Synchronization of Partial Differential Systems via Diffusion Coupling

In this paper, we address the synchronization problem of coupled partial differential systems (PDSs). First, the asymptotical synchronization and the H_∞ synchronization of N-coupled PDSs with space-independent coefficients are considered without or with spatio-temporal disturbance, respectively. The sufficient conditions to guarantee the asymptotical synchronization and the H_∞ synchronization are derived. The effect of the spatial domain on the synchronization of the coupled PDSs is also presented. Then the problem of asymptotical synchronization of N-coupled PDSs with space-dependent coefficients is dealt with and the sufficient condition to guarantee the asymptotical synchronization is obtained by using the Lyapunov-Krasovskii method. The condition of the H_∞ synchronization for N-coupled PDSs with space-dependent coefficients is also presented. Both conditions are given by integral inequalities, which are difficult to be verified. In order to avoid solving these integral inequalities, we adopt the semi-discrete difference method to turn the PDSs into an equivalent spatial space state system, then the sufficient condition of the H_∞ synchronization for N-coupled PDSs is given by an LMI, which is easier to be verified. Further, the relationship between the sufficient conditions for the H_∞ synchronization, obtained by the Lyapunov-Krasovskii method and semi-discrete difference method respectively, is investigated. Finally, two examples of coupled PDSs are given to illustrate the correctness of our results obtained in this paper.