Formation control of unmanned surface vehicles with vision sensor constraints

This paper presents a practical formation control strategy for unmanned surface vehicles (USVs) under sensor constraints with no communication interchange. The team of USVs equipped with monocular visions are modeled in a Leader-Follower (L-F) formation. The formation controller relies on line-of-sight (LOS) range and bearing information received from the forward looking camera. The onboard vision sensor is assumed to be able to measure the range and bearing information of the leader, and the vision sensor's capability is restricted due to limited Field of View (FOV) and visual range. An outer-loop backstepping controller is first designed to stabilize the formation, then an inner-loop controller is designed to cope with the sensor constraints in order not to lose the leader's information. The proposed controller guarantees that the formation is always maintained. The effectiveness of the proposed strategy is demonstrated by numerical simulations.