Leader-follower formation control of autonomous underwater vehicles using position information only

Leader-follower formation control of autonomous underwater vehicles was studied, and a formation control algorithm was presented, of which the followers only need to use the position and heading informations of leader rather than its velocity, angular velocity and dynamic model informations. A reference trajectory of the followers was derived from the leader's sailing state and the desired formation, and a virtual vehicle, which trajectory coincides with the reference route at a limited time, was designed by only using the leader's position and heading information. An adaptive variable structure control law was proposed for the follower in consideration of the parameter uncertainty of vehicle and the ocean current disturbance. The law enables the follower to move along the trajectory of virtual vehicle to keep the follower at a desired distance for formation purpose. Simulation results show that the proposed control law is valid.