Event-triggered finite-time attitude consensus control of multiple rigid-body systems based on distributed observers

The problem of leader-following attitude consensus for multiple rigid-body systems is addressed for communication limitation in this paper. The leader and followers are described in unit quaternions forms. For each follower, a nonlinear finite-time distributed observer is proposed to estimate the states of the leader, and the event-triggered finite-time sliding mode controllers are constructed by using the estimation information to decrease the system's communication and computation consumption. The result demonstrates that in a finite time, the attitude tracking error can converge to an invariant set, and the communication interaction is decreased by the proposed event-triggered-based controller. Moreover, Zeno behavior is rigorously proved to be excluded, and the lower bound of the triggered time interval is provided. Finally, a numerical simulation is provided to validate the efficiency of the proposed control protocol.