Objective  This paper aims to analyze the horizontal trajectory tracking of an underwater vehicle.

  Methods  First, the 3-DOFs motion equation is derived based on the plane trajectory tracking control target of the underwater vehicle, and the damping term parameters and additional mass term parameters of the vehicle are obtained through the commercial CFD software STAR-CCM+ and ANSYS AQWA respectively. Combined with the dynamic configuration of the vehicle and calculated hydrodynamic parameters, a control strategy is designed on the basis of backstepping and sliding mode control technology. Finally, using the designed control strategy, the trajectory tracking simulation calculation is carried out on the Matlab/Simulink platform for both the linear and nonlinear motion trajectories of the vehicle on the horizontal plane.

  Results  The numerical simulation results show that the underwater vehicle can achieve good tracking effects for both kinds of motion trajectories, and the propeller thrust changes smoothly.

  Conclusions  The controller designed in this paper can enable an underwater vehicle to track its target trajectory quickly and maintain a good continuous tracking effect.