Gustavo Silva Castilho de Avellar

This paper presents a solution for the problem of minimum time coverage of ground areas using a group of unmanned air vehicles (UAVs) equipped with image sensors. The solution is divided into two parts: (i) the task modeling as a graph whose vertices are geographic coordinates determined in such a way that a single UAV would cover the area in minimum time; and (ii) the solution of a mixed integer linear programming problem, formulated according to the graph variables defined in the first part, to route the team of UAVs over the area. The main contribution of the proposed methodology, when compared with the traditional vehicle routing problem’s (VRP) solutions, is the fact that our method solves some practical problems only encountered during the execution of the task with actual UAVs. In this line, one of the main contributions of the paper is that the number of UAVs used to cover the area is automatically selected by solving the optimization problem. The number of UAVs is influenced by the vehicles’ maximum flight time and by the setup time, which is the time needed to prepare and launch a UAV. To illustrate the methodology, the paper presents experimental results obtained with two hand-launched, fixed-wing UAVs.

This paper addresses the ongoing process of development of a small hand-held multiple unmanned aerial vehicle platform for surveillance and monitoring. The project cover all phases of development, from aerodynamic design and mechanical assembly, through fine tuning low level control loops and design of an attitude and heading reference system, up to implementation of navigation algorithms and finally flight testing. Commercial hardware is used to speed up development, allowing the team responsible for implementing the navigation algorithms to execute and test while the team responsible for the aerodynamics and electronics can design and compare results.

Este trabalho versa sobre análise de estabilidade e projeto de controladores para sistemas fuzzy Takagi-Sugeno (TS) contínuos no contexto de desigualdades matriciais lineares (LMIs). Aplicando uma estratégia de relaxaçao a um tipo de funçao de Lyapunov fuzzy proposta recentemente, é possível obter novas condições de estabilidade descritas por LMIs. Essas novas condições conferem novos graus de liberdade ao problema LMI, reduzindo o conservadorismo. Mais do que isso, tal estratégia permite a síntese de controladores inteiramente por meio de LMIs, uma característica bem mais atrativa do que os procedimentos baseados em desigualdades matriciais bilineares (BMIs) presentes na literatura. Teste numéricos e simulações ilustram as vantagens da nova metodologia.