A novel waterway navigability assessment method based on encounter safety analysis of ship autonomous navigation

• An autonomous navigation-based waterway navigability assessment way is proposed to replace traditional human-dependent methods, aiming to address issues of high cost, extended assessment periods, and poor repeatability. • A ship navigation behavior generation method is proposed, which involves non-uniform flow calculation, encounter situation generation, potential field based path planning , and Integral-Line-Of-Sight (ILOS) based path tracking. • Waterway navigability is evaluated with autonomous navigation in combination of the indexes involving ship-ship and ship-shore distance, track band, and ship dynamic domain for both upstream and downstream waterway sections. To address the challenge of evaluating the ship navigation safety for the construction or regulation stage of waterways, this study proposes a navigability assessment method by analyzing ship maneuverability and encounter safety. A mathematical model of typical ship motion is established, considering the effects of non-uniform water flow and shallow water, along with a visualized 3D model of the waterways. Then, we introduce a ship navigation behavior generation method, covering the generation of navigation encounter scenarios, the improved potential field-based path planning, and the Integral-Line-Of-Sight (ILOS)-based path tracking. To resolve the inconsistency in inland waterway navigability assessment, a comprehensive navigability assessment model is developed, incorporating the ship trajectory index, safety domain, track band, and navigation rules for both upstream and downstream waterway sections. The proposed method is tested on the curved and bridge areas of the Tang River waterway in China. The results demonstrate that the proposed method can assess the waterway navigability autonomously and efficiently, which can provide scientific decision-making suggestions for waterway and maritime authorities.