Design of coordinated path following controller for multiple autonomous underwater vehicle considering obstacles and collision avoidance

In this paper the problem of coordinated path following for a group of Autonomous Underwater Vehicle (AUV) subjected to obstacle and collision avoidance is considered. At first a back stepping controller is used for an AUV to design a path following controller and its stability is examined via Lyapunov criteria. Then using of graph theory, modeling of interconnection between AUV systems is addressed and by this modeling the coordinated path following controller for multiple AUV is designed. After all the problem of obstacles and collision avoidance is considered appropriately. For this purpose, each obstacle involving a limit cycle of an ellipse and if the collision or conflict of one AUV to the surrounded environmental obstacles will be detected, the obstacle avoidance algorithm is activated to prevent collision. Also the same algorithm for collision avoidance in between all AUV systems in the group is implemented. Finally the depicted results illustrate the effectiveness and performances of the proposed controller apparently for a sample AUV,which its hydrodynamics coefficients are available in references.