Distributed finite-time state observer-based formation control for multiple underactuated AUVs under directed topology

In this paper, a distributed finite-time state observer-based formation control scheme under directed topology is proposed for multiple underactuated autonomous underwater vehicles (AUVs) in the presence of uncertain dynamics and unknown time-varying external disturbances. Firstly, a distributed finite-time state observer is proposed for each follower AUV to estimate the position and velocity of the leader within a finite time. Then, a finite-time disturbance observer is constructed to estimate the compound disturbances lumped by the uncertain dynamics and unknown time-varying external disturbances. Further, a distributed finite-time formation control law is proposed by incorporating the above two observers into the dynamic surface control method, which ensures that the AUVs achieve the desired formation pattern within a finite time. Theoretical analysis and simulation results indicate that the proposed formation control law can make the multiple AUVs achieve the desired formation within a finite time.