Distributed Control for Collective Behaviour in Micro-unmanned Aerial Vehicles

Full version unavailable due to 3rd party copyright restrictions.The work presented herein focuses on the design of distributed autonomous controllers for collective behaviour of Micro-unmanned Aerial Vehicles (MAVs). Two alternative approaches to this topic are introduced: one based upon the Evolutionary Robotics (ER) paradigm, the other one upon flocking principles. Three computer simulators have been developed in order to carry out the required experiments, all of them having their focus on the modelling of fixed-wing aircraft flight dynamics. The employment of fixed-wing aircraft rather than the omni-directional robots typically employed in collective robotics significantly increases the complexity of the challenges that an autonomous controller has to face. This is mostly due to the strict motion constraints associated with fixed-wing platforms, that require a high degree of accuracy by the controller. Concerning the ER approach, the experimental setups elaborated have resulted in controllers that have been evolved in simulation with the following capabilities: (1) navigation across unknown environments, (2) obstacle avoidance, (3) tracking of a moving target, and (4) execution of cooperative and coordinated behaviours based on implicit communication strategies. The design methodology based upon flocking principles has involved tests on computer simulations and subsequent experimentation on real-world robotic platforms. A customised implementation of Reynolds’ flocking algorithm has been developed and successfully validated through flight tests performed with the swinglet MAV. It has been notably demonstrated how the Evolutionary Robotics approach could be successfully extended to the domain of fixed-wing aerial robotics, which has never received a great deal of attention in the past. The investigations performed have also shown that complex and real physics-based computer simulators are not a compulsory requirement when approaching the domain of aerial robotics, as long as proper autopilot systems (taking care of the ”reality gap” issue) are used on the real robots.EOARD (European Office of Aerospace Research & Development), euCognitio

Mathematical optimization methods for aircraft conflict resolution in air traffic control

Air traffic control is a very dynamic and heavy constrained environment where many decisions need to be taken over short periods of time and in the context of uncertainty. Adopting automation under such circumstances can be a crucial initiative to reduce controller workload and improve airspace usage and capacity. Traditional methods for air traffic control have been exhaustively used in the last decades and are reaching their limits, therefore automated approaches are receiving a significant and growing attention. In this thesis, the focus is to obtain optimal aircraft trajectories to ensure flight safety in the short-term by solving optimization problems. During cruise stage, separation conditions require a minimum of 5 Nautical Miles (NM) horizontally or 1000 feet (ft) vertically between any pair of aircraft. A conflict between two or more aircraft is a loss of separation among these aircraft. Air traffic networks are organized in flight levels which are separated by at least 1000 ft, hence during cruise stage, most conflicts occur among aircraft flying at the same flight level. This thesis presents several mathematical formulations to address the aircraft conflict resolution problem and its variants. The core contribution of this research is the development of novel mixed integer programming models for the aircraft conflict resolution problem. New mathematical optimization formulations for the deterministic aircraft conflict resolution problem are analyzed and exact methods are developed. Building on this framework, richer formulations capable of accounting for aircraft trajectory prediction uncertainty and trajectory recovery are proposed. Results suggest that the formulations presented in thesis are efficient and competitive enough with the state-of-art models and they can provide an alternative solution to possibly fill some of the gaps currently present in the literature. Furthermore, the results obtained demonstrate the impact of these models in solving very denser air space scenarios and their competitiveness with state-of-the-art formulations without regarding variable discretization or non-linear components

BORDER NATURES. The Environment as Weapon at the Edges of Greece

This practice-based PhD critically investigates the complex imbrications of political violence and environmental processes resulting in the construction of so-called “natural” borders: national boundaries where nature is understood to delimit and fortify the nation-state. Taking the frontiers of Greece as a case study, the thesis seeks to demonstrate that, contrary to conceptions of natural borders as spaces that operate devoid of human intervention, their materiality and natural processes are in fact hybridized and engineered by states to perform the specific, deadly tasks of deterrence, exclusion and erasure. Part I (Ghost Habitats) explores the mountainous, trilateral border area of the Prespa/Prespa/Prespës lakes between Greece, North Macedonia, and Albania, to consider how the delineation and enforcement of the border reconfigures regional ecosystems to render them into “wild” frontiers, subject to different legal orders than the remainder of sovereign territory. Part II (Anáchoma), co-researched with colleague Ifor Duncan (PhD, CRΑ/Post-doctoral fellow at Ca’ Foscari University, Venice) considers the Evros/Meriç/Maritsa river between Greece, Turkey and Bulgaria as an apparatus of border violence and obfuscation, as well as a body which records, stores, and occasionally reveals this violence through seasonal shifts in its hydrological cycle. Part III (Grey Rocks, Black Waves) examines the archipelagic border of the Aegean Sea between Greece and Turkey, to discuss how its geographically and historically dense materiality is mobilized as a defensive infrastructure against contemporary migration at sea, and to reflect on a spatial and visual practice that attempts to decode this matter to reveal traces of state violence. In each case sovereign power organises, and is organised around, specific ecological processes to disperse the causal agencies of violence enacted against disempowered border subjects, and aspiring crossers. Incorporating a methodology that borrows from disciplines as diverse as forensics, filmmaking, archaeology, botany, and oceanography, the thesis contests commonplace understandings of territorial limits as lines that are simply scripted over natural backdrops, to critically include the multiple human agencies and their insidious use of ecological dynamics for the work of border defence. To describe these hybrid boundary environments, and the complex causal relationships they engender, the thesis introduces the operative concept of “border natures”: a synthesis of nature, space, technology and law, and connecting actors as diverse as border authorities, fences, technologies of surveillance, political and legal orders, human and more-than-human forms of life - rivers, waves, and mountains

Index

Janus.Net vol.14, nº

The scientific way of warfare: Order and chaos on the battlefields of modernity.

The thesis of the present work is that throughout the modern era the dominant corpus of scientific ideas, as articulated around key machine technologies, has been reflected in the contemporary theories and practices of warfare in the Western world. Over the period covered by this thesis - from the ascendancy of the scientific worldview in the seventeenth and eighteenth centuries to present day - an ever more intimate symbiosis between science and warfare has established itself with the increasing reliance on the development and integration of technology within complex social assemblages of war. This extensive deployment of scientific ideas and methodologies in the military realm allows us to speak of the constitution and perpetuation of a scientific way of warfare. There are however within the scientific way of warfare significant variations in the theories and practices of warfare according to the prevalence of certain scientific ideas and technological apparatuses in given periods of the modern era. The four distinctive regimes I thereupon distinguish are those of mechanistic, thermodynamic, cybernetic, and chaoplexic warfare. Each of these regimes is characterised by a differing approach to the central question of order and chaos in war, on which hinge the related issues of centralisation and decentralisation, predictability and control

Multi-Agent Systems

A multi-agent system (MAS) is a system composed of multiple interacting intelligent agents. Multi-agent systems can be used to solve problems which are difficult or impossible for an individual agent or monolithic system to solve. Agent systems are open and extensible systems that allow for the deployment of autonomous and proactive software components. Multi-agent systems have been brought up and used in several application domains