Chaos synchronization of Chua's circuit and Lorenz system based on strictly positive realness

A valid method to synchronize Chua's circuit and Lorenz system is proposed. Through substituting the chaotic variables with the error variables in Chua's circuit, a modified error system is constructed. With the aid of the strictly positive realness of transfer function matrix, the synchronization controller is designed without considering the boundaries of the chaotic variables and the nonlinear terms of the error system. Some relevant numerical simulation results are given to illustrate the effectiveness of this method.