ISEL - Eng. Mecan. - Comunicações
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- Diagnosing Power Transistor Faults in Multilevel T-Type Based Nine Switch Inverter Using Center of Mass IndexesPublication . Monteiro, Joaquim; Amaral, Tito; Silva, J. Fernando; Pinto, Sonia; Fernao Pires, VitorNine-switch voltage source inverters (NSVSI) are DC-AC converters that utilize a reduced number of switches, making them advantageous for dual or six-phase motors. To enhance the quality of the output voltage and provide fault tolerant capability, NSVSI topologies, like the T-Type-based NSVSI, have been modified to operate as multilevel converters. However, to ensure fault-tolerant capability, a fault diagnosis algorithm for power transistors must be developed. Therefore, this paper proposes a novel fault detection and diagnosis algorithm to identify faulty transistors in a multilevel T-Type-based NSVSI. This method is based on the development of specific indices derived from the center of mass of the output currents. The proposed technique offers a fast and reliable solution, demonstrating robustness under various load conditions. The effectiveness of this method will be validated through a series of simulation tests.
- Towards a hardware-in-the-loop quantum optical ground station simulator and testbedPublication . Niehus, Manfred; Simão, José; Silva, João Castanheira da; Serrador, António; Carvalho, João M.; Gonçalves Cavaco Mendes, Mário JoséA single pass Bennett-Brassard 1984 protocol quantum key distribution downlink from a small quantum satellite in low earth orbit to an optical ground station is studied with the objective to develop the framework for a hardware-in-the-loop quantum optical ground station simulator and testbed.
- Hardware-in-the-loop testing framework for active accumulator wave energy convertersPublication . Guedes Soares, Carlos; Gonçalves Cavaco Mendes, Mário José; Gaspar, José; Zeng, ChenThe hardware-in-the-loop technique is a hybrid co-simulation approach that joins real physical and virtual components. The real components may be the power take-off while the virtual ones the numerical models of sea wave and wave energy converter hydrodynamics. This simulation approach has been published with some regularity, however a review of the state-of-the-art has not been found, in particular in the research field dedicated to wave energy converters. Thus, the objective of this paper is to provide the ongoing results of such review, such as the generic testing framework and taxonomy, and their articulation on the simulation of a new oil-hydraulic power take-off concept. In this new concept, different power take-off nominal pressures may be regulated according to different sea states, by changing the hydraulic accumulator charging characteristics. Therefore, this active accumulator is intended to allow an increase on the range of possible Power Take-Off damping forces, thus, better wave energy harvesting performance. The paper results are also intended to support novice and advanced researchers to design simulation approaches in a clear and appropriate manner.
- Oracle for guidance with deep neural networks in reusable launch vehicle landingPublication . Igreja, José; Lemos, Joao MOracles are of paramount importance for Deep Neural Networks training. In this paper, an oracle developed for landing reusable launch vehicles is created from a linearizing feedback control law that can perform a prescribed landing trajectory tracking. The oracle is then used to train a Deep Neural Network that can be used as a guidance system for landing maneuvers. Verification is performed by Monte-Carlo.
- A photorealistic digital twin for a tank truck washing robotic systemPublication . Vicente, Luís; Lomelino, Pedro; Carreira, Fernando; Campos, Francisco M.; Gonçalves Cavaco Mendes, Mário José; Calado, J. M. F.In the current industrial context, the adoption of a digital twin (DT) has proven to be an appropriate tool to optimize the entire lifecycle of a system. This vision includes the adoption of a DT, in the collaborative network of organizations from the virtual modeling of a system, through its control, operation, namely simulation, implementation, and monitoring/supervision. To take full advantage of DTs, it is essential that they are as photorealistic as possible, allowing all kinds of simulations to be carried out, for example testing vision algorithms. In this context, this paper presents the development of a DT that is integrated as a collaborative system to monitor all phases of the life cycle of a robot destined to wash tank truck. The Unreal Engine 4 software was used to develop a DT and the communication architecture was designed, using the standard OPC UA protocol.
- MySafeFiller adaptador para o enchimento de garrafas de água impresso em 3DPublication . Monge, Nuno; Matos, M.; Sousa, Ana Catarina; Barreiros, Ana Maria; Gonçalves Cavaco Mendes, Mário José; Costa, Alexandra; Silva, HugoO MySafeFiller facilita o enchimento de todo o tipo garrafas de água reutilizáveis, com diferentes diâmetros de bocais e diferentes tamanhos, em qualquer torneira de abastecimento de água potável, bebedouro público ou dispensador de água, permite encher a garrafa inclinada sem esta encostar à torneira e sem verter água. Além disso, evita a contaminação do local de abastecimento pelo contacto com o bocal de uma garrafa, e do bocal da garrafa pelo contacto com o local de abastecimento, torneira de abastecimento de água potável, bebedouro público ou dispensador de água.
- Medidas para poupança de água – abordagens concretas implementadas no ISEL através do projeto de sustentabilidade MySafeWaterPublication . Matos, Manuel; Monge, Nuno; Gonçalves Cavaco Mendes, Mário José; Sousa, Ana Catarina; Silva, Hugo; Costa, Alexandra; Barreiros, Ana MariaO Projeto MySafeWater pretendeu fomentar o uso eficiente da água através de ações concretas para uma melhor gestão dos recursos hídricos numa escola do Ensino Superior, prevenindo a produção de resíduos, diminuído a pegada ecológica. Tendo por base os objetivos, este projeto assentou em três grandes eixos de atuação que serão descritos em detalhe na comunicação a apresentar e resumidamente descritos de seguida.
- O projeto MySafeWater no ISELPublication . Barreiros, Ana Maria; Silva, Hugo; Matos, Manuel; Gonçalves Cavaco Mendes, Mário José; Monge, Nuno; Sousa, Ana Catarina; Costa, AlexandraO projeto MySafeWater pretendeu promover os objetivos nacionais e europeus, em matéria de Ambiente, no que se refere essencialmente à promoção do “consumo da água da torneira como forma ambientalmente sustentável de consumo, prevenindo a produção de resíduos e diminuindo a pegada ecológica”, através da informação e da conscientização do papel dos cidadãos na promoção do desenvolvimento sustentável em aspetos como a qualidade da água para consumo humano, abrangendo a participação ativa do público e pela sensibilização ambiental e a participação passiva do público.
- Industry 4.0 in maintenance: Using condition monitoring in electric machinesPublication . Domingues, NunoIndustry traditionally considered maintenance as a cost and a necessity to replace equipment and machines, but the path has changed to better focus on maintenance to prevent faults and it was designated as predictive. The ones motivated to take these advantages are faced with two of the biggest barriers: the investment it requires and the difficulty to develop algorithms. The costs of installation are still high, but the avoided costs surpass it. Also, Internet of Things (IoT) has brought a big shift, which is been known as the industry 4.0. One of the potentials in maintenance is the conditioning monitoring. Condition monitoring sensors and devices are now linked to maintenance platforms, providing real-time data. This new connectivity is both more affordable and easier to implement than predictive maintenance. Real-time data allows managers to adjust preventive maintenance plans while providing greater reliability. At the same time, artificial intelligence manages this data to recognize patterns, which is one of the most promising advances in digital reliability. So, regardless of the ability to immediately implement a preventive maintenance plan, condition monitoring is an asset itself. The present paper presents the common faults on electric machines, their effects, their impact on the industry and the main techniques on condition control to prevent them. It is also added the reflection on the use of IoT to enhance the potential of condition control maintenance. The implementation of continuous improvement actions throughout the life of the equipment allows to increase efficiency, either by overcoming weaknesses or by adapting production or operational capacities to processes, production or maintenance, avoiding under maintenance or over maintenance and minimizing operating costs.
- A framework based on fuzzy logic to manage risk in an open innovation contextPublication . Santos, Ricardo; Abreu, António; Calado, João Manuel Ferreira; Soares, José Miguel; Martins, José Duarte MoleiroVirtual enterprises (VE), is well-known to make use of open innovation to achieve competitiveness, through innovation on product development. However, its limited resources, combined with the innovation resulted from the diversity of partners involved, rises some challenges to its management, specifically regarded with risk management. To fulfill these requirements, risk management's models, have been conceived to assist managers, on preventing threats with such risks, although without adequately incorporate the influence of each process domain on product development, as well as the subjectivity regarding human perception. In order to consider these issues, this work presents an approach, supported by fuzzy logic, to assess the risk's level on product development in an open innovation context. The model robustness, will be assessed through a case study, where it will be also discussed the benefits and challenges found.