Fractional-order state observers for integer-order linear systems

This paper addresses the state observation problem for linear, time-invariant, single-input single-output, integer-order systems with known parameters, using non-integer-order (fractional-order) ob- servers. This study is aimed to establish if this is possible and if so what would it be the advantages. A novel fractional-order ob- server is proposed, for which the convergence of the estimation error is theoretically guaranteed, and its performance is compared to classic integer-order Luenberger state observer through simulations. Accord- ing to simulation results, it is possible to establish some advantages of the proposed fractional-order observer over the classic integer-order Luenberger observer, mainly in the error convergence speed and in the attenuation of the effects of high-frequency disturbances.