dc.contributor.advisor Hovd, Morten nb_NO dc.contributor.author Sætermoen, Anders nb_NO dc.date.accessioned 2014-12-19T14:07:53Z dc.date.available 2014-12-19T14:07:53Z dc.date.created 2013-10-05 nb_NO dc.date.issued 2013 nb_NO dc.identifier 653779 nb_NO dc.identifier ntnudaim:8842 nb_NO dc.identifier.uri http://hdl.handle.net/11250/261055 dc.description.abstract Model Predictive Control (MPC) is a method much used in the petroleum industries because it can handle multiple states and constraints, and it finds optimal control inputs. The MPC method in this thesis is called contractive set MPC. Contractive set MPC is based on similar principles as the well known dual mode MPC, which consists of a terminal set where the state need to lie inside at the end of the prediction horizon, for constraints to hold on the infinite horizon.Contractive in contractive set MPC refers to the special terminal set being contractive by a certain scalar value, and the basic idea of contractive set MPC is to calculate the terminal set off-line which allows the use of a less time complex on-line controller (linear programming problem) compared to standard MPC methods which also solves an optimization problem repeatedly on-line but instead a quadratic optimization problem is solved repeatedly on-line. The requirements of additional control methods may become apparent if the resulting special terminal set is a very small subset of the state constraint set. Contractive set MPC is therefore enabled for processes which requires fast sampling rates. Another attractive property of the contractive set MPC method is that once the special set has been calculated, more precisely called the supremal (A,B)-invariant lambda-contractive set, closed loop stability easy follows from the properties this set exhibits. Another topic of this thesis is an approximation of the supremal (A,B)-invariant lambda-contractive set, therefore it is not the supremal set any more, but its properties still applies. By using the proposed method in this thesis, an approximation is obtained such that the bad time complexity of the existing recurrence algorithm is avoided, this enables contractive set MPC for processes of high dimension.A review of existing theory is given, and the behaviour of the existing method in the literature is elaborated by two examples in lower dimensions, and the idea to obtain the approximation is sketched at the same time. nb_NO dc.language eng nb_NO dc.publisher Institutt for teknisk kybernetikk nb_NO dc.title Contractive set MPC nb_NO dc.type Master thesis nb_NO dc.source.pagenumber 66 nb_NO dc.contributor.department Norges teknisk-naturvitenskapelige universitet, Fakultet for informasjonsteknologi, matematikk og elektroteknikk, Institutt for teknisk kybernetikk nb_NO
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