Fixed-Time Formation-Containment of Nonlinear Systems Using Intermittent Output and Connectivity

This article addresses the distributed fixed-time formation-containment problem of uncertain nonlinear systems considering intermittent output, connectivity, and actuation simultaneously. With the backstepping procedure, a unified fixed-time event-triggered formation-containment framework is established, achieving fast convergence while conserving resources. Different from existing fixed-time event-triggered results, the vexing issue of nondifferentiable virtual control laws caused by discontinuous outputs is resolved through a novel filter. Additionally, an asynchronous event-triggered fixed-time distributed estimator is constructed to reduce the communication cost among neighbors, eliminating the need for continuous monitoring and transmission of estimator states as seen in related results. Then, a fixed-time event-triggered control law without periodic actuation is proposed. The practical fixed-time stability of the closed-loop system is proven by adopting the Lyapunov theory. The feasibility of the explored control algorithm is illustrated by simulation and experiment involving unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs).