Adaptive Formation Control of Multiple Underactuated Autonomous Underwater Vehicles

Abstract

In this paper, we present a 3D formation control scheme for a group of torpedo-type underactuated autonomous underwater vehicles (AUVs). These multiple AUVs combined with an unmanned surface vessel (USV) construct a sort of star-topology acoustic communication network where the USV is at the center point. Due to this kind of topological feature, this paper applies a virtual school concept. This is a geometric graph where each node is taken as a virtual leader for each specific AUV and assigned its own reference trajectory. For each individual vehicle, its formation strategy is simple: just follow the trajectory of its corresponding virtual leader so as for multiple AUVs to compose the given formation. As for the formation subject, this paper mainly focuses on the formation tracking problem rather than the formation producing. For the torpedo-type vehicle considered in this paper, there are only three control inputs (surge force, pitch, and yaw moments) available for its underwater 3D motion and therefore this is a typical underactuated system. For the following vehicle’s trajectory, a sort of potential field method is used for obstacle avoidance, and a neural network-based adaptive scheme is applied to on-line approximate the vehicle’s unknown nonlinear dynamics, and the uncertainty terms including modeling errors, measurement noises, and external disturbances are handled by the properly designed robust scheme. The proposed formation method can guarantee the uniform ultimate boundedness (UUB) of the closed-loop system. Numerical studies are also carried out to verify the effectiveness of the proposed scheme.

Trajectory Tracking Control of Unmanned Underwater Vehicle Based on Projected Perpendicular Guidance Method with Disturbance Observer

“…Ref. [8] proposed a three-dimensional formation control scheme for torpedo-type UUVs. Meanwhile, Ref.…”

Distributed Path Tracking for Autonomous Underwater Vehicles Based on Pseudo Position Feedback

“…There have thus far been extensive works devoted to the formation control of an AUV swarm. A group of torpedo-type AUVs was investigated in [23] under the centralized management by an unmanned surface vessel, constituting a star-like command and communication system, with the unmanned surface vessel being the center. The formation is achieved by assigning each AUV its corresponding reference trajectory.…”

“…In terms of communication topology, reference [23] adopted a centralized structure with the unmanned surface vessel as the communication center, whereas [24,25] adopted the leader-follower approach, whose communication topology is essentially a pure tree-like structure. In [26][27][28][29][30][31], based on graph theory, the communication topology is relaxed to be freely designed as long as the associated communication graph is connected.…”

“…In [23][24][25][26][27][28][29][30][31], the absolute position feedback of the AUV is necessary to stabilize the closed-loop system dynamics so that the control objective of tracking or formation can be fulfilled, while, as indicated by [18,20,22], the global localization of AUVs might be costly in an underwater environment, and might sometimes even be impossible, such as in a deep ocean environment. To address this issue, in this paper, the proposed control method only needs a relative position measurement of the neighboring AUVs over the communication network to achieve reference path tracking and maintain a relative formation, which makes it more practical and cost competitive in contrast to the existing results.…”