Three-dimensional robust formation control for multiple uncrewed underwater vehicles based on Port-Hamiltonian theory under external disturbance

This article studies the formation control problem of multiple uncrewed underwater vehicles (UUVs) under time-varying external disturbances. The formation system is composed of a leader UUV and two follower UUVs. A three-dimensional (3D) formation robust control protocol of multi-UUV is presented based on the interconnection and damping assignment passivity-based control (IDA-PBC) method and the disturbance observer (DOB) technique. Firstly, the original UUV models are transformed into the Port-Hamiltonian (PH) structure. Next, the desired closed-loop PH system of the UUVs is constructed. With the IDA-PBC method, the design procedure of the formation controller is equal to solving matching equations, making the controller design intuitive. The DOB technique is introduced to compensate for the external time-varying disturbances to improve the robustness of the formation system. Finally, simulation results show that the proposed method accomplishes satisfactory formation performance and demonstrates the effectiveness of the proposed control protocol.