Robust adaptive tracking control of UMSVs under input saturation: A single-parameter learning approach

This paper investigates the robust adaptive trajectory tracking control problem for unmanned marine surface vessels (UMSVs) subject to nonparametric uncertainties and external disturbances under input saturation. The non-smooth saturation nonlinearity is replaced by the Gaussian error function. The lumped uncertain term including nonparametric uncertainties, external disturbances and approximation error is formulated by the linear parameterization-like form with a single unknown parameter. Combining the parameter adaptive technique with backstepping design tool, single parameter learning-based tracking control schemes are developed, which involves both full state feedback and output feedback control. The theoretical analysis indicates that under our proposed schemes, all signals in the closed-loop trajectory tracking control system are bounded. Simulation results and comparison illustrate the effectiveness of the developed schemes.