Adaptive quasi-optimal gains tuning of PI-fuzzy controllers

This paper proposes a new methodology for tuning the scaling factors, or gains, of fuzzy proportional-integral controllers, where the closed loop system performance is explicitly taken into account. The tuning problem is formulated as an online constrained non-linear optimization problem using a linear model structure to capture the system´s dynamics. The model parameters are updated online using the most recent information collected from the plant. In the case of stringent sampling times the optimization routine is prematurely stopped before a local minimum is reached and the obtained gains subsequently provided to the controller. Experimental results from a testbed illustrate the relevance of the proposed tuning technique.