Robust Observer-Based Synchronization of Unified Chaotic Systems in the Presence of Dead-Zone Nonlinearity Input

In this paper, the synchronization of unified chaotic systems in the presence of practical constraints is considered. Constraints that this paper is considered are: dead-zone nonlinearity input, model uncertainty, external disturbance and the unavailability of state variables. First, the dynamical model of the unified chaotic systems in the presence of aforesaid constraints is introduced. Then, an observer-based adaptive controller is designed which guarantees robust synchronization between two unified chaotic systems (i.e. master and slave systems). For this purpose, a theorem is given and according to a Lyapunov stabilization approach, it is guaranteed that the proposed controller leads to robust synchronization objective despite the dead-zone nonlinearity input and also uncertainty terms. Finally, the computer simulations show proper performance of the proposed law in robust synchronization of the unified chaotic systems