Realization:
Rafal Noga(CV)
Supervision:
Prof. Cesar de Prada
Prof. Toshiyuki Ohtsuka
Dr. Enrique Blanco Vinuela
Dr. Juan Casas Cubillos
Keywords
nonlinear model predictive control (NMPC), distributed parameter system, cryogenics, super fluid helium, EcosimPro
Timeframe
Project has been started on March 1, 2008 and was expected to finish by end of February 2011
Homepage of the project
NMPC for the Superfluid Helium Cryogenic Circuit at the LHC Arcs
(Actualized on 29-03-2012)
We have been studying application of the Nonlinear Model Predictive Control (NMPC) for the Superfluid Helium Cryogenic Circuit at the Large Hadron Collider (LHC) Arcs. Our goal is to improve the temperature stabilisation of the LHC superconducting magnets, operating under a number of constraints. This needs development of a first principles, distributed parameters, numerical model of the LHC superconducing magnets temperature dynamics, that should eventually be simplified in order to enable real-time non-linear optimisation of control actions. Regarding the optimisation, we use Continuation/GMRES method that works at very low computing cost. Based on the LHC operational experience, we redefined the constraint set and developed a non-linear cost function that corresponds the best to the control objectives. The potential of the NMPC to improve the stabilisation of the magnets temperature and the real time feasibility have been demonstrated in a numerical study using a simplified model. However, the experimental validation of the controler and state estimator based on the simplified model has failed. Now, we develop optimization based on more complete process model.
Bibliography
[1] R Noga. "PhD Thesis description: Non-linear Model based Predictive Control (NMPC)of the Large Hydron Collider's (LHC) Super fluid Helium Cryogenic Circuit". University of Valladolid, CERN. 2008 (Download)[2] R Noga. Modeling and control of the String2 LHC Prototype at CERN. Master's thesis, Gdansk University of Technology, University of Karlsruhe, Grenoble Institute of Technology, 2007. (Download)
[3]R Noga, C de Prada. First principles modeling of the Large Hadron Colliders (LHC) Super Fluid Helium Cryogenic Circuit. In Proceedings of 20th European Modeling and Simulation Symposium (EMSS08), 2008. (Download)
[4] R Noga, T Ohtsuka, C de Prada, E Blanco, and J Casas. Nonlinear Model Predictive Control for the Superfluid Helium Cryogenic Circuit of the Large Hadron Collider. In Proceedings of the 2010 IEEE International Conference on Control Applications, 2010. (Download)
[5] R Noga, T Ohtsuka, C de Prada, E Blanco, and J Casas. Simulation Study on Application of Nonlinear Model Predictive Control to the Superfluid Helium Cryogenic Circuit. Accepted to IFAC WC2011, 2010. (Download)
[6] R Noga, T Ohtsuka. NMPC for stiff, distributed parameter system: Semi-Automatic Code Generation and optimality condition evaluation. Submitted to PC2011, 2010. (Download Paper,Download Presentation)