1,720,984 research outputs found
Simulation and optimization of industrial production lines
No full textSimulation and optimization techniques are the pillars of for the Virtual Commissioning of modern digital factories. In particular, industrial production lines are complex systems formed by a set of machines that have several cross-dependencies (i. e., the production efficiency of a machine impact deeply performance figures of the others and affects the whole line productivity). The simulation and optimization of production lines is an integrated approach that allows finding efficiently optimized production parameters. This paper presents an example of application of the simulation to the virtual design and optimization of an industrial production line
Big Data per la diagnosi avanzata dei guasti e sistemi di monitoraggio:gestire la complessità di sistemi in ambienti distribuiti
No full textAl giorno d’oggi, il numero di dispositivi interconnessi sta aumentando
notevolmente: dispositivi utilizzati nella vita di tutti i giorni sono una
importante sorgente di dati che può essere usata per qualunque scopo.
Acquisire valore da questi dati è il compito più importante: i dati
possono essere usati per conoscere i trend all’interno dell’ambiente di
interesse, predirne il comportamento e perciò generare nuovi dati.
Questa visione può essere applicata alla gestione delle macchine
automatiche, dando la possibilità di analizzare il loro stato di
funzionamento, comprenderne e migliorarne il throughput ed effettuare
le necessarie operazioni di manutenzione in tempo.
Perciò, in un ambiente così strutturato ed interconnesso, un alto volume
di dati viene generato giorno dopo giorno, creando i Big Data: questi
sono a loro volta utilizzati per effettuare analisi approfondite e realizzare
avanzati sistemi di monitoraggio.
Il lavoro di tesi si basa su un progetto sviluppato in collaborazione con
Elettric80 S.p.A., con l’obiettivo di sviluppare un sistema di monitoraggio
per sistemi AGV a guida laser, per poi corredare l’offerta commerciale
dell’azienda. La tesi mostra inizialmente lo stato dell’arte ad oggi delle
tecniche di manutenzione, dopodiché introduce i concetti teorici su cui
essa si basa, quali:
• Big Data;
• Message Brokers;
• Sistemi di containerizzazione software;
• Hardware In the Loop;
• Industria 4.0.
La metodologia utilizzata nel progetto di tesi viene quindi illustrata: i
requisiti di progetto vengono raccolti ed analizzati. Una prima
architettura concettuale viene quindi definita: questa deve rispettare
diversi vincoli tra cui anche quello di poter gestire una grande mole di
dati, nonché poterli salvare agilmente su database. Infatti, Elettric80 ha
diversi clienti che gestiscono anche centinaia di AGV a guida laser ed il
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sistema dovrà essere in grado di poter gestire agevolmente tale
complessità.
Basandosi su questa architettura, le soluzioni software sono scelte in
modo da poter soddisfare i requisiti di progetto. La soluzione finale
viene quindi spiegata in tutte le sue componenti: partendo dalla
macchina avente il compito di poter inviare dati provenienti dai propri
sensori, un sistema installato su un server ha l’onere di acquisire tali dati,
processarli e poterli mostrare in real-time o in batches.
Soluzioni come NoSQL databases (Apache Cassandra) e Message
Brokers (Apache Kafka) sono punti cardini dell’architettura, in quanto
permettono di poter gestire agevolmente le enormi moli di dati
provenienti da tutte le macchine presenti presso il cliente, di poter quindi
analizzarli e salvarli in modo sicuro. Determinate tipologie di analisi sono
state definite con Elettric80 durante lo sviluppo della soluzione software:
analisi quali la qualità della navigazione e dei dati provenienti dai sensori
macchina sono state implementate. Una web dashboard avrà quindi il
compito di poter mostrare i dati raccolti ed analizzati. Infine, soluzioni
aggiuntive sono state implementate in modo da poter rendere tale
architettura solida: controlli vengono effettuati affinché tutti i
componenti funzionino correttamente ed azioni automatiche vengono
intraprese nel caso in cui non funzioni inaspettatamente (risoluzione
automatica delle problematiche ed allertamento dei tecnici).
Infine, i risultati raggiunti vengono quindi spiegati e commentati, nonché
l’organizzazione del lavoro mostrata. I lavori futuri vengono quindi
illustrati nell’ultimo capitolo.Nowadays, the number of interconnected devices is increasing
dramatically: devices used in everyday life are a source of data that can
be used for any purpose.
Gaining value from this data is the most important task: data can be
used for understanding the interested environmental trends, predicting
their behaviour and thus, generating new data. This view can be applied
to the management of automated machines, providing with the
possibility to analyse their working status, to understand and improve
their throughput and to accomplish the necessary maintenance
operations in time.
Thus, in a so structured and interconnected environment, high volumes
of data are being generated day by day, creating Big Data which are
ready to serve deep analyses and develop advanced monitoring
solutions.
The work thesis is based on a project developed in collaboration with
Elettric80 S.p.A., with the aim of developing a monitoring system for its
laser guided AGV systems, to then be part of the company commercial
offer. The thesis initially shows the state of the art of maintenance
techniques, then introduces the theoretical concepts on which it is
based, such as:
• Big Data;
• Message Brokers;
• Software containerisation systems;
• Hardware In the Loop;
• Industry 4.0.
The methodology used in the project is then illustrated: its requirements
are collected and analysed. A first conceptual architecture is then
defined: this must respect several constraints including the capability to
manage a large amount of data, as well as being capable to save them
easily on the database. In fact, Elettric80 has several customers who also
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manage hundreds of laser guided AGVs and the system must be able to
easily handle this complexity.
Based on this architecture, software solutions are chosen to meet the
design requirements. The final solution is then explained in all its
components: starting from the machine having the task of being able to
send data from its sensors, a system installed on a server is responsible
for acquiring such data, processing and showing it in a real-time fashion
or in terms of batches.
Solutions such as NoSQL databases (Apache Cassandra) and Message
Brokers (Apache Kafka) are milestones of the architecture, as they allow
you to easily manage huge amounts of data coming from all the
machines of the customer, to analyse and save them safely. Certain types
of analyses were defined with Elettric80 during the development of the
software solution: analyses such as the quality of navigation and data
coming from the machine sensors were implemented. A web dashboard
will then have the task of showing the collected and analysed data.
Finally, additional solutions have been implemented in order to make
this architecture solid: checks are carried out so that all the components
work properly and act in case they are not working as expected
(automatic troubleshooting and technician alerting).
Finally, the achieved results are explained and commented as well as the
way the project has been leaded shown. Future works are explained in
the last chapter
Simulation and Optimisation of Production Lines in the Framework of the IMPROVE Project
No full textSimulation is the key technology to enhance the product and production engineering processes. This paper presents an example of application of the simulation to the virtual design and optimization of a industrial production lin
Jaguar 4×4 UGV: An autonomous deployment of a wireless sensor network
No full textIn this research is reported the result of the
autonomous navigation reached with the Jaguar 4x4
platform, a commercial Unattended Ground Vehicle (UGV).
The presentation is composed mainly in three sections. The
first one present the kinematic and dynamic model used to
represent the UGV. It is a 4x4 robot with anolonomous
constraints. The second one, based on the model adopted,
presents the results of the development of an autonomous
drive system for outdoor scenario. The third section
addresses the navigation of the UGV in presence and
coordination with a wireless sensor network
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Delay-Tolerant, Low-Power Protocols for Large Security-Critical Wireless Sensor Networks
Full text linkThis paper reports the analysis, implementation, and experimental testing of a delay-tolerant and energy-aware protocol for a wireless sensor node, oriented to security applications. The solution proposed takes advantages from different domains considering as a guideline the low power consumption and facing the problems of seamless and lossy connectivity offered by the wireless medium along with very limited resources offered by a wireless network node. The paper is organized as follows: first we give an overview on delay-tolerant wireless sensor networking (DTN); then we perform a simulation-based comparative analysis of state-of-the-art DTN approaches and illustrate the improvement offered by the proposed protocol; finally we present experimental data gathered from the implementation of the proposed protocol on a proprietary hardware node
Wireless and Ad Hoc Sensor Networks: An Industrial Example Using Delay Tolerant, Low Power Protocols for Security-Critical Applications
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