Decentralized Control

Several real-world large-scale systems can be viewed as interconnections of linear/nonlinear subsystems with constraints on information flow between the subsystems. We have addressed the decentralized control problem for large-scale systems under various sets of assumptions on the subsystem structures and interconnection topologies. We have also applied these results to a variety of large-scale systems including power networks, smart structures, and satellite formations. Our results on nonlinear control techniques have enabled us to weaken the required assumptions on the structures of the individual subsystems and also on the interconnection (or coupling) among the subsystems. We have also extended the results to include adaptations to compensate for unknown system parameters and also to provide robustness to uncertain terms and appended nonlinear dynamics. Furthermore, we have investigated techniques to achieve decentralized attenuation of disturbance inputs and provided explicit guaranteed bounds on the disturbance attenuation along with tuning strategies to achieve desired disturbance attenuation properties through the proper choice of controller parameters. Decentralization of the control may be achieved both through a centralized or a decentralized design of the decentralized controllers. In our research, both strategies have been utilized.