Linear estimator for fractional systems

We address the issue of state estimation of nonlinear incommensurate fractional-order systems via linear observer in this paper. The basic idea is proposed under a synchronization framework which makes the response system a linear observer for the state of the drive system. By developing this approach, a linear time-invariant synchronization error system is obtained, and stability analysis is relied on the theory of linear incommensurate fractional-order systems. The suggested tool proves to be effective and systematic in achieving global synchronization. Simulation results verify and illustrate the effectiveness of the proposed method on some new fractional-order hyperchaotic systems.