EN - PCCIN - Produção Científica do Centro de Investigação Naval (CINAV)
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Browsing EN - PCCIN - Produção Científica do Centro de Investigação Naval (CINAV) by Sustainable Development Goals (SDG) "09:Indústria, Inovação e Infraestruturas"
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- Advanced Methodologies Applied in a Dynamic Maintenance ContextPublication . Lampreia, S.; Lobo, Victor; Vairinhos, V.Maintaining military systems in a dynamic context presents unique challenges that require advanced methodologies to ensure the operational readiness and effectiveness of the Armed Forces. This article analyses and discusses advanced methodologies applied in the maintenance of military technology, highlighting their contributions to the optimization of the maintenance process in constantly evolving operational environments. Initially, we address the importance of predictive maintenance, which uses techniques such as real-time data analysis, condition monitoring and machine learning algorithms to predict failures and proactively schedule maintenance interventions. This approach minimizes downtime, and costs associated with corrective maintenance, significantly increasing the availability of military systems. Additionally, we explore the application of emerging technologies, databases and the use of smart sensors integrated into military equipment. These technologies enable the continuous collection of performance and condition data, enabling a more comprehensive understanding of the state of each component and system. This not only facilitates early detection of anomalies, but also supports data driven decision making, resulting in more efficient and accurate maintenance. The use of condition-based maintenance approaches is also discussed in this article. These methodologies consider not only the age or time of use of the equipment, but also its actual state of operation. By continuously monitoring operating conditions, it is possible to extend the life of systs, reduce unnecessary wear and tear, and plan maintenance interventions more effectively. Finally, we highlight the importance of integrating computer-aided maintenance management systems and decision support systems. The combination of these tools provides a comprehensive environment for planning, executing and analysing maintenance activities, enabling more efficient resource management and a more agile response to operational demands. In short, this article demonstrates how the adoption of advanced methodologies in the maintenance of military technology is fundamental to ensuring the operational readiness and effectiveness of the Armed Forces in a dynamic and constantly evolving context.
- Digital to analog converter based on pulse-width addingPublication . Viegas, Vitor; Pereira, J. M. DiasThis paper presents a digital-to-analog converter(DAC) based on the pulse width created naturally by the binary counting sequence. Theconcept involves combining the counting impulses of the bits to forma pulse-width modulated signal,where the mean voltage is proportional to the input digital code. We propose a circuit capable of achieving this using general purpose components. Although our design targets 8bits, it is scalable for any number of nibbles. The paper details simulations conducted to verify the proper functioning of the circuit and to evaluate its performance.Tests were performed to determine the static characteristics of the converter, measure its differentia nonlinearity(DNL),and observe its step response. Instaticterms,theconverterexhibitednegligiblegainandoffseterrors,withaDNLbelow1LSB(least significant bit).The converter operated correctly without any missing codes. In dynamic terms,the converter demonstrated a band width of 10kHzand behaved like a second-orderlow-pass filter with critical damping.
- A dual-proposal device for condition-based maintenance and energy harvesting in the context of IIoT applicationsPublication . Pereira, José Dias; Viegas, Vitor; Postolache, Octavian; Girão, Pedro SilvaThis paper presents a dual-purpose device for condition-based maintenance (CBM) and for energy harvesting (EH) in IIoT applications. Vibration monitoring in industrial environments is a key indicator for predictive maintenance purposes and for energy harvesting. The paper includes the description of the hardware and software of a flexible platform that permits vibration measurements, vibration sensor calibration and energy harvesting testing. The vibration exciter included in the platform can be controlled by the output signal of a common signal generator. The platform also includes a differential temperature sensor that can gather additional data for CBM purposes. The final part of the paper includes experimental results of a vibration sensor under characterization and of the performance evaluation of a commercial EH module.
- Dynamic Maintenance Based on Fuzzy LogicPublication . Lampreia Suzana; Mestre, Inês; Morgado T. & Navas H.Currently, certain maritime assets are confronted with the challenge of optimizing their performance, even when resources are limited. They strive to minimize intervention actions on equipment while upholding safety standards and acceptable performance levels. Ships, which are not yet autonomous, serve as maritime assets responsible for transporting personnel and systems. Maintaining these ships with high performance is imperative to ensuring the safety of both material and personnel. This not only prevents damage to the ships themselves but also mitigates the potential for personnel injuries and sea pollution. Organizations, scientific community, and stakeholders have been actively developing advanced systems to monitor data from ship equipment within the scope of maintenance management. This helps in preventing breakdowns and ensures real time knowledge about the equipment's condition. These systems employ various techniques for condition control using algorithms, statistical equations, and other methodologies on the collected data. In this investigation Fuzzy Logic will be applied to data from a selected equipment. For the case study, an air compressor from an ocean patrol vessel has been selected. This air compressor plays a crucial role on Navy ships and has been chosen by the Organization's Maintenance Management Centre for monitoring working hours and operational status.
- Evolution on the Generation and Analysis of Single Imputation Synthetic Datasets in Statistical Disclosure Control.Publication . Moura, R.; Coelho, C. A.; Sinha, B.
- Gait assessment using microwave radars mounted on standard walkerPublication . Postolache, Octavian; Pereira, José Dias; Viegas, Vítor—Gait rehabilitation is a complex process considering the complexity of movement that involves different parts of the human body. To assure the safety of the rehabilitation process walking aids are a common indication in clinics, the standard walker being one of the most prescribed taking into account its stability. Embedding sensors on the level of the walker can provide additional capabilities associated with gait monitoring that may be used to evaluate the user gait ehabilitation outcome. Sensing user motion during walker usage can be also used to avoid wrong usage that can conduct to falls. In the current study a standard walker with two Microwave Doppler radars was implemented to extract information on user gait during the rehabilitation process as well as information about the sequence of the standard walker usage. The signals acquired from the measurement channels were considered for time-frequency analysis, including features extraction such as mean instantaneous frequency (MIF) and mean instantaneous bandwidth (MIB) to characterize normal and abnormal gait. The capabilities of time-frequency analysis methods as the starting point on gait classification is also considered.
- Machine Learning applied to LCA of mechanical components obtained by SLMPublication . Alves, J.; Morgado, Pereira M.; Lampreia, S.Over time, industries are starting to be concern about their impact on the environment, and therefore new technologies, have arrived with the capability of improving the sustainability of the industrial paradigm. Machine Learning (ML) and Artificial Intelligence (AI) are taking over the global industry, by offering new data drive solutions capable of optimizing decision-making and operation. Meanwhile, new advanced manufacturing technologies such as Selective Laser Melting (SLM), also known as 3D printing, are spreading through the market, due to the new doors unlocked by the possibility of manufacturing high for a minimal time and use of material. Together, these new technologies of industry 4.0, promise to bring an all-new future, sustainable and resilient. The aim of this work is to analyze how can ML and AI expand each phase of the LCA of a light alloy, produced by SLM, in order to improve the sustainability of this new advanced manufacturing technologies.
- Navy Ship Dynamic MaintenancePublication . Lampreia, S.; Vairinhos, V.; Lobo, V.A maintenance system complemented with condition monitoring is suggest being implemented in Navy Ships to allow its patrol on the large maritime territory of Portugal with high performance and operationality. To that an advanced maintenance system is required oriented towards Condition Monitoring. That must be done while maximizing system performance, as well as improved high level of ship availability and minimal oil consumption in the form e.g. lubricants or refrigerant gases but also marine gasoil reducing the environment impact. To meet these objectives, we propose the development of a Dynamic Maintenance Management System (DMMS) based on dynamic prioritization process for technical interventions. That is where Failure Modes, Effects and Criticality Analysis (FMECA) comes in - a structured risk analysis framework to mitigate the propensity of failures occurring with consequences on ship systems and persons. With FMECA, maintenance priorities can be changed somewhat dynamically due to components and failure modes that are most critical based on actual performance.
- Ship Dynamic MaintenancePublication . Lampreia, Suzana; Vairinhos, Valter; Lobo, Victor; Morgado, Teresa; Navas, HelenaConsidering the extent of the Portuguese sea and the naval ships necessary for its monitoring, the implementation of a maintenance system addressing those ships condition monitoring, is needed. That system must guarantee, also, a high performance of ships and systems availability, reduced pollution control, lubricants, refrigerant gases and marine gasoil consumptions. To achieve all this, a dynamic maintenance manage ment system (DMMS) based on a dynamic management of technical interventions is required. In this paper some risk analysis maintenance techniques are explored, and the most applicable ones will be applied to selected ship equipment. In the present research, a case study of a specific equipment is presented and the corresponding risk analysis in maintenance context is studied. The case study illustrates the importance of having a dynamic maintenance system allowing to act when needed, and, in case of no action, the risk of non-maintenance. To validate our theory the research results and its analysis will be highlighted, and, finally, some conclusions are presented.
- The Colombia Armed Conflict - A Review Until 2020Publication . Lampreia, S.Colombian armed conflict origins remote to the beginning of 20 cen tury, and even after the 2016 peace agreement, it is a reality. Colombia's armed conflict existed by the force of the armed hand of the FARC and other insur gents’ groups, they financed themselves in illegal acts like arms and drug traf ficking, abductions, coercion, and extortion. Till 2020, several FARC dissidents have returned to the guerrillas because they doubted Colombian political power defense their interests. This paper objective is to give a perspective of origins of the armed conflict in Colombia, and its development up to 2020. To expose the conflict, the facts and literature will be related demonstrating the conflict dy namic and involved actors. To support state-of-the-art during the 2016 peace agreement implementation, it was proceeded to interviews to some ex-observers that provided humanitarian support in the United Nations. In the end, it is pos sible to understand better the conflict, and it was made some reflections, which can contribute for possible solutions for the conflict.