Parameter-optimized Multivariable Control Systems

Abstract

Parameter-optimized multivariable controllers are characterized by a given controller structure and by the choice of free parameters using optimization criteria or tuning rules. Unlike single variable control systems, the structure of a multivariable controller consists not only of the order of the different control algorithms but also of the mutual arrangement of the coupling elements, as in chapter 18. Corresponding to the main and coupling transfer elements of multivariable processes, one distinguishes main and coupling controllers (cross controllers). The main controllers R _ii are directly dedicated to the main elements G _ii of the process and serve to control the variables y _i close to the reference variables w _i, see Figure 19.1a. The coupling controllers R _ij couple the single loops on the controller side, Figure 19.1b-d. They can be designed to decouple the loops completely or partially or to reinforce the coupling This depends on the process, the acting disturbance and command signals and on the requirements on the control performance.