Adaptive Control Of Attitude Maneuver And Vibration Suppression For Flexible Spacecraft

As an important component of spacecraft control system, the attitude control affects the precision of the spacecraft keeping at a predetermined pointing or location in orbit. Thus, research on spacecraft attitude control has great significance and it is a hot and difficult point in the field of control. In this paper, aiming at the attitude maneuver control problem of a flexible spacecraft with parametric uncertainties, external disturbances, elastic vibration and the unmeasured vibration variables, the main research results are as follows:The attitude maneuver and disturbance suppression control problem is investigated on the basis of considering main body and flexible structure as a whole. An open-loop modal observer with simple structure is constructed by utilizing the inherent physical properties of flexible appendages to solve the problem of the unmeasurable modal. And then a feedback controller on the obtained modal estimates, measurable quaternion and angular velocity is designed with the help of the adaptive backstepping technique. The proposed controller enhances the damping of active vibration and guarantees the robust stability of the closed-loop system and also the L2 -gain performance for the external torque disturbance under the case with parametric uncertainties and external disturbances.The vibration suppression of flexible accessories is realized by employing the technique of active vibration suppression control, i.e. electricity intelligent elements are attached to the flexible accessories to provide an auxiliary control to enhance the flexible damping. And then a feedback controller is designed for the purpose of attitude maneuver and vibration suppression. In the design of this controller, the coupling between flexible appendage and rigid body is not neglected, meanwhile, the uncertainties of system parameters and the external disturbances are considered. The theoretical analysis is given to demonstrate that the proposed controller is a suitable solution to the problem of the attitude maneuver and the vibration suppression.Based on a certain type of spacecraft with practical physical data, simulation is researched for the two proposed output feedback control methods, and the comparison with existing results in related literatures is given to illustrate the effectiveness and feasibility of the two methods to attitude maneuver and vibration suppression issue.