Plant model frequency scale decomposition for identification and control design

There are processes whose dynamic behavior is defined at different frequencies, their models being difficult to deal with as a whole. The modeling and the control design procedures can be simplified if the process is split in different components characterizing its behavior in a given range of frequencies. This idea was successfully applied in the iterative identification and control design strategy and it was reported in some previous papers. In this paper, assuming the full model of the plant, the control is designed dealing with partial process models being appropriate to represent the plant behavior in the frequency range where this control is intended to act. This brings some advantages: first, the control design is simplified as it only takes care of a range of frequencies. Moreover, in order to save resources, the control can be implemented in a multirate scheme. Several examples of processes with flexible components are considered to design their control.