Abstract:In order to improve the response and vibration suppression abilities of stabilized platform servo system, a novel vibration suppression strategy was proposed by using an integration of fractional-order improved disturbance observer (FIDOB) based on adaptive grey predictive controller (AGPC) in stabilized platform system. A method of system modeling output module was established based on GM(1,1) power module and an adaptive adjust module was designed. The predicted error and actual error were combined together to form an integrate error, according to the values of the actual control system error and the predicted error, the prediction step and predicted error weight were adjusted to improve the response ability of system and decrease the influence of predicted error on the system output. The fractional-order improved DOB was established, and the robust stability was derived in detail. FIDOB was used to obtain disturbance estimate and generate compensation signal, and as the order of Q-filter was expanded to realnumber domain, FIDOB had a wide range to select a suitable tradeoff between robustness and vibration suppression. Finally, numerical simulation results illustrated that the method can suppress external disturbances and measurement noise well, and it can also improve the response ability of system. The proposed control strategy was simple in control-law derivation, and its effectiveness was validated by numerical simulations. In numerical simulation experiments, with the interference of friction and measurement noise, the tracking error of stabilized platform system was no more than 0.1rad/s. In the static and dynamic experiments, the regulating time of the stabilized platform was decreased by 0.258s, and the stable precision was increased by 1.5°~2.5°.
