Robust control of a platoon of underwater autonomous vehicles

Effective control systems for a variety of underwater autonomous vehicles have been developed and are in use. These systems generally assume the vehicle is operating independently of other nearby vehicles. However, there is recent and growing interest in the coordinated control of a platoon of vehicles acting cooperatively to achieve an objective that a single vehicle operating alone cannot achieve. This paper presents the design of a robust multivariable controller for decentralized leader-follower control of a platoon of autonomous underwater vehicles. A three degree-of-freedom model of the REMUS underwater vehicle is used as an example case for control in a plane. The design is based on Linear Quadratic Gaussian Regulator theory with Loop Transfer Recovery. A way point guidance system is used for lead vehicle navigation. Follower vehicles maintain specified range and bearing to adjacent vehicles. The resulting control system is used in a computer simulated search for randomly distributed mines. A three vehicle fleet is used to demonstrate superiority, in terms of area coverage and elapsed time, over a single vehicle search. Simulations are performed both with and without ocean current disturbances. A unique formation swap maneuver is introduced to make an efficient 180 degree turn in a mow-the-lawn type multi-vehicle search.