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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.
- 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.
- Simulation and Control of a Cyber-Physical System under IEC 61499 StandardPublication . Santos, Adriano A; Silva, A. Ferreira daIEC 61499 standard provides an architecture for control systems using function blocks (FB), languages, and semantics. These devices can be interconnected and communicate with each other. Each device contains several resources and algorithms with a communication FB at the end, which can be created, configured, and deleted without affecting other resources. Physical element can be represented by a FB that encapsulates the functionality (data/events, process, return data/events) in a single module that can be reused and combined. This work presents a simplified implementation of a modular control system using a low-cost device. In the prototyping of the application, we use 4diac to control, model and validate the implementation of the system on a programmable logic controller. It is proved that this approach can be used to model and simulate a cyber-physical system as a single element or in a networked combination. The control models provide a reusable FB design.
- IEC 61499 REPLICATION FOR FAULT TOLERANT SYSTEMPublication . Santos, Adriano A.; Sousa, Mário de; Magalhães, Pessoa; Silva, António Ferreira daThe IEC 61499 was developed thinking about the new generation of distributed control and automation systems. This provides essential resources for the development of distributed systems such as encapsulation, portability and reconfiguration. In this sense, and to ensure confidence in the operation should be implemented fault tolerance techniques dealing with hardware failures and errors off software associated with us where the distributed application runs. In this paper, we propose an approach to deal with failures in distributed systems tolerance problems, based on a replication model based on replication software/hardware as a means to achieve confidence in the operation.
- Reducing Volume to Increase Capacity—Measures to Reduce Transport Energy for Recyclable Waste CollectionPublication . Santos, Adriano A; Silva, A. Ferreira da; Gouveia, António; Felgueiras, Carlos; Caetano, NídiaThe production of municipal waste is increasing all over the world. Although a significant part of the waste is collected as commingled waste, much of it is recyclable if disposed of properly. Thus, separate deposition and collection plays an extremely important role today, more than ever, not only in terms of preventing pollution but also from the point of view of recycling as a driver of circular economy and of efficient use of resources. This work is focused on the development of compaction equipment to be applied to containers, which allows a more efficient approach to the process of collecting waste for recycling. As a management option, recycling depends on collective behavior which is based on individual acts. Therefore, individual use of plastic/metal compaction systems can help meet recycling targets, even as a complement to conventional bins. Thus, herein a proposal is presented for a plastic/metal collection station with a built-in compaction element that allows for the compacting of the separated waste, individually, in an easily accessible drawer. Sorting and compacting waste before collection will result in a reduction of the number of collection/transport stops, which will also translate into higher energy efficiency, cost savings, optimization of the transported tons/km ratio, and profitability.