Time-varying formation of second-order discrete-time multi-agent systems under non-uniform communication delays and switching topology with application to UAV formation flying

In this study, the time-varying formation control problem for the second-order discrete-time multi-agent systems is investigated, where both the non-uniform communication time-delays and switching topology are taken into account. A linear discrete-time formation protocol is developed based on the neighbouring relative position and velocity information. Using the state transformation method and properties of the stochastic matrix, the formation feasibility condition is given and sufficient conditions for the discrete-time multi-agent systems to accomplish the time-varying formation are established. An unmanned aerial vehicles (UAVs) formation experiment platform is constructed. Using four quadrotor UAVs, UAV formation flying experiments are performed to verify the effectiveness and reliability of the discrete-time formation protocol. The experimental results show that the theoretical results can be used to deal with the time-varying formation control problem for multiple UAVs system with communication delays and switching topology.