Sliding-Mode-Observer-Based Time-Varying Formation Tracking for Multispacecrafts Subjected to Switching Topologies and Time-Delays

In this article, the time-varying practical formation problem is investigated for a group of spacecrafts subjected to switching topologies, and time-delays. First, a sliding mode observer is designed to estimate the derivatives of time-varying delays. In virtue of the self-stable region, the sufficient condition is provided to guarantee that the error dynamics of the super-twisting sliding mode observer is convergent. Then, the sliding-mode-observer-based formation tracking protocol is designed using position, and velocity of the neighboring agents with time-varying delays. Sufficient conditions are established in terms of average dwell time such that the studied multispacecraft system could achieve the goal of time-varying formation with switching topologies. Finally, an example on the multispacecraft system is provided to illustrate effectiveness of the proposed methodology.