Decentralized adaptive backstepping stabilization of nonlinear interconnected systems

In this paper, we consider the problem of designing decentralized adaptive controllers for a class of nonlinear interconnected systems with dynamic interactions and unmodelled dynamics depending on both subsystem inputs and outputs. All the subsystems controllers only employ local information and are designed by applying the standard adaptive backstepping technique without any modification. It is shown that these local controllers can globally stabilize the overall interconnected system and regulate all the subsystem outputs to zero. Furthermore, no a priori information on subsystem parameters or interactions is required.