Loading...
8 results
Search Results
Now showing 1 - 8 of 8
- 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.
- 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.
- 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.
- Reliability of Replicated Distributed Control Systems Applications Based on IEC 61499Publication . Santos, Adriano A; Silva, A. Ferreira da; Magalhães, António; de Sousa, MárioThe use of industrial and domestic equipment is increasingly dependent on computerized control systems. This evolution awakens in the users the feeling of reliability of the equipment, which is not always achieved. However, system designers implement fault-tolerance methodologies and attributes to eliminate faults or any error in the system. Industrially, the increase in system reliability is achieved by the redundancy of control systems based on the replication of conventional and centralized programmable logic controllers. In distributed systems, reliability is achieved by replicating and distributing the most critical elements, leaving a single copy of the remaining components. On the other hand, given the nature of the distributed systems, it will also be necessary to ensure that the data set received by each of the replicas has the same order. Thus, any change in the order and data set received will result in different results, in each of the replicas, which may manifest in erroneous behavior. In this paper, the interactions and the erroneous behavior of the replicas are explained, depending on the data set received, in a fault tolerant distributed system. Its tendency, behavior and possible influences on reliability are presented, considering the failure rate and availability based on the mean time to failure.
- Symbolic Manipulation for Optimization of Boolean Functions for Control of Pneumatic and Electropneumatic CircuitsPublication . Silva, A. Ferreira da; Santos, Adriano ANeste artigo é descrito um programa desenvolvido em PROLOG, que realiza uma manipulação simbólica computacional dos Mapas de Karnaugh (MK), para obter o conjunto de equações lógicas otimizadas que possibilite o controlo de circuitos pneumáticos ou electropneumáticos. A manipulação simbólica de um MK é governada por um conjunto de regras genéricas que permitem obter a minimização/otimização de equações lógicas para controlo do circuito. Essa complexidade advém da explosão combinatória que resulta do aumento do número de cilindros que constituem o ciclo a automatizar. As abordagens de aprendizagem simbólica foram implementadas realizando uma busca no espaço de padrões simbólicos do MK. Esta busca permite com o uso de regras, reduzir o universo de procura no espaço de padrões simbólicos e, obter a solução ideal para controlar o circuito pneumático ou electropneumático desejado