Mittermaier, Heinz KarlLe Roux, Johan DerikCraig, Ian Keith2025-03-192025-03-192024Mittermaier, H.K., Le Roux, J.D., Craig, I.K. 2024,'Model-plant mismatch detection using the plant-model ratio : the influence of multivariable systems containing both fast and slow dynamics', IFAC-PapersOnLine, vol. 58, no. 25, Pg. 55-60, ISSN 2405-8963, https://doi.org/10.1016/j.ifacol.2024.10.2405-8963 (online)10.1016/j.ifacol.2024.10.237http://hdl.handle.net/2263/101596The plant-model ratio, developed to diagnose model-plant mismatch present in model-based controllers, inherits the same limitations from the frequency-based analysis that the method is based on. Nonetheless, the plant-model ratio shows the capacity to counteract the effect of non-linear dynamics within processes due to the ability to diagnose parametric model-plant mismatches for first-order plus time delay models. The plant-model ratio is developed before being validated on the Wood-Berry distillation column. One of the prominent limitations of frequency analysis, the filtering effects of time constant differences, is investigated and quantified for the Wood-Berry distillation column, showing the effect of time constant differences on each parametric model-plant mismatch diagnosis.en© 2024 The Authors. This is an Open Access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/).Controller performance monitoringGrinding mill circuitModel predictive controlModel-plant mismatchProcess performance monitoringSDG-09: Industry, innovation and infrastructureSDG-12: Responsible consumption and productionArticle