Nonlinear control law design of unmanned surface vessels

Waypoint tracking design is an attractive and importantissue for unmanned surface vessels. The traditional control law design based on the assumptions that the kinematics and dynamics is linear or can be linearized will be no longer useful or effective to this waypoint tracking design due to the nonlinearities of kinematics and dynamics of motion of unmanned surface vessels for tracking applications. For solving this tracking problem and taking the nonlinear characteristics of the unmanned surface vessels into consideration, a feedback linearization based control law with considering nonlinear horizontal three degrees of freedom motion dynamics of a class of unmanned surface vessels is proposed and positions and yaw/heading angle are simultaneously tracked. The tracking error between unmanned surface vessels and waypoints can be proven to converge to zero asymptotically for this proposed nonlinear control law, and simulation results show the control performance of this method for the trajectory tracking problem of unmanned surface vessels.