Adaptive-Disturbance-Observer Based Backstepping Control for Underwater Vehicle-Manipulator Systems

To resolve problems involving undersea vehicle-manipulator systems(UVMSs) with coupling terms, model uncertainties, and disturbances, an adaptive-disturbance-observer-based backstepping control method is proposed. Ocean multi-source disturbances are described by a linear exosystem and an adaptive disturbance observer is presented to estimate the disturbances. To address saturation of the actuators, an auxiliary dynamic system is given. A backstepping control method is then presented to ensure that the closed-loop tracking system is bounded by the Lyapunov theory. Finally, simulations are conducted on a kind of UVMS with two joints, and the simulation results demonstrate that the proposed method exhibits better performance in terms of trajectory tracking and antidisturbance than the traditional proportional-integral-derivative control method.