Distributed prescribed-time attitude consensus tracking control for multiple flexible spacecraft under time-varying actuator faults

This study investigates the problem of prescribed-time attitude consensus tracking control for multiple flexible spacecraft subjected to time-varying actuator faults. The flexible spacecraft are modeled using partial differential equations (PDEs) and are interconnected via a directed graph. To ensure that the attitude consensus with predefined accuracy is achieved within a prescribed time, a novel distributed hierarchical control strategy is proposed, comprising a distributed estimator layer and a local control layer. First, considering that each flexible spacecraft can only exchange information with its local neighbors, a distributed prescribed-time estimator is designed to enable the follower spacecraft to accurately estimate the leader’s attitude and angular velocity within the prescribed time. Subsequently, based on these estimations, a novel adaptive prescribed performance controller is designed for the follower flexible spacecraft in the local control layer, leveraging adaptive techniques and a state transformation-based prescribed performance control (PPC) approach. The advantage of this controller is that it enables each follower to track the leader’s attitude with guaranteed prescribed performance, while ensuring that the structural vibrations of the flexible appendages remain bounded, even under time-varying actuator faults. Finally, the stability of the system under the proposed distributed control strategy is rigorously proven, and numerical simulations are conducted to evaluate its performance.