Development of Sophisticated Unmanned Software Systems and Applications to UAV Formation

Ph.DDOCTOR OF PHILOSOPH

A NOVEL MESSAGE ROUTING LAYER FOR THE COMMUNICATION MANAGEMENT OF DISTRIBUTED EMBEDDED SYSTEMS

Fault tolerant and distributed embedded systems are research areas that have the interest of such entities as NASA, the Department of Defense, and various other government agencies, corporations, and universities. Taking a system and designing it to work in the presence of faults is appealing to these entities as it inherently increases the reliability of the deployed system. There are a few different fault tolerant techniques that can be implemented in a system design to handle faults as they occur. One such technique is the reconfiguration of a portion of the system to a redundant resource. This is a difficult task to manage within a distributed embedded system because of the distributed, directly addressed data producer and consumer dependencies that exist in common network infrastructures. It is the goal of this thesis work to develop a novel message routing layer for the communication management of distributed embedded systems that reduces the complexity of this problem. The resulting product of this thesis provides a robust approach to the design, implementation, integration, and deployment of a distributed embedded system

Detailed design of a class I UAV for maritime surveillance

ALFAL/ENGAER 138081-J João Correia. Examination Committee: Chairperson: MGEN/ENGAER 076441-J Paulo Manuel Veloso Gonçalves Guerra (DMSA); Supervisor: MAJ/ENGAER 129905-A Luís Filipe da Silva Félix (AFA); Supervisor: CAP/ENGAER 131603-G João Vítor Aguiar Vieira Caetano (AFA); Member of the Committee: Doutor Frederico José Prata Rente Reis Afonso (IST)Esta tese destina-se ao design estrutural em materiais compósitos de um Veículo Aéreo Não-Tripulado (VANT) de classe I para vigilância marítima. A intenção de expandir o uso de VANTs pela Força Aérea Portuguesa (FAP), na ampla área de jurisdição portuguesa e nas operações internacionais, motivou a necessidade de desenvolver uma nova plataforma capaz de cumprir todos os requisitos operacionais e tecnológicos. A presente tese começa pela definição dos sistemas a bordo necessários para a aeronave, nomeadamente a carga útil, aviónicos e propulsão. O design estrutural ao nível conceptual e preliminar envolveu o planeamento da disposição geral da aeronave para atingir uma margem estática longitudinal válida e a determinação do envelope de voo com rajada para determinar o factor de carga da aeronave. Este parâmetro vai definir a caracterização das forças aerodinâmicas e inérciais para a manobra crítica de voo. O projecto detalhado da aeronave foi realizado através de modelação em Desenho Assistido por Computador (CAD) com o objetivo de minimizer o peso estrutural. O design foi confirmado por uma análise numérica de tensões através de uma Análise de Elementos Finitos (FEA) e foi alcançada convergência para os valores obtidos de tensão e de deslocamento. O design desenvolvido é capaz de suportar a condição de carga crítica sem falha estrutural. A configuração da aeronave com todos os sistemas a bordo apresenta um peso dentro dos limites para a respectiva classe e uma autonomia de oito horas para operações de vigilância marítima. O design desenvolvido pode apresentar outras configurações, e tem uma autonomia máxima de doze horas.This thesis concerns the composite structural design of a class I Unmanned Aerial Vehicle (UAV) for maritime surveillance. The intention to expand the UAV use by Portuguese Air Force (FAP), over the broad area of Portuguese jurisdiction and in international operations, motivated the need to develop a new platform capable to fulfil all the operational and technological requirements. This thesis starts by defining all the necessary onboard systems for the aircraft, namely the payload, avionics and propulsion. The conceptual and preliminary structural design involved planning the general layout to achieve a valid longitudinal static margin and determining the aircraft flight envelope with gust loads to determine the design load. This design driver set the aerodynamic and inertial load characterization of the critical flight manoeuvre. The aircraft detailed design was performed through Computed Aided Design (CAD) modelling with the objective of minimizing the structural weight. The design was endorsed by a numerical stress analysis through a Finite Element Analysis (FEA) and achieved convergence for the stress and displacement results. The developed design withstands the critical load condition without failure of the structure. The aircraft configuration with full payload presents a weight within its class range and an endurance of eight hours for maritime surveillance operations. The implemented design supports other configurations, presenting an endurance up to twelve hours.N/

On parallel hybrid-electric propulsion system for unmanned aerial vehicles

This paper presents a review of existing and current developments and the analysis of Hybrid-Electric Propulsion Systems (HEPS) for small fixed-wing Unmanned Aerial Vehicles (UAVs). Efficient energy utilisation on an UAV is essential to its functioning, often to achieve the operational goals of range, endurance and other specific mission requirements. Due to the limitations of the space available and the mass budget on the UAV, it is often a delicate balance between the onboard energy available (i.e. fuel) and achieving the operational goals. One technology with potential in this area is with the use of HEPS. In this paper, information on the state-of-art technology in this field of research is provided. A description and simulation of a parallel HEPS for a small fixed-wing UAV by incorporating an Ideal Operating Line (IOL) control strategy is described. Simulation models of the components in a HEPS were designed in the MATLAB Simulink environment. An IOL analysis of an UAV piston engine was used to determine the most efficient points of operation for this engine. The results show that an UAV equipped with this HEPS configuration is capable of achieving a fuel saving of 6.5%, compared to the engine-only configuration