CENTRALIZED ROBUST MULTIVARIABLE CONTROLLER DESIGN USINGOPTIMIZATION

Abstract

The paper deals with the determination of controller parameters for multivariable systems by
means of parameter optimization. In order to reduce the computational burden, the starting
point in the optimization is determined through information provided by the feedback controller
parameterized using the multivariable internal model controller (IMC) computed from the
plant’s p/q moment approximant and the original plant’s multi-loop controller parameter
magnitudes. Thereafter, controller parameter optimization proceeds to completion using the
MATLAB optimization toolbox which is widely available. A potency of this technique is that all
performance specifications and stipulated constraints are easily accommodated in the problem
formulation thus facilitating complete problem solution in one go. The technique has been
found to be effective for all plants considered so far and generally produces closed loop
systems with favorable characteristics when compared to systems designed by similar methods.