Autonomous Navigation for Unmanned Aerial Systems - Visual Perception and Motion Planning

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Vision-based Learning for Drones: A Survey

Drones as advanced cyber-physical systems are undergoing a transformative shift with the advent of vision-based learning, a field that is rapidly gaining prominence due to its profound impact on drone autonomy and functionality. Different from existing task-specific surveys, this review offers a comprehensive overview of vision-based learning in drones, emphasizing its pivotal role in enhancing their operational capabilities under various scenarios. We start by elucidating the fundamental principles of vision-based learning, highlighting how it significantly improves drones' visual perception and decision-making processes. We then categorize vision-based control methods into indirect, semi-direct, and end-to-end approaches from the perception-control perspective. We further explore various applications of vision-based drones with learning capabilities, ranging from single-agent systems to more complex multi-agent and heterogeneous system scenarios, and underscore the challenges and innovations characterizing each area. Finally, we explore open questions and potential solutions, paving the way for ongoing research and development in this dynamic and rapidly evolving field. With growing large language models (LLMs) and embodied intelligence, vision-based learning for drones provides a promising but challenging road towards artificial general intelligence (AGI) in 3D physical world

Controlo multi-drones com suporte a missões autónomas

Recent advancements regarding miniaturization of sensors and instruments, as well as the reduction of their cost, promoted a growth in the usage of drones in an increasingly wide range of scenarios such as search and rescue, agriculture and environmental monitoring. However, most currently available mechanisms for drone control still require a constantly aware pilot, thus limiting the convenience of executing complex missions, especially when more than one drone is involved. Major drone and flight controller manufacturers, however, are displaying an increasing interest in providing programming interfaces and development kits that enable the execution of basic autonomous flight, including commands such as taking off, landing and waypoint navigation. These interfaces facilitate the integration of said drones in platforms that aim to abstract manual control from their users. This dissertation proposes a complete and modular solution for controlling one or more drones, enabling an inexperienced user to plan, execute and monitor complex missions with various participants, also implementing the required functionality for the collaboration of a set of drones in the execution of such missions. The proposed solution consists in a modular platform composed of loosely coupled components. Each component is individually designed to handle specific tasks such as flight control hardware interfacing, telemetry acquisition and storage, and mission planning. Components accomplish their interactions by using message brokers, while user interaction is achieved through intuitive web and mobile applications. The functionality of the solution is evaluated through the completion of four experiments, which represent typical scenarios where the control platform may be used. These experiments cover both single-drone and multi-drone functionality, with the first two covering tasks carried out by one drone, while the last two represent scenarios where multiple drones collaborate towards a common goal.Com os avanços recentes na redução do tamanho dos sensores e instrumentos, assim como na redução de custos dos mesmos, a utilização de drones é cada vez mais comum e abrange um número cada vez superior de casos de utilização tais como missões de procura e resgate, agricultura e monitorização ambiental. Contudo, a maior parte das alternativas existentes para controlo ainda exigem a atenção constante de um piloto, limitando a conveniência da execução de missões complexas, sobretudo quando nelas participa mais que um drone. Os principais fabricantes de drones e controladores de vôo, no entanto, disponibilizam cada vez mais frequentemente interfaces para a execução de funções básicas de vôo autónomo, como por exemplo a descolagem, aterragem e a navegação baseada em coordenadas geográficas. A existência cada vez mais comum destas interfaces permite a integração de drones em plataformas que têm como objectivo a abstração do seu controlo directo. Esta dissertação propõe uma solução modular completa para controlo de um ou mais drones, permitindo a um utilizador inexperiente o planeamento, execução e monitorização de missões complexas com vários participantes, implementando também a funcionalidade necessária para a colaboração de vários drones na execução de uma missão. A solução proposta consiste numa plataforma modular, composta por componentes que são executados de forma independente. Cada componente é individualmente desenvolvido para executar tarefas específicas como a comunicação com o controlador de vôo, a aquisição e armazenamento de telemetria e o planeamento de missões. Os componentes realizam as suas interações através da utilização de filas de mensagens, enquanto a interação com o utilizador é realizada através de aplicações intuitivas web ou mobile. As funcionalidades da solução proposta são avaliadas através da execução de quatro testes distintos, que representam cenários típicos em que a plataforma de controlo pode ser usada. Estes testes cobrem a utilização de um ou mais drones, sendo que as duas primeiras tarefas são executadas apenas por um drone e as últimas duas representam cenários em que vários drones colaboram para alcançar um objectivo comum.Apoio financeiro do POCTI no âmbito do III Quadro Comunitário de Apoio. Apoio financeiro da FCT e do FSE no âmbito do III Quadro Comunitário de Apoio.Mestrado em Engenharia de Computadores e Telemátic

Design of a DDP controller for autonomous autorotative landing of RW UAV following engine failure

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, April 2016A Rotary Wing Unmanned Aerial Vehicle (RW UAV) as a platform and its payload consisting of sophisticated sensors would be costly items. Hence, a RW UAV in the 500 kg class designed to fulfil a number of missions would represent a considerable capital outlay for any customer. Therefore, in the event of an engine failure, a means should be provided to get the craft safely back on the ground without incurring damage or causing danger to the surrounding area. The aim of the study was to design a controller for autorotative landing of a RW UAV in the event of engine failure. In order to design a controller for autorotative landing, an acceleration model was used obtained from a study by Stanford University. FLTSIM helicopter flight simulation package yielded necessary RW UAV response data for the autorotation regimes. The response data was utilized in identifying the unknown parameters in the acceleration model. A Differential Dynamic Programming (DDP) control algorithm was designed to compute the main and tail rotor collective pitch and the longitudinal and lateral cyclic pitch control inputs to safely land the craft. The results obtained were compared to the FLTSIM flight simulation response data. It was noted that the mathematical model could not accurately model the pitch dynamics. The main rotor dynamics were modelled satisfactorily and which are important in autorotation because without power from the engine, the energy in main rotor is critical in a successful execution of an autorotative landing. Stanford University designed a controller for RC helicopter, XCell Tempest, which was deemed successful. However, the DDP controller was designed for autonomous autorotative landing of RW UAV weighing 560 kg, following engine failure. The DDP controller has the ability to control the RW UAV in an autorotation landing but the study should be taken further to improve certain aspects such as the pitch dynamics and which can possibly be achieved through online parameter estimation.MT 201

Multi-query Path Planning for an Unmanned Fixed-Wing Aircraft

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106491/1/AIAA2013-4791.pd

Design, Deployment, Navigation, and Control of Mobile Robots for Perception and Sensor Data Collection

Aerial robots, including rotary-wing and fixed-wing unmanned aerial vehicles or UAVs, have shown great capabilities in surveying as well as search and rescue from above. However, either rotary-wing or fixed-wing UAVs have nearly insoluble flaws. In order to overcome the under-actuating nature of multi-rotor UAVs, Chapter 2 proposes modeling methods and control schemes for fully-actuated hexacopters. Additionally, rotary-wing robots suffer from limited battery life as well as lack of fail-safe mechanism upon losing motors, while fixed-wing robots lacks the ability to take off and land vertically. Therefore, Chapter 4 proposes a bio-inpired hybrid aerial robot to extend mutli-rotor flight time and fail-safe capability and provide fixed-wing glider with vertical take-off and landing or VTOL capability. Moreover, to extend the flight time and optimize the energy consumption of multi-rotor UAVs, Chapter 3 proposes a multi-disciplinary design optimization based flight trajectory optimizer involving linear rotor inflow models to reduce flight time or energy consumption of specific missions.In terms of unmanned ground vehicles or UGVs used for perception and mapping, there has been a research gap to provide a low-cost, highly agile over-actuated chassis design. Chapter 5 proposes a 3D-printable double Ackermann steering chassis design with 2-wheel standing and balancing capability to fill in this gap. Chapter 6, on the other hand, proposes the system design of a UGV capable of performing perception and mapping in a limited lighting, unstructured, and GPS-denied environment based on a nevertheless nonholonomic chassis, where primary concern becomes the reliability in performing real-time mapping and preservation of solely static environment.The last but not least topic discussed in this dissertation is to promote the role of UAV imagery in earthquake response. In Chapter 7 we combine the traditional UAV plan view perspective with north and east elevation view video data to provide motion estimation in all 6 degrees of freedom, as well as proposing Video Transformer for motion tracking.All in all, with attempts to expand and promote the designs, deployment and control schemes of both aerial and ground mobile robots, this dissertation strives to provide case study results and state-of-the-art methods for future robotics studies

USE OF UNMANNED AERIAL VEHICLES (UAV) FOR URBAN TREE INVENTORIES

In contrast to standard aerial imagery, unmanned aerial systems (UAS) utilize recent technological advances to provide an affordable alternative for imagery acquisition. Increased value can be realized through clarity and detail providing higher resolution (2-5 cm) over traditional products. Many natural resource disciplines such as urban forestry will benefit from UAS. Tree inventories for risk assessment, biodiversity, planning, and design can be efficiently achieved with the UAS. Recent advances in photogrammetric processing have proved automated methods for three dimensional rendering of aerial imagery. Point clouds can be generated from images providing additional benefits. Association of spatial locational information within the point cloud can be used to produce elevation models i.e. digital elevation, digital terrain and digital surface. Taking advantage of this point cloud data, additional information such as tree heights can be obtained. Several software applications have been developed for LiDAR data which can be adapted to utilize UAS point clouds. This study examines solutions to provide tree inventory and heights from UAS imagery. Imagery taken with a micro-UAS was processed to produce a seamless orthorectified image. This image provided an accurate way to obtain a tree inventory within the study boundary. Utilizing several methods, tree height models were developed with variations in spatial accuracy. Model parameters were modified to offset spatial inconsistencies providing statistical equality of means. Statistical results (p = 0.756) with a level of significance (α = 0.01) between measured and modeled tree height means resulted with 82% of tree species obtaining accurate tree heights. Within this study, the UAS has proven to be an efficient tool for urban forestry providing a cost effective and reliable system to obtain remotely sensed data

A Review of the Operational Use of UAS in Public Safety Emergency Incidents

The domain of public safety in the form of search \& rescue, wildland firefighting, structure firefighting, and law enforcement operations have drawn great interest in the field of aerospace engineering, human-robot teaming, autonomous systems, and robotics. However, a divergence exists in the assumptions made in research and how state-of-the-art technologies may realistically transition into an operational capacity. To aid in the alignment between researchers, technologists, and end users, we aim to provide perspective on how small Uncrewed Aerial Systems (sUAS) have been applied in 114 real world incidents as part of a technical rescue team from 2016 to 2021. We highlight the main applications, integration, tasks, and challenges of employing UAS within five primary use cases including searches, evidence collection, SWAT, wildland firefighting, and structure firefighting. Within these use cases, key incidents are featured that provide perspective on the evolving and dynamic nature of UAS tasking during an operation. Finally, we highlight key technical directions for improving the utilization and efficiency of employing aerial technology in all emergency types.Comment: Accepted to the International Conference of Unmanned Aerial Systems (ICUAS) 202