23 KB218 KB18 KB200020242012Mauder, TomasSandera, CenekStetina, Jozefštevilka:4letnik:46str. 325-328ISSN:1580-2949COBISSID:936106URN:URN:NBN:SI:doc-VD0AQLOAenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijecontinuous castingfuzzy optimizationheuristic optimizationhevristična optimizacijakontinuirno litjemehka optimizacijatemperature fieldtemperaturno poljeA fuzzy-based optimal control algorithm for a continuous casting process| Algoritem, ki temelji na mehki logiki, za optimalni nadzor kontinuirnega procesa ulivanja|Nowadays, continuous casting is used for processing almost one hundred percent of liquid steel into an intermediate shape. Steel with a poor structure and many defects is not acceptable to final customers, and therefore the producers must put strong emphases on its quality. Many serious steel defects can be eliminated by a preceding computer simulation, optimization and a proper control of the casting process. This paper describes an algorithm that optimizes the control parameters to ensure both a high production rate and a high quality of the products. These controlled parameters are the casting speed and all the cooling rates in the secondary cooling zone. The main principle of the algorithm is to get the surface and core temperatures to the prescribed values corresponding to the required ductility of steel. The whole optimization procedure consists of two separate parts, i.e., the numerical simulation of the process and the decision-making part based on fuzzy logic for modifying the control parameters. By incorporating the fuzzy logic into the optimization process, the algorithm has a very robust behaviour and an easy adaptation for different grades of steel. This algorithm runs in an off-line version and can be used as a preparation tool for a real casting process where the proper setting of the casting parameters is crucial for achieving high-quality products at an economical pricePostopek kontinuirnega ulivanja za pridobivanje vmesne oblike se danes uporablja pri obdelavi skoraj stoodstotnega deleža tekočega jekla. Jeklo s slabo strukturo in številnimi napakami ni sprejemljivo za končne kupce, zato morajo proizvajalci veliko pozornosti posvetiti kakovosti jekla. S predhodnimi računalniškimi simulacijami, z optimizacijo in ustreznim nadzorom procesa ulivanja se lahko odpravijo mnoge resne napake jekla. V tem prispevku je opisan algoritem za optimizacijo parametrov nadzora, ki zagotavlja visoko stopnjo proizvodnje ter visoko kakovost izdelkov. Med omenjene parametre nadzora spadata hitrost ulivanja in hitrost ohlajevanja v sekundarni coni ohlajanja. Glavno načelo algoritma je, da površina in temperatura sredice dosežeta določene vrednosti, ki ustrezajo zahtevani razteznosti jekla. Celoten postopek optimizacije obsega dva med seboj ločena dela - numerično simulacijo postopka in pa del, namenjen odločanju, ki temelji na mehki logiki za spreminjanje parametrov nadzora. Z integracijo mehke logike v postopek optimizacije algoritem doseže zelo robustno vedenje in enostavno prilagoditev različnim vrstam jekla. Ta algoritem deluje v različici off-line in se lahko uporablja kot pripravljalno orodje za dejanski proces ulivanja, kjer je ustrezna nastavitev parametrov ulivanja ključnega pomena za proizvodnjo visokokakovostnih izdelkov po ekonomični ceniTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije