IA*QB: An Efficient Trajectory Planning Approach for the Automatic Berthing of Unmanned Surface Vessel

Trajectory planning plays an important role in the automatic berthing of Unmanned Surface Vessel (USV). This study proposes IA*QB approach for the USV's berthing trajectory planning in the harbor. First, a global path is obtained by the A * algorithm. Considering the path generated by the traditional A * algorithm is unsuitable for the USV to track at the corners, quasi B-spline is employed to smooth the path. Subsequently, path points with approximately equal spacing are selected as waypoints in the trajectory. Furthermore, the quadratic interpolation method is proposed at the end of the berthing trajectory. Thus, the USV's velocity can be decreased to zero linearly. Simulation results show the effectiveness and the superiority of the proposed approach.