Design and experimental evaluation of a multivariable self-tuning PID controller

In this paper, a new multivariable self-tuning PID controller design scheme is proposed. The proposed control scheme has a static matrix pre-compensator in order to reduce the interaction terms of the process transfer function matrix. The static matrix pre-compensator is adjusted by an on-line estimator. The p x p pre-compensated multivariate system is then controlled via 'p' univariate self-tuning PID controllers, whose parameters are adjusted by a second identifier placed around the pre-compensated plant. The PID parameters are calculated on-line based on the relationship between the PID and generalized minimum variance control laws. The proposed scheme is experimentally evaluated on a 2 x 2 level plus temperature control system, Experimental results illustrate the effectiveness of this new scheme.