Trend of Autonomous Navigation Technology for Unmanned Ship

In this paper, we present a comprehensive review of the latest autonomous navigation technologies for unmanned ships. Maritime trade has increased enormously along with the evolution of industrial economies over the last century. The unmanned ship has received worldwide attention as a next-generation transportation vessel. It can change the paradigm of global maritime trade. In this paper, first, we present the global trend of unmanned ship development by reviewing the major research project currently conducted by several research groups. One of them describes the three steps of an unmanned ship according to the level of autonomy. The core technologies of the unmanned ship are classified into three categories in terms of safety, efficiency, and connectivity. The state-of-the-art technologies and the remaining challenges in each category are reviewed comprehensively.