Ambiente de simulação para o sistema de exploração robótica subaquática UNEXMIN

Underwater mines exploration is a valued, complex, expensive and time-consuming task. The unstable nature of the underwater environment with lack of visibility and the existence of obstructions create the need for complex navigation software which requires numerous missions and hardware/software validations. When testing and verifying control algorithms for such an operation, a simulation environment can be a very helpful tool. This also includes tools for the development of unmanned vehicle software, algorithm benchmarking and system preliminary validation. The objective in this thesis was to start the development of a simulation platform that can be used when developing and testing control systems for AUV operations. The simulator will include a dynamic model of an AUV in addition to complex world and sensor models such as DVL, IMU, Multibeam, Mechanical Scanning Imaging Sonar (MSIS), cameras, SLS and others. The simulated world includes water graphics, mine meshes, underwater visibility, currents, and hydrodynamics. Control of the robot in simulation is performed by keyboard or joystick over thrusters. The platform must be universal, such that users can implement their own algorithms easily and get immediate simulation results without needing to implement a complete control system. There should also be an easy transition between testing the control system on the simulated AUV and applying it to the real AUV. Robot Operating System (ROS) and Gazebo were used in the development of the platform. The platform with sensors and navigation was validated with real-world tests comparison.A exploração de minas subaquáticas ´e uma tarefa valiosa, complexa, dispendiosa e demorada. A natureza instável do ambiente subaquático, com falta de visibilidade e a existência de obstruções, cria a necessidade de software de navegação complexo, qual requer inúmeras missões e validações de hardware/software. Ao testar e verificar os algoritmos de controle para tal operação, um ambiente de simulação pode ser uma ferramenta muito útil. Isto também inclui ferramentas para o desenvolvimento de software de veículos não tripulados, benchmarking de algoritmos e validação preliminar do sistema. O objetivo desta tese foi iniciar o desenvolvimento de uma plataforma de simulação que possa ser usada no desenvolvimento e teste de sistemas de controle para operações de AUV. O simulador incluirá um modelo dinâmico de um AUV, além de modelos complexos do mundo e sensores, como DVL, IMU, Multibeam, MSIS, câmaras, SLS e outros. O mundo simulado inclui gráficos de ´agua, malhas de minas, visibilidade subaquática, correntes e hidrodinâmica. O controle do robô ´e realizado por teclado ou joystick sob as dinâmicas de propulsão. O simulador deve ser universal, de modo que os usuários possam implementar seus próprios algoritmos facilmente e obter resultados imediatos de simulação sem a necessidade de implementar um sistema de controle completo. Também deve haver uma transição fácil entre testar o sistema de controle no AUV simulado e aplicá-lo ao AUV real. ROS e Gazebo foram usados no desenvolvimento da plataforma. A plataforma com sensores e navegação foi validada com comparação de testes reais

Replacing internal communication protocol in UNIC control system

This thesis examines OPC-UA (Open Platform Communications Unified Architecture) and investigate how it could be used in Wärtsilä for performing internal communication on their UNIC engine control system. Features of OPC-UA are compared to the currently used in-house built protocol to find out if changing the protocol would be feasible. OPC-UA is a communication specification that standardizes information exchange of industrial automation. This thesis introduces the key concepts of the specification such as information modelling, client-server communication model, publish-subscribe communication model, and the available transportation mappings defining the concrete protocols for transportation. In addition, the current communication implementation of the control system and the services provided for system software components are inspected. After inspections, a general mapping is made between the currently provided services and the OPC-UA features. It is also discussed what transportation protocols shall be chosen for OPC-UA. The objective of the thesis is to list requirements for performing internal communication by using OPC-UA. Requirements are set for the OPC-UA software development kit features based on the mapped services and protocols. The mapped protocols also introduce requirements for the network stack of the platform software. Based on the feature mappings an architectural proposal for OPC-UA implementation on the control system is presented. It is shown how the different OPC-UA software components could be distributed between the different hardware modules of the system, how the information model and communication interfaces could be initialized in the source code, and how the servers of the different hardware modules could be aggregated into a single server. It is also presented how the information model of the control system could be structured. A short performance comparison is performed by comparing the data frame structure of the current implementation and the mapped counterpart. Finally, it is concluded that in theory OPC UA is feasible for performing the internal communication as it provides a lot of options for implementing the tasks of the current service handlers, but in practice the change contains some risks such as immaturity of the technology. Furthermore, the change would require a lot of work, and it could be questioned if the business value of the protocol change is worth the investment.Tässä opinnäytetyössä tarkastellaan OPC-UA:ta (Open Platform Communications Unified Architecture), ja selvitetään miten OPC-UA-tiedonsiirtoa voitaisiin käyttää Wärstilän UNIC-moottorinohjausjärjestelmän sisäisen tiedonsiirron suorittamiseen. OPC-UA ominaisuuksia verrataan tällä hetkellä käytössä olevaan yrityksen itse valmistamaan protokollaan, jotta saadaan selville, olisiko protokollan vaihtaminen mahdollista. OPC-UA on tietoliikennespesifikaatio, joka standardoi teollisen automaation tiedonvaihdon. Tässä opinnäytetyössä esitellään spesifikaation keskeisimmät käsitteet kuten tiedon mallintaminen, asiakas-palvelin-viestintämalli, julkaise-tilaa-viestintämalli sekä käytettävissä olevat tiedon siirtomenetelmät, jotka määrittelevät konkreettiset tiedonsiirtoon käytettävät protokollat. Tarkasteltavana on myös ohjausjärjestelmän nykyinen viestintätoteutus ja sen tarjoamat palvelut järjestelmän eri ohjelmistokomponenteille. Tarkastusten jälkeen tehdään yleinen kartoitus tämänhetkisten palvelujen ja OPC-UA:n ominaisuuksien välille. Opinnäytetyön tavoitteena on listata vaatimukset sisäisen viestinnän suorittamiselle OPC-UA:n avulla. Käytettävälle OPC-UA-ohjelmistokehityspaketille asetetaan vaatimukset kartoitettujen palvelujen ja protokollien perusteella. OPC-UA:n tarjoamat protokollat asettavat myös vaatimuksia alustaohjelmiston verkkopinolle. Ominaisuuskartoitusten perusteella esitetään myös arkkitehtoninen ehdotelma OPC-UA:n toteuttamiselle ohjausjärjestelmässä. Ehdotelma osoittaa, kuinka eri OPC-UA-ohjelmistokomponentit voitaisiin jakaa järjestelmän eri laitteistomoduulien kesken, miten tietomalli ja tietoliikennerajapinnat voidaan alustaa lähdekoodissa ja kuinka eri moduulien palvelimet voitaisiin yhdistää yhdeksi palvelimeksi. Lisäksi esitetään miten järjestelmän tietomalli voisi rakentua. Lyhyt teoreettinen suorituskykyvertailu suoritetaan vertaamalla nykyisen toteutuksen datakehysrakennetta ja kartoitettua vastinetta. Lopuksi todetaan, että teoriassa OPC-UA on käyttökelpoinen sisäisen viestinnän suorittamiseen, koska se tarjoaa paljon vaihtoehtoja nykyisten palvelunkäsittelijöiden tehtävien toteuttamiseen. Käytännössä muutokseen sisältyy kuitenkin riskejä, kuten tekniikan tuoreuteen liittyvä epäkypsyys. Muutos vaatisi paljon työtä ja protokollamuutoksen tuottama liikearvo on hieman kyseenalainen verrattuna vaadittuun investointiin

IoT Middleware Platforms for Smart Energy Systems: An Empirical Expert Survey

Middleware platforms are key technology in any Internet of Things (IoT) system, considering their role in managing the intermediary communications between devices and applications. In the energy sector, it has been shown that IoT devices enable the integration of all network assets to one large distributed system. This comes with significant benefits, such as improving energy efficiency, boosting the generation of renewable energy, reducing maintenance costs and increasing comfort. Various existing IoT middlware solutions encounter several problems that limit their performance, such as vendor locks. Hence, this paper presents a literature review and an expert survey on IoT middleware platforms in energy systems, in order to provide a set of tools and functionalities to be supported by any future efficient, flexible and interoperable IoT middleware considering the market needs. The analysis of the results shows that experts currently use the IoT middleware mainly to deploy services such as visualization, monitoring and benchmarking of energy consumption, and energy optimization is considered as a future application to target. Likewise, non-functional requirements, such as security and privacy, play vital roles in the IoT platforms’ performances

A Service-Oriented Approach for Network-Centric Data Integration and Its Application to Maritime Surveillance

Maritime-surveillance operators still demand for an integrated maritime picture better supporting international coordination for their operations, as looked for in the European area. In this area, many data-integration efforts have been interpreted in the past as the problem of designing, building and maintaining huge centralized repositories. Current research activities are instead leveraging service-oriented principles to achieve more flexible and network-centric solutions to systems and data integration. In this direction, this article reports on the design of a SOA platform, the Service and Application Integration (SAI) system, targeting novel approaches for legacy data and systems integration in the maritime surveillance domain. We have developed a proof-of-concept of the main system capabilities to assess feasibility of our approach and to evaluate how the SAI middleware architecture can fit application requirements for dynamic data search, aggregation and delivery in the distributed maritime domain

Filtering Real-Time Linked Data Streams

Viimastel aastetel on veebis kiiresti kasvanud lingitud andmete hulk. Lingitud andmeid, mis on tihti kodeeritud RDF-formaadis, peetakse “viie tärni” andmeteks avatud andmete kontekstis tänu nende kasutatavusele ja potentsiaalile. Kuigi on märgata progressi lingitud andmete tehnoloogiate arengus ja nende töötlemises, pole veel suudetud nende täit potentsiaali saavutada. Üks väljakutsetest on lingitud andmevoogude peal järelduste tegemine, mis on alles hiljuti hakkanud uuringutes koguma hoogu. Nende tulemusena on pakutud välja päringu keeled nagu C-SPARQL ja loodud tuletusmootorite implementatsioonid. Neid mootoreid on senini testitud ainult akadeemilistes keskkondades. Selle töö eesmärk on luua täielikult töötav prototüüp lingitud andmevoogude töötlemiseks sõnumipõhistes süsteemides, mis suudab lingitud andmetest koosnevat sõnumite järjekorda näha kui andmevoogu ja filtreerida seda C-SPARQL-i mootoriga, mis oli üks esimesi omalaadseid. Selle süsteemi südames olevat C-SPARQL-i mootorit testisime CityBench võrdlusuuringu programmiga võttes arvesse ärivaldkonda kuuluvat reaalaja rakendust Inforegister NOW!, mis on veel arendusfaasis.The amount of linked data in the Web has increased rapidly in recent years. Linked data, often encoded in RDF, is considered as five-star data in the context of open data due to its usability and potential. Although there has been progress in development of linked data technologies and data processing models, still the full potential of linked data has not been realized. One of the challenges is reasoning over linked data streams, which has just recently gained momentum in research. As a result query languages, such as C-SPARQL, have been proposed and corresponding stream reasoning engines have been implemented. However, such implementations have been evaluated so far mostly in academic settings. This work describes a fully functional proof of concept implementation of a stream reasoning system for message-oriented systems, which is capable of exposing a message queue as a linked data stream, which can be filtered by using C-SPARQL - one of the earliest linked data processing engines. The performance of the C-SPARQL engine, which lies at the heart of the implementation, is evaluated by using CityBench benchmark with settings of an enterprise-scale real-time economy application Inforegister NOW!, which is currently under development

Message Flow Analysis with Complex Causal Links for Distributed ROS 2 Systems

Distributed robotic systems rely heavily on the publish-subscribe communication paradigm and middleware frameworks that support it, such as the Robot Operating System (ROS), to efficiently implement modular computation graphs. The ROS 2 executor, a high-level task scheduler which handles ROS 2 messages, is a performance bottleneck. We extend ros2_tracing, a framework with instrumentation and tools for real-time tracing of ROS 2, with the analysis and visualization of the flow of messages across distributed ROS 2 systems. Our method detects one-to-many and many-to-many causal links between input and output messages, including indirect causal links through simple user-level annotations. We validate our method on both synthetic and real robotic systems, and demonstrate its low runtime overhead. Moreover, the underlying intermediate execution representation database can be further leveraged to extract additional metrics and high-level results. This can provide valuable timing and scheduling information to further study and improve the ROS 2 executor as well as optimize any ROS 2 system. The source code is available at: https://github.com/christophebedard/ros2-message-flow-analysis.Comment: 14 pages, 12 figure

Distributing Real Time Data From a Multi-Node Large Scale Contact Center Using Corba

This thesis researches and evaluates the current technologies available for developing a system for propagation of Real-Time Data from a large scale Enterprise Server to large numbers of registered clients on the network. The large scale Enterprise Server being implemented is a Contact Centre Server, which can be a standalone system or part of a multi-nodal system. This paper makes three contributions to the study of scalable real-time notification services. Firstly, it defines the research of the different technologies and their implementation for distributed objects in today\u27s world of computing. Secondly, the paper explains how we have addressed key design challenges faced when implementing a Notification Service for TAO, which is our CORBA-compliant real-time Object Request Broker (ORB). The paper shows how to integrate and configure CORBA features to provide real-time event communication. Finally, the paper analyzes the results of the implementation and how it compares to existing technologies being used for the propagation of Real-Time Data

Distributed computing in space-based wireless sensor networks

This thesis investigates the application of distributed computing in general and wireless sensor networks in particular to space applications. Particularly, the thesis addresses issues related to the design of "space-based wireless sensor networks" that consist of ultra-small satellite nodes flying together in close formations. The design space of space-based wireless sensor networks is explored. Consequently, a methodology for designing space-based wireless sensor networks is proposed that is based on a modular architecture. The hardware modules take the form of 3-D Multi-Chip Modules (MCM). The design of hardware modules is demonstrated by designing a representative on-board computer module. The onboard computer module contains an FPGA which includes a system-on-chip architecture that is based on soft components and provides a degree of flexibility at the later stages of the design of the mission.EThOS - Electronic Theses Online ServiceGBUnited Kingdo