117 research outputs found
Modeling and Simulation Methodologies for Digital Twin in Industry 4.0
The concept of Industry 4.0 represents an innovative vision of what will be the factory of the future. The principles of this new paradigm are based on interoperability and data exchange between dierent industrial equipment. In this context, Cyber- Physical Systems (CPSs) cover one of the main roles in this revolution. The combination of models and the integration of real data coming from the field allows to obtain the virtual copy of the real plant, also called Digital Twin. The entire factory can be seen as a set of CPSs and the resulting system is also called Cyber-Physical Production System (CPPS). This CPPS represents the Digital Twin of the factory with which it would be possible analyze the real factory. The interoperability between the real industrial equipment and the Digital Twin allows to make predictions concerning the quality of the products. More in details, these analyses are related to the variability of production quality, prediction of the maintenance cycle, the accurate estimation of energy consumption and other extra-functional properties of the system. Several tools [2] allow to model a production line, considering dierent aspects of the factory (i.e. geometrical properties, the information flows etc.) However, these simulators do not provide natively any solution for the design integration of CPSs, making impossible to have precise analysis concerning the real factory. Furthermore, for the best of our knowledge, there are no solution regarding a clear integration of data coming from real equipment into CPS models that composes the entire production line. In this context, the goal of this thesis aims to define an unified methodology to design and simulate the Digital Twin of a plant, integrating data coming from real equipment. In detail, the presented methodologies focus mainly on: integration of heterogeneous models in production line simulators; Integration of heterogeneous models with ad-hoc simulation strategies; Multi-level simulation approach of CPS and integration of real data coming from sensors into models. All the presented contributions produce an environment that allows to perform simulation of the plant based not only on synthetic data, but also on real data coming from equipments
Forder Application
Dissertação de Mestrado em Engenharia InformáticaIn Portugal eating out is a part of the lifestyle. People meet in coffee shops and restaurants, creating
business opportunities for the owners of the places. In the summer season there are many bars that open
their terrace service. Like many business, there are some ‘quiet times’ during the day – moments, when
the place doesn’t receive so many clients.
This project proposes an idea on how to maintain the efficiency of the outdoor service with possibly
lower costs for the company. The application presented in the given project enables clients to make their
requests directly from the table using a cellphone. In the next step the employee receives a notification
with the request and he can prepare and deliver the order. Combining Proximity Communication Technologies
and a web and mobile application, the communication between a client and an employee may
turn out to be fast and comfortable. This solution can have an impact on the number of employees during
a calmer time. It is also expected that the client will be able to receive his order in the faster way, through
the implemented innovation
Automated Validation of State-Based Client-Centric Isolation with TLA <sup>+</sup>
Clear consistency guarantees on data are paramount for the design and implementation of distributed systems. When implementing distributed applications, developers require approaches to verify the data consistency guarantees of an implementation choice. Crooks et al. define a state-based and client-centric model of database isolation. This paper formalizes this state-based model in, reproduces their examples and shows how to model check runtime traces and algorithms with this formalization. The formalized model in enables semi-automatic model checking for different implementation alternatives for transactional operations and allows checking of conformance to isolation levels. We reproduce examples of the original paper and confirm the isolation guarantees of the combination of the well-known 2-phase locking and 2-phase commit algorithms. Using model checking this formalization can also help finding bugs in incorrect specifications. This improves feasibility of automated checking of isolation guarantees in synthesized synchronization implementations and it provides an environment for experimenting with new designs.</p
A Problem-Oriented Approach for Dynamic Verification of Heterogeneous Embedded Systems
This work presents a virtual prototyping methodology for the design and verification of industrial devices in the field level of industrial automation systems. This work demonstrates that virtual prototypes can help increase the confidence in the correctness of a design thanks to a deeper understanding of the complex interactions between hardware, software, analog and mixed-signal components of embedded systems and the physical processes they interact with
New Secure IoT Architectures, Communication Protocols and User Interaction Technologies for Home Automation, Industrial and Smart Environments
Programa Oficial de Doutoramento en TecnoloxÃas da Información e das Comunicacións en Redes Móbiles. 5029V01Tese por compendio de publicacións[Abstract]
The Internet of Things (IoT) presents a communication network where heterogeneous
physical devices such as vehicles, homes, urban infrastructures or industrial machinery
are interconnected and share data. For these communications to be successful, it is
necessary to integrate and embed electronic devices that allow for obtaining environmental
information (sensors), for performing physical actuations (actuators) as well as
for sending and receiving data (network interfaces).
This integration of embedded systems poses several challenges. It is needed for these
devices to present very low power consumption. In many cases IoT nodes are powered by
batteries or constrained power supplies. Moreover, the great amount of devices needed in
an IoT network makes power e ciency one of the major concerns of these deployments,
due to the cost and environmental impact of the energy consumption. This need for low
energy consumption is demanded by resource constrained devices, con
icting with the
second major concern of IoT: security and data privacy. There are critical urban and
industrial systems, such as tra c management, water supply, maritime control, railway
control or high risk industrial manufacturing systems such as oil re neries that will
obtain great bene ts from IoT deployments, for which non-authorized access can posse
severe risks for public safety. On the other hand, both these public systems and the
ones deployed on private environments (homes, working places, malls) present a risk for
the privacy and security of their users. These IoT deployments need advanced security
mechanisms, both to prevent access to the devices and to protect the data exchanged
by them.
As a consequence, it is needed to improve two main aspects: energy e ciency of IoT
devices and the use of lightweight security mechanisms that can be implemented by
these resource constrained devices but at the same time guarantee a fair degree of
security.
The huge amount of data transmitted by this type of networks also presents another
challenge. There are big data systems capable of processing large amounts of data,
but with IoT the granularity and dispersion of the generated information presents a
new scenario very di erent from the one existing nowadays. Forecasts anticipate that there will be a growth from the 15 billion installed devices in 2015 to more than 75
billion devices in 2025. Moreover, there will be much more services exploiting the data
produced by these networks, meaning the resulting tra c will be even higher. The
information must not only be processed in real time, but data mining processes will
have to be performed to historical data.
The main goal of this Ph.D. thesis is to analyze each one of the previously described
challenges and to provide solutions that allow for an adequate adoption of IoT in
Industrial, domestic and, in general, any scenario that can obtain any bene t from the
interconnection and
exibility that IoT brings.[Resumen]
La internet de las cosas (IoT o Internet of Things) representa una red de intercomunicaciones
en la que participan dispositivos fÃsicos de toda Ãndole, como vehÃculos,
viviendas, electrodomésticos, infraestructuras urbanas o maquinaria y dispositivos industriales.
Para que esta comunicación se pueda llevar a cabo es necesario integrar
elementos electr onicos que permitan obtener informaci on del entorno (sensores), realizar
acciones f sicas (actuadores) y enviar y recibir la informaci on necesaria (interfaces de
comunicaciones de red).
La integración y uso de estos sistemas electrónicos embebidos supone varios retos. Es
necesario que dichos dispositivos presenten un consumo reducido. En muchos casos
deberÃan ser alimentados por baterÃas o fuentes de alimentación limitadas. Además,
la gran cantidad de dispositivos que involucra la IoT hace necesario que la e ciencia
energética de los mismos sea una de las principales preocupaciones, por el coste e
implicaciones medioambientales que supone el consumo de electricidad de los mismos.
Esta necesidad de limitar el consumo provoca que dichos dispositivos tengan unas
prestaciones muy limitadas, lo que entra en conflicto con la segunda mayor preocupación
de la IoT: la seguridad y privacidad de los datos. Por un lado existen sistemas crÃticos
urbanos e industriales, como puede ser la regulación del tráfi co, el control del suministro
de agua, el control marÃtimo, el control ferroviario o los sistemas de producción industrial
de alto riesgo, como refi nerÃas, que son claros candidatos a benefi ciarse de la IoT, pero
cuyo acceso no autorizado supone graves problemas de seguridad ciudadana. Por otro
lado, tanto estos sistemas de naturaleza publica, como los que se desplieguen en entornos
privados (viviendas, entornos de trabajo o centros comerciales, entre otros) suponen
un riesgo para la privacidad y también para la seguridad de los usuarios. Todo esto
hace que sean necesarios mecanismos de seguridad avanzados, tanto de acceso a los
dispositivos como de protección de los datos que estos intercambian.
En consecuencia, es necesario avanzar en dos aspectos principales: la e ciencia energética de los dispositivos y el uso de mecanismos de seguridad e ficientes, tanto
computacional como energéticamente, que permitan la implantación de la IoT sin
comprometer la seguridad y la privacidad de los usuarios. Por otro lado, la ingente cantidad de información que estos sistemas puede llegar
a producir presenta otros dos retos que deben ser afrontados. En primer lugar, el
tratamiento y análisis de datos toma una nueva dimensión. Existen sistemas de big
data capaces de procesar cantidades enormes de información, pero con la internet de
las cosas la granularidad y dispersión de los datos plantean un escenario muy distinto
al actual. La previsión es pasar de 15.000.000.000 de dispositivos instalados en 2015
a más de 75.000.000.000 en 2025. Además existirán multitud de servicios que harán
un uso intensivo de estos dispositivos y de los datos que estos intercambian, por lo
que el volumen de tráfico será todavÃa mayor. Asimismo, la información debe ser
procesada tanto en tiempo real como a posteriori sobre históricos, lo que permite
obtener información estadÃstica muy relevante en diferentes entornos.
El principal objetivo de la presente tesis doctoral es analizar cada uno de estos retos
(e ciencia energética, seguridad, procesamiento de datos e interacción con el usuario)
y plantear soluciones que permitan una correcta adopción de la internet de las cosas
en ámbitos industriales, domésticos y en general en cualquier escenario que se pueda
bene ciar de la interconexión y
flexibilidad de acceso que proporciona el IoT.[Resumo]
O internet das cousas (IoT ou Internet of Things) representa unha rede de intercomunicaci
óns na que participan dispositivos fÃsicos moi diversos, coma vehÃculos, vivendas,
electrodomésticos, infraestruturas urbanas ou maquinaria e dispositivos industriais.
Para que estas comunicacións se poidan levar a cabo é necesario integrar elementos
electrónicos que permitan obter información da contorna (sensores), realizar accións
fÃsicas (actuadores) e enviar e recibir a información necesaria (interfaces de comunicacións
de rede).
A integración e uso destes sistemas electrónicos integrados supón varios retos. En
primeiro lugar, é necesario que estes dispositivos teñan un consumo reducido. En
moitos casos deberÃan ser alimentados por baterÃas ou fontes de alimentación limitadas.
Ademais, a gran cantidade de dispositivos que se empregan na IoT fai necesario que a
e ciencia enerxética dos mesmos sexa unha das principais preocupacións, polo custo e
implicacións medioambientais que supón o consumo de electricidade dos mesmos. Esta
necesidade de limitar o consumo provoca que estes dispositivos teñan unhas prestacións
moi limitadas, o que entra en con
ito coa segunda maior preocupación da IoT: a
seguridade e privacidade dos datos. Por un lado existen sistemas crÃticos urbanos e
industriais, como pode ser a regulación do tráfi co, o control de augas, o control marÃtimo,
o control ferroviario ou os sistemas de produción industrial de alto risco, como refinerÃas,
que son claros candidatos a obter benefi cios da IoT, pero cuxo acceso non autorizado
supón graves problemas de seguridade cidadá. Por outra parte tanto estes sistemas de
natureza pública como os que se despreguen en contornas privadas (vivendas, contornas
de traballo ou centros comerciais entre outros) supoñen un risco para a privacidade e
tamén para a seguridade dos usuarios. Todo isto fai que sexan necesarios mecanismos
de seguridade avanzados, tanto de acceso aos dispositivos como de protección dos datos
que estes intercambian.
En consecuencia, é necesario avanzar en dous aspectos principais: a e ciencia enerxética
dos dispositivos e o uso de mecanismos de seguridade re cientes, tanto computacional
como enerxéticamente, que permitan o despregue da IoT sen comprometer a seguridade
e a privacidade dos usuarios.
Por outro lado, a inxente cantidade de información que estes sistemas poden chegar
a xerar presenta outros retos que deben ser tratados. O tratamento e a análise de
datos toma unha nova dimensión. Existen sistemas de big data capaces de procesar
cantidades enormes de información, pero coa internet das cousas a granularidade e
dispersión dos datos supón un escenario moi distinto ao actual. A previsión e pasar
de 15.000.000.000 de dispositivos instalados no ano 2015 a m ais de 75.000.000.000 de
dispositivos no ano 2025. Ademais existirÃan multitude de servizos que farÃan un uso
intensivo destes dispositivos e dos datos que intercambian, polo que o volume de tráfico
serÃa aÃnda maior. Do mesmo xeito a información debe ser procesada tanto en tempo
real como posteriormente sobre históricos, o que permite obter información estatÃstica
moi relevante en diferentes contornas.
O principal obxectivo da presente tese doutoral é analizar cada un destes retos
(e ciencia enerxética, seguridade, procesamento de datos e interacción co usuario) e
propor solucións que permitan unha correcta adopción da internet das cousas en ámbitos
industriais, domésticos e en xeral en todo aquel escenario que se poda bene ciar da
interconexión e
flexibilidade de acceso que proporciona a IoT
MODELING HYPERBARIC CHAMBER ENVIRONMENT AND CONTROL SYSTEM
Deep water activities are essential for many industrial fields, for instance in repairing and
installation of underwater cables, pipes and constructions, marine salvage and rescue opera-
tions. In some cases, these activities must be performed in deep water and hence require
special equipment and prepared and experienced personnel. In some critical situations, re-
motely controlled vehicles (ROVs) can't be used and a human diver intervention is required.
In the last case, divers are required to perform work at high depths, which could be as low
as 300m below the water surface. Usually, this is the limit depth for commercial diving and
when operations must be carried out even deeper, ROVs remain only possibility to perform
them. In the past, the safety regulations were less strict and numerous operations on depth
of 300-350 meters of seawater were conducted. However, in the beginning of the 90s gov-
ernments and companies started to impose limits on depths of operation; for instance, in
Norway maximum operational depth for saturation divers is limited to 180 meters of sea-
water (Imbert et al., 2019).
Obviously, harsh environmental conditions impose various limitations on performed activi-
ties; indeed, low temperature, poor visibility and high pressure make it difficult not only to
operate at depth, but even to achieve the point of intervention.
One of the main problems is related to elevated pressure, which rises for about 1 bar for each
10 meters of water depth and could achieve up to 20-25 bars at required depth, while pressure
inside divers\u2019 atmospheric diving suites must be nearly the same. Considering this, there are
several evident limitations. First is related to the fact that at high atmospheric pressure oxy-
gen becomes poisonous for human body and special breath gas mixtures are required to
avoid health issues. The second one is maximum pressure variation rate which would not
cause damage for the human body; indeed, fast compression or decompression could easily
cause severe damages and even death of divers. Furthermore, surveys found that circa 1/3 of
divers experience headache during decompression which usually last for at least several
hours and up to several days (Imbert et al., 2019). The same study indicates that majority of
the divers experience fatigue after saturation and it lasts on average more than 4 days before
return to normal. Obviously, risk of accidents increases with high number of compression-
decompression cycles.
To address these issues, in commercial deep water diving the common practice is to perform
pressurization only one time before the start of the work activity which typically lasts 20-30
days and consequent depressurization after its end. Hence, divers are living for several weeks
in isolated pressurized environments, typically placed on board of a Dive Support Vessel
(DSV), usually barge or a ship, and go up and down to the workplace using submersible
decompression chamber also known as the bell.
While long-term work shifts provide numerous advantages, there is still necessity to perform
life support supervision of the plant, the bell and the diving suits, which require presence of
well qualified personnel. Currently, most of training activities are performed on empty plant
during idle time, but obviously this approach is low efficient and costly, as well as accom-
panied by the risk to broke equipment.
To address such issues, this research project proposes utilization of simulator of plant and
its life support system, devoted to train future Life-Support Supervisors (LSS), taking into
account gas dynamics, human behaviour and physiology as well as various aspect of opera-
tion of saturation diving plants
A Disease Tracking EHR for Ghana
The goal of the project was to develop a disease tracking electronic health record (EHR) system for Ghana in order to improve efficiency within medical facilities and to increase the quality of patient care. There are only a few medical facilities that have implemented EHR systems, and even fewer with immunization and disease tracking. Our proposed system, VermaMS, stores a history of patient visits for every patient diagnosed with malaria, tuberculosis, or meningitis. Users of the application are able to view patient data graphically as well as generate a report that contains information on each patient’s visit. VermaMS is intended to be used in conjunction with the current EHR systems, but it could potentially be developed into a full EHR system of its own in the future
Co-Simulation in Virtual Verification of Vehicles with Mechatronic Systems
In virtual verification of vehicle and mechatronic systems, a mixture of subsystems are integrated numerically in an offline simulation or integrated physically in a hardware-in-loop (HIL) simulation. This heterogeneous engineering approach is crucial for system-level development and widely spreads with\ua0the industrial standard, e.g. Functional Mock-Up Interface (FMI) standard.For the engineers, not only the local subsystem and solver should be known,\ua0but also the global coupled dynamic system and its coupling effect need to be\ua0understood. Both the local and global factors influence the stability, accuracy, numerical efficiency and further on the real-time simulation capability.In this thesis, the explicit parallel co-simulation, which is the most common and closest to the integration with a physical system, is investigated.In the vehicle development, the vehicle and the mechatronic system, e.g. an\ua0Electrcial Power Assisted Steering (EPAS) system can be simulated moreefficiently by a tailored solver and communicative step. The accuracy and\ua0numerical stability problem, which highly depends on the interface dynamics, can be investigated similarly in the linear robust control framework. The\ua0vehicle-mechatronic system should be coupled to give a smaller loop gain for robustness and stability. Physically, it indicates that the splitting part\ua0should be less stiff and the force or torque variable should be applied towardsthe part with a higher impedance in the force-displacement coupling. Furthermore, to compensate the troublesome low-passed and delay effect fromthe coupling, a new coupling method based on H∞ synthesis is developed,\ua0which can improve the accuracy of co-simulation. The method shows robustness to the system dynamics, which makes it more applicable for a complex\ua0vehicle-mechatronic system
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