Monitoring process gains used in LP-MPC systems

GERMAN A. BUSTOS; ALEJANDRO H. GONZÁLEZ; JACINTO L. MARCHETTI

Buenos Aires

Congreso; AADECA 2012 – Semana del Control Automático –23º Congreso Argentino de Control Automático; 2012

AADECA

Stationary process gains are critical model parameters to determine targets in commercial MPC technologies. Consequently, important savings can be reached by acceding to an early prevention method capable of detecting whether the actual process moves away from the modeled dynamics or not, particularly by indicating when the process gains are not more represented by those included in the model identified during commissioning stages. A subspace identification method, which works on closed-loop operation, is used here to estimate the process gain matrix. The main reason for using this strategy is that the closedloop monitoring method requires transient regime identification of the process (i.e., not only stationary, but dynamic identification). In this first version the goal is to achieve a method capable of identifying those gains of a multivariable model that start moving away from the original values. The anticipated knowledge of these events could provide a warning to process engineers and prevent from targeting process conditions with wrong gain estimations. The regular follow-up of the gain matrix should also help to localize those dynamics needing an updating identification.