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1
Shaw, Christine. "Locomotion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0001/MQ42201.pdf.
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Josset, Nicolas. "Functional contribution of the mesencephalic locomotor region to locomotion." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/30430.
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Parce qu'il est naturel et facile de marcher, il peut sembler que cet acte soit produit aussi facilement qu'il est accompli. Au contraire, la locomotion nécessite une interaction neurale complexe entre les neurones supraspinaux, spinaux et périphériques pour obtenir une locomotion fluide et adaptée à l'environnement. La région locomotrice mésencéphalique (MLR) est un centre locomoteur supraspinal situé dans le tronc cérébral qui a notamment pour rôle d'initier la locomotion et d'induire une transition entre les allures locomotrices. Cependant, bien que cette région ait initialement été identifiée comme le noyau cunéiforme (CnF), un groupe de neurones glutamatergiques, et le noyau pédonculopontin (PPN), un groupe de neurones glutamatergiques et cholinergiques, son corrélat anatomique est encore un sujet de débat. Et alors qu'il a été prouvé que, que ce soit lors d’une stimulation de la MLR ou pour augmenter la vitesse locomotrice, la plupart des quadrupèdes présentent un large éventail d'allures locomotrices allant de la marche, au trot, jusqu’au galop, la gamme exacte des allures locomotrices chez la souris est encore inconnue. Ici, en utilisant l'analyse cinématique, nous avons d'abord décidé d'identifier d’évaluer les allures locomotrices des souris C57BL / 6. Sur la base de la symétrie de la démarche et du couplage inter-membres, nous avons identifié et caractérisé 8 allures utilisées à travers un continuum de fréquences locomotrices allant de la marche au trot puis galopant avec différents sous-types d'allures allant du plus lent au plus rapide. Certaines allures sont apparues comme attractrices d’autres sont apparues comme transitionnelles. En utilisant une analyse graphique, nous avons également démontré que les transitions entre les allures n'étaient pas aléatoires mais entièrement prévisibles. Nous avons ensuite décidé d'analyser et de caractériser les contributions fonctionnelles des populations neuronales de CnF et PPN au contrôle locomoteur. En utilisant des souris transgéniques exprimant une opsine répondant à la lumière dans les neurones glutamatergiques (Glut) ou cholinergiques (CHAT), nous avons photostimulé (ou photo-inhibé) les neurones glutamatergiques du CnF ou du PPN ou les neurones cholinergiques du PPN. Nous avons découvert que les neurones glutamatergiques du CnF initient et modulent l’allure locomotrice et accélèrent le rythme, tandis que les neurones glutamatergiques et cholinergiques du PPN le ralentissent. En initiant, modulant et en accélérant la locomotion, notre étude identifie et caractérise des populations neuronales distinctes de la MLR. Définir et décrire en profondeur la MLR semble d’autant plus urgent qu’elle est devenue récemment une cible pour traiter les symptômes survenant après une lésion de la moelle épinière ou liés à la maladie de Parkinson.Because it is natural and easy to walk, it could seem that this act is produced as easily as it is accomplished. On the contrary, locomotion requires an intricate and complex neural interaction between the supraspinal, spinal and peripheric neurons to obtain a locomotion that is smooth and adapted to the environment. The Mesencephalic Locomotor Region (MLR) is a supraspinal brainstem locomotor center that has the particular role of initiating locomotion and inducing a transition between locomotor gaits. However, although this region was initially identified as the cuneiform nucleus (CnF), a cluster of glutamatergic neurons, and the pedunculopontine nucleus (PPN), a cluster of glutamatergic and cholinergic neurons, its anatomical correlate is still a matter of debate. And while it is proven that, either under MLR stimulation or in order to increase locomotor speed, most quadrupeds exhibit a wide range of locomotor gaits from walk, to trot, to gallop, the exact range of locomotor gaits in the mouse is still unknown. Here, using kinematic analysis we first decided to identify to assess locomotor gaits C57BL/6 mice. Based on the symmetry of the gait and the inter-limb coupling, we identified and characterized 8 gaits during locomotion displayed through a continuum of locomotor frequencies, ranging from walk to trot and then to gallop with various sub-types of gaits at the slowest and highest speeds that appeared as attractors or transitional gaits. Using graph analysis, we also demonstrated that transitions between gaits were not random but entirely predictable. Then we decided to analyze and characterize the functional contributions of the CnF and PPN’s neuronal populations to locomotor control. Using transgenic mice expressing opsin in either glutamatergic (Glut) or cholinergic (CHAT) neurons, we photostimulated (or photoinhibited) glutamatergic neurons of the CnF or PPN or cholinergic neurons of the PPN. We discovered that glutamatergic CnF neurons initiate and modulate the locomotor pattern, and accelerate the rhythm, while glutamatergic and cholinergic PPN neurons decelerate it. By initiating, modulating, and accelerating locomotion, our study identifies and characterizes distinct neuronal populations of the MLR. Describing and defining thoroughly the MLR seems all the more urgent since it has recently become a target for spinal cord injury and Parkinson’s disease treatment.
3
Karlsson, Rasmus, and Alvar Sveninge. "Virtual Reality Locomotion : Four Evaluated Locomotion Methods." Thesis, Högskolan Väst, Avd för informatik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-11651.
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Virtual Reality consumer hardware is now available for the masses through the HTC Vive, Oculus Rift and PlayStation VR. Locomotion or virtual travel inside immersive experiences is an area which is yet to be fully solved due to space constraints, problems with retaining immersion and potential sickness. This thesis had the goal of evaluating user preferences for four locomotion methods in Virtual Reality with a first generation HTC Vive through the gaming platform Steam. The theoretical framework provides an elementary understanding of the field of Virtual Reality and how humans interact and get affected by locomotion in that context. To contextualize the experience of evaluating the locomotion systems the Hedonic-Motivation System Adoption Model is used as it covers intrinsic motivation which is common in video games, social networking and virtual worlds. An extensive process for games selection has been performed which has resulted in four locomotion methods with four games per method. Sixteen participants got to test one locomotion method each where their gameplay got recorded for later observation. After each game session answers were provided by the participants based on surveys and after completion of all games a questionnaire gauged their sickness level. The conclusion proved inconclusive. While the results without interpretation showed the locomotion method Artificial as the overall winner a range of potential problems were found with the study in general. Some problems included observations which did not provide the expected results, introducing doubt into either how the study was conducted or the reliability of certain users. A larger sampler size along with a better study procedure could possibly have provided a more conclusive answer.
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Tu, Fu Keung. "Smooth locomotion in VR : Comparing head orientation and controller orientation locomotion." Thesis, Blekinge Tekniska Högskola, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20239.
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Background. Virtual reality (VR) technology has evolved to a stage where affordable consumer devices are available. Still, there are limitations to technology which causes compromises to be made. One of the big problems in VR is locomotion, especially regarding immersion and comfort. There are two common ways for locomotion in VR, Teleportation and smooth continuous locomotion. Smooth locomotion is often considered superior for immersion but commonly causes simulation sickness.Objectives. This paper is comparing two different methods of smooth locomotion, one based on head orientation and the other based on controller orientation. The objective is to determine which method is preferred regarding comfort, immersion and ease of use.Methods. To identify the strength and weaknesses of each method, a VR experiment was designed which simulates tasks common in video games. A comparative study was made with fifteen subjects.The fifteen participants performed tasks involving exploring a VR environment and using the VR controller to shoot at targets. After using each of the methods the subjects then answered questionnaires about the usability and the simulations sickness caused by the method. Other data was collected on how well the task was performed such as number of targets hit.Results. The users ranked controller orientation locomotion higher for perceived naturalness and likeability and was ranked lower for items relating to restrictiveness and difficulty. No significant difference was found regarding simulator sickness and performance.Conclusion. Controller orientation locomotion ranked at least as good or better than head orientation locomotion in all categories. This shows that it is the preferred orientation method in this use case where the application is similar to a first person shooter game.
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Truong, Tan Viet Anh. "Un modèle de locomotion humaine unifiant comportements holonomes et nonholonomes." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2010. http://tel.archives-ouvertes.fr/tel-00512405.
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Notre motivation est de comprendre la locomotion humaine pour un meilleur contrôle des systèmes virtuels (robots et mannequins). La locomotion humaine a été étudiée depuis longtemps dans des domaines différents. Nous considérons la locomotion comme le déplacement d'un repère attaché au corps humain (direction et orientation) au lieu de la trajectoire articulaire du corps complet. Notre approche est basée sur le fondement calculatoire de la locomotion humaine. Le but est de trouver un modèle qui explique la forme de la locomotion humaine dans l'espace. Pour ce faire, nous étudions tout d'abord le comportement des trajectoires au sol pendant la locomotion intentionnelle. Quand un humain marche, il met un pied devant l'autre et par conséquence, l'orientation du corps suit la direction tangente de la trajectoire. C'est ce qu'on appelle l'hypothèse de comportement nonholonome. Cependant, dans le cas d'un pas de côté, l'orientation du corps n'est plus semblable à la direction de trajectoire, et l'hypothèse n'est plus valable. Le comportement de la locomotion devient holonome. Le but de la thèse est de distinguer ces deux comportements et de les exploiter en neuroscience, robotique et animation graphique. La première partie de la thèse présente une étude qui permet de déterminer des configurations de comportement holonome par un protocole expérimental et par une fonction qui segmente les comportements nonholonomes et holonomes d'une trajectoire. Dans la deuxième partie, nous établissons un modèle unifiant comportements nonholonomes et holonomes. Ce modèle combine trois vitesses générant la locomotion humaine : tangentielle, angulaire et latérale. Par une approche de commande optimale inverse nous proposons une fonction multi-objectifs qui optimise des trajectoires calculées pour les rendre proches des trajectoires humaines naturelles. La dernière partie est l'application qui utilise les deux comportements pour synthétiser des locomotions humaines dans un environnement d'an imation graphique. Chaque locomotion est caractérisée par trois vitesses et est donc considérée comme un point dans l'espace de commande 3D (de trois vitesses). Nous avons collecté une librairie qui contient des locomotions de vitesses différentes - des points dans l'espace 3D. Ces points sont structurés en un nuage de tétraèdres. Quand une vitesse désirée est donnée, elle est projetée dans l'espace 3D et on trouve le tétraèdre qui la contient. La nouvelle animation est interpolée par quatre locomotions correspondant aux quatre sommets du tétraèdre. On expose plusieurs scénarios d'animations sur un personnage virtuel.
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Hanson, Nardie Kathleen Igraine. "Cognitive and locomotor strategies of arboreal locomotion in non-human apes and humans." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/7122/.
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Arboreal travel for large apes is energetically demanding and risky due to the complexity of the forest canopy. Careful selection of supports is therefore essential for safe and efficient locomotion. This thesis investigates the factors involved in route and support selection in bonobos (Pan paniscus) and in modern human (Homo sapiens) tree climbers. Naturalistically housed bonobos were given a choice of two ropes, one that provided easy access and another that required more demanding postures, with which to access a hard-to-reach food goal. The bonobos selected a rope based on its distance from the goal and its flexibility. Decision making in human tree climbers was investigated using a novel combination of qualitative (participant interviews) and quantitative (observations of behaviour) data. Participants were asked to collect goals from within a tree crown three times each. Interviews revealed that participants either considered risk avoidance or ease/efficiency as the main factor influencing their decisions whilst climbing. Those considering risk took longer to complete each climb, but became quicker after their first climb. These studies demonstrate that the demands of the arboreal environment require knowledge of the functional properties of supports and that memory of specific routes may increase the efficiency of arboreal locomotion.
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Sui, Yi. "Locomotion over a washboard." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/51931.
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The purpose of this thesis is to study the problem when a microorganism
swims very close to a shaped boundary. In this problem, we model the swimmer
to be a two-dimensional, infinite periodic waving sheet. For simplicity,
we only consider the case where the fluid between the swimmer and the
washboard is Newtonian and incompressible. We assume that the swimmer
propagates waves along its body and propels itself in the opposite direction.
We consider two cases in our swimming sheet problem and the lubrication
approximation is applied for both cases. In the first case, the swimmer has a
known fixed shape. Various values of wavenumber, amplitude of the restoring
force and amplitude of the topography were considered. We found the
instantaneous swimming speed behaved quite differently as the wavenumber
was varied. The direction of the swimmer was also found to depend on the
amplitude of the restoring force. We also found some impact of the topographic
amplitude on the relationship between average swimming speed and
the wavenumber. We extended the cosine wave shaped washboard to be a
more general shape and observed how it affected the swimming behaviour.
In the second case, the swimmer is assumed to be elastic. We were interested
to see how different values of wavenumber, stiffness and amplitude of
the restoring force could change the swimming behaviour. With normalized stiffness and wavenumber, we found the swimmer remained in a periodic
state with small forcing amplitude. While the swimmer reached a steady
state with unit swimming speed for high forcing amplitude. However, for
other values of stiffness and wavenumber, we found the swimmer's swimming
behaviour was very different.Science, Faculty of
Mathematics, Department of
Graduate
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Arnold, Dirk. "Evolution of legged locomotion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24085.pdf.
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Byl, Katie. "Metastable legged-robot locomotion." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46362.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 195-215).
A variety of impressive approaches to legged locomotion exist; however, the science of legged robotics is still far from demonstrating a solution which performs with a level of flexibility, reliability and careful foot placement that would enable practical locomotion on the variety of rough and intermittent terrain humans negotiate with ease on a regular basis. In this thesis, we strive toward this particular goal by developing a methodology for designing control algorithms for moving a legged robot across such terrain in a qualitatively satisfying manner, without falling down very often. We feel the definition of a meaningful metric for legged locomotion is a useful goal in and of itself. Specifically, the mean first-passage time (MFPT), also called the mean time to failure (MTTF), is an intuitively practical cost function to optimize for a legged robot, and we present the reader with a systematic, mathematical process for obtaining estimates of this MFPT metric. Of particular significance, our models of walking on stochastically rough terrain generally result in dynamics with a fast mixing time, where initial conditions are largely "forgotten" within 1 to 3 steps. Additionally, we can often find a near-optimal solution for motion planning using only a short time-horizon look-ahead. Although we openly recognize that there are important classes of optimization problems for which long-term planning is required to avoid "running into a dead end" (or off of a cliff!), we demonstrate that many classes of rough terrain can in fact be successfully negotiated with a surprisingly high level of long-term reliability by selecting the short-sighted motion with the greatest probability of success. The methods used throughout have direct relevance to machine learning, providing a physics-based approach to reduce state space dimensionality and mathematical tools to obtain a scalar metric quantifying performance of the resulting reduced-order system.
by Katie Byl.
Ph.D.
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Chan, Brian 1980. "Bio-inspired fluid locomotion." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/49762.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (leaves 95-99).
We have developed several novel methods of locomotion at low Reynolds number, for both Newtonian and non-Newtonian fluids: Robosnails 1 and 2, which operate on a lubrication layer, and the three-link swimmer which moves in an unbounded fluid. Robosnail 1 utilizes lubrication pressures generated in a Newtonian fluid under a steadily undulating foot to propel itself forward. Tractoring force and velocity measurements are in agreement with analytic and numerical solutions. Robosnail 2, modeled after real land snails, uses in-plane compressions of a flat foot on a mucus substitute such as Laponite or Carbopol. Robosnail 2 exploits the non-Newtonian qualities (yield-stress, shear thinning) of the fluid solution to locomote. The glue-like behavior of the unyielded fluid allows Robosnail 2 to climb up a 90 degree incline or inverted 180 degree surfaces. The three-link swimmer is a device composed of three rigid links interconnected by two out-of-phase oscillating joints. It is the first experimental test that successfully demonstrates that a swimmer of its kind can translate in the Stokes limit.
by Brian Chan.
Ph.D.
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Rocci, Lisa. "Locomotion: A Cinematic Approach." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/32428.
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The landscape is not static, but perceived dynamically and should be designed for the unique sorts of movement that occur. Within the site of Carpinteria, Californiaâ s Amtrak train station lies an opportunity to maximize public space through an investigation of those in motion at this place of convergence, including cars, busses, pedestrians, skateboarders, bicyclists, and trains. A cinematic process of design allows for exploration of distinct character movements and resulting unique perceptions of the site in terms of scale, rhythm, texture, color, and perceived desire or needs. These stories are then sculpted onto the land, recording physically threads of speed, moments of pause, and elements of fascination. The â newâ station is presented as a movie, unveiling a landscape perceived and created dynamically through the eyes of those in motion.Master of Landscape Architecture
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Searcy, Jack Candler. "The Impetus of Locomotion." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90381.
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The "Impetus of Locomotion" takes the implication of a force in which movement happens. This thesis takes this connotatively resonant idea in which movement is construed and creates a static definition of it in a building, in this case a high speed rail station - a literal translation of movement. Through design interventions of modes of transportation, wayfinding, and architectural form, the impetus of locomotion is defined.Master of Architecture
Architectural movement is an abstract concept in which the way certain forms and spaces are shaped and/or arranged in such a way that creates or invokes a feeling of motion in the architecture itself while remaining static. The goal of this thesis is to achieve this principle in a fundamental way using those arrangements and forms. On the technical side of my project scope, I have researched and implemented the literal modes of movement which would culminate in one location. These concepts of both architectural and literal modes of movement come together in the form of an intramodal station in Houston, Texas.
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Wang, Hongfei. "Tool-Assisted Humanoid Locomotion." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1460717947.
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Lo, On-Yee. "Visuospatial attention during locomotion." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/19711.
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Locomotion requires visuospatial attention. However, the role and cortical control of visuospatial attention during locomotion remain unclear. Four experiments were conducted in this study to examine the role and cortical control of visuospatial attention during locomotion in healthy young adults. In the first experiment, we employed a visuospatial attention task at different phases of obstacle crossing during gait. The results suggested that toe-obstacle clearance was significantly reduced for the trailing limb when distraction interfered with visuospatial attention during the approaching phase of obstacle crossing. In the second experiment, subjects performed a visual Stroop task while approaching and crossing an obstacle during gait. The results for the second experiment indicated toe-obstacle clearance was significantly increased for the leading and trailing limbs. Taken together, it was found that different visual attention tasks lead to distinct modifications on obstacle crossing behaviors. In the third and fourth experiments, anodal transcranial direct current stimulation (tDCS) was applied over the right posterior parietal cortex (PPC) to examine the aftereffects on attention function and locomotor behavior. The results suggested that the orienting attention was significantly improved after anodal tDCS. In addition, the aftereffects of anodal tDCS potentially enhanced cognitive and motor performance while interacting with a challenging obstacle-crossing task in young healthy adults, suggesting that the right PPC contributes to attending visuospatial information during locomotion. This study demonstrated that visuospatial attention is critical for planning during locomotion and the right PPC contributes to this interplay of the neural processing of visuospatial attention during locomotion.
This dissertation includes previously published and unpublished co-authored material.
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INVERNIZZI, FABIO. "Human locomotion energy harvesting." Doctoral thesis, Università degli studi di Pavia, 2018. http://hdl.handle.net/11571/1214837.
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Hoinville, Thierry. "Evolution de contrôleurs neuronaux plastiques : de la locomotion adaptée vers la locomotion adaptative." Versailles-St Quentin en Yvelines, 2007. http://www.theses.fr/2007VERS0022.
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Evolutionary robotics mainly focused on evolving neural controllers that are structurally and parametrically fixed, for the control of robots that can roll, walk, swim or fly. This approach led to the design of controllers that are well adapted to constant environments, but not adaptive to varying conditions. To tackle this issue, some researchers suggest to evolve plastic, rather than fixed, neural controllers. Our work follows this way and aims to design plastic neural controllers for legged robots subject to external perturbations, as well as possible mechanical damages. First, we propose a review of the main known forms of neuronal plasticity and their modeling. This review is mostly intended to the roboticists audience. Then, we draw a state of the art of evolving plastic neural controllers and criticize the biological realism of the developed models. On this background, we provide a first contribution centered on thedilemma of evolving both flexible and stable neural controllers. Thus,we suggest to use homeostatic constraints to stabilize CTRNNs incorporating adaptive synapses. We applied this method with success to the locomotion of a one-legged robot, confronted to an external perturbation. Finally, we present a second work based on the knowledge acquired on the biological central pattern generators (CPG) and their plasticity. In practice, we evolve neural relaxation oscillators subject to neuromodulation, for the adaptive locomotion of a modular myriapod robot, that could experience leg amputationsLes recherches menées en robotique évolutionniste se sont avant tout focalisées sur l'évolution de contrôleurs neuronaux structurellement et paramétriquement figés, pour la locomotion de robots qui roulent, marchent, nagent ou volent. Cette démarche a permis la conception de contrôleurs bien adaptés à des environnements constants, mais non adaptatifs aux variations de ceux-ci. Pour y remédier, certains roboticiens ont suggéré de faire évoluer des neuro-contrôleurs non plus figés, mais plastiques. Notre approche s'inscrit dans ce revirement et vise à ce que les robots à pattes puissent adapter leur locomotion aussi bien aux perturbations extérieures, qu'aux éventuelles détériorations de leurs structures mécaniques. Nous proposons en premier lieu une revue des phénomènes de plasticiténeuronale et de leur modélisation, destinée essentiellement aux roboticiens. Nous dressons ensuite un état de l'art de l'évolution de neuro-contrôleurs plastiques et critiquons la plausibilité biologique des modèles développés. Notre première contribution s'inspire des travaux de la robotique évolutionniste et aborde le dilemme de l'évolution de contrôleurs à la fois flexibles et stables. Ainsi, nous employons des contraintes homéostatiques pour stabiliser la plasticité de contrôleurs assurant la locomotion d'un robot monopode confronté à une perturbation freinant son avancée. Notre deuxième contribution s'inspire des connaissances acquises sur les générateurs centraux de pattern (CPG) et leur plasticité. Ainsi,nous proposons l'évolution d'oscillateurs à relaxation soumis à neuromodulation pour la locomotion adaptative d'un robot myriapode confronté à d'éventuelles amputations de pattes
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Harper, David Gordon. "Kinematics and mechanics of fast-starts of rainbow trout Oncorhynchus mykiss and northern pike Esox lucius." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31018.
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Film is commonly used to estimate the fast-start performance of fish. An analysis of hypothetical, film-derived, and accelerometer-measured acceleration-time data of fish fast-starts indicates that the total error in film studies is the sum of the sampling frequency error (i.e., the error due to over-smoothing at low film speeds) and measurement error. The error in film based studies on the acceleration performance of fish is estimated to be about 33 to 100% of the maximum acceleration, suggesting that other methods of estimating acceleration should be employed.
The escape performance of rainbow trout Oncorhynchus mykiss and northern pike Esox lucius (mean lengths 0.32 m and 0.38 m, respectively) were measured here with subcutaneously implanted accelerometers. Acceleration-time plots reveal two types of escape fast-starts for trout and three for pike. Simultaneous high-speed ciné films demonstrate a kinematic basis for these differences. Trout performing C-shaped fast-starts produce a unimodal acceleration-time plot (type I), while during S-shaped fast-starts a bimodal acceleration-time plot (type II) results. Pike also exhibit similar type I and II fast-starts, but also execute a second S-shaped fast-start that does not involve a net change of direction. This is characterized by a trimodal acceleration-time plot (type III).
Intraspecific and interspecific comparisons of displacement, time, mean and maximum velocity, and mean and maximum acceleration rate indicate that fast-start performance is significantly higher for pike than for trout, for all performance parameters. This indicates that performance is related to body form. Overall mean maximum acceleration rates for pike were 120.2 ± 20 m s⁻² (x ± 2S.E.) and 59.7 ± 8.3 m s⁻² for trout.
Performance values directly measured from the accelerometers exceed those previously reported. Maximum acceleration rates for single events reach 97.8 m s⁻² and 244.9 m s⁻² for trout and pike, respectively. Maximum final velocities of 7.06 m s⁻¹ (18.95 L s⁻¹, where L is body length) were observed for pike and 4.19 m s⁻¹ (13.09 L s⁻¹) for trout; overall mean maximum velocities were 2.77 m s⁻¹ for trout and 3.97 m s⁻¹ for pike.
The fast-start performance of pike during prey capture was also measured with subcutaneously implanted accelerometers. Acceleration-time plots and simultaneous high-speed cin6 films reveal four behaviours with characteristic kinematics and mechanics. As for the escape data, fast-start types are identified by the number of large peaks that appear in the acceleration-time and velocity-time data.
Comparisons of mean performance were made between each type of feeding fast-start. Type I fast-starts were of significantly (i.e., p < 0.05) shorter duration (0.084 s) and displacement (0.132 m) than type III (0.148 s and 0.235 m) and type IV (0.189 s and 0.307 m) behaviours, and higher mean and maximum acceleration (38.6 and 130.3 m s⁻², respectively) than the type II (26.6 and 95.8 m s⁻²), type III (22.0 and 91.2 m s⁻²), and type IV (18.0 and 66.6 m s⁻²) behaviours. The type II behaviours were also of shorter duration and displacement, and of higher mean acceleration than type IV fast-starts, and were of significantly shorter duration than the type LU behaviours.
Prey capture performance was compared to escapes by the same individuals. When data are combined, regardless of mechanical type, mean acceleration (37.6 versus 25.5 m s⁻²), maximum acceleration (120.2 versus 95.9 m s⁻²), mean velocity (1.90 versus 1.57 m s⁻¹), and maximum velocity (3.97 versus 3.09 m s⁻¹) were larger, and duration shorter (0.108 versus 0.133 s) during escapes than during prey capture. No differences were found
through independent comparisons of the performance of feeding and escape types II and III, but type I escapes had significantly higher mean velocity (2.27 versus 1.58 m s⁻¹), maximum velocity (4.70 versus 3.12 m s⁻¹), and mean acceleration (54.7 versus 38.6 m s⁻²) than the type I feeding behaviours.
Prey capture performance was also related to prey size, apparent prey size (defined as the angular size of the prey on the pike's retina), and strike distance (the distance from the pike to the prey at the onset of the fast-start). Mean and maximum acceleration increased with apparent size and decreased with strike distance, while the duration of the event increased with strike distance and decreased with apparent size. No relation was found between the actual prey size and any performance parameter.
Strike distance ranged from 0.087 to 0.439 m, and decreased as the apparent size increased from 2.6 to 9.9° (r² = 0.75). The type I behaviour was usually employed when the strike distance was small and the prey appeared large. As strike distance increased and apparent size decreased, there was a progressive selection of type II, then III, then IV behaviours.Science, Faculty of
Zoology, Department of
Graduate
18
Thornton, Thomas Lance. "Computer animation of quadrupedal locomotion." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1400.
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A discussion of the theory and methodology for creating believable quadrupedal
locomotion for computer animation applications. The study focuses on a variety of
issues related to producing realistic animal gait animations and includes a case study for
rigging and animating the various gaits of a horse. Visualization of unnatural gaits for
the horse will also be discussed and animated. The process of rigging involves setting
up the character control system in a high-end 3d computer animation program such as
Maya which is used extensively by the computer graphics industry.
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Wright, Jonathan. "Intelligent methods for locomotion optimisation." Thesis, University of Portsmouth, 2015. https://researchportal.port.ac.uk/portal/en/theses/intelligent-methods-for-locomotion-optimisation(306f8931-16b5-4b75-9bfc-d75c070af420).html.
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This thesis presents, critical compares and develops new methods to control and optimise locomotion for a range of systems. Jumping and running locomotion skills are examined in detail, and intelligent methods are discussed and adapted to optimise for correct form of motion, and performance outcomes. Existing control techniques are summarised and compared, including traditional analytical methods, central pattern generator oscillator systems, pattern generating neural networks, rule based systems and other specialist methods. Optimisation and learning methods presented in the literature are also summarised, and while several methods exist, modern global search methods were limited to genetic algorithms. This thesis applies particle swarm optimisation and quantum inspired evolutionary algorithms to vertical jump and walking optimisation, comparing their performance to a genetic algorithm. Improvements were developed for both binary and real-value variants of quantum inspired evolutionary algorithms, to benefit performance on the real-value problems involved in locomotion control. These improvements consisted of modifications to their rotation gate operators, including a novel scheme to reduce premature convergence in the binary methods, based on limiting the range of less significant bits. Methods were applied in simulated environments, although they can be adapted to real world robotic control, or for reference in optimising motion in humans. A discussion of the susceptibility of simulation runs to poor physical modelling was presented, as this was a significant problem during research. Results were generally mixed, to the extent that all tested methods may be usefully examined more in future work. The central pattern generators tested generated successful patterns more often than a recurrent neural network, and the results of the optimisation algorithms did not show sufficient advantage of one over the others.
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Tersteeg, Margaretha Cornelia Antonia. "Locomotion and stance at height." Thesis, Manchester Metropolitan University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555606.
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Postural threat induced by height affects the control of movement. The aim of this thesis was to develop a better understanding of the extent and the mechanisms through which postural threat can affect movement. The first study showed that a postural threat induced with a height of 80 cm (walkway width 22 cm) did not affect the gait pattern or arousal levels of young healthy adults. Whereas a height of 3.5 m did, an increase in arousal and a more cautious gait pattern compared to walking at ground level were observed. The influence of visual information was tested by occluding visual information of the drop when walking on a 3.5 m high walkway while retaining the danger. Occluding the visual information lead to reduced arousal but still a cautious gait pattern was observed which did not differ from walking at this height with the presence of visual information of the drop. So visually driven balance mechanisms were not the dominant cause of the gait adaptations observed at height (3.5 m). In a third study the walking task was repeated several times. While walking at a walkway raised 3.85 m off the ground a tendency to reduce the lateral centre of mass (COM) movement was observed. It was proposed that a minimizing lateral COM movement was prioritized. The thesis continued with two studies exploring the effect of cognitive factors on adaptations seen in conditions of postural threat. A one-leg stance task was performed repeatedly on various locations. Risk of the task, quantified by a simple model based on the constraint in recovery possibilities, could not explain the adaptations (increased co-contraction index, flexion of the stance leg and increased heart rate) to the one-leg stance task completely. A priori expectations of the task were shown to influence the one-leg stance task: anticipation and familiarization were observed in two separate studies. Furthermore, exposure (position further along the walkway) did influence the execution of the one-leg stance task. The final study of this thesis investigated the response to galvanic vestibular stimulation (GVS) during standing. GVS elicits a lateral body sway. The maximum lateral displacement of the body was significantly reduced while standing on a 3.85 m high walkway compared to standing on the ground. However the initial vestibular reflexes were unaffected. The results suggest that feed forward control did not influence the vestibular reflexes under postural threat.
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Tard, Céline. "Modulation corticale de la locomotion." Thesis, Lille 2, 2015. http://www.theses.fr/2015LIL2S067/document.
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Les patients atteints de maladie de Parkinson présentent des troubles de la marche, parfois paroxystiques, pouvant être aggravés ou améliorés par les stimuli environnementaux. L'attention portée, soit aux stimuli extérieurs, soit à la marche, pourrait ainsi moduler la locomotion.L’objectif principal était donc de mieux caractériser la manière dont les stimuli environnementaux modulent par le biais de réseaux attentionnels la locomotion. Ceci a été étudié chez les sujets sains puis chez les patients parkinsoniens, avec ou sans enrayage cinétique.Nous avons d'abord défini précisément les déficits attentionnels des patients, avec ou sans troubles de la marche. Ils présentaient respectivement des difficultés en flexibilité mentale et plus particulièrement en attention divisée.Nous avons ensuite exploré l'interaction attention-locomotion grâce à l'étude de la préparation motrice. Ainsi, nous avons pu démontrer que les ajustements posturaux anticipés étaient un marqueur sensible de l’attention. Chez les patients, ils pouvaient témoigner d’une altération de l'interaction attention-programmation motrice.L'étude des régions cérébrales activées lors de la locomotion visuo-guidée chez ces patients a permis de confirmer l'implication de structures corticales attentionnelles. Un déséquilibre d’activation au sein du réseau pariéto-prémoteur (nécessaire à la modulation de l'action motrice en fonction des stimuli externes) était présent.Enfin, nous avons essayé de modifier l'excitabilité du cortex prémoteur via des techniques de stimulation magnétique transcrânienne répétitive afin de moduler la locomotion visuo-guidéePatients with Parkinson 's disease present gait impairments, sometimes sudden and unexpected, either improved or deteriorated with environmental stimuli. Attention focalization, either on external stimuli or on gait, could then modulate locomotion.The main objective was to better characterize how environmental stimuli would modulate locomotion, via attentional networks, in healthy subjects and in parkinsonian patients, with or without freezing of gait.At first, we precisely defined the attentional deficits in patients, with or without gait impairment. They showed altered performance respectively in mental flexibility and in divided attention.Then, we explored the attention-locomotion interaction by studying motor preparation. So, we highlighted that anticipatory postural adjustments were a sensitive marker of attention. In patients, they evidenced an alteration of the attention-motor program interaction.Studying the brain activation during the visuo-driven locomotion in these patients confirmed the involvement of cortical attentional regions. We observed an imbalance inside the parieto-premotor network (useful to modulate motor action according external stimuli)Finally, we tried to change the excitability of the premotor cortex with transcranial magnetic stimulation to modulate visuo-driven locomotion
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Vaughan, Christopher Leonard (Kit). "The biomechanics of human locomotion." Doctoral thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/3491.
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Includes bibliographical references.
The thesis on CD-ROM includes Animate, GaitBib, GaitBook and GaitLab, four quick time movies which focus on the functional understanding of human gait. The CD-ROM is available at the Health Sciences Library.
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Meglan, Dwight Alan. "Enhanced analysis of human locomotion." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1239984087.
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Farkhatdinov, Ildar. "Modeling verticality estimation during locomotion." Paris 6, 2013. http://www.theses.fr/2013PA066085.
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Nous proposons un modèle du système vestibulaire. Le développement du modèle est basé sur les principes de la dynamique de Newton-Euler, régissant le mouvement des corps contraints à osciller en trois dimensions dans un référentiel non-Galiléen. Les otolithes du système vestibulaire constituent un exemple de tel système et ont été modélisés comme des pendules sphériques amortis. Deux modèles ont été proposés. Le modèle medial est constitué d’une seule oreille interne se trouvant au centre de la tête. Le modèle latéral est constitué de deux oreilles internes situées latéralement par rapport au centre de la tête. Un test d’observabilité a permis de montrer que pour que l’orientation de la tête soit une quantité observable, la tête doit être stabilisée. Nous montrons que le problème de l’ambiguïté gravito-inertielle peut être résolu si la tête est stabilisée horizontalement. Ces résultats ont été appliqués pour estimer la verticalité gravitationnelle lors de la locomotion dans le cas linéarisé et dans le cas non-linéaire. Les résultats des simulations ont montré que les erreurs d'estimation sont significativement plus faibles et que les observateurs convergent plus rapidement et de façon plus robuste quand la tête est stabilisée. Cela conduit à un système non-linéaire où observation et la commande sont combinés, pouvant être stabilisé par rapport à la verticale gravitationnelle. Les résultats sont testés avec un système expérimental spécialement conçu pour représenter le système tête-cou et les organes vestibulaires. Les résultats sont utiles à l'analyse de la perception spatiale chez les humains et pour l’amélioration des capacités sensorielles des systèmes robotiquesA nonlinear model of the vestibular system is proposed. The model was constructed from general considerations regarding the Newton-Euler dynamics governing the three-dimensional movements of bodies constrained to oscillate in non-inertial frames, such as the otoliths, which were modeled as spherical damped pendula. Two configurations were considered. The medial model considered only one inner ear located in the center of a head. The lateral model considered two inner ears located laterally with respect to the center of rotation of the head. An observability test was used to verify whether the reconstruction of the head orientation with respect to the gravitational vertical was possible from otoliths measurements only. It could be shown that in order for the head vertical orientation to be observable, the head had to be stabilized during locomotion. It was shown that the gravitoinertial ambiguity could be resolved if the head was horizontally stabilized. The results were applied to solve the head vertical orientation estimation problem. The simulations indicated that the estimation errors were smaller and the observers converged faster when head was stabilized during locomotion, leading to a nonlinear, combined observation-control system that could be stabilized with respect to the gravitational vertical. The results were tested with an experimental setup that comprised an actuated gimbal mechanism to represent the head-neck system and a liquid-based inclinometer that represented the otoliths organs. The findings derived from this research would be helpful for analyzing spatial perception in humans, and for improving the perceptual capabilities of robotic systems
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Tickle, Peter George. "Breathing and locomotion in birds." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/breathing-and-locomotion-in-birds(1fcd3865-bc57-492d-9123-443815907bfc).html.
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Birds are a diverse group of vertebrates, with over 10,000 extant species. Diversification into volant, aquatic and terrestrial environmental niches has precipitated a remarkable morphological diversity between species. Birds have a unique respiratory system consisting of a rigid lung connected to an air sac system. Air is pumped into the respiratory system via movements of the ribcage and sternum. Previous research identified the uncinate processes, ossified projections extending from the vertebral ribs, as critical respiratory and locomotor structures. Uncinate processes facilitate inspiration and expiration through associated muscles that displace the ribs and therefore sternum. External intercostal muscles project from the processes and function during locomotion to stabilise body roll. Therefore uncinate processes provide a link between breathing and locomotion in birds. The objective of my PhD is to extend beyond this basic research on uncinate processes to investigate how diversity in avian body morphology relates to the fundamental functions of breathing and locomotion.While the function of uncinate processes in respiration has been identified, the mechanism whereby ventilatory movements are elicited is not known. Therefore I present a model that demonstrates how respiratory movements of the skeleton are facilitated by the lever action of uncinate processes. Furthermore, variation in process and sternal morphology is driven by adaptation to different forms of locomotion. Therefore fundamental differences in breathing mechanics may be associated with specialisation to locomotor behaviour. Detailed developmental studies of the uncinate processes in birds are almost nonexistent. I provide the first detailed description of developmental changes in the uncinate processes in the turkey. Ossification of the uncinate processes begins around the time of hatch. However, the base is cartilaginous upon hatching and so the lever action of the processes may be compromised in the chick. I provide further evidence for a functional link between process length and respiratory physiology, since elongated processes support an elevated resting metabolic rate in birds. This link was further explored in physiological experiments where the energetic cost of walking in the barnacle goose was manipulated by load carrying. Carrying extra mass on the sternum is more energetically costly than an equivalent back load indicating that the cost of breathing increased. A directly proportional relationship exists between increasing mass of back load and metabolic rate, while sternal loads were approximately twice as expensive to carry during locomotion. Leg loads incurred the greatest increase in metabolism. Finally, I demonstrate how uncinate processes functioned as respiratory structures in basal avian species and a theropod ancestor of modern birds. Development of the uncinate processes may have been an important step in the evolution of the avian lung - air sac system.The principal findings of the five first author research articles presented in this PhD thesis shed important new light on the ventilatory mechanics in birds and highlight interactions between breathing and locomotion. Diversity in avian body morphology driven by adaptation to various locomotor behaviours has resulted in modification of the respiratory system.
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Carpentier, Justin. "Computational foundations of anthropomorphic locomotion." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30376/document.
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La locomotion anthropomorphe est un processus complexe qui met en jeu un très grand nombre de degrés de liberté, le corps humain disposant de plus de trois cents articulations contre une trentaine chez les robots humanoïdes. Pris dans leur ensemble, ces degrés de liberté montrent une certaine cohérence rendant possible la mise en mouvement du système anthropomorphe et le maintien de son équilibre, dans le but d'éviter la chute. Cette thèse met en lumière les fondements calculatoires à l'origine de cette orchestration. Elle introduit un cadre mathématique unifié permettant à la fois l'étude de la locomotion humaine, et la génération de trajectoires locomotrices pour les robots humanoïdes. Ce cadre consiste en une réduction de la dynamique corps-complet du système pour ne considérer que sa projection autour du centre de gravité, aussi appelée dynamique centroïdale. Bien que réduite, nous montrons que cette dynamique centroïdale joue un rôle central dans la compréhension et la formation des mouvements locomoteurs. Pour ce faire, nous établissons dans un premier temps les conditions d'observabilité de cette dynamique, c'est-à-dire que nous montrons dans quelle mesure cette donnée peut être appréhendée à partir des capteurs couramment employés en biomécanique et en robotique. Forts de ces conditions d'observabilité, nous proposons un estimateur capable de reconstruire la position non-biaisée du centre de gravité. A partir de cet estimateur et de l'acquisition de mouvements de marche sur divers sujets, nous mettons en évidence la présence d'un motif cycloïdal du centre de gravité dans le plan sagittal lorsque l'humain marche de manière nominale, c'est-à-dire sans y penser. La présence de ce motif suggère l'existence d'une synergie motrice jusqu'alors ignorée, soutenant la théorie d'une coordination générale des mouvements pendant la locomotion. La dernière contribution de cette thèse porte sur la locomotion multi-contacts. Les humains ont une agilité remarquable pour effectuer des mouvements locomoteurs qui nécessitent l'utilisation conjointe des bras et des jambes, comme lors de l'ascension d'une paroi rocheuse. Comment doter les robots humanoïdes de telles capacités ? La difficulté n'est certainement pas technologique, puisque les robots actuels sont capables de développer des puissances mécaniques suffisantes. Leurs performances, évaluées tant en termes de qualité des mouvements que de temps de calcul, restent très limitées. Dans cette thèse, nous abordons le problème de génération de trajectoires multi-contacts sous la forme d'un problème de commande optimale. L'intérêt de cette formulation est de partir du modèle réduit de la dynamique centroïdale tout en répondant aux contraintes d'équilibre. L'idée originale consiste à maximiser la vraisemblance de cette dynamique réduite vis-à-vis de la dynamique corps-complet. Elle repose sur l'apprentissage d'une mesure d'occupation qui reflète les capacités cinématiques et dynamiques du robot. Elle est effective : l'algorithmique qui en découle est compatible avec des applications temps réel. L'approche a été évaluée avec succès sur le robot humanoïde HRP-2, sur plusieurs modes de locomotions, démontrant ainsi sa polyvalenceAnthropomorphic locomotion is a complex process that involves a very large number of degrees of freedom, the human body having more than three hundred joints against thirty in humanoid robots. Taken as a whole, these degrees of freedom show a certain coherence making it possible to set the anthropomorphic system in motion and maintain its equilibrium, in order to avoid falling. This thesis highlights the computational foundations behind this orchestration. It introduces a unified mathematical framework allowing both the study of human locomotion and the generation of locomotive trajectories for humanoid robots. This framework consists of a reduction of the body-complete dynamics of the system to consider only its projection around the center of gravity, also called centroid dynamics. Although reduced, we show that this centroidal dynamics plays a central role in the understanding and formation of locomotive movements. To do this, we first establish the observability conditions of this dynamic, that is to say that we show to what extent this data can be apprehended from sensors commonly used in biomechanics and robotics. Based on these observability conditions, we propose an estimator able to reconstruct the unbiased position of the center of gravity. From this estimator and the acquisition of walking motions on various subjects, we highlight the presence of a cycloidal pattern of the center of gravity in the sagittal plane when the human is walking nominally, that is, to say without thinking. The presence of this motif suggests the existence of a motor synergy hitherto unknown, supporting the theory of a general coordination of movements during locomotion. The last contribution of this thesis is on multi-contact locomotion. Humans have remarkable agility to perform locomotive movements that require joint use of the arms and legs, such as when climbing a rock wall. How to equip humanoid robots with such capabilities? The difficulty is certainly not technological, since current robots are able to develop sufficient mechanical powers. Their performances, evaluated both in terms of quality of movement and computing time, remain very limited. In this thesis, we address the problem of generating multi-contact trajectories in the form of an optimal control problem. The interest of this formulation is to start from the reduced model of centroid dynamics while responding to equilibrium constraints. The original idea is to maximize the likelihood of this reduced dynamic with respect to body-complete dynamics. It is based on learning a measurement of occupation that reflects the kinematic and dynamic capabilities of the robot. It is effective: the resulting algorithmic is compatible with real-time applications. The approach has been successfully evaluated on the humanoid robot HRP-2, on several modes of locomotion, thus demonstrating its versatility
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Tapia, Siles Silvia Cecilia. "Robotic locomotion in turbulent flow." Paris 6, 2011. http://www.theses.fr/2011PA066414.
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Certains poissons utilisent les turbulences de leur milieu pour réduire les coûts énergétiques liés à la nage. Par exemple, les truites ont la capacité de synchroniser leur allures par rapport à la succession stéréotypée de vortex caractérisant une allée de Karman (Karman vortex street). Les truites peuvent ainsi garder une position stationnaire à contre-courant en consommant très peu d'énergie ou réduire, de 4 à 6 fois, la force nécessaire pour nager à l'intérieur d'un banc, en exploitant les allées de Karman induites par les poissons les devançant. En s'inspirant du comportement des poissons, notre travail a porté sur les méthodes de contrôle d'une telle locomotion pour des robots poissons. Dans ce cadre, nos principales les contributions sont les suivantes : Un modèle cinématique simplifié d'allée de Karman. Ce modèle donne les repères cinématiques pour modéliser les contrôleurs. L'approche présentée est basée sur des concepts de stabilité de l'allée de Karman. Le modèle proposé est une segmentation cinématique d'une allée de Karman stable. La génération et le contrôle biomimétiques de mouvements rythmiques de nage semi-passive. Trois contrôleurs sont proposés afin de fusionner le système Environnement-Corps-Control avec des approches différentes de contrôle : Approche externe. On essaye d’imiter le mouvement du poisson en ajustant les articulations pour suivre l’ondulation désirée. Approche bio inspiré. On utilise le modèle d'un Central Pattern Generator pour générer les mouvements. Approche conceptuelle. On utilise des oscillateurs Adaptatifs en Fréquence pour apprendre la fréquence du KVS
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Frith, Harold Russ. "Energetics of fast-starts in northern pike, Esox lucius." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30834.
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Fast-starts are high powered events of short duration, used by fish for prey capture and escape from predation. Here, the energetic cost of fast-starts in escape and prey capture for a fast-start specialist, the northern pike, Esox lucius, are determined and physiological and behavioural constraints assessed. This is done by comparing costs with literature values for physiological limits set my muscle mechanics and biochemistry, and comparing costs with other components of the energy budget.
The combination of high speed film analysis (200-250Hz) and hydrodynamic models are used to determine the mechanical costs, hydrodynamic efficiencies and power output of fast-starts in prey capture (S-starts) and escape behaviour (C-starts). Excess post-exercise oxygen consumption (EPOC) is used to estimate the metabolic cost of fast-starts.
A comparison of model predictions with required (acceleration) force estimates shows results are within 22% and similar to previous findings at lower film speeds. The caudal region including the caudal, dorsal and anal fins contribute the most to thrust (>90%) and the dorsal and anal fins contribute 28%. Due to the necessity for deceleration of fin sections during each tail beat, kinematics are not always optimal as predicted by the Weihs model.
Mechanical power output, hydrodynamic efficiency and kinematic parameters (maximum velocities and maximum angle of attack of the caudal fin) are determined for fast-starts during prey capture and escape. Hydrodynamic efficiency averages 0.37
(range: 0.34 to 0.39) for C-starts and 0.27 (range: 0.16 to 0.37) for S-starts. The acceleration of added mass contributes the most to power output at 39%. Power output and efficiency for S-starts are more variable than C-starts and hydromechanical efficiency increases with number of tail beats for S-starts. Maximum muscle power output and maximum muscle stress during fast-starts in comparison to literature values for muscle function shows muscle power output during fast-starts is at its physiological limit but muscle stress is not.
Metabolic efficiency is higher at 0.094 for C-starts than S-starts at 0.047. However, muscle efficiency estimates are similar averaging 0.252 for both fast-start types.
Mean energetic cost of fast-starts is determined to be 26.5 J/kg for C-starts and 18.6 J/kg for S-starts. Based on the observation that pike can repeatedly fast-start up to 170 times before becoming exhausted and on estimates of available energy reserves from literature values for ATP and CrP concentrations in white muscle, the duration of fast-starts is concluded to not be limited by muscle physiology. Average power output is found to be similar for C and S-starts at 406 to 412 W/kg. Only hydrolysis of ATP and CrP can supply energy at this rate. Therefore, based on fish white muscle biochemistry and mechanics, power output during fast-starts appears to be limited by muscle physiology.
The cost of fast-starts represents 0.03 to 2% of maintenance costs for pike and therefore only 5 to 30 fast-starts per day would be required to increase the daily energy budget by 10%. In addition, the cost of fast-starts represents 0.52 to 27.4% of surplus energy available from assimilated prey. Therefore, the
cost of fast-starts can be significant and reducing fast-start duration is a probable strategy for minimising activity costs and thus increasing the energy available for growth or reproduction.Science, Faculty of
Zoology, Department of
Graduate
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Ross, Kyla Turpin. "Quantitative Analysis of Feedback During Locomotion." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14110.
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It is known that muscles possess both intrinsic and reflexive responses to stretch, both of which have been studied extensively. While much is known about heterogenic and autogenic reflexes during XER, these have not been well characterized during locomotion. In this study, we mapped the distribution of autogenic and heterogenic feedback in hindlimb extensor muscles using muscle stretch in the spontaneously locomoting premammillary decerebrate cat. We used natural stimulation and compared stretch-evoked force responses obtained during locomotion with those obtained during XER. The goal was to ascertain whether feedback was modulated between the two states. We found that heterogenic feedback pathways, particularly those emanating from MG, remained inhibitory during locomotion while autogenic feedback specifically in MG increases in gain. Furthermore, increases in MG gain were due to force-dependent mechanisms. This suggests that rather than an abrupt transition from inhibition to excitation with changes in motor tasks, these pathways coexist and contribute to maintaining interjoint coordination. Increases in autogenic gain provide a localized loading reflex to contribute to the completion of the movement. The results of these experiments are clinically significant, particularly for the rehabilitation of spinal cord injured patients. To effectively administer treatment and therapy for patients with compromised spinal reflexes, a complete understanding of the circuitry is required.
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Chatani, Kaoru. "Development of Locomotion in Japanese Macaques." 京都大学 (Kyoto University), 1999. http://hdl.handle.net/2433/181431.
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Sjöström, Henrik. "DeepConvLSTM on single accelerometer locomotion recognition." Thesis, Umeå universitet, Institutionen för datavetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-142516.
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This project aims to evaluate the deep neural network architecture Deep-ConvLSTM to classify locomotive human activities using data from a single accelerometer. The evaluation involves comparisons to a simpler convolutional neural network and a hyperparameter evaluation in regards to the networks number of convolutional layers. The benchmark OPPORTUNITY dataset is used for training and evaluation from which triaxial accelerometer data from hips and legs are extracted. The results of the evaluation suggests that DeepConvLSTM outperforms simpler models on most locomotive activity recognition, especially at filtering out unclassified data. Further the results show that DeepConvLSTMs performance improves with a higher number of convolutional layer, but the number of limited by the architectures lack of padding and is compensated by longer training times.
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Gerritsen, Karin Gerarda Maria. "Computer simulation of FES-assisted locomotion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ31026.pdf.
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Webb, Jeffrey B. "Exploration of a hybrid locomotion robot /." Online version of thesis, 2007. http://hdl.handle.net/1850/4492.
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Carter, Brian Edward. "Omni-directional locomotion for mobile robots." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1173804459.
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Bhat, Shubham K. Kurzweg Timothy P. "Locomotion of magnetic objects in fluids /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2864.
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Wang, Suwen. "Physics-based animation of primate locomotion." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/37098.
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Quadrupedal animals commonly appear in films and video games, and their locomotion is of interests to several research and industrial communities. Because of the difficulty of handling and motion capturing these animals, physics-based animation
is a promising method for synthesizing quadrupedal locomotion. In this thesis, we investigate control strategies for animating a gorilla model, as an example of primate quadrupeds.
We review the state of the art in quadrupedal animation and robotics, and in particular a control framework designed for a simulated dog. We investigate the essential control strategy modifications as necessitated by the unique characteristics of gorilla morphology and locomotion style. We generate controllers for physically realistic walking and trotting gaits for a 3D gorilla model. We also rig a 3D mesh model of a gorilla with Maya, a commercial animation software. Gorilla gait motions are synthesized in our simulation using the rigged skeleton, and synthesized gaits are exported though a motion data pipeline back to Maya for rendering.
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Wardle, Javan Brent. "Hexapod robot locomotion over uneven terrain." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360453.
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Mitchell, Zak. "Dragonfly locomotion : ecology, form and function." Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/21211/.
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The Odonata is a charismatic insect order remarked for their flight ability. They are a useful model system for ecological and evolutionary processes, but in particular their strong and unique flight abilities make them a model taxon to study the biomechanics of flight. Movement is fundamental to a range of processes in biology, including population spatial dynamics. With increasingly urgent demands to understand and predict the impacts of climate change, uncovering the processes driving the movement of populations is paramount. Currently the macroecological patterns caused by climate change are reasonably well documented – particularly for the Odonata. However the mechanisms driving population movements are less clear. Despite considerable advances in our knowledge of the biomechanics of insect flight, little of this has been applied in an ecological context. This thesis aims to identify the gaps in our knowledge of macroecological processes and how biomechanical techniques can advance the field. I have set out a number of methods demonstrating how the biomechanics of flight in Odonata impacts ecological patterns. Range shifts are perhaps one of the best detailed impacts of climate change. At some level they must be driven by the movements of individuals, yet many studies have found little evidence to correlate flight ability and dispersal in insects. Using laboratory measures of flight performance I show that climate induced range shifts in the Odonata are limited by flight efficiency. This has important implications for conservation, as knowing how flight ability is able to restrict a species’ range shift will aid reserve design and future ecosystem predictions. The possible reason behind the lack of evidence linking flight ability and dispersal is the use of proxies for flight performance, and the assumptions of the relationship between these measures and actual flight performance. Indeed, in the literature there are a host of different often mutually exclusive assumptions regarding the role of morphology in shaping flight ability. I provide empirical evidence of how wing morphology affects flight performance, showing that a large proportion of assumptions made within the literature are not supported, or are only weakly supported. This calls into question how prevalent the effects of flight performance on dispersal are, given the use of misleading assumptions. In many systems the state of adult organisms is strongly dependent on the experience of juveniles. For the Odonata, a number of mass and size carry-over effects exist between larva and adult forms, but whether locomotory performance is linked in this way is as of yet unknown. Here I show that there is no correlation between larval and adult locomotory performance, suggesting that muscle development mechanisms are different for larvae and adults. Except for existing mass and size effects, flight performance should not be strongly affected by larval conditions. Finally, various behaviours have the capacity to affect dispersal in a species. One of the behaviours recently empirically confirmed in the Odonata is that of reversible polarotaxis: initial repulsion from polarised light sources as immature adults and the attraction back to polarised light as mature adults. I predicted that reversible polarotaxis would help aid dispersal, repelling insects from natal habitats and encouraging them to find new ones. However, the individual-based model of dispersal that I developed shows that reversible polarotaxis is more important in speeding up the progression through life stages, reducing the time taken to reach feeding habitats and to return to breeding sites. Individuals without polarotaxis would experience higher mortality and lower rates of energy uptake (taking longer to find food) and also higher mortality rates taking longer to return to breeding sites (including lower reproductive success from potentially spending less time at breeding sites). All the work here is then synthesised to create a comprehensive description of Odonata flight morphology (form), its effects on flight performance (function) and the ecological patterns it generates (ecology). I demonstrate that biomechanics can provide important insights into ecological processes – in this case, that flight performance is an important limiting factor for range expansions, where other limitations are perhaps not present. In addition flight morphology is strongly linked with flight performance, suggesting that up to 74% of studies have used incorrect assumptions regarding the links between morphology and performance.
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Bhat, Aditya. "Locomotion Trajectory Generation For Legged Robots." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-theses/1167.
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This thesis addresses the problem of generating smooth and efficiently executable locomotion trajectories for legged robots under contact constraints. In addition, we want the trajectories to have the property that small changes in the foot position generate small changes in the joint target path. The first part of this thesis explores methods to select poses for a legged robot that maximises the workspace reachability while maintaining stability and contact constraints. It also explores methods to select configurations based on a reduced-dimensional search of the configuration space. The second part analyses time scaling strategy which tries to minimize the execution time while obeying the velocity and acceleration constraints. These two parts effectively result in smooth feasible trajectories for legged robots. Experiments on the RoboSimian robot demonstrate the effectiveness and scalability of the strategies described for walking and climbing on a rock climbing wall.
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Briggs, Randall (Randall Miller). "Tail use in bioinspired quadrupedal locomotion." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74491.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 17-18).
Tails are seen in nature to be used in an amazing number of different applications. Many of these applications seen in nature may be of use to bioinspired roboticists in the future. I have provided a brief review of tail use as seen in nature. An experiment was performed using the MIT Cheetah to investigate the usefulness of tails in one particular instance. The Cheetah was set to stand while a large, standardized disturbance was introduced by means of a clay "wrecking ball." Two cases were observed: one where the tail was actively stationary and another where the tail was swung in order to counteract the disturbance. The actively swung tail was seen to keep the body in the stable region longer than the stationary tail, thus providing the robot additional time to correct for the disturbance with the next foot fall.
by Randall Briggs.
S.B.
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Kim, Julie Ju Youn. "Locomotion : a railroad museum for Chattanooga." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/67425.
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Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1994.Includes bibliographical references (leaves 84-86).
This thesis is about exploring an architecture that serves a dual purpose: one, as witness to the past, and, two, as evidence of a constantly changing built environment. It is about exploring a landscape rich with associative memories. Through the design of a railroad museum on abandoned railroad lines in Chattanooga, Tennessee, this thesis seeks to define an architecture that is integrated with the industrial landscape in an interdependent relationship. Using the museum as a design mechanism, the intention is to evoke memories of the past through the present architectural experience.
by Julie Ju Youn Kim.
M.Arch.
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Dai, Hongkai Ph D. Massachusetts Institute of Technology. "Robust bipedal locomotion on unknown terrain." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78465.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 57-60).
A wide variety of bipedal robots have been constructed with the goal of achieving natural and efficient walking in outdoor environments. Unfortunately, there is still a lack of general schemes enabling the robots to reject terrain disturbances. In this thesis, two approaches are presented to enhance the performance of bipedal robots walking on modest terrain. The first approach searches for a walking gait that is intrinsically easily stabilized. The second approach constructs a robust controller to steer the robot towards the designated walking gait. Mathematically, the problem is modeled as rejecting the uncertainty in the guard function of a hybrid nonlinear system. Two metrics are proposed to quantify the robustness of such systems. The first metric concerns the 'average performance' of a robot walking over a stochastic terrain. The expected LQR cost-to-go for the post-impact states is chosen to measure the difficulty of steering those perturbed states back to the desired trajectory. A nonlinear programming problem is formulated to search for a trajectory which takes the least effort to stabilize. The second metric deals with the 'worst case performance', and defines the L₂ gain for the linearization of the hybrid nonlinear system around a nominal periodic trajectory. In order to reduce the L₂ gain, an iterative optimization scheme is presented. In each iteration, the algorithm solves a semidefinite programming problem to find the quadratic storage function and integrates a periodic differential Riccati equation to compute the linear controller. The simulation results demonstrate that both metrics are correlated to the actual number of steps the robot can traverse on the rough terrain without falling down. By optimizing these two metrics, the robot can walk a much longer distance over the unknown landscape.
by Hongkai Dai.
S.M.
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Stavrakakis, Sophia. "Biomechanical studies of locomotion in pigs." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2510.
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Lameness is a major cause of lost productivity for the pig industry. The objective of this PhD was to develop an objective motion capture method for growing pigs and assess (1) the repeatability and sensitivity of the method (2) the gait characteristics of pigs housed on different floor types and (3) gait differences in pigs with conformational deficiencies, joint disease and/or clinical lameness. Infrared camera-based motion capture was applied to three different cohorts of pigs in three experiments, including an observational study following 84 gilts from grower- to second-parity stage. 3D coordinate data of reflective skin markers attached to head, neck, trunk and leg anatomical landmarks were collected. Temporal (time), linear (displacement) and angular (joint angles) kinematic gait parameters were calculated. Repeatability of the method varied with amount of overlying tissue and/or prominence of anatomical landmarks used for marker placement, but not necessarily with walking speed. Gait development of pigs reared on fully-slatted, partly-slatted or deep straw-bedded floors was not different. Lameness detection and evaluation was possible using relative linear and temporal kinematics. The within-stride trajectory of head and pelvic regions during walking differentiated pigs with front and multi-leg lameness from normal pigs, respectively. The ipsilateral swing-to-stance time ratio detected lameness in hind legs, but was not affected during multi-leg lameness. The frequency and magnitude of irregular steps was increased in lame pigs and in pigs with subclinical joint lesions of osteochondrosis diagnosed post slaughter. Step irregularity (as reflected in the step-to-stride length ratio) was also predictive of impending lameness. The step-to-stride length ratio is a dimensionless and ideal parameter to monitor pigs of different age and size, moving at a self-chosen walking speed. Flexion asymmetry and joint flexion patterns were indicative of locomotor problems in some cases. Gait analysis therefore offers potential for automated prediction and early detection of lameness.
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Cowie, Dorothy. "The development of visually guided locomotion." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670086.
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Goslin, Brian Richard. "Economy and efficiency of human locomotion." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1007177.
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Human locomotor economy and efficiency are highly variable. This study investigated the role that stature plays in this variation, by evaluating metabolic and respiratory responses to walking and running at speeds set relative to one's stature. Four groups of subjects: male, high V0₂ max (n = 11); male, average V0₂ max (n = 10); female, high V0₂ max (n = 10); and female, average V0₂ max (n = 11) were habituated to treadmill locomotion prior to the measurement of maximal oxygen consumption (V0₂ max). The V0₂ max test entailed 1 km.h⁻¹ increases per min from 3 to 6 km.h⁻¹ walking, and 7 - 17 km.h⁻¹ running then 1% grade increments per min until exhaustion. On each of four other occasions, the subject walked or ran at 6 of a variety of relative speeds - walking at 0.5, 0.7, 0.9, 1.1, 1.3; running at 1.5, 1.7, 1.9 and for selected subjects 2.1, 2.3 and 2.5 statures.s⁻¹ ,and grades - 0%, +3%, -3%. Steady-state respiratory and metabolic responses, and treadmill speed were monitored by an on-line computer system developed for this study. Cadence and RPE were also monitored. All subjects demonstrated an exponential relationship between V0₂ and walking relative speed (st.s⁻¹) (RS) . V0₂ (ml.kg⁻¹.min⁻¹ ) = 4.747 * e(1.371*RS) During running this relationship was essentially linear . The variability of economy at relative speed (9.08%) and absolute speed (9. 01%) did not differ. Male and female subjects did not differ in response to absolute speed but females were more economical at relative speeds (p<0.05). Those with high and average aerobic capacity did not differ in locomotor economy at relative speed. Higher freely-chosen stride length was associated with a higher V0₂ response as velocity increased. The V0₂ of uphill walking was 1.4 times greater than that for downhill walking (running: 1.28 times) . Stride length decreased with increasing speed in uphill locomotion but the reverse was the case for downhill. The economy and efficiency of walking was greater than that of running. Walking economy was maximal between 0.7 and 0.9 st. s⁻¹. Running economy remained essentially unaffected by increased velocity. The setting of locomotor velocity relative to stature does not minimize inter-subject variability in metabolic and respiratory response .
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FRANCOIS, CHARLES. "Contribution a la locomotion dynamiquement stable." Paris, ENMP, 1996. http://www.theses.fr/1996ENMP0613.
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Les travaux exposes dans cette these portent sur l'etude d'une nouvelle loi de commande du plus simple des robots a pattes: le monopode planaire. Celui-ci est constitue d'une seule patte telescopique supportant un corps. Muni d'une structure mecanique appropriee, et correctement commande, le monopode planaire peut se comporter, sur sol plan, comme une roue, en ne depensant de l'energie que pour accelerer ou pour ralentir. A vitesse moyenne constante, sa consommation d'energie faible. Bien que de conception relativement elaboree, la commande proposee est simple dans son implementation puisqu'il s'agit d'un retour d'etat lineaire constant par morceaux, recalcule au debut de chaque pas et parametre par la vitesse d'avancement desiree
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Doorly, Nicole C. "A Neuromechanical Model for Cockroach Locomotion." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1291140045.
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Helps, Timothy Nicolas. "Economically optimal designs for legged locomotion." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687425.
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Legged systems are capable of locomotion in a far wider range of environments compared with wheeled or tracked vehicles. Man-made legged locomotion systems are currently economically inferior to wheeled vehicles, tracked vehicles, and legged locomotion systems which exist in nature. In previous research, trajectory optimisation has been applied to legged locomotion systems of a certain design to improve economy, however there has been little work in which the economy of legged locomotion systems is improved through design. This thesis describes the search for economically optimal designs of legged locomotion systems using parametric analysis. An abstract mathematical model of a legged locomotion system was constructed which included an imperfect spring element and electromagnetic actuator. Several actuation strategies were developed which allowed the model to be controlled to perform continuous locomotion. Six performance metrics were identified whose reduction in value implied an increase in economy. The model was simulated performing four locomotion exercises of increasing complexity, beginning with a system oscillating in the absence of gravity and ending with a planar locomotion system. Across these four locomotion exercises, the effect of system architecture, actuation strategy and key system parameters upon economy was determined. Two prototype legged locomotion systems were also constructed for comparison with simulation. It was not possible to simultaneously minimise all performance metrics because minimisation of some performance metrics required choices of system architecture, actuation strategy or system parameter which prevented minimisation of other performance metrics. The economically optimal design of a legged locomotion system was one which minimised the maximum force and peak power requirements of the locomotion system's actuator. Parallel compliance was economically superior to series compliance, which is particularly noteworthy given the comparative rarity of parallel compliance in current man-made legged locomotion systems.
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Yamashita, Daichi. "The mechanics of human sideways locomotion." Kyoto University, 2014. http://hdl.handle.net/2433/188791.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第18353号
人博第666号
新制||人||160(附属図書館)
25||人博||666(吉田南総合図書館)
31211
京都大学大学院人間・環境学研究科共生人間学専攻
(主査)准教授 神﨑 素樹, 教授 森谷 敏夫, 准教授 久代 恵介, 教授 小田 伸午
学位規則第4条第1項該当
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Rosen, Sarah Tucker Carole Seliktar Rahamim. "The propulsion dynamics of human locomotion /." Philadelphia, Pa. : Drexel University, 2009. http://hdl.handle.net/1860/3020.
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