Research On Attitude Prescribed Performance Control Of Spacecraft

The advanced spacecraft is subject to multiple physical constraints such as actuation saturation,communication capacity,actuator faults,limited response velocity and etc.,to name a few.How to achieve a safe,reliable,intelligent and autonomous attitude control has attracted considerable attention.In this dissertation,with consideration of system uncertainty(like the uncertain inertial matrix and actuator faults)and attitude constraints,we carry out some investigations on the attitude control for a single or multiple spacecraft.The main contributions are summarized as follows.(1)On low-complexity prescribed performance control of a class of unknown large-scale nonlinear systems.We propose a low-complexity low-complexity prescribed performance control(PPC)approach for the large-scale nonlinear systems.Without any online approximations for the unknown nonlinearities,we design a PID-like controller to realize the system tracking control in the PPC control structure.(2)On intelligent and autonomous leader-following attitude control via using the data-driven control strategy.In the presence of unknown inertial matrix and external disturbance,we propose an intelligent and autonomous attitude consensus control approach for the leader-following spacecraft formation.First,we design a two-layer nominal PPC controller to guarantee the transient and steady-state performance for the angular and angular velocity tracking error systems.Second,to enhance the robustness and adaptiveness,the data-driven control strategy is introduced to design an adaptive compensation controller along the two-layer nominal PPC controller.Finally,with the two controllers,the follower spacecraft can track the leader’s attitude command successfully.(3)On safe and reliable attitude fault-tolerant PPC control of flexible spacecraft via using event-triggered control strategy.In practice,actuator faults will degrade the control performance and even lead to the instability of the spacecraft.Meanwhile,most of the current attitude control approaches are time-triggered,namely,the relevant control schemes are updated based on the system sampling time.This will lead to various fuel assumptions and impose strong physical pressure on the actuator.To tackle the foregoing problems,we creatively propose a novel event-triggered fault-tolerant PPC attitude control approach for the flexible spacecraft subject to unknown inertial matrix and uncertain disturbance.Under the proposed approach,the flexible spacecraft can track the given attitude command with ultra-low updating frequency.(4)On output feedback attitude PPC control of postcapture combined spacecraft based on a finite-time convergent differentiator.In practice,the full state information of spacecraft is difficult to obtain due to the lack of efficient onboard sensors.This makes all the full-state information feedback control approaches ineffective.To solve this problem,we propose a part-state feedback PPC control approach for the postcapture combined spacecraft via only using the output feedback information.In this approach,we first design a finite-time convergent differentiator to estimate the unknown angular velocity information.Then,based on the estimated velocity information,a robust PPC controller is devised to realize the attitude tracking control.(5)On appointed-time attitude PPC control of spacecraft.Finite-time attitude maneuvering control has attracted considerable attention owing to the specific on-orbit missions.In this paper,we creatively propose a brand-new appointed-time attitude control approach for spacecraft in the presence of unknown inertial matrix and uncertain perturbations.Compared with the existing works,the proposed control approach can realize appointed-time attitude tracking control without using any state fractional forms and symbolic functions.Thus,the controller structure is computationally simple and easily achieved online.