2,777 research outputs found

    Full Automation of Air Traffic Management in High Complexity Airspace

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    The thesis is that automation of en-route Air Traffic Management in high complexity airspace can be achieved with a combination of automated tactic planning in a look-ahead time horizon of up to two hours complemented with automated tactic conflict resolution functions. The literature review reveals that no significant results have yet been obtained and that full automation could be approached with a complementary integration of automated tactic resolutions AND planning. The focus shifts to ‘planning for capacity’ and ‘planning for resolution’ and also – but not only – for ‘resolution’. The work encompasses a theoretical part on planning, and several small scale studies of empirical, mathematical or simulated nature. The theoretical part of the thesis on planning under uncertainties attempts to conceive a theoretical model which abstracts specificities of planning in Air Traffic Management into a generic planning model. The resulting abstract model treats entities like the planner, the strategy, the plan and the actions, always considering the impact of uncertainties. The work innovates in specifying many links from the theory to the application in planning of air traffic management, and especially the new fields of tactical capacity management. The second main part of the thesis comprises smaller self-containing works on different aspects of the concept grouped into a section on complexity, another on tactic planning actions, and the last on planners. The produced studies are about empirical measures of conflicts and conflict densities to get a better understanding of the complexity of air traffic; studies on traffic organisation using tactical manoeuvres like speed control, lateral offset and tactical direct using fast time simulation; and studies on airspace design like sector optimisation, dynamic sectorisation and its optimisation using optimisation techniques. In conclusion it is believed that this work will contribute to further automation attempts especially by its innovative focus which is on planning, base on a theory of planning, and its findings already influence newer developments

    Coordinated Robot Navigation via Hierarchical Clustering

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    We introduce the use of hierarchical clustering for relaxed, deterministic coordination and control of multiple robots. Traditionally an unsupervised learning method, hierarchical clustering offers a formalism for identifying and representing spatially cohesive and segregated robot groups at different resolutions by relating the continuous space of configurations to the combinatorial space of trees. We formalize and exploit this relation, developing computationally effective reactive algorithms for navigating through the combinatorial space in concert with geometric realizations for a particular choice of hierarchical clustering method. These constructions yield computationally effective vector field planners for both hierarchically invariant as well as transitional navigation in the configuration space. We apply these methods to the centralized coordination and control of nn perfectly sensed and actuated Euclidean spheres in a dd-dimensional ambient space (for arbitrary nn and dd). Given a desired configuration supporting a desired hierarchy, we construct a hybrid controller which is quadratic in nn and algebraic in dd and prove that its execution brings all but a measure zero set of initial configurations to the desired goal with the guarantee of no collisions along the way.Comment: 29 pages, 13 figures, 8 tables, extended version of a paper in preparation for submission to a journa

    Toward Robots with Peripersonal Space Representation for Adaptive Behaviors

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    The abilities to adapt and act autonomously in an unstructured and human-oriented environment are necessarily vital for the next generation of robots, which aim to safely cooperate with humans. While this adaptability is natural and feasible for humans, it is still very complex and challenging for robots. Observations and findings from psychology and neuroscience in respect to the development of the human sensorimotor system can inform the development of novel approaches to adaptive robotics. Among these is the formation of the representation of space closely surrounding the body, the Peripersonal Space (PPS) , from multisensory sources like vision, hearing, touch and proprioception, which helps to facilitate human activities within their surroundings. Taking inspiration from the virtual safety margin formed by the PPS representation in humans, this thesis first constructs an equivalent model of the safety zone for each body part of the iCub humanoid robot. This PPS layer serves as a distributed collision predictor, which translates visually detected objects approaching a robot\u2019s body parts (e.g., arm, hand) into the probabilities of a collision between those objects and body parts. This leads to adaptive avoidance behaviors in the robot via an optimization-based reactive controller. Notably, this visual reactive control pipeline can also seamlessly incorporate tactile input to guarantee safety in both pre- and post-collision phases in physical Human-Robot Interaction (pHRI). Concurrently, the controller is also able to take into account multiple targets (of manipulation reaching tasks) generated by a multiple Cartesian point planner. All components, namely the PPS, the multi-target motion planner (for manipulation reaching tasks), the reaching-with-avoidance controller and the humancentred visual perception, are combined harmoniously to form a hybrid control framework designed to provide safety for robots\u2019 interactions in a cluttered environment shared with human partners. Later, motivated by the development of manipulation skills in infants, in which the multisensory integration is thought to play an important role, a learning framework is proposed to allow a robot to learn the processes of forming sensory representations, namely visuomotor and visuotactile, from their own motor activities in the environment. Both multisensory integration models are constructed with Deep Neural Networks (DNNs) in such a way that their outputs are represented in motor space to facilitate the robot\u2019s subsequent actions

    Adaptive shared-control of a robotic walker to improve human-robot cooperation in gait biomechanical rehabilitation

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    Dissertação de mestrado integrado em Engenharia Biomédica (especialização em Eletrónica Médica)Sessões de reabilitação de pacientes com deficiências na marcha é importante para que a qualidade de vida dos mesmos seja recuperada. Quando auxiliadas por andarilhos robóticos inteligentes as sessões têm mostrado melhorias significativas, face aos resultados obtidos por métodos clássicos. O andarilho WALKit é um dos dispositivos mencionados e permite ser conduzido por parte do paciente enquanto um especialista supervisiona todo o processo de forma a evitar colisões e quedas. Este processo de supervisão é moroso e requer constante presença de um especialista para cada paciente. Nesta dissertação é proposto um controlador autónomo e inteligente capaz de partilhar a condução do andarilho pelo paciente e pelo supervisor evitando colisões com obstáculos. Para remover a necessidade constante do médico supervisor, um módulo de condução autónoma foi desenvolvido. O modo autónomo proposto usa um sensor Light Detection and Ranging e o algoritmo de Simultaneous Localization and Mapping (Cartographer) para obter mapas e a localização do andarilho. Seguidamente, os planeadores global e local , A* e Dynamic Window Approach respetivamente, traçam caminhos válidos para o destino, interpretáveis pelo andarilho. Usando o modo autónomo como especialista e as intenções do paciente, o controlador partilhado usa o algoritmo Proximal Policy Optimization, aprendendo o comportamento pretendido através de um processo de tentiva e erro, maximizando a recompensa recebida através de uma função pré-estabelecida. Uma rede neuronal com camadas convolucionais e lineares é capaz de inferir o risco enfrentado pelo sistema paciente-WALKit e determinar se o modo autónomo deve assumir controlo de forma a neutralizar o risco mencionado. Globalmente foram detetados erros inferiores a 38 cm no sistema de mapeamento e localização. Quer nos cenários de testagem do controlador autónomo, quer nos do controlador partilhado, nenhuma colisão foi registada garantindo em todas as tentativas a chegada ao destino escolhido. O modo autónomo, apesar de evitar obstáculos, não foi capaz de alcançar certos destinos não contemplados em ambientes de reabilitação. O modo partilhado mostrou também certas transições bruscas entre modo autónomo e intenção que podem comprometer a segurança do paciente. É necessário, como trabalho futuro, estabelecer métricas de validação objetivas e testar o controlador com pacientes de forma a corretamente estimar o desempenho.Rehabilitation sessions of patients with gait disabilities is important to restore quality of life. When aided by intelligent robotic walkers the sessions have shown significant improvements when compared to the results obtained by classical methods. The WALKit walker is one of the devices mentioned and allows the patient to drive it while a medical expert supervises the entire process in order to avoid collisions and falls. This supervision process takes time and requires constant presence of a medical expert for each patient. This dissertation proposes an intelligent controller capable of sharing the walker’s drivability by the patient and the supervisor, avoiding collisions with obstacles. To remove the constant need of a supervisor, an autonomous driving module was developed. The proposed autonomous mode uses a Light Detection and Ranging sensor and the Simultaneous Localization and Mapping (Cartographer ) algorithm to obtain maps and the location of the walker. Then, the global and local planners, A * and Dynamic Window Approach respectively, draw valid paths to the destination, interpretable by the walker. Using the autonomous mode as a expert and the patient’s intentions, the SC uses the Proximal Policy Optimization algorithm, learning the intended behavior through a trial and error process, maximizing the reward received through a pre-established function. One neural network with convolutional and linear layers is able to infer the risk faced by the patient-WALKit system and determine whether the autonomous mode should take control in order to neutralize the mentioned risk. Globally, errors smaller than 38 cm were detected in the mapping and localization system. In the testing scenarios of the autonomous controller and in the SC no collisions were recorded guaranteeing the arrival at the chosen destination in all attempts. The autonomous mode, despite avoiding obstacles, was not able to reach certain destinations not covered in rehabilitation environments. The shared mode has also shown certain sudden transitions between autonomous mode and intention that could compromise patient safety. It is necessary, as future work, to establish objective validation metrics and testing the controller with patients is necessary in order to correctly estimate performance

    Sampling-Based Motion Planning: A Comparative Review

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    Sampling-based motion planning is one of the fundamental paradigms to generate robot motions, and a cornerstone of robotics research. This comparative review provides an up-to-date guideline and reference manual for the use of sampling-based motion planning algorithms. This includes a history of motion planning, an overview about the most successful planners, and a discussion on their properties. It is also shown how planners can handle special cases and how extensions of motion planning can be accommodated. To put sampling-based motion planning into a larger context, a discussion of alternative motion generation frameworks is presented which highlights their respective differences to sampling-based motion planning. Finally, a set of sampling-based motion planners are compared on 24 challenging planning problems. This evaluation gives insights into which planners perform well in which situations and where future research would be required. This comparative review thereby provides not only a useful reference manual for researchers in the field, but also a guideline for practitioners to make informed algorithmic decisions.Comment: 25 pages, 7 figures, Accepted for Volume 7 (2024) of the Annual Review of Control, Robotics, and Autonomous System

    System-Oriented Runway Management Concept of Operations

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    This document describes a concept for runway management that maximizes the overall efficiency of arrival and departure operations at an airport or group of airports. Specifically, by planning airport runway configurations/usage, it focuses on the efficiency with which arrival flights reach their parking gates from their arrival fixes and departure flights exit the terminal airspace from their parking gates. In the future, the concept could be expanded to include the management of other limited airport resources. While most easily described in the context of a single airport, the concept applies equally well to a group of airports that comprise a metroplex (i.e., airports in close proximity that share resources such that operations at the airports are at least partially dependent) by including the coordination of runway usage decisions between the airports. In fact, the potential benefit of the concept is expected to be larger in future metroplex environments due to the increasing need to coordinate the operations at proximate airports to more efficiently share limited airspace resources. This concept, called System-Oriented Runway Management (SORM), is further broken down into a set of airport traffic management functions that share the principle that operational performance must be measured over the complete surface and airborne trajectories of the airport's arrivals and departures. The "system-oriented" term derives from the belief that the traffic management objective must consider the efficiency of operations over a wide range of aircraft movements and National Airspace System (NAS) dynamics. The SORM concept is comprised of three primary elements: strategic airport capacity planning, airport configuration management, and combined arrival/departure runway planning. Some aspects of the SORM concept, such as using airport configuration management1 as a mechanism for improving aircraft efficiency, are novel. Other elements (e.g., runway scheduling, which is a part of combined arrival/departure runway scheduling) have been well studied, but are included in the concept for completeness and to allow the concept to define the necessary relationship among the elements. The goal of this document is to describe the overall SORM concept and how it would apply both within the NAS and potential future Next Generation Air Traffic System (NextGen) environments, including research conducted to date. Note that the concept is based on the belief that runways are the primary constraint and the decision point for controlling efficiency, but the efficiency of runway management must be measured over a wide range of space and time. Implementation of the SORM concept is envisioned through a collection of complementary, necessary capabilities collectively focused on ensuring efficient arrival and departure traffic management, where that efficiency is measured not only in terms of runway efficiency but in terms of the overall trajectories between parking gates and transition fixes. For the more original elements of the concept-airport configuration management-this document proposes specific air traffic management (ATM) decision-support automation for realizing the concept

    Investigating the Nature of and Methods for Managing Metroplex Operations

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    A combination of traffic demand growth, Next Generation Air Transportation System (NextGen) technologies and operational concepts, and increased utilization of regional airports is expected to increase the occurrence and severity of coupling between operations at proximate airports. These metroplex phenomena constrain the efficiency and/or capacity of airport operations and, in NextGen, have the potential to reduce safety and prevent environmental benefits. Without understanding the nature of metroplexes and developing solutions that provide efficient coordination of operations between closely-spaced airports, the use of NextGen technologies and distribution of demand to regional airports may provide little increase in the overall metroplex capacity. However, the characteristics and control of metroplex operations have not received significant study. This project advanced the state of knowledge about metroplexes by completing three objectives: 1. developed a foundational understand of the nature of metroplexes; 2. provided a framework for discussing metroplexes; 3. suggested and studied an approach for optimally managing metroplexes that is consistent with other NextGen concept

    A Software Suite for the Control and the Monitoring of Adaptive Robotic Ecologies

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    Adaptive robotic ecologies are networks of heterogeneous robotic devices (sensors, actuators, automated appliances) pervasively embedded in everyday environments, where they learn to cooperate towards the achievement of complex tasks. While their flexibility makes them an increasingly popular way to improve a system’s reliability, scalability, robustness and autonomy, their effective realisation demands integrated control and software solutions for the specification, integration and management of their highly heterogeneous and computational constrained components. In this extended abstract we briefly illustrate the characteristic requirements dictated by robotic ecologies, discuss our experience in developing adaptive robotic ecologies, and provide an overview of the specific solutions developed as part of the EU FP7 RUBICON Project
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