Three-Stage Continuous-Time Feedback Controller Design

In this chapter, the results of two-stage continuous-time feedback controller design from Chap. 2 are extended to the three-stage feedback controller design. This facilitates control of three subsets of system state variables representing three artificial or natural subsystems of a system under consideration. The presentation follows the recent papers of Radisavljevic-Gajic and Milanovic (2016) and Radisavljevic-Gajic et al. (2017). The new technique introduces simplicity and requires only solutions of reduced-order subsystem level algebraic equations for the design of appropriate local controllers. The local feedback controllers are combined to form a global controller for the system under consideration. The technique presented facilitates designs of independent full-state feedback controllers at the subsystem levels. Different types of local controllers, for example, eigenvalue assignment, robust, optimal in some sense (L1, H2, H∞,…), observer-driven, Kalman filter-driven controllers, may be used to control different subsystems. This feature has not been available for any other known linear feedback controller design technique.