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- An IEC 61499 Replication for Distributed Control ApplicationsPublication . Santos, Adriano A; Silva, A. Ferreira da; Sousa, Mário de; Magalhaes, PessoaModern industrial environment control programs are distributed among several devices. The IEC 61499 standard defines function blocks with which distributed control applications may be developed, and how these are interpreted and executed. Its functionality and the inherent support for dynamic reconfiguration provide the required infrastructure for Industry 4.0 and industrial IoT applications. However, by their distributed nature new challenges are posed, especially about how modes of failure are handled. To avoid system malfunctions and breakdowns due to partial failures, the authors propose a new framework were the concept of replication can be applied maintaining internal state synchronised. This paper presents an example of how the replication framework on the FORTE IEC 6499 execution platform can be developed and voting strategies, along with the results obtained in the implementation with the standard communication SIFBs available on the Eclipse 4diacTM.
- Simulation of Cyber-Physical Intelligent Mechatronic Component Behavior Using Timed Automata ApproachPublication . Santos, Adriano A; Silva, A. Ferreira da; Pereira, FilipeThis article presents a new approach for the simulation of Cyber-Physical Intelligent Mechatronics Components using process evolution based on the timed approach. The purpose of this article is to address the issue of implementing the Intelligent Mechatronics Components control from the bench point of view and its simulation considering a virtual system composed of a single programmable logic controller and a touchscreen. For this, we intend to develop a systematic approach that allows modeling physical cybernetic systems based on timed automata. The proposed methodology makes it possible to define, in a systematic way, the formalisms and tools to model the controller and the respective plant. These global models can be used to simulate and validate systems based on development tools like UPPAAL software, so the proposed approach intends to systematically define their development. To present and explain the proposed methodology, a Modular Production System was used to distribute objects as a physical element. A virtual platform based on the Simatic TIA Portal was developed to monitor and validate the methodology.
- Recyclable waste collection: Increasing ecopoint filling capacity to reduce energy for transportationPublication . Santos, Adriano A; Silva, António Ferreira da; Gouveia, António; Caetano, Nídia; Felgueiras, CarlosUrban waste production is increasing around the world. In the present Covid-19 context, an emergent flow of waste growth, as well as of pollution in general, stems from confinement and the use of protective masks. Although part of the waste is considered commingled, much is recyclable, if properly disposed off. Hence, recycling plays today, more than ever, an extremely important role, not only in terms of pollution prevention, but also from the point of view of the circular economy and of resources use efficiency. Thus, this work is focused on developing an approach to assist in recycling wastes. As a management option, recycling depends on a collective behavior, that relies on individual acts. Therefore, the individual use of plastic/metal compaction systems can help reaching the recycling targets, even as a complement to conventional commingled waste bins. Thus, we present a proposal for a plastic/metal collection station with a built-in compaction element that allows one to compact separated waste, individually, in an easily accessible drawer. Sorting and compaction of waste before collection will then result in a reduction of the number of collection/transportations stops, which will also translate into higher efficiency, reduction of costs, optimization of transported tons/km ratio, and profitability.
- Determinism of Replicated Distributed Systems–A Timing Analysis of the Data Passing ProcessPublication . Santos, Adriano A; Silva, A. Ferreira da; Magalhães, António; Sousa, Mário deFault-tolerant applications are created by replicating the software or hardware component in a distributed system. Communications are normally carried out over an Ethernet network to interact with the distributed/replicated system, ensuring atomic multicast properties. However, there are situations in which it is not possible to guarantee that the replicas process the same data set in the same order. This occurrence will lead to inconsistency in the data set produced by the replicas, that is, the determinism of the applications is not guaranteed. To avoid these inconsistencies, a set of Function Blocks has been proposed which, taking advantage of the inherent properties of Ethernet, can guarantee the synchronism and determinism of the real-time application. This paper presents this set of Function Blocks, focusing our action on the development of reliable distributed systems in real-time. This demonstrates that the developed Function Blocks can guarantee the determinism of the replicas and, as such, that the messages sent are processed, in the same order and according to the time in which they were made available.
- Teaching Control Pneumatic and Electro-pneumatic Circuits – A New MethodPublication . Silva, António Ferreira da; Santos, Adriano A.Karnaugh map is a method to simplify a logical equation, or convert a truth table in the corresponding logic circuit. This paper presents an alternative way to use the Karnaugh maps that minimizes the logical conditions of command for pneumatic circuits, whether the command is pneumatic or electric. In the last case, the method also permits the control of the circuit through a programmable controller (PLC). In practice, ensure a series of sequential movements in an automatic cycle is to find the set of equations which are executed ensure the realization of the desired sequence. The application of the method itself becomes dispensable analysis of speed or course of the cylinders (irrelevant features to the materialization of the command sequence). It means therefore that the control cylinders equations that will allow his movements (called output variables) are function only of two types of variables (input variables), the position of each cylinder (end-of-stroke valves) and if necessary memory variables. The proposed methodology ensures not only the desired sequential cycle, as well as the minimization of the variables necessary for control commands. To simplify substantially the explanation of the method, it is assumed that each pneumatic cylinder is associated with two end-of-stroke valves for detecting its position. The description as well as the applicability of the proposed methodology will be illustrated using a concrete problem of industrial automation. The methodology described here, will extend its use not only in industrial applications, but also the educational level in terms of engineering schools allowing a particular use in the automation of laboratories in the field of pneumatic control circuits and sequential electro (it is currently teaching in automation course unit of mechanical engineering in ISEP).
- Methodology for manipulation of Karnaugh maps designing for pneumatic sequential logic circuitsPublication . Santos, Adriano A; Silva, António Ferreira daThis paper presents an alternative way to use the Karnaugh maps, which minimises logical conditions used for ON/OFF control, in either pneumatic and electro pneumatic circuits. In the last case, the methodology allows the control of the circuit through a programmable logic controller (PLC). In this kind of processes, controlling pneumatic cylinders is a problem that not only depends on the state of the information present but also in terms of knowledge of past actions. In practice, ensuring a series of sequential movements in an automatic cycle is to find the set of equations that should be executed to ensure the realisation of the desired sequence. It means therefore that the equations that will allow the movements of each cylinder are functions only of two types of input variables, the position of each cylinder and if necessary, memory variables. One of the major merits that arise from the use of the proposed method is the simplicity of obtaining electrical schematic command circuit. The proposed methodology ensures not only the desired sequential cycle, as well as the minimisation of the variables necessary for control commands.
- A Simulation Tool Using AI Technics and Karnaugh Maps for Learning and Control Digital PneumaticsPublication . Silva, António Ferreira da; Santos, Adriano AThis paper describes a software, developed in PROLOG, called ISEPCPC (Intelligent System for Electric and Pneumatic Control of Pneumatic Circuits). It uses PROLOG clauses, Artificial Intelligence (AI) techniques (an Expert System), and Karnaugh Map’s methodology. The main objective is to compute the set of optimized logic equations that enables either an electric or a pneumatic control of any, but mainly complex pneumatic circuits. As the complexity of the circuit increases, as the result of a combinatorial explosion generated by the increase in the number of cylinders involved, the more difficult it becomes to obtain the control equations (often requiring the use of auxiliary memories). This software automatically obtains the equations which will yield minimized circuit configuration. These equations, can be used either in electro or pneumatic control. A practical application example of the software will be shown to prove its applicability. The minimum number of equations required to control the circuit will be used in programming a PLC that will control the circuit.
- Hydroagriculture project - A Portuguese case studyPublication . Silva, Paulo; Felgueiras, Carlos; Almeida Santos, Adriano Manuel; Pereira, FilipeWater plays an essential role in the social fabric and comfort of society, as it plays an important role in our survival and subsistence, in its accessibility, in economic activities, and in the particular case of this study, in the manufacture of agricultural products and activities. In a developing society, and with the number of the human population increasing, consumerism takes place, resulting in an increasing need to use space, resources and food. Agriculture is an ancient activity that serves as the basis for ensuring the subsistence and resilience of the population, producing crops and different types of food, from vegetables, fruits, legumes, seeds, etc... and they all have one thing in common: The existence of water. If there are fields suitable for agriculture, but there is no water, they become unusable. Water improvement and supply projects can drastically change this situation, thus stimulating agricultural production. The analysis of this case study, the largest hydroagriculture project in Europe nowadays, aims to highlight the importance of carrying out hydroagriculture projects and the impact they can have on society, demonstrating that this project considerably increases the production of the rice harvest in Portugal through the artificial irrigation of land that previously could not be used for this purpose.
- An Energy Storage System for the Alto Douro Wind Power Plant: A Technical StudyPublication . Magalhães, Alexandre; Xavier, Celso; Felgueiras, Carlos; Pereira, Filipe; Almeida Santos, Adriano Manuel; da Silva, A. Ferreira; Silva, Paulo; Caetano, Nídia; Machado, JoséRenewable energies are crucial to meeting global demand for environmentally friendly energy at a time when fossil fuels are being cut back. In recent years, and essentially due to the reduced reserves of fossil fuels, Portugal has been promoting investment in renewable energies as a way of freeing itself from energy imports and dependence on fossil fuels. However, despite the high number of hours of sunshine per day and the use of wind and hydraulic energy, production is unstable due to climate variability. All this climate instability translates into fluctuations in the energy released to the grid. In order to minimize this problem, energy storage systems have become a key element in guaranteeing the stability of the renewable energy supply at times of low production. This article presents a feasibility analysis of a renewable energy storage system with the aim of maximizing the profitability of a wind farm located in Portugal's Alto Douro region. As a starting point, a demand analysis is presented, as well as simulations of the system's performance in terms of energy use and profitability as a function of efficiency and power. Taking these assumptions and the analysis into account, a modular lithium battery storage system with high efficiency and fast charging and discharging powers was chosen.
- Electrification of a remote rural farm with solar energy: Contribution to the development of smart farmingPublication . Santos, Adriano A; Pereira, Filipe; Silva, António Ferreira da; Caetano, Nídia; Felgueiras, Carlos; Machado, JoséRural farms constitute a vital component of a country’s agricultural landscape, traditionally reliant on energy installations known for their reliability yet notorious for their energy-intensive and inefficient characteristics. While the smart farm concept, integrating renewable energy sources and resource management technologies, has seen widespread adoption in domestic and industrial sectors, rural farms have been slower to embrace these innovations. This study presents a groundbreaking solution, deployed on a rural farm in Portugal, resulting in an impressive 83.24% reduction in energy consumption sourced from the grid. Notably, this achievement translates to a substantial reduction in CO2 emissions, aligning with the growing need for environmentally sustainable farming practices. The technical intricacies of this pioneering solution are comprehensively described and juxtaposed with other scientific case studies, offering valuable insights for replication. This initiative represents a vital first step towards the integration or combination of conventional farming with photovoltaic energy production, exemplified by agrivoltaic systems. In conclusion, this research showcases the potential for rural farms to significantly enhance energy efficiency and financial viability, thereby contributing to a more sustainable and cost-effective agricultural sector. These findings serve as a model for similar endeavors, paving the way for a greener and more economically viable future for rural farming practices.