Adaptive Decentralized Output-Feedback Control Dealing With Static/Dynamic Interactions and Different-Unknown Subsystem Control Directions

In this article, we present an adaptive decentralized control scheme for a class of interconnected uncertain systems with subsystems having different yet unknown control directions and involving static nonlinear interactions as well as input and output dynamic interactions. A new form of K-filters is designed for each subsystem, and only local information is employed to generate control signals. A new Nussbaum-type function is developed with a key property that allows for the quantification of the interconnections among multiple Nussbaum-type functions for the subsystems with different control directions in a single inequality. By using appropriately chosen Lyapunov functions, global stability of the resulting closed-loop system is rigorously established. Simulation results are included to demonstrate the effectiveness of the proposed methodology.