本論文の目的は，体表から無侵襲に肩甲骨運動を推定する方法を確立すること，肩甲骨運動を拡大する運動介入としての肩甲骨エクササイズを明らかにすること，そのエクササイズが投球動作中の肩甲骨運動に与える即時的な効果を検討することとした．その結果，本研究で考案した推定方法によって肩甲骨姿勢の推定精度は向上した．また体幹運動をともなった肩甲骨エクササイズによって投球動作中の肩甲骨後傾運動が増加した． / 博士(スポーツ健康科学) / Doctor of Philosophy in Health and Sports Science / 同志社大学 / Doshisha University

The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. This thesis deals with the design of ultra-fast electro-mechanical actuators based on the so-called Thomson coil (TC) actuator. The simulation of a (TC) actuator constitutes a multi-physical problem where electromagnetic, thermal, and mechanical aspects must be considered. Moreover, it is complex since all those variables are co-dependent and have to be solved for simultaneously. As a result, a multi-physics simulation model that can predict the behavior and performance of such actuators with a high degree of accuracy was developed. Furthermore, other actuator concepts were also investigated and modeled in light of searching for a drive with a superior efficiency. The theory behind the force generation principles of two different types of ultra-fast electromechanical actuators, the TC and the double sided coil (DSC), were compared by the use of static, frequency, and comprehensive transient multi-physics finite element simulation models. Although, simulation models serve as a powerful tool for modeling and designing such state of the art actuators, without validation, they are weak and prone to errors since they rely on approximations and simplifications that might not always hold. Therefore, a prototype was built in the laboratory and the model was validated experimentally. Finally, it is important to note that the drives in this thesis are intended to actuate metallic contacts. As such, their behavior and performance upon mechanical loading was studied. Furthermore, some scaling techniques were applied to boost their performance and efficiency. / <p>QC 20130422</p>

Arbeitsplätze im Gartenbau sind trotz fortschreitender Mechanisierung durch einen hohen Anteil an Handarbeit gekennzeichnet. Die aktuellen Rahmenbedingungen im Gartenbau erfordern für die Zukunft einen effizienteren Einsatz des Faktors Arbeit in wirtschaftlichen und an Attraktivität gewinnenden Arbeitssystemen. Die Entwicklung solcher Systeme erfordert ein Verfahren zur objektiven Bewertung vorhandener und neuer Betriebs- und Arbeitsabläufe. Die vorliegende Arbeit beschreibt die Weiterentwicklung eines auf der Verfolgung von Infrarot-Leuchtdioden basierenden 3-D-Bewegungsanalysesystems. Dazu wurde das Kamerasystem der Firma Wente/Thiedig um eine vom System unabhängige Software erweitert. Die für die Bewertung herangezogenen Indikatoren werden ausführlich beschrieben und im Ergebnisteil auf ihre Eignung überprüft. Aufgrund der digitalen Aufzeichnung der Bewegungen erhöht sich die Aussagekraft durch einen größeren Stichprobenumfang und eine höhere Messgenauigkeit erheblich. Um die Aussagekraft und den Erkenntnisgewinn aus den softwareseitig ermittelten Indikatoren zu überprüfen, wurden Anwendungsversuche mit verschiedenen Fragestellungen durchgeführt, die im zweiten Teil der Arbeit beschrieben werden. Am Beispiel der Produktauflage auf ein Förderband werden die Einflüsse spezifischer Gestaltungsparameter auf die Leistungsfähigkeit des Gesamtsystems verdeutlicht. Die Veränderung der Bandgeschwindigkeit wirkte sich stark auf die erzielten Leistungen aus. In einem weiteren Versuch werden zwei Sitzplätze auf Spargelerntehilfen über die Bewegungsanalyse miteinander verglichen. Mehrere Indikatoren belegen die Vorzüge des mit Kniepolstern ausgestatteten Sitzplatzes. Die Ergebnisse der beiden Versuche zeigen, dass es gelungen ist, zahlreiche relevante Indikatoren für den Vergleich der aufgezeichneten Bewegungen zu bilden. Der Nutzer gewinnt aus den Bewegungsdaten Informationen, die eine objektive Entscheidungsfindung ermöglichen. Als besonders wertvoll ist der Erkenntnisgewinn bezüglich einer menschengerechten Arbeitsplatzgestaltung zu bewerten, um für die Weiterentwicklung gartenbaulicher Arbeitssysteme neben der Wirtschaftlichkeit andere Entscheidungskriterien zu fördern. / Despite the fast technical progress modern horticultural work places still require a lot of manual work. The current development in the horticultural sector demands a more efficient implementation of manpower and an increasing attractiveness of simple manual tasks for the future. The design of such systems demands a method to objectively evaluate present and new work systems. This thesis describes a largely improved 3-D-motion analysis system based on the tracking of infrared light diodes. The camera system manufactured by Wente/Thiedig is extended by a newly developed independent software to evaluate the motion data. From the recorded motion data quantitative parameters and qualitative parameters are calculated. Several graphical functions within the new software facilitate the understanding of the motion data. The available objective measures of comparison are described in detail in chapter four. In the experiments they are reviewed for their suitability. The digital recording of the motion data allows a large sample size. Accuracy and explanatory power as well as the level of confidence are increased. To proof their suitability and the increase of information gained with the measures of comparison practical experiments were carried out. These are described in the fifth chapter of this thesis. A workstation for placing products on on a conveyor belt is varied to show the influence of design parameters on the operating efficiency. The speed of the conveyor movement strongly affected the output. In another experiment two seat constructions built for asparagus harvesting aids are compared by motion analysis. Several measures of comparison suggest to favor the seat with knee pads. The results from all practical experiments show that relevant measures of comparison were defined to successfully compare the motion data. The user of the newly developed analyzing program gains valuable information to make a truly impartial decision. The motion analysis systems enables scientists to gather a multitude of information out of one experiment, which formerly required a combination of several methods. A more of information to rate human factors is notedly valuable, encouraging the development of horticultural work systems towards incorporating economic and ergonomic criteria.

The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. In comparison with traditional alternating current (AC) breakers, they should operate and interrupt fault currents in a time frame of a few milliseconds. The aim of this thesis is focused on the design of ultra-fast electro-mechanical actuator systems suitable for such HVDC breakers.Initially, holistic multi-physics and hybrid models with different levels of complexity and computation time were developed to simulate the entire switch. These models were validated by laboratory experiments. Following a generalized analysis, in depth investigations involving simulations complemented with experiments were carried out on two of the sub-components of the switch: the ultra-fast actuator and the damper. The actuator efficiency, final speed, peak current, and maximum force were explored for different design data.The results show that models with different levels of complexity should be used to model the entire switch based on the magnitude of the impulsive forces. Deformations in the form of bending or elongation may deteriorate the efficiency of the actuator losing as much as 35%. If that cannot be avoided, then the developed first order hybrid model should be used since it can simulate the behavior of the mechanical switch with a very good accuracy. Otherwise, a model comprising of an electric circuit coupled to an electromagnetic FEM model with a simple mechanics model, is sufficient.It has been shown that using a housing made of magnetic material such as Permedyn, can boost the efficiency of an actuator by as much as 80%. In light of further optimizing the ultra-fast actuator, a robust optimization algorithm was developed and parallelized. In total, 20520 FEM models were computed successfully for a total simulation time of 7 weeks. One output from this optimization was that a capacitance of 2 mF, a charging voltage of 1100 V and 40 turns yields the highest efficiency (15%) if the desired velocity is between 10 m/s and 12 m/s.The performed studies on the passive magnetic damper showed that the Halbach arrangement gives a damping force that is two and a half times larger than oppositely oriented axially magnetized magnets. Furthermore, the 2D optimization model showed that a copper thickness of 1.5 mm and an iron tube that is 2 mm thick is the optimum damper configuration. / <p>QC 20150422</p>

Submitted by Larissa Vitoria Cardoso Cusielo (larissavitoria@id.uff.br) on 2017-05-22T15:59:28Z No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Manoel Coelho da Silva Neto - Dissertação Final.compressed.pdf: 2147671 bytes, checksum: c046094e9eb88ea2c91f4ebc1857ab0e (MD5) Manoel Coelho da Silva Neto - Produto Final.pdf: 4043748 bytes, checksum: ed0f262e5d26eb90ede963337eadcabc (MD5) / Rejected by Biblioteca do Aterrado BAVR (bavr@ndc.uff.br), reason: oi on 2017-05-22T16:23:42Z (GMT) / Submitted by Larissa Vitoria Cardoso Cusielo (larissavitoria@id.uff.br) on 2017-05-22T17:10:03Z No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Manoel Coelho da Silva Neto - Dissertação Final.compressed.pdf: 2147671 bytes, checksum: c046094e9eb88ea2c91f4ebc1857ab0e (MD5) Manoel Coelho da Silva Neto - Produto Final.pdf: 4043748 bytes, checksum: ed0f262e5d26eb90ede963337eadcabc (MD5) / Approved for entry into archive by Biblioteca do Aterrado BAVR (bavr@ndc.uff.br) on 2017-08-21T15:45:13Z (GMT) No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Manoel Coelho da Silva Neto - Dissertação Final.compressed.pdf: 2147671 bytes, checksum: c046094e9eb88ea2c91f4ebc1857ab0e (MD5) Manoel Coelho da Silva Neto - Produto Final.pdf: 4043748 bytes, checksum: ed0f262e5d26eb90ede963337eadcabc (MD5) / Made available in DSpace on 2017-08-21T15:45:13Z (GMT). No. of bitstreams: 3 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Manoel Coelho da Silva Neto - Dissertação Final.compressed.pdf: 2147671 bytes, checksum: c046094e9eb88ea2c91f4ebc1857ab0e (MD5) Manoel Coelho da Silva Neto - Produto Final.pdf: 4043748 bytes, checksum: ed0f262e5d26eb90ede963337eadcabc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Ciências Exatas. Programa de Pós-Graduação em Ensino de Física. Volta Redonda,RJ. / Esta dissertação apresenta uma atividade de ensino centrada no aluno para tópicos de cinemática, utilizando Tecnologias de Informação e Comunicação (TICs) e o game Angry Birds como motivador do engajamento do aluno no processo de aprendizagem. Em nosso projeto, conduzido no Colégio Estadual Conde Pereira Carneiro, em Angra dos Reis, RJ, os alunos cumpriram atividades de recuperação escolar em aulas vagas do próprio turno de presença, onde, capturando uma sessão de jogo de Angry Birds em vídeo, posteriormente analisavam os movimentos nele contidos no software Tracker. Com isso, trabalharam-se todos os conceitos fundamentais da cinemática, como posição, deslocamento, velocidade e aceleração, além de tópicos da cinemática, como movimento uniforme, acelerado e de projéteis. Os resultados sugerem que este tipo de atividade é efetiva em promover uma maior aproximação do aluno à disciplina de Física, proporcionando engajamento e estimulando autonomia e independência no aprendizado do estudante, qualidades desejáveis em qualquer metodologia de ensino. / This work presents a student-centered teaching activity for teaching kinematics, using Communication and Information Tecnologies, and the game Angry Birds as the motivator for student engagement in the learning process. Our project, conducted at Colégio Estadual Conde Pereira Carneiro, in Angra dos Reis, RJ, consisted of sessions where students captured a playing session of Angry Birds in video, with later analysis of the motion of the birds through the software Tracker. They dealt, thus, with all the fundamental concepts of kinematics, such as position, displacement, velocity and acceleration, as well as with topics specific to kinematics, such as uniform and accelerated motion and projectile motion. The results suggest that this kind of activity promotes a greater closeness to the discipline of Physics, as well as engagement and independence in learning, something highly desirable in teaching and learning.

The master’s thesis deals with a design of the computational method for the analysis of swimmers training with the use of an inertial measurement unit. The developed algorithm uses quaternion-based Unscented Kalman filter and merges accelerometer and gyroscope measurements. The proposed method enables analysis of velocity, acceleration and inclination of a swimmer. Verification of the method was based on an underwater video camera capturing and a tethered velocity meter.

No description available.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal. / Parmi la multitude de fonctions que le système visuel effectue, la perception du mouvement est l'une des plus importantes. Il a été clairement démontré qu'il existe des sites cérébraux spécifiques pour la détection, l'analyse et l'intégration du mouvement. De façon classique, les mécanismes neurophysiologiques qui sous-tendent ces processus sont attribués aux aires corticales. Le thalamus quant à lui, est généralement considéré comme un « relais passif », c'est à dire qui transmet l'information sensorielle vers le cortex sans modifier le signal entrant. Le but de ce projet sera de préciser les mécanismes nerveux impliqués dans la perception et l'intégration du mouvement et plus précisément, la contribution des régions cérébrales sous-corticales et corticales intimement liés par des connexions réciproques. Ces régions sont: le complexe LP-pulvinar, situé dans le thalamus, l'aire extra-striée postero-médiane suprasylvienne (PMLS) et le cortex ectosylvien visuel antérieur (AEV); deux régions corticales ayant un rôle spécialisé dans l'analyse du mouvement. Les expériences ont été réalisées sur des chats adultes normaux anesthésiés. Une microélectrode d'enregistrement a été descendue dans ces trois sites afin d'enregistrer l'activité des neurones. Les réponses neuronales à des réseaux sinusoïdaux, des patrons texturés (« bruit visuel ») et des « plaids » ont été caractérisé pour étudier les mécanismes qui sous-tendent l'intégration du mouvement au niveau cellulaire. Afin de caractériser d'avantage ce lien, l'influence des aires corticales sur les propriétés thalamiques a été déterminée par inactivation locale réversible (i.e. micro-injection de l'acide y-aminobutyrique; GABA) ou par inactivation permanente plus vaste (i.e. ablation chirurgicale). Les résultats de cette étude se résument comme suit : 1) les propriétés des réponses neuronales du PMLS au bruit visuel sont similaires à celles du LP-pulvinar. Ce résultat suggère que les processus d'analyse impliquant une boucle cortico-thalamique PMLS-LP sont comparables au niveau cortical et sous-cortical. 2) les neurones du PMLS et du LP peuvent coder le mouvement relatif entre un objet et son arrièreplan. De plus, l'inactivation réversible du LP perturbe ces réponses au niveau du PMLS. Ces résultats sont essentiels dans l'établissement d'un lien fonctionnel entre ces deux régions quant à l'analyse de certains aspects du mouvement. 3) certains neurones du complexe LP-pulvinar sont capables d'intégrer l'information directionnelle telle que définie par des « plaids ». Ceci constitue la première démonstration de propriétés de haut-niveau en dehors du cortex. De plus, cette découverte suggère que le LP-pulvinar participe de façon parallèle et en coopération avec le cortex dans l'analyse de scènes visuelles complexes via l'exploitation des boucles cortico-thalamiques. Les résultats de cette étude sont importants non seulement pour appuyer des notions théoriques novatrices sur le rôle du thalamus, mais aussi dans le but de réévaluer et de préciser les mécanismes nerveux qui sous-tendent la perception du mouvement et l'intégration sensorielle en général. / Among the multitude of functions the visual system carries out, the perception of motion is one of the most important. It has been clearly demonstrated that the visual system contains numerous specialised areas implicated in the detection, analysis, and integration of motion. Classically, the neurophysiological mechanisms underlying these processes have been uniquely attributed to regions of the cerebral cortex. The thalamus for its part, has generally been regarded as a passive relay transferring information to the cortex without any modification of the sensory signal. The purpose of this study is to investigate the neurophysiological mechanisms implicated in the perception and integration of motion and more specifically, delineate the contribution of cortical and subcortical structures that are intimately related via reciprocal connections. These areas are: the LP-pulvinar complex; located in the thalamus, and the extrastriate posteromedial lateral suprasylvian (PMLS) and anterior ectosylvian visual (AEV) cortical areas; two regions whose role in motion analysis are well established. Experiments were carried out on normal adult anaesthetised cats. A recording microelectrode was descended in one of the aforementioned areas to record neuronal activity. Neuronal responses to drifting sine-wave gratings, moving texture patterns ("visual noise"), and "plaid patterns" were recorded in order to investigate the mechanisms underlying the integration of motion information at the neuronal level. As a continuation of the study, the influence of cortical motion areas on recorded thalannic responses will be determined by local reversible deactivation (i.e. microinjection of y-aminobutyric acid; GABA) or by irreversible deactivation (i.e. surgical ablation). The results of the study are as follows: 1) Response properties of PMLS neurons to moving texture patterns are similar to those found in the LP-pulvinar connplex. These results suggest that motion processing along both components of the PMLS-LP cortico-thalamic loop is carried out within a similar envelope of analysis. 2) Neurons in both PMLS and LP are able to code the relative motion of an object with respect to its background. Furthermore, reversible deactivation of LP disrupts these responses in PMLS. These results are important in establishing that both these areas are functionally linked in the analysis of specific aspects of motion. 3) The fact that pattern-selective responses to moving plaids can be found in the LP-pulvinar complex suggests that this area is capable of carrying out higher-order motion computations. The importance of this later results is two-fold. First, these findings represent the first demonstration that higher-order properties exists outside extrastriate cortical areas. Second, they further suggest that certain thalamic nuclei, via the establishment of cortico-thalamic loops, participate in parallel and in co-operation with the cortex in the analysis of complex visual scenes. The results of this study are important not only to reinforce current and novel theoretical notions regarding the role of the thalamus, but also in the re-evaluation of the neurophysiological mechanisms involved in motion perception and sensory integration as a whole.

Human motion analysis (HMA) can play a crucial role in sports and healthcare by providing unique insights on movement mechanics in the form of objective measurements and quantitative data. Traditional, state of the art, marker-based techniques, despite their accuracy, come with financial and logistical barriers, and are restricted to laboratory settings. Markerless systems offer much improved affordability and portability, and can potentially be used outside of laboratories. However, these advantages come with a significant cost in accuracy. This thesis attempts to address the challenge of democratizing HMA by leveraging recent advances in smartphone technology and machine learning.\newline\newlineThis thesis evaluates two modalities of performing markerless HMA: Single smartphone using Apple Arkit, and multiple smartphone setup using OpenCap, and compares both to a state of the art multiple-camera marker-based system from Vicon. Additionally, this thesis presents and evaluates two approaches to improving the single smartphone modality: Employing a Gaussian Process Model (GPR), and a Long-short-term-memory (LSTM) neural network to refine the single smartphone data to align with the marker-based result. Specific movements were recorded simultaneously with all three modalities on 13 subjects to build a dataset. From this, GPR and LSTM models were trained and applied to refine the single camera modality data. Lower limb joint angles, and joint centers were evaluated across the different modalities, and analyzed for potential use in real-world applications. While the findings of this thesis are promising, as both the GPR and LSTM models improve the accuracy of Apple Arkit, and OpenCap providing accurate and consistent results. It is important to acknowledge limitations regarding demographic diversity and how real-world environmental factors may influence its application. This thesis contributes to the efforts in narrowing the gap between marker-based HMA methods, and more accessible solutions. / Rörelseanalys av människokroppen (HMA) kan spela en betydelsefull roll i både idrott och hälso- och sjukvården. Genom objektiv och kvantitativ data ger den unik insikt i mekaniken bakom rörelser. Traditionella, toppmoderna, markör-baserade tekniker är mycket precisa, men medför finansiella och logistikbaserade barriärer, och finns endast tillgängliga i laboratorier. Markör-fria system erbjuder mycket bättre pris, portabilitet och kan potentiellt användas utanför laboratorier. Dessa fördelar går dock hand i hand med en betydande minskning av nogrannhet. Denna avhandling försöker ta itu med utmaningen att demokratisera HMA genom att utnyttja de senaste framstegen inom smartphoneteknik och maskininlärning. Denna avhandling utvärderar två sätt att utföra markör-fri HMA: Genom att använda en smartphone som kör Apple Arkit, och en uppsättning med flera smartphones som kör OpenCap. Båda modaliteter jämförs med ett markör-baserat system som använder flera kameror, från Vicon. Dessutom presenteras och utvärderas två metoder för att förbättra modaliteten med endast en smartphone: Användning av en Gaussisk Process modell för Regression (GPR) och ett Long-short-term-memory (LSTM) neuronnät för att förbättra data från en smartphone modalititeten, så att det bättre överenstämmer med det markör-baserade resultatet. Specifika rörelser spelades in samtidigt med alla tre modaliteter på 13 försökspersoner för att bygga upp ett dataset. Utifrån detta tränades GPR- och LSTM-modeller och användas för att förbättra data från en kamera modaliteten (Apple Arkit). Ledvinklar och ledcentra för de nedre extremiteterna utvärderades i de olika modaliteterna och analyserades för potentiell använding i verkliga tillämpningar. Även om resultaten av denna avhandling är lovande, då både GPR- och LSTM-modellerna förbättrar nogrannheten hos Apple Arkit, och OpenCap ger korrekta och konsekventa resultat, så är det viktigt att erkänna begränsningarna när det gäller demografisk mångfald och hur miljöfaktorer i verkligheten kan påverka tillämpningen.

Les chutes chez les personnes âgées représentent un problème important de santé publique. Des études montrent qu’environ 30 % des personnes âgées de 65 ans et plus chutent chaque année au Canada, entraînant des conséquences néfastes sur les plans individuel, familiale et sociale. Face à une telle situation la vidéosurveillance est une solution efficace assurant la sécurité de ces personnes. À ce jour de nombreux systèmes d’assistance de services à la personne existent. Ces dispositifs permettent à la personne âgée de vivre chez elle tout en assurant sa sécurité par le port d'un capteur. Cependant le port du capteur en permanence par le sujet est peu confortable et contraignant. C'est pourquoi la recherche s’est récemment intéressée à l’utilisation de caméras au lieu de capteurs portables. Le but de ce projet est de démontrer que l'utilisation d'un dispositif de vidéosurveillance peut contribuer à la réduction de ce fléau. Dans ce document nous présentons une approche de détection automatique de chute, basée sur une méthode de suivi 3D du sujet en utilisant une caméra de profondeur (Kinect de Microsoft) positionnée à la verticale du sol. Ce suivi est réalisé en utilisant la silhouette extraite en temps réel avec une approche robuste d’extraction de fond 3D basée sur la variation de profondeur des pixels dans la scène. Cette méthode se fondera sur une initialisation par une capture de la scène sans aucun sujet. Une fois la silhouette extraite, les 10% de la silhouette correspondant à la zone la plus haute de la silhouette (la plus proche de l'objectif de la Kinect) sera analysée en temps réel selon la vitesse et la position de son centre de gravité. Ces critères permettront donc après analyse de détecter la chute, puis d'émettre un signal (courrier ou texto) vers l'individu ou à l’autorité en charge de la personne âgée. Cette méthode a été validée à l’aide de plusieurs vidéos de chutes simulées par un cascadeur. La position de la caméra et son information de profondeur réduisent de façon considérable les risques de fausses alarmes de chute. Positionnée verticalement au sol, la caméra permet donc d'analyser la scène et surtout de procéder au suivi de la silhouette sans occultation majeure, qui conduisent dans certains cas à des fausses alertes. En outre les différents critères de détection de chute, sont des caractéristiques fiables pour différencier la chute d'une personne, d'un accroupissement ou d'une position assise. Néanmoins l'angle de vue de la caméra demeure un problème car il n'est pas assez grand pour couvrir une surface conséquente. Une solution à ce dilemme serait de fixer une lentille sur l'objectif de la Kinect permettant l’élargissement de la zone surveillée. / Elderly falls are a major public health problem. Studies show that about 30% of people aged 65 and older fall each year in Canada, with negative consequences on individuals, their families and our society. Faced with such a situation a video surveillance system is an effective solution to ensure the safety of these people. To this day many systems support services to the elderly. These devices allow the elderly to live at home while ensuring their safety by wearing a sensor. However the sensor must be worn at all times by the subject which is uncomfortable and restrictive. This is why research has recently been interested in the use of cameras instead of wearable sensors. The goal of this project is to demonstrate that the use of a video surveillance system can help to reduce this problem. In this thesis we present an approach for automatic detection of falls based on a method for tracking 3D subject using a depth camera (Kinect from Microsoft) positioned vertically to the ground. This monitoring is done using the silhouette extracted in real time with a robust approach for extracting 3D depth based on the depth variation of the pixels in the scene. This method is based on an initial capture the scene without any body. Once extracted, 10% of the silhouette corresponding to the uppermost region (nearest to the Kinect) will be analyzed in real time depending on the speed and the position of its center of gravity . These criteria will be analysed to detect the fall, then a signal (email or SMS) will be transmitted to an individual or to the authority in charge of the elderly. This method was validated using several videos of a stunt simulating falls. The camera position and depth information reduce so considerably the risk of false alarms. Positioned vertically above the ground, the camera makes it possible to analyze the scene especially for tracking the silhouette without major occlusion, which in some cases lead to false alarms. In addition, the various criteria for fall detection, are reliable characteristics for distinguishing the fall of a person, from squatting or sitting. Nevertheless, the angle of the camera remains a problem because it is not large enough to cover a large surface. A solution to this dilemma would be to fix a lens on the objective of the Kinect for the enlargement of the field of view and monitored area.