Distribute consensus control for underactuated AUVs system based on disturbance observer

The underactuated autonomous underwater vehicles (AUVs) distribute consensus control problem with external disturbances is addressed in this paper. Inspired by previous works, we first reconstruct the underactuated AUV model by choosing the hand position rather than pivot point as the output of system. The new model of underactuated AUV can simplify the controller design, and the tracking errors in three degrees of freedom can be stabilized with two torques easily. Then, a novel fixed-time disturbance observer (DO) which can achieve zero estimation error in the settling time is proposed for each vehicle to determine the external disturbance. Based on the DO, a distributed consensus control for underactuated AUVs is proposed by combining the backstepping and fixed-time techniques. Ultimately, one simulation example is provided to validate the performance of controller.