Tracking control of USV under conditions of liquid sloshing, input saturation, and external disturbances

This paper investigates the attitude tracking control of USVs under conditions of input saturation, external environmental disturbances, and liquid sloshing in fuel tanks. Firstly, the USV is coupled with the moving pulsing ball model (MPBM), and the coupled model is used to address the aforementioned three issues. For external environmental disturbances, a nonlinear disturbance observer is employed to estimate the disturbance values; The forces and torques generated by liquid sloshing are estimated using an radial basis function neural network (RBFNN); The input saturation problem is resolved by using a first-order filter to generate the controller. Finally, the coupled USV-MPBM system is theoretically and practically verified using Lyapunov theory and simulation data. The results show that the system can achieve good attitude control under the proposed controller, and the liquid sloshing is also effectively suppressed.