Anti-roll control and maneuverability test of X-rudder autonomous underwater vehicle

  Objective  Aiming at solving the roll problem of the new X-rudder autonomous underwater vehicle (XAUV) during field tests, a series of anti-roll fixed depth and heading control experiments and maneuverability tests are carried out.

  Method  First, the XAUV's system structure and function are introduced, and its mathematical model is established. Second, based on the previous field test results, the roll problem of the XAUV in surface navigation is analyzed. A roll control experiment with an open-loop differential rudder angle is then carried out, and an anti-roll tracking controller is designed on the basis of feedback linearized PD control of yaw and roll, incremental feedback control of depth and constrained nonlinear programming. Finally, a series of maneuverability tests is carried out in a maneuvering basin to verify the effectiveness and functionality of the proposed method, and the maneuverability of the XAUV.

  Results  The test results show that under the same hull, the rotation diameter of the cruciform rudder is 1.2 times that of the X-rudder. Moreover, with the proposed control method, the roll angle of the XAUV can be effectively reduced to 2° when the propeller speed is 1 680 r/min, and the depth and heading control of the XAUV can be ensured at the same time.

  Conclusion  The X-rudder can improve the maneuverability of AUVs with its unique roll control ability. The anti-roll fixed depth and heading control strategy proposed in this paper can make full use of the maneuverability advantages of the XAUV, and realize effective roll angle control simultaneously with depth and heading control.