REVISTA DYNA NEW TECHNOLOGIES

Key words:

Algoritmo genético, Controlador PI, Optimización Multiobjetivo.

Article type:

ARTICULO DE INVESTIGACION / RESEARCH ARTICLE

Section:

RESEARCH ARTICLES

This work aims at tuning a PI controller for application for an experimental temperature control process, modeled by a first order plus time delay system, taking into account the robustness requirements at several operating points, and it can be applied in real situations in the industry that have similar processes. The main contribution of this work is the proposal of a control strategy by posing a multiobjective optimization problem focused on solving the set point changes and load disturbance attenuation issues. The tuning strategy takes into account the presence of unstructured uncertainty due to dynamics not included in the mathematical model, and the magnitude of the control signal to avoid saturating the actuator module. The variation of the plant parameters due to nonlinear behavior was also considered. The minimization of this effect was sought by imposing a bound on the sensitivity function. The optimization problem is solved via a known multiobjective genetic algorithm (NSGA-II). As a consequence of the application of this tuning method of the PI tuning, good results were obtained concerning the responses to set point changes and load perturbation input, in spite of the fact that the magnitude of the step signal is considerable in relation to the operating conditions. In the experimental equipment under study, this increase is equivalent to twenty degrees Celsius of temperature. Furthermore, the results allow concluding that it is possible to choose different combinations of the PI controller parameters, which take into account the trade-off between a good set point tracking and load disturbance attenuation.