Unit-Based Trajectory Planning Methods for MASS in Inland Waters.

Trajectory planning is a fundamental function of Maritime Autonomous Surface Ships (MASS), which has attracted numerous attention from the public. Due to huge inertia, limited navigable waters, and strong demands for computational efficiency, it is a challenge to find an optimal and feasible trajectory for MASS in restricted waters, such as inland waters. Thus, an improved approach for trajectory planning of inland MASS based on the trajectory library has been proposed. First, a controller with the ship dynamic model is developed to generate the trajectory units, which are collected into a trajectory library with specific principles; Then, the trajectory planning is modeled as an optimization problem, where the units in the library are served as decision space and the objective of the problem is to find the best sequence of trajectory units connecting the starting point and the ending point. To validate and demonstrate the proposed method, an inland environment from Zhejiang Province is simulated and the proposed method is compared with the original library-based motion planning method. The results reveal the potential of the proposed method in inland waters.