Robust Consensus of Constrained AUVs With Non-Uniform Time-Varying Delays and Disturbances

Constrained consensus formation tracking of autonomous underwater vehicle (AUV) networks is a challenging problem to solve, especially when the networks are possibly subject to nonuniform, time-varying communication delays and marine disturbances. This article presents a systematic design framework to achieve formation objectives while ensuring network stability under such uncertainties. First, a coordinate transformation is applied to the AUV kinematics to address nonholonomic constraints. A distributed consensus protocol is then used to coordinate the motion of vehicles, and utilizing the transformed kinematic model, the desired linear velocity and approach angles are determined accordingly. By employing the graph representation and Lyapunov-Krasovskii functional method, a robust stability criterion is derived in terms of linear matrix inequalities (LMIs) for a delayed network with disturbances. To improve the quality of AUV motion control, on top of the conventional backstepping controller, a sequential optimization procedure is developed for the first time, which enables optimizing the robust performance online while respecting motion constraints. Moreover, the overall stability of the resulting formation system is established. Finally, comparative simulations are carried out to verify the effectiveness and superiority of the proposed method.