Distributed containment control of the underactuated vessels with collision/obstacle avoidance and connectivity maintenance

For the problems of obstacle/collision avoidance and connectivity maintenance of the underactuated vessel formation under the condition of unavailable velocity measurements, a finite -time coordinated formation control scheme based on an improved potential energy function (PEF) is proposed, which improves the safety of the formation system and realizes the vessel formation closer to the actual application. Firstly, a finite -time extended state observer (FTESO) is designed to quickly estimate the velocity and compound disturbances information simultaneously. Secondly, in the kinematic equation, the coupling term of surge velocity and attitude angle is used as the control input to realize the containment control of the leader in any state. Then, a new exponential potential energy function (EPEF) is designed, which can achieve the purpose of fast obstacle/collision avoidance and connectivity maintenance. Subsequently, by combining the improved PEF and the super -twisting algorithm (STA), the finite -time coordinated formation controllers based on the super -twisting sliding mode are designed to realize the safe navigation control of the underactuated vessel formation in the process of coordinated path following. And it is proved by stability analysis that all signals of the formation system are uniformly ultimately bounded. Finally, simulation results and comparative analysis verify that the proposed control method can satisfy the actual safety requirements of the underactuated vessel formation and the formation system has better robustness.