Research On Attitude Tracking Control Method Of Combined Spacecraft After Target Acquisitio

The attitude tracking control of the combined spacecraft is the basis and premise of the on-orbit service and the guarantee of the on-orbit service.With the increasing requirements of space missions,the in-orbit service of space has put forward higher requirements on the control ability of spacecraft,and the control of the combined spacecraft has to adapt to various scenes.Under this background,this paper takes the target captured composite spacecraft as the research object,and considers respectively the tracking control strategy of the composite when the rotational inertia of the composite is known,there is uncertainty of the rotational inertia of the composite,and the rotational inertia of the composite is unknown.Firstly,the attitude kinematics model of the assembled spacecraft is derived,and the attitude error dynamics model of the assembled spacecraft is derived by modifying Rodrigo parameters as the state quantity to describe the attitude.Aiming at the error dynamics model of the combined spacecraft,the attitude tracking controller based on the preset performance control is designed to constrain the transient performance of the system when it converges.Further considering the combination of moment of inertia of spacecraft exist uncertainty and external disturbance,will use the combination of RBF neural network to estimate inertia uncertainties and external disturbance,and then based on the default performance of sliding mode controller to control system,through the numerical simulation analysis verified the result of the controller control.An adaptive controller is designed to control the attitude of the spacecraft under the circumstance that the rotor inertia of the combined spacecraft formed by the service spacecraft is unknown.Firstly,the error dynamics equation of the composite spacecraft is linearized.In order to optimize the tracking of the composite spacecraft to the expected attitude,the expected error trajectory based on polynomial is designed.The rotational inertia of the composite spacecraft is estimated by an adaptive method combined with sliding mode control,and the composite spacecraft is controlled.Finally,numerical simulation is used to verify and analyze.The attitude control of the combined spacecraft is carried out by a preset performance controller without parameter identification for the condition that the moment of inertia of the combined spacecraft is completely unknown.First,considering that the service spacecraft USES the reaction flywheel to control the assembly spacecraft,the assembly error dynamic equation containing the reaction flywheel is established.Considering the spacecraft cannot be measured under the condition of angular velocity information,using tracking differentiator of micro component assembly spacecraft attitude error estimate,in order to further improve the transient performance of the system,considering the combination of the unknown parameters,design the performance without parameter identification of the default controller,using the controller to control the combination.And the numerical simulation is carried out to verify and analyze.