Distributed cooperative dual closed loop velocity-attitude consensus controller for rendezvous of the underactuated AUV swarm in 3-dimensional space

This paper addresses a distributed cooperative dual closed loop controller for the rendezvous process of the crowded underactuated AUV swarm recovery system in 3-dimensional space. Inspired by biological behaviors, the rendezvous process of the AUV swarm transforms into a flocking problem. Different from the traditional flocking problem, it is difficult to obtain the accurate position information of AUV in underwater environment. In the outer loop, the proposed velocity-attitude consensus protocol only uses the velocity and attitude information of neighbors in the communication range of AUV to handle the flocking issue of the AUV swarm. Moreover, the protocol guarantees the AUV swarm separation, cohesion, velocity matching and attitude synchronization, if no collision and the dynamically switch topology connectedness are preserved at the initial position. In the inner loop, the proposed fractional integral terminal sliding mode controller provides practical available control input for the actuator. In addition, the exponential consensus of velocity and attitude and the locally asymptotic stability of the system are rigorously proved by max-min, graph theory and Lyapunov method. Finally, straightforward simulation results confirm the feasibility of the distributed cooperative controller.