Trajectory planning for unmanned surface vehicles operating under wave-induced motion uncertainty in dynamic environments:

We present a deliberative trajectory planning method to avoid collisions with traffic vessels. It also plans traversal across wavefields generated by these vessels and minimizes the risk of failure. Our method searches over a state-space consisting of pose and time. And, it produces collision-free and minimum-risk trajectory. It uses a lookup table to account for motion uncertainty and failure risk. We also present speed-up techniques to increase performance. Our wave-aware planner produces plans that (1) have shorter execution times and safer when compared to previously developed reactive planning schemes and (2) comply with user-defined wave-traversal constraints and Collision Regulations (COLREGs

Planning for Autonomous Operation of Unmanned Surface Vehicles

The growing variety and complexity of marine research and application oriented tasks requires unmanned surface vehicles (USVs) to operate fully autonomously over long time horizons even in environments with significant civilian traffic. The autonomous operations of the USV over long time horizons requires a path planner to compute paths over long distances in complex marine environments consisting of hundreds of islands of complex shapes. The available free space in marine environment changes over time as a result of tides, environmental restrictions, and weather. Secondly, the maximum velocity and energy consumption of the USV is significantly influenced by the fluid medium flows such as strong currents. Finally, the USV have to operate in an unfamiliar, unstructured marine environment with obstacles of variable dimensions, shapes, and motion dynamics such as other unmanned surface vehicles, civilian boats, shorelines, or docks poses numerous planning challenges. The proposed Ph.D. dissertation explores the above mentioned problems by developing computationally efficient path and trajectory planning algorithms that enables the long term autonomous operation of the USVs. We have developed a lattice-based 5D trajectory planner for the USVs operating in the environment with the congested civilian traffic. The planner estimates collision risk and reasons about the availability of contingency maneuvers to counteract unpredictable behaviors of civilian vessels. Secondly, we present a computationally efficient and optimal algorithm for long distance path planning in complex marine environments using A* search on visibility graphs defined over quad trees. Finally, we present an A* based path planning algorithm with newly developed admissible heuristics for computing energy efficient paths in environment with significant fluid flows. The effectiveness of the planning algorithms is demonstrated in the simulation environments by using systems identified dynamics model of the wave amplitude modular vessel (WAM-V) USV14

Filtering based multi-sensor data fusion algorithm for a reliable unmanned surface vehicle navigation

When considering the working conditions under which an unmanned surface vehicle (USV) operates, the navigational sensors, which already have inherent uncertainties, are subjected to environment influences that can affect the accuracy, security and reliability of USV navigation. To combat this, multi-sensor data fusion algorithms will be developed in this paper to deal with the raw sensor measurements from three kinds of commonly used sensors and calculate improved navigational data for USV operation in a practical environment. Unscented Kalman Filter, as an advanced filtering technology dedicated to dealing with non-linear systems, has been adopted as the underlying algorithm with the performance validated within various computer-based simulations where practical, dynamic navigational influences, such as ocean currents, provide force against the vessel’s structure, are to be considered

Mobile Radio Channel Measurements for air-to-ground and non-conventional future applications

La tesi si suddivide in quattro parti: due iniziali di tipo compilativo e le altre due sperimentali. Nella prima parte vengono descritti gli UAVs: classificazioni e applicazioni da un punto di vista delle telecomunicazioni e della sicurezza; una seconda parte sempre compilativa, espone invece una panoramica sulle caratteristiche del canale Air-to-Ground e la possibilità di modelling attraverso diversi scenari. La terza parte rappresenta il corpo della tesi, in quanto presenta la descrizione di una campagna di misure condotta in ambiente industriale, fatta con due diversi setup di misure: onde mm e UWB. Dopo la presentazione dello scopo, vengono poi trattati gli esperimenti, descritto l'equipment ed estratte le conclusioni mostrando funzioni come il Power Angle Profile e la Risposta Impulsiva. L'ultimo capitolo tratta infine di una campagna da condurre in ambiente urbano, presentando però solo il piano di misure, in quanto i risultati saranno a breve disponibili

A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

UAV Based 5G Network: A Practical Survey Study

Unmanned aerial vehicles (UAVs) are anticipated to significantly contribute to the development of new wireless networks that could handle high-speed transmissions and enable wireless broadcasts. When compared to communications that rely on permanent infrastructure, UAVs offer a number of advantages, including flexible deployment, dependable line-of-sight (LoS) connection links, and more design degrees of freedom because of controlled mobility. Unmanned aerial vehicles (UAVs) combined with 5G networks and Internet of Things (IoT) components have the potential to completely transform a variety of industries. UAVs may transfer massive volumes of data in real-time by utilizing the low latency and high-speed abilities of 5G networks, opening up a variety of applications like remote sensing, precision farming, and disaster response. This study of UAV communication with regard to 5G/B5G WLANs is presented in this research. The three UAV-assisted MEC network scenarios also include the specifics for the allocation of resources and optimization. We also concentrate on the case where a UAV does task computation in addition to serving as a MEC server to examine wind farm turbines. This paper covers the key implementation difficulties of UAV-assisted MEC, such as optimum UAV deployment, wind models, and coupled trajectory-computation performance optimization, in order to promote widespread implementations of UAV-assisted MEC in practice. The primary problem for 5G and beyond 5G (B5G) is delivering broadband access to various device kinds. Prior to discussing associated research issues faced by the developing integrated network design, we first provide a brief overview of the background information as well as the networks that integrate space, aviation, and land

Technology Assessment of eVTOL Personal Air Transportation System

This thesis intended to provide a holistic vision on the potential consequences of the introduction of emerging electrical Vertical Takeoff and Landing (e VTOL) Personal Air Transportation System (PATS) to contribute to the forming of public and policy opinion, and to assess the impacts and the feasibility of that. Instead of looking from a detailed vehicle design viewpoint, we tried to understand the need, the impacts, and the perceptions and the concerns of stakeholders. Thus, it was set a framework and methodology starting with a technology assessment point of view in the light of transportation system analysis. Limitations of the current ground and airline transportation systems, increasing congestion, poor block speed, combined with expanding population and demand for affordable on- demand mobility are driving the development of future transportation technology and policy. The third wave of aeronautics might be the answer and could bring about great new capabilities for society that would bring aviation into a new age of being relevant in daily lives since eVTOL PATS is envisioned as the next logical step in the natural progression in the history of disruptive transportation system innovations. However, there are a lot of questions. Although there was difficulty since the system was an emerging air transportation mode, an interdisciplinary study has been conducted to assess the impacts of developing such a capability. The research questions were determined to address the research objectives. What is the current state of mobility and eVTOL air transportation mode? What are the potential benefits of eVTOL air transportation mode for user and society? What are the perceptions of service providers, regulator, and user? What are the main challenges including technology, regulation, operation, social and environment aspects to enable the system? What are the enabling technologies? Nevertheless, with the results obtained lately from the research activities, revolutionary technologies and regulations are bringing us closer to eVTOL PATS reality every day. It can be argued that a new socio-technical transition will come about like the transition from horse drawn carriers to cars. Even if it is still a long way to go, it seems rather likely that the time has been arriving in the next decade. Their existence and operation would therefore need to be taken into consideration for today’s planning considerations and construction projects to be able to have this emerging air transportation mode available in the future. As the technology underlying eVTOL PATS evolves, wider eVTOL adoption across various markets is likely to be supported further if a set of key challenges such as safety and security, ease of use and autonomy, noise, infrastructure, and air traffic management are overcome. Achieving drastic improvements in ease of use, safety and community acceptable noise are the most critical steps towards the future feasibility of this market. Multi-use demos and demonstrating successful operation with early vehicles, namely eVTOL PATS prototype field operations, will create public acceptance and understanding of potentials in emerging air transportation mode for public good, use and learn in multiple applications. The overall perception of the user, service provider and regulator are positive, and the support is high. Shortly, a successful implementation and sustainable transition will depend on overcoming technological hurdles, regulatory frameworks, operational safety, cost competitiveness, and sensibilities of the affected communities. There is a need to enable people and goods to have the convenience of on-demand, point-to-point safe travel, further, anywhere in less travel time, through a network of pocket airports/vertiports, and there is a significant potential benefit so that policy makers, regulators and metropoles’ transportation planning departments should consider an inclusion of eVTOL air transportation mode into the scenarios and policies of the future.Esta tese pretende fornecer uma visão holística sobre as potenciais consequências da introdução do Sistema de Transporte Aéreo Pessoal (PATS) de Decolagem e Pouso Vertical elétrico emergente (e VTOL) para contribuir para a formação de opinião pública e política, e para avaliar os impactos e a viabilidade disso. Em vez de olhar de um ponto de vista detalhado o projeto do veículo, tentamos entender a necessidade, os impactos, as percepções e as preocupações das partes interessadas. Assim, foi definido um quadro e uma metodologia partindo de um ponto de vista de avaliação de tecnologia à luz da análise do sistema de transporte. As limitações dos atuais sistemas de transporte terrestre e aéreo, o aumento do congestionamento, a baixa velocidade do tráfego, combinados com a expansão da população e a mobilidade com procura acessível estão impulsionando o desenvolvimento de futuras tecnologias e políticas de transporte. A terceira onda da aeronáutica pode ser a resposta e pode trazer grandes novas capacidades para a sociedade que trariam a aviação para uma nova era de ser relevante na vida cotidiana, uma vez que o VTOL PATS é visto como o próximo passo lógico na progressão natural na história das inovações disruptivas do sistema de transporte. No entanto, há muitas perguntas. Embora tenha havido dificuldade por se tratar de um modo de transporte aéreo emergente, um estudo interdisciplinar foi realizado para avaliar os impactos do desenvolvimento de tal capacidade. As questões de investigação foram determinadas para atender aos objetivos do projeto. Qual é o estado atual da mobilidade e do modo de transporte aéreo eVTOL? Quais são os benefícios potenciais do modo de transporte aéreo eVTOL para o utilizador e a sociedade? Quais são as percepções dos provedores de serviços, regulador e utilizador? Quais são os principais desafios, incluindo tecnologia, regulamentação, operação, aspectos sociais e ambientais para habilitar o sistema? Quais são as tecnologias facilitadoras? No entanto, com os resultados obtidos ultimamente nas atividades de pesquisa, tecnologias e regulamentações revolucionárias estão nos aproximando cada dia mais da realidade do VTOL PATS. Pode-se argumentar que uma nova transição sócio-técnica ocorrerá como a transição de carruagens puxadas por cavalos para automóveis. Mesmo que ainda seja um longo caminho a percorrer, parece bastante provável que a hora esteja chegando na próxima década. A sua existência e operação, portanto, precisam ser levadas em consideração para as questões de planeamento e projetos de construção de hoje para poder ter esse modo de transporte aéreo emergente disponível no futuro. À medida que a tecnologia subjacente ao eVTOL PATS evolui, é provável que a adoção mais ampla do eVTOL em vários mercados seja ainda mais apoiada se um conjunto de desafios importantes, como segurança e proteção, facilidade de uso e autonomia, ruído, infraestrutura e gestão de tráfego aéreo forem superados. Alcançar melhorias drásticas na facilidade de uso, segurança e ruído aceitável pela comunidade são os passos mais críticos para a viabilidade futura deste mercado. Demonstrações multi-uso e demonstração de operação bem- sucedida com veículos iniciais, ou seja, operações de campo do protótipo eVTOL PATS, criarão aceitação pública e compreensão dos potenciais no modo de transporte aéreo emergente para o bem público, uso e aprendizado em várias aplicações. A percepção geral do utilizador, prestador de serviço e regulador é positiva, e o suporte é alto. Uma implementação bem-sucedida e uma transição sustentável dependerá da superação de obstáculos tecnológicos, estruturas regulatórias, segurança operacional, competitividade de custos e sensibilidade das comunidades afetadas. Há uma necessidade de permitir que pessoas e mercadorias tenham a conveniência de viagens seguras de que necessitam, ponto a ponto, e além disso, em qualquer lugar em menos tempo de viagem. Isso pode ser feito por meio de uma rede de aeroportos/vertiports, e há um benefício potencial significativo para que os formuladores de políticas, reguladores e departamentos de planeamento de transporte das grandes metrópoles considerem a inclusão do modo de transporte aéreo eVTOL nos cenários e políticas do futuro

Planning the future of smart cities with swarms of fully autonomous unmanned aerial vehicles using a novel framework

The autonomy of unmanned aerial vehicles (UAVs) - self-governing in the aerospace discipline has been a remarkable research area with the development of the advanced bespoke microcontrollers embedded with advanced AI techniques for the last several decades. The road forward about the operational environment is certain about the swarms of fully automated UAVs (FAUAVs), that is, urban areas. Therefore, the planning the future of cities with swarms of fully autonomous unmanned aerial vehicles is explored in this paper to optimise the use of this type of autonomy with a diverse range of applications and a contemporary methodology is proposed using a synergistic holistic framework equipped with various effective and efficient techniques along with a novel FAUAV routing approach customisable to the constraints of FAUAVs and urban areas. The framework consists of a decentralized agent-based control architecture that monitors and controls the swarms of resource-constraint FAUAVs for their real-time requirements in optimising their urban uses. The results demonstrate that the constraints of FAUAVs can be mitigated significantly in urban areas and their use in realising their diverse range of missions can be optimised using the proposed methodology

Robust Multi-sensor Data Fusion for Practical Unmanned Surface Vehicles (USVs) Navigation

The development of practical Unmanned Surface Vehicles (USVs) are attracting increasing attention driven by their assorted military and commercial application potential. However, addressing the uncertainties presented in practical navigational sensor measurements of an USV in maritime environment remain the main challenge of the development. This research aims to develop a multi-sensor data fusion system to autonomously provide an USV reliable navigational information on its own positions and headings as well as to detect dynamic target ships in the surrounding environment in a holistic fashion. A multi-sensor data fusion algorithm based on Unscented Kalman Filter (UKF) has been developed to generate more accurate estimations of USV’s navigational data considering practical environmental disturbances. A novel covariance matching adaptive estimation algorithm has been proposed to deal with the issues caused by unknown and varying sensor noise in practice to improve system robustness. Certain measures have been designed to determine the system reliability numerically, to recover USV trajectory during short term sensor signal loss, and to autonomously detect and discard permanently malfunctioned sensors, and thereby enabling potential sensor faults tolerance. The performance of the algorithms have been assessed by carrying out theoretical simulations as well as using experimental data collected from a real-world USV projected collaborated with Plymouth University. To increase the degree of autonomy of USVs in perceiving surrounding environments, target detection and prediction algorithms using an Automatic Identification System (AIS) in conjunction with a marine radar have been proposed to provide full detections of multiple dynamic targets in a wider coverage range, remedying the narrow detection range and sensor uncertainties of the AIS. The detection algorithms have been validated in simulations using practical environments with water current effects. The performance of developed multi-senor data fusion system in providing reliable navigational data and perceiving surrounding environment for USV navigation have been comprehensively demonstrated