Design and application of fractional-order improved disturbance observer

In order to reduce the influence of disturbance interference and measurement noise on stabilized platform tracking performance, disturbance observer (DOB) is applied to platform servo system. In view of the non-ideal performance of classical disturbance observer about suppressing measurement noise, a novel fractional-order improved disturbance observer (FIDOB) is proposed based on the structure of classical DOB, and FIDOB has a wider range to select a suitable trade off between robustness and vibration suppression. Simulation results show that FIDOB can suppress external disturbances and model perturbation well, and the suppression performance of measurement noise is improved, too.