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Kalyadin, Dmitry. „Robot data and control server for Internet-based training on ground robots“. [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002111.
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Serdel, Quentin. „Semantic-assisted Autonomous Ground Robot Navigation in Unstructured Environments“. Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPAST139.
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Cette thèse porte sur la navigation autonome de robots terrestres dans des environnements non structurés et dépourvus de télécommunications. Afin d'employer des robots mobiles pour effectuer des tâches complexes telles que l'exploration planétaire ou des opérations de sauvetage, ils doivent bénéficier d'une autonomie complète, notamment pour leur navigation sans carte préalable. Les dernières avancées dans le domaine de l'apprentissage profond permettent l'extraction d'informations sémantiques à partir des données capteurs d'un robot. L'exploitation de ces informations, relatives à la nature des éléments de l'environnement du robot, est une piste prometteuse pour l'amélioration de la sécurité et de l'autonomie des systèmes de navigation. Leur intégration dans un processus de cartographie en ligne et l'exploitation de la représentation produite pour la planification de chemins sont abordées via la notion de traversabilité du terrain. La complexité de calcul et la robustesse aux données bruitées sont des aspects cruciaux à prendre en compte. De nouvelles méthodes sont proposées pour la construction de telles représentations et leur exploitation pour la planification de trajectoires. Elles ont été intégrées dans un système complet de navigation robotique et utilisées avec succès dans un scénario réelThe content of this PhD thesis deals with the autonomous navigation of ground robots in telecommunication-denied unstructured environments. In order to employ mobile robots to perform complex tasks such as planetary exploration or search-and-rescue operations, they must be trusted with complete autonomy, notably for their map-less navigation. Thanks to recent advances in the domain of deep-learning, the efficient extraction of semantic information from a robot sensor data is now possible. The exploitation of this information, relating to the nature of the robot surroundings elements, is a promising lead toward the improvement of the safety and autonomy of navigation systems. The integration of semantic labelling into an online mapping process and the exploitation of the resulting environment representation for informative path planning are tackled via the notion of terrain traversability. Computational complexity and robustness to noisy inputs are crucial aspects to be considered. New methods are therefore proposed for the online construction of such representations and their exploitation for path planning. They have been integrated in a complete robot navigation system and successfully employed in a real-world scenario
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Shah, Syed Irtiza Ali. „Single camera based vision systems for ground and; aerial robots“. Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37143.
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Efficient and effective vision systems are proposed in this work for object detection for ground&aerial robots venturing into unknown environments with minimum vision aids, i.e. a single camera. The first problem attempted is that of object search and identification in a situation similar to a disaster site. Based on image analysis, typical pixel-based characteristics of a visual marker have been established to search for, using a block based search algorithm, along with a noise and interference filter. The proposed algorithm has been successfully utilized for the International Aerial Robotics competition 2009. The second problem deals with object detection for collision avoidance in 3D environments. It has been shown that a 3D model of the scene can be generated from 2D image information from a single camera flying through a very small arc of lateral flight around the object, without the need of capturing images from all sides. The forward flight simulations show that the depth extracted from forward motion is usable for large part of the image. After analyzing various constraints associated with this and other existing approaches, Motion Estimation has been proposed. Implementation of motion estimation on videos from onboard cameras resulted in various undesirable and noisy vectors. An in depth analysis of such vectors is presented and solutions are proposed and implemented, demonstrating desirable motion estimation for collision avoidance task.
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Baleia, José Rodrigo Ferreira. „Haptic robot-environment interaction for self-supervised learning in ground mobility“. Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/12475.
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Dissertação para obtenção do Grau de Mestre em
Engenharia Eletrotécnica e de ComputadoresThis dissertation presents a system for haptic interaction and self-supervised learning mechanisms to ascertain navigation affordances from depth cues. A simple pan-tilt telescopic arm and a structured light sensor, both fitted to the robot’s body frame, provide the required haptic and depth sensory feedback. The system aims at incrementally develop the ability to assess the cost of navigating in natural environments. For this purpose the robot learns a mapping between the appearance of objects, given sensory data provided by the sensor, and their bendability, perceived by the pan-tilt telescopic arm. The object descriptor, representing the object in memory and used for comparisons with other objects, is rich for a robust comparison and simple enough to allow for fast computations. The output of the memory learning mechanism allied with the haptic interaction point evaluation prioritize interaction points to increase the confidence on the interaction and correctly identifying obstacles, reducing the risk of the robot getting stuck or damaged. If the system concludes that the object is traversable, the environment change detection system allows the robot to overcome it. A set of field trials show the ability of the robot to progressively learn which elements of environment are traversable.
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Sharma, Rajnikant. „Bearing-Only Cooperative-Localization and Path-Planning of Ground and Aerial Robots“. BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2884.
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In this dissertation, we focus on two fundamental problems related to the navigation of ground robots and small Unmanned Aerial Vehicle (UAVs): cooperative localization and path planning. The theme running through in all of the work is the use of bearing only sensors, with a focus on monocular video cameras mounted on ground robots and UAVs. To begin with, we derive the conditions for the complete observability of the bearing-only cooperative localization problem. The key element of this analysis is the Relative Position Measurement Graph (RPMG). The nodes of an RPMG represent vehicle states and the edges represent bearing measurements between nodes. We show that graph theoretic properties like the connectivity and the existence of a path between two nodes can be used to explain the observability of the system. We obtain the maximum rank of the observability matrix without global information and derive conditions under which the maximum rank can be achieved. Furthermore, we show that for the complete observability, all of the nodes in the graph must have a path to at least two different landmarks of known location. The complete observability can also be obtained without landmarks if the RPMG is connected and at least one of the robots has a sensor which can measure its global pose, for example a GPS receiver. We validate these conditions by simulation and experimental results. The theoretical conditions to attain complete observability in a localization system is an important step towards reliable and efficient design of localization and path planning algorithms. With such conditions, a designer does not need to resort to exhaustive simulations and/or experimentation to verify whether a given selection of a control strategy, topology of the sensor network, and sensor measurements meets the observability requirements of the system. In turn, this leads to decreased requirements of time, cost, and effort for designing a localization algorithms. We use these observability conditions to develop a technique, for camera equipped UAVs, to cooperatively geo-localize a ground target in an urban terrain. We show that the bearing-only cooperative geo-localization technique overcomes the limitation of requiring a low-flying UAV to maintain line-of-sight while flying high enough to maintain GPS lock. We design a distributed path planning algorithm using receding horizon control that improves the localization accuracy of the target and of all of the UAVs while satisfying the observability conditions. Next, we use the observability analysis to explicitly design an active local path planning algorithm for UAVs. The algorithm minimizes the uncertainties in the time-to-collision (TTC) and bearing estimates while simultaneously avoiding obstacles. Using observability analysis we show that maximizing the observability and collision avoidance are complementary tasks. We provide sufficient conditions of the environment which maximizes the chances obstacle avoidance and UAV reaching the goal. Finally, we develop a reactive path planner for UAVs using sliding mode control such that it does not require range from the obstacle, and uses bearing to obstacle to avoid cylindrical obstacles and follow straight and curved walls. The reactive guidance strategy is fast, computationally inexpensive, and guarantees collision avoidance.
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Staub, Nicolas. „Models, algorithms and architectures for cooperative manipulation with aerial and ground robots“. Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30169/document.
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Les dernières années ont vu le développement de recherches portant sur l'interaction physique entre les robots aériens et leur environnement, accompagné de l'apparition de nombreux nouveaux systèmes mécaniques et approches de régulation. La communauté centrée autour de la robotique aérienne observe actuellement un déplacement de paradigmes des approches classiques de guidage, de navigation et de régulation vers des tâches moins triviales, telle le développement de l'interaction physique entre robots aériens et leur environnement. Ceci correspond à une extension des tâches dites de manipulation, du sol vers les airs. Cette thèse contribue au domaine de la manipulation aérienne en proposant un nouveau concept appelé MAGMaS, pour " Multiple Aerial Ground Manipulator System ". Les motivations qui ont conduites à l'association de manipulateurs terrestres et aériens pour effectuer des tâches de manipulation coopérative, résident dans une volonté d'exploiter leurs particularités respectives. Les manipulateurs terrestres apportant leur importante force et les manipulateurs aériens apportant leur vaste espace de travail. La première contribution de cette thèse présente une modélisation rigoureuse des MAGMaS. Les propriétés du système ainsi que ses possibles extensions sont discutées. Les méthodes de planning, d'estimation et de régulation nécessaire à l'exploitation des MAGMaS pour des tâches de manipulation collaborative sont dérivées. Ce travail propose d'exploiter les redondances des MAGMaS grâce à un algorithme optimal d'allocation de forces entre les manipulateurs. De plus, une méthode générale d'estimation de forces pour robots aériens est introduite. Toutes les techniques et les algorithmes présentés dans cette thèse sont intégrés dans une architecture globale, utilisée à la fois pour la simulation et la validation expérimentale. Cette architecture est en outre augmentée par l'addition d'une structure de télé-présence, afin de permettre l'opération à distances des MAGMaS. L'architecture générale est validée par une démonstration de levage de barre, qui est une application représentative des potentiels usages des MAGMaS. Une autre contribution relative au développement des MAGMaS consiste en une étude exploratoire de la flexibilité dans les objets manipulés par un MAGMaS. Un modèle du phénomène vibratoire est dérivé afin de mettre en exergue ses propriétés en termes de contrôle. La dernière contribution de cette thèse consiste en une étude exploratoire sur l'usage des actionneurs à raideur variable dans les robots aériens, dotant ces systèmes d'une compliance mécanique intrinsèque et de capacité de stockage d'énergie. Les fondements théoriques sont associés à la synthèse d'un contrôleur non-linéaire. L'approche proposée est validée par le biais d'expériences reposant sur l'intégration d'un actionneur à raideur variable léger sur un robot aérienIn recent years, the subject of physical interaction for aerial robots has been a popular research area with many new mechanical designs and control approaches being proposed. The aerial robotics community is currently observing a paradigm shift from classic guidance, navigation, and control tasks towards more unusual tasks, for example requesting aerial robots to physically interact with the environment, thus extending the manipulation task from the ground into the air. This thesis contributes to the field of aerial manipulation by proposing a novel concept known has Multiple Aerial-Ground Manipulator System or MAGMaS, including what appears to be the first experimental demonstration of a MAGMaS and opening a new route of research. The motivation behind associating ground and aerial robots for cooperative manipulation is to leverage their respective particularities, ground robots bring strength while aerial robots widen the workspace of the system. The first contribution of this work introduces a meticulous system model for MAGMaS. The system model's properties and potential extensions are discussed in this work. The planning, estimation and control methods which are necessary to exploit MAGMaS in a cooperative manipulation tasks are derived. This works proposes an optimal control allocation scheme to exploit the MAGMaS redundancies and a general model-based force estimation method is presented. All of the proposed techniques reported in this thesis are integrated in a global architecture used for simulations and experimental validation. This architecture is extended by the addition of a tele-presence framework to allow remote operations of MAGMaS. The global architecture is validated by robust demonstrations of bar lifting, an application that gives an outlook of the prospective use of the proposed concept of MAGMaS. Another contribution in the development of MAGMaS consists of an exploratory study on the flexibility of manipulated loads. A vibration model is derived and exploited to showcase vibration properties in terms of control. The last contribution of this thesis consists of an exploratory study on the use of elastic joints in aerial robots, endowing these systems with mechanical compliance and energy storage capabilities. Theoretical groundings are associated with a nonlinear controller synthesis. The proposed approach is validated by experimental work which relies on the integration of a lightweight variable stiffness actuator on an aerial robot
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Yang, Jian. „Real-time trajectory planning for ground and aerial vehicles in a dynamic environment“. Orlando, Fla. : University of Central Florida, 2008. http://purl.fcla.edu/fcla/etd/CFE0002031.
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Birchmore, Frederick Christopher. „A holistic approach to human presence detection on man-portable military ground robots“. Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1464660.
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Thesis (M.S.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed July 2, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 85-90).
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Klamt, Tobias [Verfasser]. „Planning Hybrid Driving-Stepping Locomotion for Ground Robots in Challenging Environments / Tobias Klamt“. Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1218301465/34.
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Archontakis, Andreas. „Assessing the flight quality of a large UAV for sensors/ground robots aerial delivery“. Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5116.
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Approved for public release; distribution is unlimitedThe new goal for unmanned aerial systems will be to find creative methods of keeping the cost low and still maintain effectiveness. This thesis discusses the importance of UAVs over the last few years, suggests the development of a low-cost, large UAV, and evaluates the results. We also examine the idea of a platform for deploying multiple aerial-delivery, parafoil-based systems and discuss scenarios for the improvement of the collaboration of the large UAV with the Snowflake project.
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Hwangbo, Ju Won. „Integration of Orbital and Ground Imagery for Automation of Rover Localization“. The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276835399.
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Hussein, Marwan. „Absolute localization of mobile robots in forest environments by correlating ground LiDAR to overhead imagery“. Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91877.
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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2014.Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
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Cataloged from PDF version of thesis.
Includes bibliographical references (pages 135-140).
A method for the autonomous geolocation of ground vehicles in forest environments is presented. The method provides an estimate of the global horizontal position of a vehicle strictly based on finding a geometric match between a map of observed tree stems, scanned in 3D by Light Detection and Ranging (LiDAR) sensors onboard the vehicle, to another stem map generated from the structure of tree crowns analyzed from aerial orthoimagery of the forest canopy. Identification of stems from 3D data is achieved by using Support Vector Machine (SVM) classifiers and height above ground filters that separate ground points from vertical stem features. Identifications of stems from overhead imagery is achieved by calculating the centroids of tree crowns extracted using a watershed segmentation algorithm. Matching of the two stem maps is achieved by using a robust Iterative Closest Point (ICP) algorithm that determines the rotation and translation required to align both datasets. The final alignment is used to calculate the absolute location of the vehicle. The localization algorithm has been tested with real-world data and has been able to estimate vehicle geoposition with errors of less than 2.1 m RMS. It is noted that the algorithm's accuracy is currently limited by the accuracy and resolution of the aerial orthoimagery used. This method can be used in real-time as a complement to the Global Positioning System (GPS) and Simultaneous Localization and Mapping (SLAM) in areas where signal coverage is inadequate due to attenuation by the forest canopy, or due to intentional denied access. The method has two key properties that are significant: i) It does not require a priori knowledge of the area surrounding the robot. ii) Based on estimated vehicle state, it uses the geometry of detected tree stems as the only input to determine horizontal geoposition.
by Marwan Hussein.
S.M. in Engineering and Management
S.M.
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Putney, Joseph Satoru. „Reactive Navigation of an Autonomous Ground Vehicle Using Dynamic Expanding Zones“. Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33224.
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Autonomous navigation of mobile robots through unstructured terrain presents
many challenges. The task becomes even more difficult with increasing obstacle density,
at higher speeds, and when a priori knowledge of the terrain is not available. Reactive
navigation schemas are often dismissed as overly simplistic or considered to be inferior
to deliberative approaches for off-road navigation. The Potential Field algorithm has
been a popular reactive approach for low speed, highly maneuverable mobile robots.
However, as vehicle speeds increase, Potential Fields becomes less effective at avoiding
obstacles.
The traditional shortcomings of the Potential Field approach can be largely
overcome by using dynamically expanding perception zones to help track objects of
immediate interest. This newly developed technique is hereafter referred to as the
Dynamic Expanding Zones (DEZ) algorithm. In this approach, the Potential Field
algorithm is used for waypoint navigation and the DEZ algorithm is used for obstacle
avoidance. This combination of methods facilitates high-speed navigation in obstaclerich
environments at a fraction of the computational cost and complexity of deliberative
methods.
The DEZ reactive navigation algorithm is believed to represent a fundamental
contribution to the body of knowledge in the area of high-speed reactive navigation.
This method was implemented on the Virginia Tech DARPA Grand Challenge vehicles.
The results of this implementation are presented as a case study to demonstrate the
efficacy of the newly developed DEZ approach.Master of Science
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Butzke, Jonathan Michael. „Planning for a Small Team of Heterogeneous Robots: from Collaborative Exploration to Collaborative Localization“. Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/1119.
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Robots have become increasingly adept at performing a wide variety of tasks in the world. However, many of these tasks can benefit tremendously from having more than a single robot simultaneously working on the problem. Multiple robots can aid in a search and rescue mission each scouting a subsection of the entire area in order to cover it quicker than a single robot can. Alternatively, robots with different abilities can collaborate in order to achieve goals that individually would be more difficult, if not impossible, to achieve. In these cases, multi-robot collaboration can provide benefits in terms of shortening search times, providing a larger mix of sensing, computing, and manipulation capabilities, or providing redundancy to the system for communications or mission accomplishment. One principle drawback of multi-robot systems is how to efficiently and effectively generate plans that use each of the team members to their fullest extent, particularly with a heterogeneous mix of capabilities. Towards this goal, I have developed a series of planning algorithms that incorporate this collaboration into the planning process. Starting with systems that use collaboration in an exploration task I show teams of homogeneous ground robots planning to efficiently explore an initially unknown space. These robots share map information and in a centralized fashion determine the best goal location for each taking into account the information gained by other robots as they move. This work is followed up with a similar exploration scheme but this time expanded to a heterogeneous air-ground robot team operating in a full 3-dimensional environment. The extra dimension adds the requirement for the robots to reason about what portions of the environment they can sense during the planning process. With an air-ground team, there are portions of the environment that can only be sensed by one of the two robots and that information informs the algorithm during the planning process. Finally, I extend the air-ground robot team to moving beyond merely collaboratively constructing the map to actually using the other robots to provide pose information for the sensor and computationally limited team members. By explicitly reasoning about when and where the robots must collaborate during the planning process, this approach can generate trajectories that are not feasible to execute if planning occurred on an individual robot basis. An additional contribution of this thesis is the development of the State Lattice Planning with Controller-based Motion Primitives (SLC) framework. While SLC was developed to support the collaborative localization of multiple robots, it can also be used by a single robot to provide a more robust means of planning. For example, using the SLC algorithm to plan using a combination of vision-based and metric-based motion primitives allows a robot to traverse a GPS-denied region.
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Pawlowski, Daniel F. „Tracking Dynamic Obstacles in a Structured Urban Environment and Subsequent Decision Making for an Autonomous Ground Vehicle“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1213804587.
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Chen, Qi. „Studies in autonomous ground vehicle control systems structure and algorithms /“. Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1165959992.
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Mathews, Nithin. „Beyond self-assembly: Mergeable nervous systems, spatially targeted communication, and supervised morphogenesis for autonomous robots“. Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/267717.
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The study of self-assembling robots represents a promising strand within the emerging field of modular robots research. Self-assembling robots have the potential to autonomously adapt their bodies to new tasks and changing environments long after their initial deployment by forming new or reorganizing existing physical connections to peer robots. In previous research, many approaches have been presented to enable self-assembling robots to form composite morphologies. Recent technological advances have also increased the number of robots able to form such morphologies by at least two orders of magnitude. However, to date, composite robot morphologies have not been able to solve real-world tasks nor have they been able to adapt to changing conditions entirely without human assistance or prior knowledge.In this thesis, we identify three reasons why self-assembling robots may not have been able to fully unleash their potential and propose appropriate solutions. First, composite morphologies are not able to show sensorimotor coordination similar to those seen in their monolithic counterparts. We propose "mergeable nervous systems" -- a novel methodology that unifies independent robotic units into a single holistic entity at the control level. Our experiments show that mergeable nervous systems can enable self-assembling robots to demonstrate feats that go beyond those seen in any engineered or biological system. Second, no proposal has been tabled to enable a robot in a decentralized multirobot system select its communication partners based on their location. We propose a new form of highly scalable mechanism to enable "spatially targeted communication" in such systems. Third, the question of when and how to trigger a self-assembly process has been ignored by researchers to a large extent. We propose "supervised morphogenesis" -- a control methodology that is based on spatially targeted communication and enables cooperation between aerial and ground-based self-assembling robots. We show that allocating self-assembly related decision-making to a robot with an aerial perspective of the environment can allow robots on the ground to operate in entirely unknown environments and to solve tasks that arise during mission time. For each of the three propositions put forward in this thesis, we present results of extensive experiments carried out on real robotic hardware. Our results confirm that we were able to substantially advance the state of the art in self-assembling robots by unleashing their potential for morphological adaptation through enhanced sensorimotor coordination and by improving their overall autonomy through cooperation with aerial robots.Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
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MURTY, VIDYASAGAR. „OBSTACLE AVOIDANCE IN AN UNSTRUCTURED ENVIRONMENT FOR THE BEARCAT“. University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1070482938.
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Murphy, Taylor Byers. „Apprehending Remote Affordances: Assessing Human Sensor Systems and Their Ability to Understand a Distant Environment“. The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374144285.
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Renaudeau, Brice. „Robotique coopérative aéro-terrestre : Localisation et cartographie hétérogène“. Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0012/document.
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Les travaux de cette thèse adressent la problématique de la coopération aéro-terrestre pour la cartographie de l’espace navigable. La nécessité d’une carte pour la navigation et la planification de chemins pour les robots terrestres n’est plus à prouver. L’utilisation d’une coopération aéro-terrestre pour créer une carte navigable à destination du robot terrestre a plusieurs intérêts. Premièrement, le drone peut cartographier rapidement une zone grâce à son champ de vision étendu et ses capacités de déplacement. Deuxièmement, la fusion des cartes créées par ces deux agents permet de tirer le meilleur profit des deux points de vue : la cohérence de la vue aérienne globale et la précision de la vue terrestre locale. Pour répondre à cette problématique, nous proposons une méthode qui s’appuie sur la création de cartes hybrides et leur fusion. Les cartes sont construites en utilisant le squelette de l’espace navigable terrestre comme support d’un graphe contenant également des informations métriques locales de l’environnement. La mise en correspondance des cartes aérienne et terrestre s’effectue à l’aide d’un appariement point à point déterminé grâce à une mesure de dissimilarité appropriée. Cette dernière est définie pour répondre aux critères d’invariance et de discriminance dans ce contexte. La mise en correspondance est ensuite utilisée pour fusionner les cartes entre elles. Les cartes fusionnées peuvent être utilisées par le robot au sol pour effectuer sa mission. Elles permettent également de propager des informations telles que des coordonnées GPS à des robots et dans des lieux où ce dispositif n’est pas disponible. Des expérimentations en environnements virtuels et réels sont réalisées pour valider cette approche et en tracer les perspectivesThis work aims to study the problem of air-ground robotic cooperation for collaborative traversability mapping. The need for a map for navigation and path planning for terrestrial robots is no longer to be proven. The use of air-ground cooperation to create a navigable map for the ground robots has several interests. First, the drone can quickly map an area through its large field of vision and traveling capabilities. Second, the fusion of maps based on these two agents makes it possible to draw the best benefits from both points of views: the coherence of the global aerial view and the accuracy of the local ground view. To answer this problem, we propose a method that relies on the construction of a unified model of hybrid maps and their fusion.The maps are built using the skeleton of the traversability space as a support for graphs also containing local metric and potentialy semantic information of the environment. The maching of aerial and ground maps is done using a point to point correlation based on an appropriate dissimilarity measure. This measure is defined to meet invariance and discriminance criteria. The matching is then used to merge the maps into an augmented traversability map. The merged maps can be used by the ground robot to perform its mission. They also make it possible to deploy information such as GPS coordinates to robots in GPS denied environments. Experiments in virtual and real world environments have been carried out to validate this approach and map out future perspetives
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Labella, Thomas Halva. „Division of labour in groups of robots“. Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210738.
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In this thesis, we examine algorithms for the division of labour in a group of robot. The algorithms make no use of direct communication. Instead, they are based only on the interactions among the robots and between the group and the environment.Division of labour is the mechanism that decides how many robots shall be used to perform a task. The efficiency of the group of robots depends in fact on the number of robots involved in a task. If too few robots are used to achieve a task, they might not be successful or might perform poorly. If too many robots are used, it might be a waste of resources. The number of robots to use might be decided a priori by the system designer. More interestingly, the group of robots might autonomously select how many and which robots to use. In this thesis, we study algorithms of the latter type.
The robotic literature offers already some solutions, but most of them use a form of direct communication between agents. Direct, or explicit, communication between the robots is usually considered a necessary condition for co-ordination. Recent studies have questioned this assumption. The claim is based on observations of animal colonies, e.g. ants and termites. They can effectively co-operate without directly communicating, but using indirect forms of communication like stigmergy. Because they do not rely on communication, such colonies show robust behaviours at group level, a condition that one wishes also for groups of robots. Algorithms for robot co-ordination without direct communication have been proposed in the last few years. They are interesting not only because they are a stimulating intellectual challenge, but also because they address a situation that might likely occur when using robots for real-world out-door applications. Unfortunately, they are still poorly studied.
This thesis helps the understanding and the development of such algorithms. We start from a specific case to learn its characteristics. Then we improve our understandings through comparisons with other solutions, and finally we port everything into another domain.
We first study an algorithm for division of labour that was inspired by ants' foraging. We test the algorithm in an application similar to ants' foraging: prey retrieval. We prove that the model used for ants' foraging can be effective also in real conditions. Our analysis allows us to understand the underlying mechanisms of the division of labour and to define some way of measuring it.
Using this knowledge, we continue by comparing the ant-inspired algorithm with similar solutions that can be found in the literature and by assessing their differences. In performing these comparisons, we take care of using a formal methodology that allows us to spare resources. Namely, we use concepts of experiment design to reduce the number of experiments with real robots, without losing significance in the results.
Finally, we apply and port what we previously learnt into another application: Sensor/Actor Networks (SANETs). We develop an architecture for division of labour that is based on the same mechanisms as the ants' foraging model. Although the individuals in the SANET can communicate, the communication channel might be overloaded. Therefore, the agents of a SANET shall be able to co-ordinate without accessing the communication channel.
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished
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Sajid, Nisar. „Toward Novel Remote-Center-of-Motion Manipulators and Wearable Hand-Grounded Kinesthetic Haptics for Robot-Assisted Surgery“. Kyoto University, 2019. http://hdl.handle.net/2433/242497.
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付記する学位プログラム名: デザイン学大学院連携プログラムKyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第21759号
工博第4576号
新制||工||1713(附属図書館)
京都大学大学院工学研究科機械理工学専攻
(主査)教授 松野 文俊, 教授 椹木 哲夫, 教授 小森 雅晴
学位規則第4条第1項該当
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Wang, Xuerui, und Li Zhao. „Navigation and Automatic Ground Mapping by Rover Robot“. Thesis, Högskolan i Halmstad, Halmstad Embedded and Intelligent Systems Research (EIS), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-6185.
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This project is mainly based on mosaicing of images and similarity measurements with different methods. The map of a floor is created from a database of small-images that have been captured by a camera-mounted robot scanning the wooden floor of a living room. We call this ground mapping. After the ground mapping, the robot can achieve self-positioning on the map by using novel small images it captures as it displaces on the ground. Similarity measurements based on the Schwartz inequality have been used to achieve the ground mapping, as well as to position the robot once the ground map is available. Because the natural light affects the gray value of images, this effect must be accounted for in the envisaged similarity measurements. A new approach to mosaicing is suggested. It uses the local texture orientation, instead of the original gray values, in ground mapping as well as in positioning. Additionally, we report on ground mapping results using other features, gray-values as features. The robot can find its position with few pixel errors by using the novel approach and similarity measurements based on the Schwartz inequality.
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Mudgal, Apurva. „Worst-case robot navigation in deterministic environments“. Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/33924.
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We design and analyze algorithms for the following two robot navigation problems:
1. TARGET SEARCH. Given a robot located at a point s in the plane, how will a robot navigate to a goal t in the presence of unknown
obstacles ?
2. LOCALIZATION. A robot is "lost" in an environment with a map of its surroundings. How will it find its true location by traveling the minimum distance ?
Since efficient algorithms for these two problems will make a robot completely autonomous, they have held the interest of both robotics and computer science communities.
Previous work has focussed mainly on designing competitive algorithms where the robot's performance is compared to that of an omniscient adversary. For example, a competitive algorithm for target search will compare the distance traveled by the robot with the shortest path from
s to t.
We analyze these problems from the worst-case perspective, which, in our view, is a more appropriate measure. Our results are :
1. For target search, we analyze an algorithm called Dynamic A*. The robot continuously moves to the goal on the shortest path which it recomputes on the discovery of obstacles. A variant of this algorithm has been employed in Mars Rover prototypes.
We show that D* takes O(n log n) time on planar graphs and also show a comparable bound on arbitrary graphs. Thus, our results show that D* combines the optimistic possibility of reaching the goal very soon while competing with depth-first search within a logarithmic factor.
2. For the localization problem, worst-case analysis compares the performance of the robot with the optimal decision tree over the set of possible locations.
No approximation algorithm has been known. We give a polylogarithmic approximation algorithm and also show a near-tight lower bound for the grid graphs commonly used in practice. The key idea is to plan travel on a "majority-rule map" which eliminates uncertainty and permits a link to the half-Group Steiner problem. We also extend the problem to polygonal maps by discretizing the domain using novel geometric techniques.
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Gomes, Fred. „Monitorização de objetos em 3-D com base em múltiplas câmaras“. Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16489.
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Mestrado em Engenharia de Automação IndustrialNo ano de 2014 foi concluído um novo edifício na Universidade de Aveiro, para o desenvolvimento de projetos em robótica. Neste edifício está localizado um campo de futebol robótico com dimensões oficiais, para o desenvolvimento do projeto CAMBADA. O futebol robótico representa um banco de ensaio inovador e atraente para os mais recentes avanços em sistemas multiagente, inteligência artificial, perceção, navegação e biped walking. O principal elemento sensor de um robô de futebol deve ser o seu sistema de perceção, muitas das vezes baseado numa câmara digital, através da qual o robô analisa o mundo circundante. Até à presente data, a validação de um sistema de visão de um jogo de futebol pode apenas ser relacionado com a forma como o robô e os seus companheiros de equipa interpretam o ambiente à sua volta. Esta dissertação tem como objetivo desenvolver um sistema de visão externo de monitorização que pode atuar como um sistema de ground truth para a validação dos objetos de interesse de um jogo de futebol robótico, principalmente os robôs e a bola. O sistema é constituído por duas a quatro câmaras, estrategicamente posicionadas no campo de futebol. O trabalho dividiu-se em quatro partes fundamentais: a seleção do método mais adequado para a aplicação; o desenvolvimento de software para efetuar a calibração das câmaras RGB; o desenvolvimento de software para obter a posição 3-D de objetos e a validação dos resultados obtidos, em termos de precisão e fiabilidade. Os resultados indicam que um sistema deste tipo parece adequado para ser utilizado como ground truth das posições da bola no campo, durante um jogo de futebol robótico.
A new building was concluded at the University of Aveiro for the development of projects in robotics, in 2014. In this building is located a robotic soccer field with official dimensions, for the development of the CAMBADA project. Robotic soccer represents an innovative and appealing test bed for the most recent advances in multi-agent systems, artificial intelligence, perception, navigation and biped walking. The main sensorial element of a soccer robot must be its perception system, most of the times based on a digital camera, through which the robot analyses the surrounding world and performs accordingly. Up to this date, the validation of the vision system of a soccer robots can only be related to the way the robot and its team mates interpret the surroundings, relative to their owns. This Master’s thesis aims the development of a external monitoring vision system that can act as a ground truth system for the validation of the objects of interest of a robotic soccer game, mainly robots and ball. The system is made of two to four digital cameras, strategically positioned above the soccer field. The developed work was divided into four main parts: the selection of the most appropriate method for the application; the development of a software to perform the calibration of the RGB cameras; the development of a software to obtain the 3-D information of objects and the validation of the obtained results, in terms of accuracy and reliability. The results prove that such a system can indeed be used as a provider for ground truth ball positions on the field during a robotic soccer game.
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Blank, Sarah T. „The robot club : robots as agents to improve the social skills of young people on the autistic spectrum“. Thesis, University of Hertfordshire, 2010. http://hdl.handle.net/2299/4407.
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To better understand the difficulties and strengths associated with both high and low functioning individuals with an autistic spectrum disorder (ASD), the hyper-systemising theory has been proposed by Baron-Cohen and colleagues. It explains the social and communication difficulties in autism and Asperger syndrome (AS) by reference to delays and deficits in empathy, whilst explaining the areas of strength by reference to intact or even superior skill in systemising (Baron-Cohen, 2002). The evidence for hypersystemising alongside hypo-empathising in autism, suggests a corresponding desire to systemise the social world. Based on this theory, the use of technology in supporting the development of social and communication skills in children with an ASD is discussed. Technology and computers rely on strict, predictable systems made up of sets of rules that can be programmed, determined and understood. Use of such technology to assist in the development of social skills in an individual with an ASD utilises an existing area of strength and engages a person in an often existing area of interest and/or obsession. This thesis describes an exploratory study using non-humanoid robots with a group of young people with either high-functioning autism (HFA) or AS, which aimed to use robots as a focus of shared attention in a more naturally occurring and systemisable environment; thus promoting more implicit learning of social skills for this clinical group. Ten children attended the ‘robot club’ for eight sessions enabling a design using a series of single case studies pooled together for multiple and individual base line comparisons. The results indicate improvements as rated by parents and the young people themselves (although not by teachers), with some evidence of statistical and clinically significant changes, for example, in communication skills specifically and with general difficulties associated with autism. The results were found to be affected by total number of sessions attended, but not by age or academic functioning. Possible implications of the findings are presented in line with theory and for clinical practise. Limitations of the study are discussed and suggestions for future research made.
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Al-Jarrah, Rami [Verfasser]. „Development of cooperation between flying robot, ground robot and ground station with fuzzy logic and image processing / Rami Al-Jarrah“. Siegen : Universitätsbibliothek der Universität Siegen, 2015. http://d-nb.info/1076911706/34.
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Chemtob, Yohann. „Collective behaviour of zibrafish and robot groups in a constrained environment“. Thesis, Université de Paris (2019-....), 2020. http://www.theses.fr/2020UNIP7017.
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Le mouvement collectif est un phénomène observable dans tout le règne animal et notamment chez les poissons. Néanmoins, malgré un grand nombre d’études sur le sujet, les mécanismes de prises de décisions durant ces évènements collectifs sont encore mal compris.Dans cette thèse, nous avons cherché à mieux comprendre les déplacements collectifs en étudiant plus précisément les prises de décision, l’organisation et la cohésion de groupe de poissons sociaux. Nos travaux utilisent le poisson-zèbre (Danio rerio), qui est un modèle d’étude dans différents domaines de recherche. Pour analyser la cohésion au sein de groupes de différentes tailles ainsi que l’organisation du leadership, nous avons développé un environnement contraint spécifique composé de deux chambres reliées par un couloir. Le comportement collectif des poissons-zèbres en environnement contraint a ensuite été décrit dans un modèle stochastique multicontextuel. Nous avons également développé un agent robotique afin de déterminer l'importance de l’aspect et du comportement pour s'intégrer de manière autonome au sein d'un groupe de poissons. Enfin, après son intégration au groupe, nous avons utilisé ce robot poisson biomimétique et autonome pour tester nos hypothèses sur les différentes règles à l’œuvre dans les mouvements collectifs en influant sur les mouvements du groupe de poisson.Nous sommes parvenus aux résultats suivants. Dans un environnement contraint, les poissons utilisent les chambres comme zones de repos et transitent fréquemment d'une zone à l'autre. Nous avons observé que la taille des groupes de poissons a une influence sur la forme et la proportion de ces transitions. La taille des groupes modifie également la cohésion entre les individus et leur utilisation de l’espace. Nous avons étudié plus précisément les prises de décision lors des transitions, et tout particulièrement le fonctionnement du leadership. Nous avons fait apparaître que le leadership est partagé entre tous les individus d’un groupe, avec néanmoins des modalités de partage hétérogènes entre les différents groupes étudiés. Le modèle stochastique développé à partir de ces différents résultats simule correctement le comportement de groupe de poisson dans un environnement contraint, en utilisant des valeurs de paramètre différentes en fonction de la position de l'agent. Nous avons réussi à intégrer un robot poisson, autonome et biomimétique, au sein de groupe de poisson-zèbre. L'utilisation du modèle stochastique pour guider le robot a mis en évidence l'importance d'un comportement biomimétique dans le phénomène de reconnaissance d'un conspécifique. Enfin, nous avons modulé le comportement du poisson-zèbre avec le robot poisson en provoquant des départs collectifs ainsi qu'en biaisant de manière significative la répartition des poissons entre les deux salles. Ces succès nous permettent de valider les hypothèses émises sur le leadership et la cohésion chez les poissons sociauxCollective movement can be observed throughout the animal kingdom, particularly in fish. Yet, despite many studies on the subject, the decision-making mechanisms of these collective events remain poorly understood.In this thesis, we want to better understand collective movement by studying more precisely the decision-making process, the organisation and the cohesion of groups of social fish. Our study focuses on the zebrafish (Danio rerio), a model used in different areas of research. To highlight those behaviours, we have developed a specific constrained environment composed of two rooms connected by a corridor. Cohesion on groups of different sizes and the organisation of leadership have been examined. The collective behaviour of zebrafish in a constrained environment was then described throughout a multi-contextual stochastic model. We have also developed a robotic agent to determine the importance of aspect and behaviour in conspecific recognition. Finally, after its integration into the group, we influenced the movements of the fish group with this biomimetic and autonomous fish robot to test our hypotheses on the different rules underlying collective movements.We have achieved the following results. In a constrained environment, fish use the rooms as resting areas and frequently move from one area to another. We observed that the size of fish groups influences the structure and proportion of these transitions. Group size also changes the cohesion between individuals and their spatial distribution. We studied more precisely the decision-making process during transitions, and in particular the mechanics of leadership. We have shown that leadership is shared among all individuals in a group, with heterogeneous sharing modalities between the different groups studied. The stochastic model developed from these results correctly simulates fish group behaviour in a constrained environment, using different parameter values according to the position of the agent. We have succeeded in integrating an autonomous and biomimetic fish robot into a group of zebrafish. The use of the stochastic model to drive the robot has highlighted the importance of biomimetic behaviour in the process of recognising a conspecific. Finally, we modulated the behaviour of the zebrafish with the fish robot by inducing collective departures as well as significantly biasing the distribution of fish between the two rooms. These positive results allow us to validate the hypotheses about leadership and cohesion among social fish
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Milionis, Georgios. „A framework for collaborative Quadrotor - ground robot missions“. Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/10654.
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The thesis proposes a real-time control algorithm for the cooperation of a joint team consisting of a Quadrotor and a Ground robot for coordinated ISR missions. The intended application focuses on indoor environments, where Global Positioning System signals are unreliable or simply unavailable so that the control algorithms must rely on local sensor information. The thesis describes the appropriate set up of the lab and includes simulations using a full dynamic model of the quadrotor and robot, demonstrating the suitability of the implemented and the proposed control scheme into a waypoint navigation scenario. The implemented controller uses the Linear Quadratic Regulator method imposed into five different channels; pitch, roll, yaw, x-y position and height, configured to the appropriate gains for smoother following of the trajectory. The proposed control scheme incorporates three key aspects of autonomy; trajectory planning, trajectory following and collaboration of the two vehicles. Using the differentially-flat dynamics property of the system, the trajectory optimization is posed as a non-linear constrained optimization within the output space in the virtual domain, not explicitly related to the time domain. A suitable parameterization using a virtual argument as opposed to time is applied, which ensures initial and terminal constraint satisfaction. The speed profile is optimized independently, followed by the mapping to the time domain achieved using a speed factor.
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Kira, Zsolt. „Communication and alignment of grounded symbolic knowledge among heterogeneous robots“. Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33941.
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Experience forms the basis of learning. It is crucial in the development of human intelligence, and more broadly allows an agent to discover and learn about the world around it. Although experience is fundamental to learning, it is costly and time-consuming to obtain. In order to speed this process up, humans in particular have developed communication abilities so that ideas and knowledge can be shared without requiring first-hand experience.
Consider the same need for knowledge sharing among robots. Based on the recent growth of the field, it is reasonable to assume that in the near future there will be a collection of robots learning to perform tasks and gaining their own experiences in the world. In order to speed this learning up, it would be beneficial for the various robots to share their knowledge with each other. In most cases, however, the communication of knowledge among humans relies on the existence of similar sensory and motor capabilities. Robots, on the other hand, widely vary in perceptual and motor apparatus, ranging from simple light sensors to sophisticated laser and vision sensing.
This dissertation defines the problem of how heterogeneous robots with widely different capabilities can share experiences gained in the world in order to speed up learning. The work focus specifically on differences in sensing and perception, which can be used both for perceptual categorization tasks as well as determining actions based on environmental features. Motivating the problem, experiments first demonstrate that heterogeneity does indeed pose a problem during the transfer of object models from one robot to another. This is true even when using state of the art object recognition algorithms that use SIFT features, designed to be unique and reproducible.
It is then shown that the abstraction of raw sensory data into intermediate categories for multiple object features (such as color, texture, shape, etc.), represented as Gaussian Mixture Models, can alleviate some of these issues and facilitate effective knowledge transfer. Object representation, heterogeneity, and knowledge transfer is framed within Gärdenfors' conceptual spaces, or geometric spaces that utilize similarity measures as the basis of categorization. This representation is used to model object properties (e.g. color or texture) and concepts (object categories and specific objects).
A framework is then proposed to allow heterogeneous robots to build models of their differences with respect to the intermediate representation using joint interaction in the environment. Confusion matrices are used to map property pairs between two heterogeneous robots, and an information-theoretic metric is proposed to model information loss when going from one robot's representation to another. We demonstrate that these metrics allow for cognizant failure, where the robots can ascertain if concepts can or cannot be shared, given their respective capabilities.
After this period of joint interaction, the learned models are used to facilitate communication and knowledge transfer in a manner that is sensitive to the robots' differences. It is shown that heterogeneous robots are able to learn accurate models of their similarities and difference, and to use these models to transfer learned concepts from one robot to another in order to bootstrap the learning of the receiving robot. In addition, several types of communication tasks are used in the experiments. For example, how can a robot communicate a distinguishing property of an object to help another robot differentiate it from its surroundings? Throughout the dissertation, the claims will be validated through both simulation and real-robot experiments.
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Sjöö, Kristoffer. „Functional understanding of space : Representing spatial knowledge using concepts grounded in an agent's purpose“. Doctoral thesis, KTH, Datorseende och robotik, CVAP, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-48400.
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This thesis examines the role of function in representations of space by robots - that is, dealing directly and explicitly with those aspects of space and objects in space that serve some purpose for the robot. It is suggested that taking function into account helps increase the generality and robustness of solutions in an unpredictable and complex world, and the suggestion is affirmed by several instantiations of functionally conceived spatial models. These include perceptual models for the "on" and "in" relations based on support and containment; context-sensitive segmentation of 2-D maps into regions distinguished by functional criteria; and, learned predictive models of the causal relationships between objects in physics simulation. Practical application of these models is also demonstrated in the context of object search on a mobile robotic platform.QC 20111125
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Hung, David, Cinthya Tang, Coby Allred, Kennon McKeever, James Murphy und Ricky Herriman. „AUTONOMOUS GROUND RECONNAISSANCE DRONE USING ROBOT OPERATING SYSTEM (ROS)“. International Foundation for Telemetering, 2017. http://hdl.handle.net/10150/627005.
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The Arizona Autonomous Club is a student organization at the University of Arizona which designs, builds, and competes with Unmanned Air Systems (UAS). This year, a 25% scale Xtreme Decathlon model aircraft was selected and successfully converted into a fully autonomous UAS for the AUVSI Student Unmanned Aerial Systems (SUAS) 2017 competition. The UAS utilizes a Pixhawk autopilot unit, which is an independent, open-hardware project aiming at providing high-end autopilot hardware at low costs and high availability. The Pixhawk runs an efficient real time operating system (RTOS) and includes sensors such as a GPS unit, IMUs, airspeed, etc. The UAS also includes an onboard imaging system, which is controlled by an onboard computer (OBC). The Pixhawk and OBC are interconnected with two ground control stations (GCS) using the Robot Operating System (ROS) framework, which is capable of extending overall system capabilities to include an expanded telemetry downlink, obstacle avoidance, and manual overrides.
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Winston, Crystal(Crystal E. ). „A Multi-modal Robot for Ground and Aerial Locomotion“. Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123246.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 39-40).
This thesis describes the design and testing of a quadcopter that capable of both driving and flying. This was achieved by mounting quadcopter motors and propellers to the center of each of the robot's four wheels. The wheels are then capable of changing orientation in order to allow the robot to either drive or fly. Each of these wheels contains a gearing and bearing system that decouples the rotation of the wheels from the rotation of the propellers and also houses the system's landing gear. The prototype described in this thesis is capable of driving on flat surfaces as well as vertical take-off and landing. Further improvements to the system would be required in order for it to perform longer flights, complex aerial maneuvers, drive on uneven surfaces, or carry additional payloads.
by Crystal Winston.
S.B.
S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Islas, Ramírez Omar Adair. „Learning Robot Interactive Behaviors in Presence of Humans and Groups of Humans“. Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066632/document.
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Au fil des dernières années les robots ont fait partie de notre quotidien. Même si nous ne les voyons pas, nous dépendons d'eux pour construire nos ordinateurs, téléphones mobiles, voitures, etcetera. Les robots sont utilisés aussi pour l'organisation des produits dans les usines. Un autre domaine de croissance est la robotique sociale. Nous pouvons voir des études tel que des robots d'aide aux enfants autistes. Il y a aussi des robots qui sont utilisés pour accueillir des personnes dans des hôtels ou dans centres commerciaux pour interagir avec les gens. Ainsi, le robot doit comprendre le comportement des personnes. Et, pour les robots mobiles, il faut savoir comment naviguer dans l'environnement humain. En ce qui concerne les environnements humains, ce travail explore la navigation acceptable socialement des robots en direction de personnes. Pour donner un exemple, quand un robot s'approche d'une personne, il ne doit pas traiter la personne comme un obstacle. Car si cette dernière est traitée comme un obstacle, le robot s'approcherait d'elle sans prendre en compte son espace personnel, ce qui la gênerait. Une personne est une entité qui doit être pris en compte sur la base des normes sociales que nous (en tant que personnes) utilisons tous les jours. Dans cette thèse, nous explorons comment un robot s'approche d'une personne. Celle-ci peut-être gênée si quelque chose ou quelqu'un envahit son espace personnel. La personne se sentira aussi menacée si elle est approchée par derrière. Ces normes sociales doivent être respectées par le robot. C'est pour cela que nous modélisons le comportement du robot à travers des algorithmes d'apprentissage. Nous faisons approcher (manuellement) un robot d'un personne plusieurs fois et le robot apprend à reproduire ce comportement. Un autre travail de cette thèse est la compréhension d'un groupe de personnes. Nous, en tant que humains, avons la capacité de le faire intuitivement. Toutefois, un robot nécessite impérativement un modèle mathématique. Enfin, nous abordons le sujet d'un robot qui s'approche d'un groupe de personnes. Nous utilisons des démonstrations pour faire apprendre le robot. Nous évaluons le bon déroulement du comportement du robot comme par exemple, en observant combien de fois le robot envahit l'espace personnel des personnes pendant la navigationIn the past years, robots have been a part of our every day lives. Even when we do not see them, we depend on them to build our computers, mobile phones, cars and more. They are also been used for organizing stocks in warehouses. And, with the growth of autonomous cars, we see them driving autonomously on highways and cities. Another area of growth is social robotics. We can see a lot of studies such as robots helping children with autism. Other robots are being used to receive people in hotels or to interact with people in shopping centers. In the latter examples, robots need to understand people behavior. In addition, in the case of mobile robots, they need to know how to navigate in human environments. In the context of human environments, this thesis explores socially acceptable navigation of robots towards people. To give an example, when a robot approaches one person, the robot shall by no means treat people as an obstacle because the robot get really close to the human and interfere with her personal space. The human is an entity that needs to be considered based on social norms that we (humans) use on a daily basis. In a first time, we explore how a robot can approach one person. A person is an entity that can be bothered if someone or something approaches invading her personal space. The person also will feel distressed when she is approached from behind. These social norms have to be respected by the robot. For this reason, we decided to model the behavior of the robot through learning algorithms. We manually approach a robot to a person several times and the robot learns how to reproduce this behavior. In a second time, we present how a robot can understand what is a group of people. We, humans, have the ability to do this intuitively. However, for a robot, a mathematical model is essential. Lastly, we address how a robot can approach a group of people. We use exemplary demonstrations to teach this behavior to the robot. We evaluate then the robot's movements by for example, observing if the robot invades people's personal space during the trajectory
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Islas, Ramírez Omar Adair. „Learning Robot Interactive Behaviors in Presence of Humans and Groups of Humans“. Electronic Thesis or Diss., Paris 6, 2016. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2016PA066632.pdf.
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Au fil des dernières années les robots ont fait partie de notre quotidien. Même si nous ne les voyons pas, nous dépendons d'eux pour construire nos ordinateurs, téléphones mobiles, voitures, etcetera. Les robots sont utilisés aussi pour l'organisation des produits dans les usines. Un autre domaine de croissance est la robotique sociale. Nous pouvons voir des études tel que des robots d'aide aux enfants autistes. Il y a aussi des robots qui sont utilisés pour accueillir des personnes dans des hôtels ou dans centres commerciaux pour interagir avec les gens. Ainsi, le robot doit comprendre le comportement des personnes. Et, pour les robots mobiles, il faut savoir comment naviguer dans l'environnement humain. En ce qui concerne les environnements humains, ce travail explore la navigation acceptable socialement des robots en direction de personnes. Pour donner un exemple, quand un robot s'approche d'une personne, il ne doit pas traiter la personne comme un obstacle. Car si cette dernière est traitée comme un obstacle, le robot s'approcherait d'elle sans prendre en compte son espace personnel, ce qui la gênerait. Une personne est une entité qui doit être pris en compte sur la base des normes sociales que nous (en tant que personnes) utilisons tous les jours. Dans cette thèse, nous explorons comment un robot s'approche d'une personne. Celle-ci peut-être gênée si quelque chose ou quelqu'un envahit son espace personnel. La personne se sentira aussi menacée si elle est approchée par derrière. Ces normes sociales doivent être respectées par le robot. C'est pour cela que nous modélisons le comportement du robot à travers des algorithmes d'apprentissage. Nous faisons approcher (manuellement) un robot d'un personne plusieurs fois et le robot apprend à reproduire ce comportement. Un autre travail de cette thèse est la compréhension d'un groupe de personnes. Nous, en tant que humains, avons la capacité de le faire intuitivement. Toutefois, un robot nécessite impérativement un modèle mathématique. Enfin, nous abordons le sujet d'un robot qui s'approche d'un groupe de personnes. Nous utilisons des démonstrations pour faire apprendre le robot. Nous évaluons le bon déroulement du comportement du robot comme par exemple, en observant combien de fois le robot envahit l'espace personnel des personnes pendant la navigationIn the past years, robots have been a part of our every day lives. Even when we do not see them, we depend on them to build our computers, mobile phones, cars and more. They are also been used for organizing stocks in warehouses. And, with the growth of autonomous cars, we see them driving autonomously on highways and cities. Another area of growth is social robotics. We can see a lot of studies such as robots helping children with autism. Other robots are being used to receive people in hotels or to interact with people in shopping centers. In the latter examples, robots need to understand people behavior. In addition, in the case of mobile robots, they need to know how to navigate in human environments. In the context of human environments, this thesis explores socially acceptable navigation of robots towards people. To give an example, when a robot approaches one person, the robot shall by no means treat people as an obstacle because the robot get really close to the human and interfere with her personal space. The human is an entity that needs to be considered based on social norms that we (humans) use on a daily basis. In a first time, we explore how a robot can approach one person. A person is an entity that can be bothered if someone or something approaches invading her personal space. The person also will feel distressed when she is approached from behind. These social norms have to be respected by the robot. For this reason, we decided to model the behavior of the robot through learning algorithms. We manually approach a robot to a person several times and the robot learns how to reproduce this behavior. In a second time, we present how a robot can understand what is a group of people. We, humans, have the ability to do this intuitively. However, for a robot, a mathematical model is essential. Lastly, we address how a robot can approach a group of people. We use exemplary demonstrations to teach this behavior to the robot. We evaluate then the robot's movements by for example, observing if the robot invades people's personal space during the trajectory
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Couch, Michael Robert. „Pneumatic Particulate Collection System for an Unmanned Ground Sampling Robot“. Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/35913.
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The design of unmanned material collection systems requires a great deal of foresight and innovative design on the engineerâ s part in order to produce solutions to problems operators may encounter in the field. In this thesis, the development of a particulate collection system for use onboard a lightweight, helicopter deployable ground robot is presented.
The Unmanned Systems Laboratory at Virginia Tech is developing a ground sampling robot to be carried in the payload pod of a Yamaha RMAX unmanned aerial vehicle. The robotâ s ultimate objective is to collect material samples from a hazardous environment. The pneumatic system presented here is a novel design developed to collect particulate without draining the resources of the robot. Vacuum samplers have been developed in the past, but they are large and cumbersome and require large amounts of electrical energy to operate. The pneumatic particulate collection system utilizes the kinetic energy from the release of compressed air to transport the particulate to a collection chamber.
Consideration is given to the drop in pressure of the air supply tank as it empties, and a feasible air supply tank design is presented. Two forms of particulate collection are investigated experimentally: jet impingement and particle entrainment (i.e. steep attack angle and parallel flow). Turbulent, free jet characteristics and critical velocities of particles are studied. Ultimately, a final design is presented that effectively collects particulate material from the top 5/8â layer of both thick and thin particle beds.Master of Science
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Ferrin, Jeffrey L. „Autonomous Goal-Based Mapping and Navigation Using a Ground Robot“. BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6190.
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Ground robotic vehicles are used in many different applications. Many of these uses include tele-operation of the robot. This allows the robot to be deployed in locations that are too difficult or are unsafe for human access. The ability of a ground robot to autonomously navigate to a desired location without a-priori map information and without using GPS would allow robotic vehicles to be used in many of these situations and would free the operator to focus on other more important tasks. The purpose of this research is to develop algorithms that enable a ground robot to autonomously navigate to a user-selected location. The goal is selected from a video feed from the robot and the robot drives to the goal location while avoiding obstacles. The method uses a monocular camera for measuring the locations of the goal and landmarks. The method is validated in simulation and through experiments on an iRobot Packbot platform. A novel goal-based robocentric mapping algorithm is derived in Chapter 3. This map is created using an extended Kalman filter (EKF) by tracking the position of the goal along with other available landmarks surrounding the robot as it drives towards the goal. The mapping is robocentric, meaning that the map is a local map created in the robot-body frame. A unique state definition of the goal states and additional landmarks is presented that improves the estimate of the goal location. An improved 3D model is derived and used to allow the robot to drive on non-flat terrain while calculating the position of the goal and other landmarks. The observability and consistency of the proposed method are shown in Chapter 4. The visual tracking algorithm is explained in Chapter 5. This tracker is used with the EKF to improve tracking performance and to allow the objects to be tracked even after leaving the camera field of view for significant periods of time. This problem presents a difficult challenge for visual tracking because of the drastic change in size of the goal object as the robot approaches the goal. The tracking method is validated through experiments in real-world scenarios. The method of planning and control is derived in Chapter 6. A Model Predictive Control (MPC) formulation is designed that explicitly handles the sensor constraints of a monocular camera that is rigidly mounted to the vehicle. The MPC uses an observability-based cost function to drive the robot along a path that minimizes the position error of the goal in the robot-body frame. The MPC algorithm also avoids obstacles while driving to the goal. The conditions are explained that guarantee the robot will arrive within some specified distance of the goal. The entire system is implemented on an iRobot Packbot and experiments are conducted and presented in Chapter 7. The methods described in this work are shown to work on actual hardware allowing the robot to arrive at a user-selected goal in real-world scenarios.
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Mirhassani, Seyedmohsen <1989>. „A Ground Robot for Search And Rescue in Hostile Environment“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8416/7/Mirhassani_final.pdf.
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The recent sheer developments in the field of robotics has encouraged the researcher to consider the robots assisting human in different aspects of life. In this context, search and rescue is a very interesting ambient where the capabilities offered by the robots can be used to not only augment the quality of service but also impose lower risk to the human members of the rescue team. To this purpose, project SHERPA has been defined to investigate an intelligent heterogeneous robotic team in a search and rescue mission.
The robotic team includes flying robots such as fixed wing and quad copters for the purpose of patrolling and surveillance and a ground rover that is mainly considered to provide a mobile power replenishment service for the quadrotors.
Navigation of the ground rover on the unstructured outdoor environment defined by the SHERPA is of the main focuses of this thesis. Due to roughness of the terrain, there are a lot of issues on the way of a successful localization. Moreover, the planning has to be compatible with the robot and environment constraints to avoid imposing a risk of mechanical damage to the system.
To accomplish the battery exchange operation, the rover is equipped with two auxiliary devices namely "Sherpa box" and "Sherpa robotic arm". In this thesis, firstly, designs of the two devices are introduced to the reader in details. Secondly, their integration with the ground rover will be covered.
Finally two important benchmarks of the SHERPA project, namely "human leashing" and "battery exchange operation", will be addressed.
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Ho, Sze-Tek Terence. „Investigating ground swarm robotics using agent based simulation“. Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FHo.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, December 2006.Thesis Advisor(s): Susan M. Sanchez. "December 2006." Includes bibliographical references (p.111-114). Also available in print.
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Rivard, Frédéric. „Localisation relative de robots mobiles opérant en groupe“. Mémoire, Université de Sherbrooke, 2005. http://savoirs.usherbrooke.ca/handle/11143/1294.
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Il y a plusieurs avantages à faire travailler des robots mobiles en groupe. Par exemple, un groupe de robots peut diviser une tâche en plusieurs sous-tâches à être effectuées individuellement par des membres du groupe. Lorsque les membres sont capables de se localiser les uns les autres, l'efficacité du groupe en est grandement augmentée. À cette fin, l'objectif du projet est de poursuivre le développement d'un système ultrasonique de localisation relative, système dénommé LAMP. Un premier prototype (LAMP-1) a été développé en 2002, mais sa fonctionnalité avec un groupe de robots n'avait pas été validée. De plus, certains problèmes d'interférence avec le système de détection d'obstacles des robots avaient été observés. Des modifications ont été apportées au système afin d'éliminer ces problèmes tout en conservant les capacités du système. La fréquence d'opération est passée de 40 kHz à 25.7 kHz et un filtre passe-bande a été ajouté afin d'éliminer les fausses détections. Une étude de différents paramètres concernant les réflecteurs utilisés pour rendre le système omnidirectionnel a aussi été effectuée. Le nouveau système (LAMP-2) affiche maintenant une portée de 6,7 m avec une erreur absolue moyenne de 8.03 mm sur la distance et de 3.07À sur l'angle. Sa période d'opération est de 300 ms pour un groupe de quatre robots. Le système LAMP-2 consomme 1.73 W et coûte environ 350 $ à fabriquer. Le système LAMP-2 a été utilisé avec succès pour contrôler des formations de quatre robots et améliore substantiellement les performances du groupe par rapport à celles obtenues lorsque la localisation des robots se fait par détection visuelle de couleur. LAMP-2 a aussi démontré qu'il peut être utilisé dans une combinaison humain-robot en équipant un humain d'un émetteur et en le faisant suivre par trois robots. Le système LAMP-2 peut être transformé en un système de positionnement absolu en plaçant un émetteur fixe dans l'environnement. Les possibilités d'utilisation très variées rendent donc le système LAMP-2 très intéressant pour différentes applications en robotique mobile.
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Rivard, Frédéric. „Localisation relative de robots mobiles opérant en groupe“. [S.l. : s.n.], 2005.
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Damers, Julien. „Lie groups applied to localisation of mobile robots“. Electronic Thesis or Diss., Brest, École nationale supérieure de techniques avancées Bretagne, 2022. http://www.theses.fr/2022ENTA0007.
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Dans le cadre du développement des énergies renouvelables, les activités offshores liées aux parcs éoliens ont grandement augmenté en nombre. Ainsi les coûts de maintenance et de surveillance de telles structures aussi bien en hommes qu'en moyens se sont accrus et cette tendance s'amplifiera sûrement au cours des prochaines années. Ceci a encouragé le développement des véhicules sous-marins autonomes (AUV). Ceux-ci sont encore très coûteux du fait des capteurs onéreux qu'ils embarquent. Ils sont donc encore rares, ce qui ne suffit pas à combler les actuels besoins. Ainsi le développement d'AUVs à bas-coût est un sujet de recherche en forte croissance. C'est dans ce champ de recherche que cette thèse vient s'inscrire. Un des problèmes principaux rencontré en robotique sous-marine est la localisation de l'engin. C'est la résolution de celui-ci qui nous servira d’objectif tout au long de ce travail. Pour ce faire, une nouvelle méthode d'intégration garantie, robuste aux incertitudes sur les conditions initiales est présentées dans ce manuscrit. Celle-ci se base sur l'utilisation des symétries de Lie appliquées aux équations différentielles. Nous la présenterons en premier lieu sur un problème théorique simple avant de l’appliquer sur le problème de localisation d’un robot sous-marinWith the development of offshore activities, the costs of maintenance and monitoring of offshore plants in terms of crew members, boats, and money have greatly increased and are still growing dramatically. This encouraged the development of autonomous underwater vehicles (AUV). These are still very expensive because of the numerous high-end sensors they need to embark on to accomplish their missions. Thus their number is relatively low. Therefore research is made to develop low-cost AUVs that could be produced in a larger amount to perform the same missions. This thesis comes within the scope of this research field. One of the main problems when dealing with AUVs is the localisation of the vehicle which will be the one addressed throughout this work. To tackle it, we present a new guaranteed integration method, which is more robust to the uncertainties on the initial condition than the ones currently available, based on Lie symmetries. This method is first presented through different simple theoretical examples. We then apply it to a localisation problem in a robotic context
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Visell, Yon. „Walking on virtual ground: physics, perception, and interface design“. Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103551.
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The sensorimotor capacities of the foot are crucial to human locomotion in diverse environments, to gathering information about walking surfaces, and to interacting with objects on the ground. Locomotion is increasingly employed to allow users to control and navigate within immersive virtual environments, but, in contrast to the hand, little attention has been given to the rendering of haptic sensations for the feet. This thesis addresses several challenges motivated by the problem of realizing haptic experiences of walking on virtual ground surfaces. First, a novel family of interfaces is introduced, based on a vibrotactile display integrated in a rigid floor plate. Its structural dynamics and controller have been optimized to ensure its ability to accurately reproduce mechanical vibrations over a wide frequency band, which was instrumental to realizing the perceptual study presented in the second part of the thesis. Distributed arrays of these devices are used to simulate virtual ground surfaces and floor-based multi-touch surfaces, whose usability for human-computer interaction is empirically demonstrated. The second component of this thesis is an experimental study of the contribution of vibrotactile sensory information to the perception of ground surface compliance. A novel haptic perceptual illusion is demonstrated, in which the apparent compliance of a floor surface is increased by vibrations felt via the plantar sole of the foot. This investigation also revealed the surprising ability of the vibrotactile floor interface to overcome, in part, a core limitation: its inability to display kinesthetic force-displacement information. The third part of the thesis analyzes texture-like mechanical signals produced through inelastic physical processes in complex, disordered materials like those encountered during walking in many natural terrains. Patterns of fluctuations accompanying sliding friction and fracture processes in quasi-brittle, heterogeneous materials subjected to time-varying loads are characterized using methods from statistical physics. This analysis was used to formulate novel algorithms for the haptic synthesis of high-frequency signatures of fracture processes in fiber composites and compressed granular media. In conclusion, this thesis presents an innovative hardware interface and techniques for interacting with virtual ground surfaces. It also demonstrates a new haptic perceptual effect that lends justification to the display paradigm adopted here. Finally, it analyzes and models transient, texture-like physical phenomena associated with stepping onto complex, natural ground materials.Les capacités sensori-motrices du pied sont essentielles à la locomotion humaine, à la collecte d'informations sur les surfaces de marche, et à l'interaction avec des objets au sol. La locomotion est de plus en plus utilisée pour interagir et naviguer dans les environnements virtuels immersifs, mais, contrairement à la main, peu d'attention a été accordée au rendu des sensations haptiques pour les pieds. Cette thèse aborde plusieurs problèmes liés à la réalisation d'expériences haptiques de marche sur des terrains virtuels. Tout d'abord, une nouvelle famille d'interfaces est présentée, fondée sur un dispositif vibrotactile intégré dans un carreau rigide. Sa dynamique structurelle et son contrôleur ont été optimisés pour assurer sa capacité à reproduire fidèlement les vibrations mécaniques dans une large bande de fréquence, ce qui était nécessaire à la réalisation de l'étude de perception présentée en deuxième partie de la thèse. Un pavage de ces dispositifs est utilisé pour simuler des terrains virtuels et des planchers tactiles multi-points, dont l'ergonomie est démontrée de manière empirique. Le deuxième volet de cette thèse est une étude expérimentale sur la contribution de l'information vibrotactile à la perception de la compliance du sol. Une nouvelle illusion perceptuelle haptique est démontrée, dans laquelle la compliance apparente du sol est augmentée par les vibrations ressenties par la plante du pied. Cette étude a également révélé l'étonnante capacité de l'interface vibrotactile à surmonter, en partie, une limitation intrinsèque : son incapacité à transmettre des informations kinesthésiques force-déplacement. La troisième partie de la thèse analyse les signaux mécaniques complexes produits par les processus physiques inélastiques dans les matériaux désordonnés tels que ceux rencontrés lors de la marche en terrain naturel. Les modèles de fluctuations accompagnant le frottement de glissement et les processus de fracture dans les matériaux hétérogènes quasi-fragiles soumis aux charges variables sont caractérisés par des méthodes de physique statistique. Cette analyse est utilisée pour formuler de nouveaux algorithmes pour la synthèse haptique des signatures à hautes fréquences des processus de fracture dans les composites de fibres et les materiaux granulaires compressés. En conclusion, cette thèse présente un dispositif vibrotactile et des techniques novateurs pour interagir avec des terrains virtuels. Elle démontre un nouvel effet perceptuel qui justifie le paradigme d'interaction haptique adopté ici. Enfin, elle analyse et modélise certains phénomènes physiques associés à la marche sur des terrains naturels complexes.
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Black, William S. „Adaptive nonlinear control for autonomous ground vehicles“. Thesis, Purdue University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1553492.
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We present the background and motivation for ground vehicle autonomy, and focus on uses for space-exploration. Using a simple design example of an autonomous ground vehicle we derive the equations of motion. After providing the mathematical background for nonlinear systems and control we present two common methods for exactly linearizing nonlinear systems, feedback linearization and backstepping. We use these in combination with three adaptive control methods: model reference adaptive control, adaptive sliding mode control, and extremum-seeking model reference adaptive control. We show the performances of each combination through several simulation results. We then consider disturbances in the system, and design nonlinear disturbance observers for both single-input-single-output and multi-input-multi-output systems. Finally, we show the performance of these observers with simulation results.
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Hager, Daniel Michael. „Situational Awareness of a Ground Robot From an Unmanned Aerial Vehicle“. Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32825.
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In the operation of unmanned vehicles, safety is a primary concern. This thesis focuses on the use of computer vision in the development of a situational awareness system that allows for safe deployment and operation of a ground robot from an unmanned aerial vehicle (UAV). A method for detecting utility cables in 3D range images is presented. This technique finds areas of an image that represent edges in 3D space, and uses the Hough transform to find those edges that take the shape of lines, indicating potential utility cables. A mission plan for stereo image capture is laid out as well for overcoming some weaknesses of the stereo vision system; this helps ensure that all utility cables in a scene are detected. In addition, the system partitions the point cloud into best-fit planes and uses these planes to locate areas of the scene that are traversable by a ground robot. Each planeâ s slope is tested against an acceptable value for negotiation by the robot, and the drop-off between the plane and its neighbors is examined as well. With the results of this analysis, the system locates the largest traversable region of the terrain using concepts from graph theory. The system displays this region to the human operator with the drop-offs between planes clearly indicated. The position of the robot is also simulated in this system, and real-time feedback regarding dangerous moves is issued to the operator.
After a ground robot is deployed to the chosen site, the system must be capable of tracking it in real time as well. To this end, a software routine that uses ARToolkitâ s marker tracking capabilities is developed. This application computes the distance to the robot, as well as the horizontal distance from camera to the robot; this allows the flight controller to issue the proper commands to keep the robot centered underneath the UAV.Master of Science
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Sridhar, Srivatsan. „Cooperative Perception in Autonomous Ground Vehicles using a Mobile Robot Testbed“. Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/88742.
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With connected and autonomous vehicles, no optimal standard or framework currently exists, outlining the right level of information sharing for cooperative autonomous driving. Cooperative Perception is proposed among vehicles, where every vehicle is transformed into a moving sensor platform that is capable of sharing information collected using its on-board sensors. This helps extend the line of sight and field of view of autonomous vehicles, which otherwise suffer from blind spots and occlusions. This increase in situational awareness promotes safe driving over a short range and improves traffic flow efficiency over a long range.
This thesis proposes a methodology for cooperative perception for autonomous vehicles over a short range. The problem of cooperative perception is broken down into sub-tasks of cooperative relative localization and map merging. Cooperative relative localization is achieved using visual and inertial sensors, where a computer-vision based camera relative pose estimation technique, augmented with position information, is used to provide a pose-fix that is subsequently updated by dead reckoning using an inertial sensor. Prior to map merging, a technique for object localization using a monocular camera is proposed that is based on the Inverse Perspective Mapping technique. A mobile multi-robot testbed was developed to emulate autonomous vehicles and the proposed method was implemented on the testbed to detect pedestrians and also to respond to the perceived hazard. Potential traffic scenarios where cooperative perception could prove crucial were tested and the results are presented in this thesis.MS
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Davis, Ronald J. „EVOLUTIONARY GROUND REACTION FORCE CONTROL OF A PROSTHETIC LEG TESTING ROBOT“. Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1396786747.
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Quaiyum, Labiba. „Model Reference Adaptive Backstepping Control of an Autonomous Ground Vehicle“. Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/64509.
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With an increased push for commercial autonomous cars, the demand of high speed systems capable of performing in unstructured driving environments is growing. In this thesis, the behavior of a bio-inspired predator prey model is considered to stimulate a more organic response to obstacles and a moving target than existing algorithms. However, the current predator prey model has a disconnect between the desired velocities commanded and the torque signals provided to the motors due the dynamics of the vehicle not accounted for. This causes the vehicle to derail from its intended trajectory at sharp turns.
In this study, we start by adding dynamic behavior to the unicycle model to account for the varying dynamics of the vehicle. A backstepping algorithm is developed to connect the predator-prey model commanding desired velocities to an appropriate torque controller for the motors of the vehicle. To account for the unknown dynamic model parameters an adaptive control approach is utilized. Three different controllers are developed and evaluated.
Out of the three, the indirect MRAC backstepping controller is deemed unsuitable due to its limitations with handling unknown parameter structure. The direct MRAC backstepping is deemed suitable and therefore simulated and implemented on the vehicle. The newly derived controller is able to overcome the disconnect and allow the vehicle to optimally track its trajectory for a velocity range of 1 m/s to 9 m/s despite varying dynamics. Lastly, the L1 adaptive backstepping controller is introduced and simulated to provide an alternative, more robust solution to the direct MRAC backstepping controller.Master of Science
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Mirza, Naeem Assif. „Grounded sensorimotor interaction histories for ontogenetic development in robots“. Thesis, University of Hertfordshire, 2008. http://hdl.handle.net/2299/2551.
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This thesis puts forward a computational framework that can be used by embodied artificial agents (and in particular autonomous robots) for ontogenetic development. The research investigates methods, endowed with which, an embodied agent can develop control structures for increasingly complex and better adapted behaviour, explicitly and incrementally from its history of interaction with its environment. The temporal horizon of an agent is extended so that past experience can be self-organized into a developing structure that can be used to anticipate the future and act appropriately in environments where state information is incomplete, such as a social environment. A formal definition of sensorimotor experience is given, and Crutchfield’s information metric is used as the basis for comparison of experiences. Information metrics are demonstrated to be able to characterize and identify time-extended behaviour. A definition of a metric space of experiences is followed by the introduction of an architecture that combines this with environmental reinforcement as the basis for a system for robot ontogeny. The architecture is demonstrated and tested in various robotic and simulation experiments. This thesis also introduces the early communication game “Peekaboo” as a tool for the study of human-robot interaction and development. The interaction history architecture is then used by two different robots to develop the capability to engage in the peekaboo game.
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El, Kamel Mohamed Anouar. „Stabilisation et régulation de robots mobiles opérant en groupe“. Phd thesis, Université d'Evry-Val d'Essonne, 2012. http://tel.archives-ouvertes.fr/tel-00876452.
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Pour les systèmes de commande sous la forme de dx/dt = f (x, u), dans la littérature, les chercheurs s'intéressaient à la stabilisation de ce système de différentes manières : asymptotique, uniformément asymptotique, partielle, en temps fini, etc. Pour aboutir à ces résultats, les méthodes utilisées font appel aux techniques suivantes : Lyapunov, Lasalle, Barbalat, surface glissante, etc. Dans cette thèse, nous nous sommes intéressés à une autre fonctionnalité de la commande, dite commande répulsive stabilisante. Les résultats ont été généralisés au cas d'un système avec dérive et sans dérive. Comme résultat, l'approche de commande qu'on propose assure la stabilité du système autour d'une position désirée et la répulsion de celui-ci par rapport à un ensemble indésirable, construit dans l'espace de navigation. Toute forme d'application sera concernée par nos résultats théoriques, on peut citer, la navigation terrestre et aérienne dans un environnement peu ou pas connu. De même, la commande qu'on propose préserve la communication inter-agent, une fois planifiées. En terme d'application, on a considéré le modèle d'un véhicule à roues type unicycle, sans tenir compte de l'orientation (cas non holonôme) et dans le cas où l'environnement contient un ou plusieurs obstacle(s). Contrairement aux résultats de la littérature, qui sont basés sur une commande à structure variable pour l'évitement d'un obstacle, la commande répulsive-stabilisante trouvée est une commande continue sur l'espace de navigation. La deuxième partie de cette thèse traite le problème de stabilité d'une formation d'agents (système multi-véhicules) qui évolue dans un environnement hostile tout en préservant la communication entre les agents. Pour réussir la formation, la décentralisation de la commande par rapport aux agents est rendue robuste à travers des graphes de communication. Ces graphes relèvent de la stratégie et objectifs de la formation. Nos résultats de stabilité ont fait l'objet d'une implémentation rigoureuse sur un simulateur réalisé sous Matlab.