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Peripheral control tools for a run-of-mine ore milling circuit
Dissertation (MEng)--University of Pretoria, 2012.
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| Format: | Thesis |
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University of Pretoria
2013
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| _version_ | 1867613591912316928 |
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| access_status_str | Open Access |
| author2 | Craig, Ian K. |
| author_browse | Craig, Ian K. |
| author_facet | Craig, Ian K. |
| collection | Thesis |
| dc_rights_str_mv | © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. p> |
| description | Dissertation (MEng)--University of Pretoria, 2012. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/26420 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:38:35.295Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/26420 Peripheral control tools for a run-of-mine ore milling circuit Craig, Ian K. laurentz.olivier@sasol.com Olivier, Laurentz Eugene Dubbel-afskatting Maling Model-aanleg-verskil Onbehandelde Disturbance observer Fractional order Dual estimation Milling Partikel-filter Steuringsafskatter Erts Model-plant mismatch Particle filter Breuk-orde Run-of-mine ore UCTD Dissertation (MEng)--University of Pretoria, 2012. Run-of-mine ore milling circuits are generally difficult to control owing to the presence of strong external disturbances, poor process models and the unavailability of important process variable measurements. These shortcomings are common for processes in the mineral-processing industry. For processes that fall into this class, the peripheral control tools in the control loop are considered to be as important as the controller itself. This work addresses the implementation of peripheral control tools on a run-of-mine ore milling circuit to help overcome the deteriorated control performance resulting from the aforementioned shortcomings. The effects of strong external disturbances are suppressed through the application of a disturbance observer. A fractional order disturbance observer is also implemented and a novel Bode ideal cutoff disturbance observer is introduced. The issue of poor process models is addressed through the detection of significant mismatch between the actual plant and the available model from process data. A closed-form expression is given for the case where the controller has a transfer function. If the controller does not have a transfer function, a partial correlation analysis is used to detect the transfer function elements in the model transfer function matrix that contain significant mismatch. The mill states and important mill parameters are estimated with the use of particle filters. Simultaneous state and parameter estimation is compared with a novel dual particle filtering scheme. A sensitivity analysis shows the class of systems for which dual estimation would provide superiorestimation accuracy over simultaneous estimation. The implemented peripheral control tools show promise for current milling circuits where proportional-integral-derivative (PID) control is prevalent, and also for advanced control strategies, such as model predictive control, which are expected to become more common in the future. AFRIKAANS : Maalkringe wat onbehandelde erts maal is oor die algemeen moeilik om te beheer as gevolg van die teenwoordigheid van sterk eksterne steurings, onakkurate aanlegmodelle en metings van belangrike prosesveranderlikes wat ontbreek. Hierdie probleme is algemeen vir aanlegte in die mineraalprosesseringsbedryf. Vir aanlegte in hierdie klas word die randbeheerinstrumente as net so belangrik as die beheerder beskou. Hierdie verhandeling beskryf die implementering van randbeheerinstrumente vir ’n maalkring wat onbehandelde erts maal, om die verswakte beheerverrigting teen te werk wat veroorsaak word deur bogenoemde probleme. Die impak van sterk eksterne steurings word teengewerk deur die implementering van ’n steuringsafskatter. ’n Breuk-orde-steuringsafskatter is ook geïmplementeer en ’n nuwe Bode ideale afsnysteuringsafskatter word voorgestel. Die kwessie van onakkurate aanlegmodelle word hanteer deur van die aanlegdata af vas te stel of daar ’n verskil is tussen die aanleg en die beskikbare model van die aanleg. ’n Uitdrukking word gegee vir hierdie verskil vir die geval waar die beheerder met ’n oordragsfunksie voorgestel kan word. Indien die beheerder nie ’n oordragsfunksie het nie, word van ‘n parsiële korrelasie-analise gebruik gemaak om die element, of elemente, in die aanleg se oordragsfunksiematriks te identifiseer wat van die werklike aanleg verskil. Die toestande en belangrike parameters in die meul word beraam deur van partikel-filters gebruikte maak. Gelyktydige toestand- en parameter-beraming word vergelyk met ’n nuwe dubbel-partikelfilter skema. ’n Sensitiwiteitsanalise wys die klas van stelsels waarvoor dubbel-afskatting meer akkurate waardes sal gee as gelyktydige afskatting. Die voorgestelde randbeheerinstrumente is toepaslik vir huidige maalkringe waar PID-beheer algemeen is, asook vir gevorderde beheerstrategieë, soos model-voorspellende beheer, wat na verwagting in die toekoms meer algemeen sal word. Copyright Electrical, Electronic and Computer Engineering unrestricted 2013-09-07T05:20:39Z 2012-07-20 2013-09-07T05:20:39Z 2012-04-23 2012-07-20 2012-07-19 Dissertation Olivier, LE 2011, Peripheral control tools for a run-of-mine ore milling circuit, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/26420 > E12/4/423/gm http://hdl.handle.net/2263/26420 http://upetd.up.ac.za/thesis/available/etd-07192012-160558/ © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. p> application/pdf University of Pretoria |
| spellingShingle | Dubbel-afskatting Maling Model-aanleg-verskil Onbehandelde Disturbance observer Fractional order Dual estimation Milling Partikel-filter Steuringsafskatter Erts Model-plant mismatch Particle filter Breuk-orde Run-of-mine ore UCTD Peripheral control tools for a run-of-mine ore milling circuit |
| title | Peripheral control tools for a run-of-mine ore milling circuit |
| title_full | Peripheral control tools for a run-of-mine ore milling circuit |
| title_fullStr | Peripheral control tools for a run-of-mine ore milling circuit |
| title_full_unstemmed | Peripheral control tools for a run-of-mine ore milling circuit |
| title_short | Peripheral control tools for a run-of-mine ore milling circuit |
| title_sort | peripheral control tools for a run of mine ore milling circuit |
| topic | Dubbel-afskatting Maling Model-aanleg-verskil Onbehandelde Disturbance observer Fractional order Dual estimation Milling Partikel-filter Steuringsafskatter Erts Model-plant mismatch Particle filter Breuk-orde Run-of-mine ore UCTD |
| url | http://hdl.handle.net/2263/26420 http://upetd.up.ac.za/thesis/available/etd-07192012-160558/ |