Extended-State-Observer-Based Event-Triggered Orbit-Attitude Tracking for Low-Thrust Spacecraft

This article addresses the coupled orbit-attitude tracking problem using low-thrust propulsion while aiming to minimize on-board spacecraft system communication. An adaptive controller is proposed by employing an event-triggered control and an extended-state-observer, where a simple strategy to tune the observer parameters is provided. Moreover, the event-triggering strategy updates and allocates the control signal to the thrusters at prescribed discrete events and is shown to significantly reduce the data-rate requirement. Finally, the performance of the controller is illustrated through numerical examples.