Trajectory Tracking for Underactuated Unmanned Surface Vessel Based on Limit Segmentation

In this paper, a novel limit segmentation method is proposed for the trajectory tracking control of an underactuated unmanned surface vessel (USV). In practical engineering, actuators (for ordinary ships, actuators are propeller and rudder) are difficult to output accurate force and moment to realize trajectory tracking. Based on the limit segmentation theory, the continuous desired trajectory is divided into a series of straight lines. In other words, the trajectory tracking problem is transformed into a series of linear tracking problems. On the basis of considering the nonlinearity of the model, Lyapunov function and nonlinear Backstepping method are employed to propose a linear tracking feedback control law. The simulation results show that the method proposed in this paper can make USV track the desired straight line and curve, and the control inputs are within a reasonable range, which verifies the correctness of the limit segmentation theory and control law.