Abstract: A global feedback stabilization algorithm based on asymmetric model is proposed for unknown model parameters in the control of an underactuated asymmetric AUV on the horizontal plane. An adaptive parameter observer is designed to get the estimated values of the real model parameters by knowing only the upper and lower bounds of the model parameters. The coupling effect caused by the asymmetric items is eliminated through global coordinate transformation. The control system is decomposed into propulsion subsystem and yaw subsystem which are designed, respectively. A second-order filter is introduced to keep the yaw rate with continuous excitation as long as the propulsion system does not converge to the origin. Lyapunov stability analysis indicates that the proposed algorithm can be used to realize the stabilization control under any initial condition without knowing the model uncertainties, and the stabilization errors are globally ultimately bounded. The simulated results show that the proposed controller is effective and robust. Key

Key words: underactuatedAUV, asymmetricmodel, parameteruncertainty, stabilization