Energy-Conserving Event-Triggered Intermittent Control for Multispacecraft Attitude Coordination

The reliance on continuous communication and uninterrupted control actions in conventional spacecraft formation control imposes a heavy burden on communication bandwidth and energy resources. To address these challenges, an energy-conserving event-triggered intermittent control strategy is proposed for multi-spacecraft attitude coordination. First, a cooperative observation problem is formulated. Second, a distributed dual-loop neural network event-triggered observer is developed. The observer employs a neural network to approximate the unknown nonlinear dynamics of the leader spacecraft, incorporates a dual-loop observer and a Zeno-free event-triggered mechanism to eliminate the need for continuous communication, and achieves accurate state estimation using only discrete-time information. These features enable short-term state prediction by the observer even when inter-spacecraft communication is unavailable. Third, a prescribed performance intermittent controller is designed based on the estimated states. The controller deactivates the actuators when the estimation becomes unreliable and reactivates them when the tracking error exceeds the prescribed performance bounds, thus reducing energy consumption without compromising tracking accuracy. Finally, numerical simulations are conducted to demonstrate the effectiveness of the proposed strategy and its advantages in energy efficiency, attitude coordination accuracy, and short-term prediction.