundary of the cable forces is presented. The consideration of the pose-dependence of the lower force boundary can minimize the cable forces and improve the energy efficiency of CDPRs.