Self-triggered formation control for multi-spacecraft attitude coordination with communication delays

Abstract

This article addresses the event-triggered formation control problem for multi-spacecraft systems subject to time-varying delays. Firstly, a formation attitude dynamics model considering communication delays is proposed, and two auxiliary trigger instants are designed to transform the event-based control problem subject to delays into the conventional event-triggered control problem. Next, a nonlinear observer based on the triggering information of neighbors is developed to estimate the lumped nonlinear term. To avoid continuous communication, a dynamic event-based formation control strategy is proposed based on the nonlinear observer. To avoid continuous computation of the trigger mechanism, a self-triggered function is developed based on the current trigger information. Moreover, the system is Zeno-free under the proposed event-based control algorithms. Finally, simulation results show that compared with the dynamic triggering function, the self-triggered function avoids continuous computation and improves the control accuracy by nearly one order of magnitude while increasing communication frequency by 67.8 %.