Experimental investigation of control updating period monitoring in industrial PLC-based fast MPC: Application to the constrained control of a cryogenic refrigerator
In this paper, a complete industrial validation of a recently published scheme for on-line adaptation of the control updating period in model predictive control is proposed. The industrial process that serves in the validation is a cryogenic refrigerator that is used to cool the supra-conductors involved in particle accelerators or experimental nuclear reactors. Two recently predicted features are validated: the first states that it is sometimes better to use less efficient (per iteration) optimizer if the lack of efficiency is over-compensated by an increase in the updating control frequency. The second is that for a given solver, it is worth monitoring the control updating period based on the on-line measured behavior of the cost function.
KeywordsFast MPC cryogenic refrigerators control updating period ODE-based optimization
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Authors would like to thank every co-worker from the SBT for their kind help to improve models and control strategy and for their time to correct and discuss this paper. Authors give special thanks to Michel Bon-Mardion, Lionel Monteiro, François Millet, Christine Hoa, Bernard Rousset and Jean-Marc Poncet from SBT for their explanation about the process and their participation on experimental campaigns.
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