Tesi di Dottorato

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Author: search.filters.author.Greco, SergioSubject: search.filters.subject.Algoritmi

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    Design and performance evaluation of algorithms for wireless self-organizing systems
    (2014-11-28) Surace, Rosario; Greco, Sergio; Loscrì, Valeria; Aloi, Gianluca
    The work done during the PhD course involves the study of the Self- Organization of wireless sensors, robots and UAV networks. In particular, this thesis investigates how each node composing the system can take advantage from the Self-Organization and from mobility, in a way to optimize some networks parameters as coverage and energy consumption. Self-Organization is a process in which pattern at the global level of a system emerges solely from numerous interactions among the lower-level components of a system. The rules specifying interactions among the systems components are executed using only local information, without reference to the global pattern [1]. Mobility, although still for some types of systems is not considered a primitive of the network: in recent years has been the subject of many studies just as useful feature to achieve certain objectives, not least the energy consumption in transmission. The network issues has been addressed using different approaches from the theoretical studies aimed at finding the maximum achievable performance benchmarks, through the introduction of appropriate optimization models, the proposal of distributed heuristics and more realistic communication protocols, and the use of biology-inspired mechanisms, such as genetic algorithms (GA) and neural networks (NN). The purpose of this type of approach is to move in the direction of networks that are able to self-organize by adapting to different environmental conditions and dynamic as well as hard scenarios (i.e. environment disasters). The rest of the thesis is organized as follows: in Chapter 1 background on Self-Organizing Systems is given. In Chapter 2 we investigate on the impact of the Propagation Environment on Controlled Mobility Algorithms; distributed heuristics to Film Sport Events with Flying Robots in Chapter 3 and Bio- Inspired approaches in Chapter 4. Finally, a new communications protocol for WSN called Decentralized Time-Synchronized Channel Swapping is analyzed in Chapter 5.
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    On the problem of checking chase termination
    (2011-11-23) Spezzano, Francesca; Palopoli, Luigi; Greco, Sergio
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    Mobile robots:localization and mapping alogorithms
    (2013-11-27) D'Alfonso, Luigi; Greco, Sergio; Muraca, Pietro; Garone, Emanuele
    In recent years, mobile robots start to be very often used in various applications involving home automation, planetary exploration, regions surveillance, rescue missions, ruins exploration. In all these elds, to accomplish its tasks, a mobile robot needs to navigate into an environment facing the localization, mapping and path planning problems. In this thesis a set of new algorithms to solve the mobile robots localization and mapping problems are proposed. The aim is to provide an accurate mobile robot estimated pose and to build a reliable map for the environment where the robot moves, ensuring algorithms computational costs low enough so that the algorithms can be used in real time, while the robot is moving. The localization problem is faced in static and dynamic contexts, assuming the environment surrounding the robot completely known, partially known or totally unknown. In the static context, localization algorithms based on the use of cameras and inertial measurement units are proposed. In the dynamic context, the mobile robots localization problem is solved by developing a set of new Kalman lter versions. About the mapping problem, two novel mapping models are de- ned. These models are used along with the proposed localization techniques to develop three algorithms able to solve the Simultaneous Localization and Mapping (SLAM) problem. All the proposed solutions are tested through numerical simulations and experimental tests in a real environment and using a real mobile robot. The results show the e ectiveness of the proposed algorithms, encouraging further researches.