Speed-gradient adaptive high-gain observers for synchronization of chaotic systems

"We address the problem of output feedback synchronization of certain chaotic systems, under parameter uncertainty. That is, given a master system, the objective is to design a slave system that copies the dynamics of the master and reconstructs both the state and the values of the constant parameters of the master system. Hence, the synchronization problem that we address enters in the framework of Pecora and Carroll and relies on adaptive observer theory. In particular, the conditions that we impose take the form of persistency of excitation.