Review of research progress of autonomous and unmanned shipping and identification of future research directions

The maritime industry is following the trend of increased autonomy and digitalisation applied in aviation, automotive, military, and chemical industries. Maritime autonomous and unmanned vehicles have received significant attention recently, both from academia and industry. This paper investigates research into the progress of the development of autonomous and unmanned shipping by employing bibliometric analysis tools VOSviewer and CiteSpace, to present a comprehensive picture of this emerging field of research. Bibliometrics is applied to investigate the collected data sample from Scopus related to predefined keywords. Bibliometric tools assist review by network visualisation, clustering, and metrics. Therefore, this paper presents an analysis aiming at (1) increasing the understanding of the structure and contents of the academic field of autonomous and unmanned shipping; (2) determining and mapping scientific networks in this field; (3) analysing and visualising major divisions within the field; (4) identifying research needs and future research directions in the field. Through clusters generated by bibliometric tools, research divisions are identified and discussed. Furthermore, potential research directions are outlined.