ABSTRACT
In this chapter, we continue further into the decentralized control techniques for interconnected systems, where we focus herein on methods for designing classes of decentralized controllers based on sliding-mode control (SMC) theory. Our effort is divided into two sections: in the first section we deal with a class of nonlinear interconnected systems with nonlinear uncertain subsystems considered where matched and mismatched uncertainties are both dealt with. In the second section, global decentralized stabilization of a class of interconnected delay systems is considered where both known and uncertain interconnections involve time delay. Matched and mismatched interconnections are treated separately to reduce the conservatism. In both sections, the approach followed allows a more general structure for the interconnections and uncertainty bounds than other literature in this area. The conservatism in the results is reduced by fully using system output information and the uncertainty bounds.
Large-scale systems are often modeled as dynamic equations composed of interconnections of lower-dimensional subsystems. One of the main features of these systems is that they are often spatially distributed, and thus the information transfer among subsystems may incur high cost or even encounter practical limitations. Moreover, system state variables are often not fully available for practical systems. Some state variables may be difficult/costly to measure and sometimes have no physical meaning and thus cannot be measured at all. It may be possible to use an observer to estimate unknown states, but this
greatly increasing the dimension of the system. In turn, this brings about further difficulties especially for large-scale systems. It is therefore pertinent to study decentralized control for large-scale interconnected systems using output feedback.
