69 resultados para Intelligent control systems
Resumo:
Tehdyss kirjallisuus- ja teoriakatsauksessa vuosien 2006 - 2010 vlisen aikana, Keski-Suomessa toimivan konepajateollisuuden jrjestelmtoimittajayrityksen toimeksiannosta, pyrittiin muodostamaan kokonaiskuva laajasta tuotannonsuunnittelun ja -ohjauksen aihealueesta. Perustutkimuskysymykset liittyivt ns. MPC-systeemiin, jolla tarkoitetaan sit, ett tuotannonsuunnittelu- ja ohjauskysymyksiss on huomioitava aina henkiliden, organisaation, teknologioiden ja prosessien muodostama kokonaisuus. Operatiivisen johtamisen tehtvn on yrityksen tuotteita koskevan kysynnn ja tarjonnan tasapainottaminen niin, ett resursseja kytettisiin ja tarvittaisiin mahdollisimman vhn vastattaessa kysyntn asiakasvaatimukset huomioiden. Tuotantostrategian pohjalta on voitava rakentaa MPC-systeemi, jonka avulla ja jota kehitten tuotanto saavuttaisi sille asetetut suorituskykytavoitteet mm. kustannusten, laadun, nopeuden, luotettavuuden sek tuottavuuskehityksen osalta. Tyss tarkasteltiin yleisen kolmitasoisen viitekehyksen kautta perinteisist MPC-systeemien perusratkaisuista hierarkkisia, suunnittelu- ja laskentaintensiivi, MRP-pohjaisia sek yksinkertaistamiseen ja nopeuteen perustuvia JIT/Lean -menetelmi. Tm viitekehys ksitt: 1) kysynnn- ja resurssien hallinnan, 2) yksityiskohtaisemman kapasiteetin ja materiaalien hallinnan sek 3) tarkemman tuotannon ja hankintojen ohjauksen sek tuotannon lattiatason osa-alueet. Johtamisen ja MPC-systeemien kehittmisen uusina aaltoina ja nkkulmina raportissa ksiteltiin mys johtamisen eri koulukuntia sek em. viitekehyksen pohjalta tarvittavia tietojrjestelmi. Olennaisimpana johtoptksen todettiin, ett MRP-pohjaisten ratkaisujen lisksi, etenkin monimutkaisia tuotteita tilausohjautuvasti valmistavien kappaletavarateollisuuden yritysten, on mahdollisesti hydynnettv mys kehittyneempi suunnittelu- ja ohjausjrjestelmi. Lisksi huomattiin, ett perinteisten strategioiden rinnalle yritysten on nostettava mys tieto- ja viestintteknologiastrategiat. On trke ymmrt, ett tydellist MPC-systeemi ei ole viel keksitty: jokaisen yrityksen tehtvksi ja vastuulle j oman totuutensa muodostaminen ja systeemins rakentaminen sen pohjalta.
Resumo:
Growing recognition of the electricity grid modernization to enable new electricity generation and consumption schemes has found articulation in the vision of the Smart Grid platform. The essence of this vision is an autonomous network with two-way electricity power flows and extensive real-time information between the generation nodes, various electricity-dependent appliances and all points in-between. Three major components of the Smart Grids are distributed intelligence, communication technologies, and automated control systems. The aim of this thesis is to recognize the challenges that Smart Grids are facing, while extinguishing the main driving factors for their introduction. The scope of the thesis also covers possible place of electricity Aggregator Company in the current and future electricity markets. Basic functions of an aggregator and possible revenue sources along with demand response feasibility calculations are reviewed within this thesis.
Resumo:
The maximum realizable power throughput of power electronic converters may be limited or constrained by technical or economical considerations. One solution to this problemis to connect several power converter units in parallel. The parallel connection can be used to increase the current carrying capacity of the overall system beyond the ratings of individual power converter units. Thus, it is possible to use several lower-power converter units, produced in large quantities, as building blocks to construct high-power converters in a modular manner. High-power converters realized by using parallel connection are needed for example in multimegawatt wind power generation systems. Parallel connection of power converter units is also required in emerging applications such as photovoltaic and fuel cell power conversion. The parallel operation of power converter units is not, however, problem free. This is because parallel-operating units are subject to overcurrent stresses, which are caused by unequal load current sharing or currents that flow between the units. Commonly, the term circulatingcurrent is used to describe both the unequal load current sharing and the currents flowing between the units. Circulating currents, again, are caused by component tolerances and asynchronous operation of the parallel units. Parallel-operating units are also subject to stresses caused by unequal thermal stress distribution. Both of these problemscan, nevertheless, be handled with a proper circulating current control. To design an effective circulating current control system, we need information about circulating current dynamics. The dynamics of the circulating currents can be investigated by developing appropriate mathematical models. In this dissertation, circulating current models aredeveloped for two different types of parallel two-level three-phase inverter configurations. Themodels, which are developed for an arbitrary number of parallel units, provide a framework for analyzing circulating current generation mechanisms and developing circulating current control systems. In addition to developing circulating current models, modulation of parallel inverters is considered. It is illustrated that depending on the parallel inverter configuration and the modulation method applied, common-mode circulating currents may be excited as a consequence of the differential-mode circulating current control. To prevent the common-mode circulating currents that are caused by the modulation, a dual modulator method is introduced. The dual modulator basically consists of two independently operating modulators, the outputs of which eventually constitute the switching commands of the inverter. The two independently operating modulators are referred to as primary and secondary modulators. In its intended usage, the same voltage vector is fed to the primary modulators of each parallel unit, and the inputs of the secondary modulators are obtained from the circulating current controllers. To ensure that voltage commands obtained from the circulating current controllers are realizable, it must be guaranteed that the inverter is not driven into saturation by the primary modulator. The inverter saturation can be prevented by limiting the inputs of the primary and secondary modulators. Because of this, also a limitation algorithm is proposed. The operation of both the proposed dual modulator and the limitation algorithm is verified experimentally.
Resumo:
The amount of installed wind power has been growing exponentially during the past ten years. As wind turbines have become a significant source of electrical energy, the interactions between the turbines and the electric power network need to be studied more thoroughly than before. Especially, the behavior of the turbines in fault situations is of prime importance; simply disconnecting all wind turbines from the network during a voltage drop is no longer acceptable, since this would contribute to a total network collapse. These requirements have been a contributor to the increased role of simulations in the study and design of the electric drive train of a wind turbine. When planning a wind power investment, the selection of the site and the turbine are crucial for the economic feasibility of the installation. Economic feasibility, on the other hand, is the factor that determines whether or not investment in wind power will continue, contributing to green electricity production and reduction of emissions. In the selection of the installation site and the turbine (siting and site matching), the properties of the electric drive train of the planned turbine have so far been generally not been taken into account. Additionally, although the loss minimization of some of the individual components of the drive train has been studied, the drive train as a whole has received less attention. Furthermore, as a wind turbine will typically operate at a power level lower than the nominal most of the time, efficiency analysis in the nominal operating point is not sufficient. This doctoral dissertation attempts to combine the two aforementioned areas of interest by studying the applicability of time domain simulations in the analysis of the economicfeasibility of a wind turbine. The utilization of a general-purpose time domain simulator, otherwise applied to the study of network interactions and control systems, in the economic analysis of the wind energy conversion system is studied. The main benefits of the simulation-based method over traditional methods based on analytic calculation of losses include the ability to reuse and recombine existing models, the ability to analyze interactions between the components and subsystems in the electric drive train (something which is impossible when considering different subsystems as independent blocks, as is commonly done in theanalytical calculation of efficiencies), the ability to analyze in a rather straightforward manner the effect of selections other than physical components, for example control algorithms, and the ability to verify assumptions of the effects of a particular design change on the efficiency of the whole system. Based on the work, it can be concluded that differences between two configurations can be seen in the economic performance with only minor modifications to the simulation models used in the network interaction and control method study. This eliminates the need ofdeveloping analytic expressions for losses and enables the study of the system as a whole instead of modeling it as series connection of independent blocks with no lossinterdependencies. Three example cases (site matching, component selection, control principle selection) are provided to illustrate the usage of the approach and analyze its performance.
Resumo:
Tss diplomityss esitelln robotisoinnin teoria ja robottisolun oheislaitteet, vaihtoehdot, toiminta ja turvallisuus. Joustavalla tuotantosolulla tarkoitetaan automaattista valmistusjrjestelm, jossa on useita toisiinsa liitettyj koneita yhteisell ohjausjrjestelmll. Solun komponentteja ovat tuotantolaitteet ja -koneet, ohjausjrjestelmt, valvontalaitteet ja anturit, toimi- ja stlaitteet sek ohjelmointijrjestelm. Joustavaa tuotantosolua voidaan kehitt tehostamalla tyntekijiden koulutusta, ohjelmointia, asetusten tekemist ja layouttia. Diplomityhn liittyv kehitystehtv koskee heinvetelisen alihankintakonepajan, Metalliset Oy:n, tuotannon tehostamista robotisoinnin avulla. Metalliset Oy:n joustavan srmyssolun kehittmiskeinoiksi valittiin nykyisen jrjestelmn tehostaminen, uuden tuotantosolun luominen olemassa olevia laitteita hydynten ja tulevaisuuden tuotantosolun kehittminen. Vertailussa parhaimmaksi osoittautui uuden tuotantosolun luominen olemassa olevia laitteita hydynten.
Resumo:
A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor has been developed and it is used to analyse a frequency-converterfed industrial squirrel-cage induction motor. Two control systems that emulate the behaviour of commercial direct-torque-controlled (DTC) and vector-controlled industrial frequency converters have been studied, implemented in the simulation software and verified by extensive laboratory tests. Numerous factors that affect the operation of a variable speed drive (VSD) and its energy efficiency have been investigated, and their significance in the simulation of the VSD results has been studied. The dependency of the frequency converter, induction motor and system losses on the switching frequency is investigated by simulations and measurements at different speeds for both the vector control and the DTC. Intensive laboratory measurements have been carried out to verify the simulation results.
Resumo:
Identification of product requirements and quality, together with the management of production are key issues in chemical engineering. Quality control of crystalline products is part of the quality of many industrially manufactured products like paper, paintings, medicines and fertilizers. In most crystallization cases, quality is described with the size, polymorph, shape and purity of the crystal. The chemical composition, hydrodynamics and driving force, together with the operating temperature are in a key position when the properties of a crystalline product are controlled with the crystallization process. This study concentrates on managing the identified properties of a crystalline product with the control of a driving force. The controlling of the driving force can be based on the change of solubility or the change of concentration. Solubility can be changed with temperature, pressure and an antisolvent. The concentration of crystallizing compound, the solute can be changed with the evaporation of the solvent and with the addition of a reagent. The present study focuses on reagent addition and temperature change as methods of changing the level of the driving force. Three control structures for direct control of supersaturation are built, one for cooling crystallization and two for reactive crystallization. Closed loop feedback control structures are based on the measurement of the solute concentration with attenuated total reflection - Fourier transform infrared spectrometer. The details of the reagent feed are analyzed with experimental studies and with results of computational fluid dynamic simulations of the inert particle pulse in the premixer and inert particle injection to the mixing tank. Nucleation in conditions of controlled reactive crystallization is analyzed with Nielsens equation of homogeneous nucleation. The resulting control systems, based on regulation of supersaturation, can be used to produce the desired polymorph of an organic product. The polymorph composition of product crystals is controlled repeatably with the decision of a set value of supersaturation level.
Resumo:
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.
Resumo:
Due to the outsourcing of manufacturing, Finlayson Oy now has a need to develop its supply chain management as its new ability. This requires development of efficient and flexible procedures and models in order to efficiently manage the companys floating assets without affecting the reliability of delivery promised for the customer. In this thesis we discuss Finlaysons supply chain management with a focus on the operations between Finlayson and its suppliers. The aim is to develop these operations and increase the reaction speed of the supply chain in order to response to the changes in demand. In order to do this we discuss different product analysis, material and inventory management and demand forecasting. In the research part of the thesis we design strategies for different products based on product classification analysis. Market behavior of different products will be modeled with demand forecasting methods and inventory control systems will be designed for different product groups based on the nature of their supplier. We will also optimize the costs and resource needs for different suppliers order-deliver processes.
Resumo:
Nykyisess valmistusteollisuudessa erilaisten robottien ja automatisoitujen tuotantovaiheiden rooli on erittin merkittv. Tarkasti suunnitellut liikkeet ja toimintavaiheet voidaan nykyisill jrjestelmill ajoittaa tarkasti toisiinsa nhden, jolloin erilaisten virhetilanteidenkin sattuessa jrjestelm pystyy toimimaan tilanteen edellyttmll tavalla. Automatisoinnin etuna on mys tuotannon muokkaaminen erilaisten tuotteiden valmistamiseen pienill muutoksilla, jolloin tuotantokustannukset pysyvt matalina mys pienten valmistuserien tapauksissa. Usean akselin laitteissa eli niin sanotuissa moniakselikytiss laitteen toimintatarkkuus riippuu jokaisen liikeakselin tarkkuudesta. Liikkeenohjauksessa on perinteisesti ollut kytss mytkytketty paikkakaskadi, jonka virityksess otetaan huomioon akselilla olevat erilaiset dynaamiset tilat ja kytettvt referenssit. Monissa nykyisiss hajautetuissa jrjestelmiss eli moniakselikytiss, joissa jokaiselle akselille on oma ohjauslaite, ei yksittisen akselin paikkavirhett huomioida muiden akseleiden ohjauksessa. Tyss tutkitaan erilaisia moniakselijrjestelmien ohjausmenetelmi ja mytkytketyn paikkakaskadin toimintaa moniakselikytss pyritn parantamaan tuomalla paikkastimen rinnalle toinen sdin, jonka tulona on akseleiden vlinen paikkaero.
Resumo:
Ympristrasituksen vhentminen, tiukkenevat pstrajat ja ehtyvt ljyvarat ovat ajaneet kulkuvlineteollisuuden hakemaan uusia vaihtoehtoja ajoneuvojen energiatehokkuuden kehittmiseksi. Hybriditeknologia tarjoaa ratkaisuja kustannustehokkuuden ja ympristystvllisyyden parantamiseksi. Hybriditeknologian yleistyess mys tykoneympristss saadaan paitsi kehitetty energiatehokkaampia ja pienemmill kyttkustannuksilla olevia tykoneita, niin mys tuotua siviiliajoneuvoista tuttuja turvallisuusominaisuuksia tykoneympristn. Perinteisten diesel-moottorien korvaaminen nopeavasteisilla ja tarkasti sdettvill shkmoottoreilla tarjoaa mahdollisuuksia toteuttaa tarkempia ja monipuolisempia stjrjestelmi kuin perinteisess ympristss. Tss diplomityss suunnitellaan luistonestojrjestelm ja elektroninen tasauspyrst hybriditykoneympristn. Jrjestelm voi kyttkohteesta riippuen pienent huomattavasti kyttkustannuksia ja mahdollistaa uusien sovellusten tuomista markkinoille, kuten esimerkiksi kntymisen avustaminen differentiaalisella ohjauksella.
Resumo:
Tulevaisuudessa shkverkko kohtaa monia haasteita, kun shkautot yleistyvt, vaatien suuren tehotarpeen. Uusiutuvan energiantuotannon epvarma huipputehon tuotanto ei vlttmtt pysty kattamaan shkautoista johtuvaa suurta tehopiikki, jos suuret mrt ajoneuvoista kytketn yht aikaa lataukseen. Jos shkajoneuvot voidaan ladata ohjatusti, ei vlttmtt tarvita lisenergian tuotantoa kattamaan kasvanutta huipputehon tarvetta. Lisksi shkajoneuvojen akut toimivat koko shkverkolle energiavarastoina, jollaista ei ole ennen ollut. lykkll shkverkolla voidaan ohjata shkajoneuvon latausta, mikli ajoneuvossa on ohjausjrjestelm ja akkujen varaustilan mittaus. Tss kandidaatin tyss ohjelmoidaan mittaus- ja ohjauskortti plug-in hybridiautoa varten, jossa on V2G-ominaisuus. Ohjainkortista toteutetaan toimintakuvaus, jonka mukaan se mys ohjelmoidaan. Ohjainkortti mittaa akkujen jnnitett ja virtaa, joista voidaan mritt akkujen varaustilat. Ohjainkortti lhett tiedot eteenpin PC:lle, jolta ohjainkortti saa kskyn toimintatilasta. Mittaustietojen perusteella voidaan seurata mahdollisia vikatilanteita. Kandidaatintyn aikana ohjainkorttia ei ehditty asentamaan ajoneuvoon, mutta laboratoriotestien mukaan voidaan todeta, ett ohjainkortti on ohjelmallisesti toimiva. Mittauksissa selvisi, ett ohjainkortin mittaustulot eivt olleet tarpeeksi tarkkoja kyttkohteeseen. Todettiin, ett ohjainkortti vaatii rakenteellisia muutoksia mittaustuloksien parantamista varten, ennen ohjainkortin kyttnottoa, mutta kandidaatintyn tavoitteet saavutettiin.
Resumo:
Johdon ohjausjrjestelmt koostuvat yksittisist jrjestelmist, jotka muodostavat yrityksen ohjausjrjestelmkokonaisuuden. Yksittiset jrjestelmt ovat sek konkreettisia, kuten budjetit, mutta mys ksitteellisempi tekijit, kuten henkilstn ohjaus. Jokaisella yrityksell on oma ohjausjrjestelmkokonaisuutensa, joka riippuu esimerkiksi yrityksen toimialasta, strategiasta ja koosta. Menestykseen yrityksen on lydettv mahdollisimman toimiva ja yhteensopiva ohjausjrjestelmkokonaisuus juuri kyseiselle yritykselle. Tmn tutkielman ensisijaisena tavoitteena on selvitt miten yritysten eroavaisuudet vaikuttavat johdon ohjausjrjestelmiin. Tutkielma tehdn selvittmll ensin mit johdon ohjausjrjestelmt ovat ja tmn jlkeen haastattelemalla erilaisten yritysten talousjohtajia niiden ohjausjrjestelmist. Tmn jlkeen vertaillaan tuloksia hallitsevaan teoriaan ja yritysten ohjausjrjestelmi toisiinsa. Tutkielmassa havaittiin selvi eroja yritysten ohjausjrjestelmien vlill.
Resumo:
RFID on radioaaltoja hyvksikyttv langaton kommunikointitekniikka, jota kytetn tunnistamaan tunnisteella merkittyj esineit tai ihmisi yksilin. RFID on jo pitkn ollut tunnettu tekniikka, mutta vasta viime vuosikymmenin sit on alettu hydyntmn kaupallisesti eri sovellusaloilla. Kandidaatintyn tarkoituksena on tehd yleiskatsaus RFID:n historiaan, jrjestelmien osiin ja niiden toimintaan sek kartoittaa RFID-markkinoiden nykytilaa ja lhitulevaisuutta sek globaalilta kannalta ett Suomessa. Lopuksi tyss tarkastellaan RFID-perusteisten kulunvalvontajrjestelmien perusominaisuuksia ja niiden toimintaa.
