In this paper; an energy-efficient tracking control method is proposed for a X rudder AUV. First; the mathematical model and trajectory tracking problem are presented. Then; an energy-efficient tracking controller is designed based on time-varying LOS guidance and feedback dynamics control law. Besides; in order to achieve energy-efficient X rudder allocation; a multi-objective optimization method is proposed. Moreover; the rudder error dynamics is considered and compensated by rudder error disturbance observer. Finally; comparative numerical simulations are carried out to demonstrate the robustness and effectiveness of the proposed approach.
In the past few decades; autonomous underwater vehicle (AUV) has played an increasingly important role in all kinds of submerged applications; including but not limited to underwater exploration; marine geosciences; monitoring; inspection (Zhang et al.; 2018); and offshore industry (Shi et al.; 2017; Zereik et al.; 2018). Therefore; it has attracted more and more attention.
To better accomplish the submerged tasks; the AUV should have good maneuverability. Among all the ways to improve maneuverability; changing the rudder structure is one of the most effective. The existing rudder structures of AUV include cross rudder; H rudder; and X rudder (Zhang et al.; 2017); etc. Compared with traditional cross rudder AUV; the X rudder AUV has more special control surface layout; much better maneuverability and flexibility since the four rudders can be operated independently (Xia et al.; 2020; Wang et al.; 2020). However; the control of the X rudder AUV is more complicated since the directions of its control surfaces are inconsistent with the moving directions of AUV; which increases the cross-couplings and the AUV can't be intuitively controlled. To the best of the authors' knowledge; the control of X rudder AUV has not been extensively studied yet. For this reason; trajectory tracking of a X-rudder AUV will be discussed in this paper.
