Parameter Identification and Tracking of a Unified System

The unified chaotic system contains the Lorenz and the Chen systems as two dual systems at the two extremes of its parameter spectrum and the Lü system as a special case. The parameter identification and tracking problem of the unified system are further investigated. In particular, a novel controller is designed for avioding the divergence of the factor 1/x. Numerical simulations are provided to show the effectiveness of these methods.