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. • Underactuated AUV swarm rendezvous problem is uniquely decoupled into velocity-attitude synchronization flocking at the kinematic level (coordination layer) and the motion control problem at the dynamic level (executive layer). • In the flocking phenomenon, the three-dimensional nonholonomic model of AUV is initially studied, and the nonlinear terms in the model are analyzed, which makes it feasible to design a simple linear control protocol. • Without any position information and complex nonlinear potential field functions, the proposed control protocol can guarantee separation, cohesion, velocity matching and attitude synchronization. • The velocity and attitudes of the underactuated AUV swarm exponentially converge to synchronization, respectively, which can ensure the efficiency of the rendezvous process. • Reasonably reduce the communication and computational burden by setting communication range and dynamic proximity network. [ABSTRACT FROM AUTHOR]