Real-time collision risk based safety management for vessel traffic in busy ports and waterways

Regional risk analysis and management of maritime accidents is one of the fundamental tasks for maritime safety management. With the heavy and complicated maritime traffic in the ports and waterways, accidents, especially ship collision accidents, have been continuously posing threats to the maritime transportation system. To achieve effective...

Long-term viscoelastic deformation monitoring of a concrete dam: A multi-output surrogate model approach for parameter identification

Dam safety monitoring has become an important topic and is critical for evaluating a dam's safety status. This study focuses on identifying the mechanical properties of a concrete dam from long-term viscoelastic deformation monitoring data. A novel inversion framework is proposed in which a surrogate model, instead of the finite element model,...

Towards real-time ship collision risk analysis: An improved R-TCR model considering target ship motion uncertainty

Collision between ships is one of the major contributors to ship accidents. To facilitate the development of the real-time collision risk analysis model for collision avoidance, in this research, an improved Rule-aware Time-varying Collision risk Model is proposed, which considers the estimation of target ship motion and the corresponding...

Collision Avoidance Systems for Maritime Autonomous Surface Ships Considering Uncertainty in Ship Dynamics

Many Collision Avoidance Systems (CAS) for autonomous ships usually presume that a ship's dynamics are completely known in advance. However, precise parameters for ships in different operating conditions are, in fact, uncertain and unknown. The parameter identification of ship dynamics is challenging and time-consuming. Thus, uncertainties in...

Global path planning for autonomous ship: A hybrid approach of Fast Marching Square and velocity obstacles methods

In this research, a hybrid approach for global path planning for Maritime Autonomous Surface Ship (MASS) is proposed, which generates the shortest path considering the collision risk and the proximity between path and obstacles. The collision risk concerning obstacles is obtained using Time-Varying Collision Risk (TCR) concept, taking into...

A ship collision avoidance system for human-machine cooperation during collision avoidance

Maritime Autonomous Surface Ships (MASS) attract increasing attention in recent years. Researchers aim at developing fully autonomous systems that replace the role of human operators. Studies either focus on supporting conflict/collision detection (for manned ships) or solving conflict automatically (for unmanned ships). The cooperation...

Ship collision avoidance methods: State-of-the-art

Collision prevention is critical for navigation safety at sea. At early ages, researchers aimed at developing navigational assistance systems for enhancing situational awareness of human operators as human is at the core of collision avoidance. Recently, autonomous vehicles have gained a remarkable amount of attention with a focus on solving...

Generalized velocity obstacle algorithm for preventing ship collisions at sea

Numerous methods have been developed for ship collision prevention over the past decades. However, most studies are based on strong assumptions, such as the need for a constant velocity of the target-ship, the limitation to two-ship scenarios, the simplification of ships’ dynamics, etc. Generalized Velocity Obstacle (GVO) algorithm can bridge...

Integration of elliptical ship domains and velocity obstacles for ship collision candidate detection

The maritime shipping industry has been making significant contributions to the development of the regional and global economy. However, maritime accidents and their severe consequences have been posing an incrementing risk to the individuals and societies. It is therefore important to conduct risk analysis on such accidents to support...

Detecting changes in extreme precipitation and extreme streamflow in the Dongjiang River Basin in southern China