927 resultados para 091302 Automation and Control Engineering


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A book about remote labs and engineering education begs to begin with the question, “Why do engineering programs include lab work?” Although this may seem like a given and not worth discussing, whenever we’re faced with innovative ideas, it’s important to “put everything on the table” in order to reassess its value to our program or goals. What is it about lab work that is of value to students? Are there elements of traditional labs that we could let go of? Are there elements that we don’t want to lose? These questions can help us to clarify how and why labs are integrated into an engineering education program.

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Työssä tarkastellaanpolttomoottorin venttiilitoimilaitteen toteuttamista sähkömekaanisesti. Tähän mennessä kehitetyt ratkaisut ja rakennetut prototyypit soveltuvat pääosin henkilöautojen vapaasti hengittävien ottomoottoreiden venttiilien ohjaukseen. Venttiilien sähkömekaanisen ohjauksen soveltuvuutta suuriin polttomoottoreihin kuten esimerkiksi voimalaitosdieseleihin on myös tarkasteltu, mutta ongelmaksi muodostuu riittävän suuren magneettisen voiman kehittäminen magneettivuon reitillä esiintyvän suuren ilmavälin takia. Työssä esitetään valmiita ja kehitteillä olevia ratkaisuja polttomoottorin venttiilien ohjaukseen sähkömekaanisesti. Lisäksi käsitellään parannusmahdollisuuksia jo valmiisiin ratkaisuihin ja käydään läpi sähkömekaanisen venttiilinohjauksen ongelmakohtia. Suomeksi ei ole kovin paljon julkaistua materiaalia polttomoottorin venttiilien sähkömekaanisesta ohjauksesta, joten työ tukeutuu pääosin Internetissä julkaistuihin artikkeleihin sekä sähköpostin välityksellä käytyihin keskusteluihin niiden tahojen kanssa, jotka tutkivat ja kehittävät polttomoottorinsähkömekaanista venttiilien ohjausta. Venttiilien sähkömekaanisen ohjauksen tutkiminen tällä hetkellä jakautuu pääpainotteisesti sähkömagneettisen osuuden ja säätöteknisen osuuden tutkimiseen ja kehittämiseen. Työssä ei mennä näiden aihepiirien syvälliseen analysointiin vaan esitetään tämän hetkisentutkimuksen painopisteet ja lähdeviitteet aihepiiriä syventäviin julkaisuihin.

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In this thesis a closer look at ZigBee wireless network protocol was made and a ZigBee evaluation device was designed and built for testing it. ZigBee is a digital wireless network technology published in 2004, which was developed for wireless control and automation systems. It is based on the IEEE 802.15.4-2003 standard, and its aim was to create a reliable wireless networking protocol with secure data transmissions, low power consumption and low manufacturing costs. The low power consumption requirement has also led to a slow data rate and a short range, but in a ZigBee network individual network devices can route messages to each other, so short range is not a problem. In automation and control systems a fast data rate is not usually an important requirement either. ZigBee network can form automatically and one ZigBee network can theoretically include thousands of devices, all of which can communicate with each other. ZigBee network is also self-healing, so an individual device dropping out of the network, like breaking down, does not affect functionality of the network. Evaluation device was designed and implemented in four different versions, which were tested with six different antenna designs. All antennas were tested at a range of 100 meters in an open terrain using two different frequencies and transmission powers. Also a range test was performed for selected antennas using transmission power of 4,5 dBm, which was maximum power of the ZigBee chip used in the evaluation device. Range test resulted in a measured range of several hundred meters, which can be considered as a good result for a short-range technology.

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Els pàncrees artificials són un horitzó pròxim que ha de millorar de manera sensible la qualitat de vida dels diabètics. El grup de recerca MICE (Modal Intervals and Control Engineering) de la Universitat de Girona intervé en la investigació d'aquests nous sistemes assistits de dosificació d'insulina, perfeccionant algoritmes que els governen

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In this study a minimum variance neuro self-tuning proportional-integral-derivative (PID) controller is designed for complex multiple input-multiple output (MIMO) dynamic systems. An approximation model is constructed, which consists of two functional blocks. The first block uses a linear submodel to approximate dominant system dynamics around a selected number of operating points. The second block is used as an error agent, implemented by a neural network, to accommodate the inaccuracy possibly introduced by the linear submodel approximation, various complexities/uncertainties, and complicated coupling effects frequently exhibited in non-linear MIMO dynamic systems. With the proposed model structure, controller design of an MIMO plant with n inputs and n outputs could be, for example, decomposed into n independent single input-single output (SISO) subsystem designs. The effectiveness of the controller design procedure is initially verified through simulations of industrial examples.

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This article looks at the use of cultured neural networks as the decision-making mechanism of a control system. In this case biological neurons are grown and trained to act as an artificial intelligence engine. Such research has immediate medical implications as well as enormous potential in computing and robotics. An experimental system involving closed-loop control of a mobile robot by a culture of neurons has been successfully created and is described here. This article gives a brief overview of the problem area and ongoing research. Questions are asked as to where this will lead in the future.

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The development of an adaptive filter system, capable of reducing significantly the effect of siren noise within the cab of an emergency vehicle, is described. The system is capable of removing the siren noise picked up by the radio microphone inside the vehicle, without degrading the wanted voice signal, thus allowing the siren to be used at all times.

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This document aims to improve the quality of the production test in vertical tanks with free water drain pipes, through a device to control the draining system. This proposal consists of an interface detector close to the tank bottle and a control valve on the pipe-drain; they are attached to a remote supervisor system, which will be minimizing the human influence in the conclusion of the test result. And for more consciousness the work shows the importance of the wells production test in the attendance and diagnosis of the productive process, informing the large number of tests executed and problems of the procedure adopted in the field today. There are many possible sources of uncertainty in this kind of test as shown in the experiments realized in the field; the object prototype of this dissertation will be made in the field, based upon the definition of parameters and characteristics of the devices proposal. For a better definition of the draining process the action results of the assessment test are shown, especially changed some for the understand ing of the real process. It shows the proposal details and the configuration that will be used in the tank of Monte Alegre s field Production Station, explaining the interface detector kind and the control system. It is the base to a pilot project now in development, named as the new project classified in the status of the new technology and production improvement of PETROBRAS in Rio Grande do Norte and Ceará. This dissertation concludes that the automation of the conventional test with the draining system will bring benefits both economically as metrologically, because it reduces the uncertainty of the test procedures with free water draining, and also decreases the number of tests with problems

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Several systems are currently tested in order to obtain a feasible and safe method for automation and control of grinding process. This work aims to predict the surface roughness of the parts of SAE 1020 steel ground in a surface grinding machine. Acoustic emission and electrical power signals were acquired by a commercial data acquisition system. The former from a fixed sensor placed near the workpiece and the latter from the electric induction motor that drives the grinding wheel. Both signals were digitally processed through known statistics, which with the depth of cut composed three data sets implemented to the artificial neural networks. The neural network through its mathematical logical system interpreted the signals and successful predicted the workpiece roughness. The results from the neural networks were compared to the roughness values taken from the worpieces, showing high efficiency and applicability on monitoring and controlling the grinding process. Also, a comparison among the three data sets was carried out.

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Pós-graduação em Engenharia Elétrica - FEIS

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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The use of alternative energy systems in the current days is an urgent necessity due to the problems that the planet is facing as the heating and loss of ozone layer. The scarcity of conventional energy is another problem that must be solved for the future of humanity. It must be considered that the people are inhabiting places moved away not always with available energy. The application of technologies as automation and control can help us to solve this problem. Therefore, this work aimed at apply an equipment of industrial usage, the Programmable Logical Controller, PLC, in alternative energies systems, as eolic generation and fotovoltaic generation used for water pumping, aiming the automatic control and the efficiency in the places where it has simultaneous availability of these sources, based in criterion of priority that previously established itself between them. It was made a hydraulic and energetic evaluation of the energy system, eolic and fotovoltaic, used in the automatic control system of pumping, in the place of accomplishment of the experiment, according to previously established physical conditions. The results have shown that the control system using the PLC is practicable and has trustworthiness. The program developed can be adapted for the use with several power plants in a specific application place. The fotovoltaic system of pumping, using a polycrystalline of 70 Watts connected to a pump Shurflo 8000, showed to be efficient with significant flows in almost all the months. The eolic system of pumping, using an eolic generator of 400 Watts assembled in place of experiment, did not demonstrate energetic capacity for use in this specific type of application.

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This document aims to improve the quality of the production test in vertical tanks with free water drain pipes, through a device to control the draining system. This proposal consists of an interface detector close to the tank bottle and a control valve on the pipe-drain; they are attached to a remote supervisor system, which will be minimizing the human influence in the conclusion of the test result. And for more consciousness the work shows the importance of the wells production test in the attendance and diagnosis of the productive process, informing the large number of tests executed and problems of the procedure adopted in the field today. There are many possible sources of uncertainty in this kind of test as shown in the experiments realized in the field; the object prototype of this dissertation will be made in the field, based upon the definition of parameters and characteristics of the devices proposal. For a better definition of the draining process the action results of the assessment test are shown, especially changed some for the understand ing of the real process. It shows the proposal details and the configuration that will be used in the tank of Monte Alegre s field Production Station, explaining the interface detector kind and the control system. It is the base to a pilot project now in development, named as the new project classified in the status of the new technology and production improvement of PETROBRAS in Rio Grande do Norte and Ceará. This dissertation concludes that the automation of the conventional test with the draining system will bring benefits both economically as metrologically, because it reduces the uncertainty of the test procedures with free water draining, and also decreases the number of tests with problems

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Recently in most of the industrial automation process an ever increasing degree of automation has been observed. This increasing is motivated by the higher requirement of systems with great performance in terms of quality of products/services generated, productivity, efficiency and low costs in the design, realization and maintenance. This trend in the growth of complex automation systems is rapidly spreading over automated manufacturing systems (AMS), where the integration of the mechanical and electronic technology, typical of the Mechatronics, is merging with other technologies such as Informatics and the communication networks. An AMS is a very complex system that can be thought constituted by a set of flexible working stations, one or more transportation systems. To understand how this machine are important in our society let considerate that every day most of us use bottles of water or soda, buy product in box like food or cigarets and so on. Another important consideration from its complexity derive from the fact that the the consortium of machine producers has estimated around 350 types of manufacturing machine. A large number of manufacturing machine industry are presented in Italy and notably packaging machine industry,in particular a great concentration of this kind of industry is located in Bologna area; for this reason the Bologna area is called “packaging valley”. Usually, the various parts of the AMS interact among them in a concurrent and asynchronous way, and coordinate the parts of the machine to obtain a desiderated overall behaviour is an hard task. Often, this is the case in large scale systems, organized in a modular and distributed manner. Even if the success of a modern AMS from a functional and behavioural point of view is still to attribute to the design choices operated in the definition of the mechanical structure and electrical electronic architecture, the system that governs the control of the plant is becoming crucial, because of the large number of duties associated to it. Apart from the activity inherent to the automation of themachine cycles, the supervisory system is called to perform other main functions such as: emulating the behaviour of traditional mechanical members thus allowing a drastic constructive simplification of the machine and a crucial functional flexibility; dynamically adapting the control strategies according to the different productive needs and to the different operational scenarios; obtaining a high quality of the final product through the verification of the correctness of the processing; addressing the operator devoted to themachine to promptly and carefully take the actions devoted to establish or restore the optimal operating conditions; managing in real time information on diagnostics, as a support of the maintenance operations of the machine. The kind of facilities that designers can directly find on themarket, in terms of software component libraries provides in fact an adequate support as regard the implementation of either top-level or bottom-level functionalities, typically pertaining to the domains of user-friendly HMIs, closed-loop regulation and motion control, fieldbus-based interconnection of remote smart devices. What is still lacking is a reference framework comprising a comprehensive set of highly reusable logic control components that, focussing on the cross-cutting functionalities characterizing the automation domain, may help the designers in the process of modelling and structuring their applications according to the specific needs. Historically, the design and verification process for complex automated industrial systems is performed in empirical way, without a clear distinction between functional and technological-implementation concepts and without a systematic method to organically deal with the complete system. Traditionally, in the field of analog and digital control design and verification through formal and simulation tools have been adopted since a long time ago, at least for multivariable and/or nonlinear controllers for complex time-driven dynamics as in the fields of vehicles, aircrafts, robots, electric drives and complex power electronics equipments. Moving to the field of logic control, typical for industrial manufacturing automation, the design and verification process is approached in a completely different way, usually very “unstructured”. No clear distinction between functions and implementations, between functional architectures and technological architectures and platforms is considered. Probably this difference is due to the different “dynamical framework”of logic control with respect to analog/digital control. As a matter of facts, in logic control discrete-events dynamics replace time-driven dynamics; hence most of the formal and mathematical tools of analog/digital control cannot be directly migrated to logic control to enlighten the distinction between functions and implementations. In addition, in the common view of application technicians, logic control design is strictly connected to the adopted implementation technology (relays in the past, software nowadays), leading again to a deep confusion among functional view and technological view. In Industrial automation software engineering, concepts as modularity, encapsulation, composability and reusability are strongly emphasized and profitably realized in the so-calledobject-oriented methodologies. Industrial automation is receiving lately this approach, as testified by some IEC standards IEC 611313, IEC 61499 which have been considered in commercial products only recently. On the other hand, in the scientific and technical literature many contributions have been already proposed to establish a suitable modelling framework for industrial automation. During last years it was possible to note a considerable growth in the exploitation of innovative concepts and technologies from ICT world in industrial automation systems. For what concerns the logic control design, Model Based Design (MBD) is being imported in industrial automation from software engineering field. Another key-point in industrial automated systems is the growth of requirements in terms of availability, reliability and safety for technological systems. In other words, the control system should not only deal with the nominal behaviour, but should also deal with other important duties, such as diagnosis and faults isolations, recovery and safety management. Indeed, together with high performance, in complex systems fault occurrences increase. This is a consequence of the fact that, as it typically occurs in reliable mechatronic systems, in complex systems such as AMS, together with reliable mechanical elements, an increasing number of electronic devices are also present, that are more vulnerable by their own nature. The diagnosis problem and the faults isolation in a generic dynamical system consists in the design of an elaboration unit that, appropriately processing the inputs and outputs of the dynamical system, is also capable of detecting incipient faults on the plant devices, reconfiguring the control system so as to guarantee satisfactory performance. The designer should be able to formally verify the product, certifying that, in its final implementation, it will perform itsrequired function guarantying the desired level of reliability and safety; the next step is that of preventing faults and eventually reconfiguring the control system so that faults are tolerated. On this topic an important improvement to formal verification of logic control, fault diagnosis and fault tolerant control results derive from Discrete Event Systems theory. The aimof this work is to define a design pattern and a control architecture to help the designer of control logic in industrial automated systems. The work starts with a brief discussion on main characteristics and description of industrial automated systems on Chapter 1. In Chapter 2 a survey on the state of the software engineering paradigm applied to industrial automation is discussed. Chapter 3 presentes a architecture for industrial automated systems based on the new concept of Generalized Actuator showing its benefits, while in Chapter 4 this architecture is refined using a novel entity, the Generalized Device in order to have a better reusability and modularity of the control logic. In Chapter 5 a new approach will be present based on Discrete Event Systems for the problemof software formal verification and an active fault tolerant control architecture using online diagnostic. Finally conclusive remarks and some ideas on new directions to explore are given. In Appendix A are briefly reported some concepts and results about Discrete Event Systems which should help the reader in understanding some crucial points in chapter 5; while in Appendix B an overview on the experimental testbed of the Laboratory of Automation of University of Bologna, is reported to validated the approach presented in chapter 3, chapter 4 and chapter 5. In Appendix C some components model used in chapter 5 for formal verification are reported.

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This paper develops H(infinity) control designs based on neural networks for fully actuated and underactuated cooperative manipulators. The neural networks proposed in this paper only adapt the uncertain dynamics of the robot manipulators. They work as a complement of the nominal model. The H(infinity) performance index includes the position errors as well the squeeze force errors between the manipulator end-effectors and the object, which represents a complete disturbance rejection scenario. For the underactuated case, the squeeze force control problem is more difficult to solve due to the loss of some degrees of manipulator actuation. Results obtained from an actual cooperative manipulator, which is able to work as a fully actuated and an underactuated manipulator, are presented. (C) 2008 Elsevier Ltd. All rights reserved.