  In this paper, we propose an efficient and accurate method for autonomous
surface vehicles to generate a smooth and collision-free trajectory considering
its dynamics constraints. We decouple the trajectory planning problem as a
front-end feasible path searching and a back-end kinodynamic trajectory
optimization. Firstly, we model the type of two-thrusts under-actuated surface
vessel. Then we adopt a sampling-based path searching to find an asymptotic
optimal path through the obstacle-surrounding environment and extract several
waypoints from it. We apply a numerical optimization method in the back-end to
generate the trajectory. From the perspective of security in the field voyage,
we propose the sailing corridor method to guarantee the trajectory away from
obstacles. Moreover, considering limited fuel ASV carrying, we design a
numerical objective function which can optimize a fuel-saving trajectory.
Finally, we validate and compare the proposed method in simulation environments
and the results fit our expected trajectory.
