A data-driven approach for ship-bridge collision candidate detection in bridge waterway

The consequences caused by bridge failures owing to the ship-bridge collision are always severe in terms of loss of life, economy, and environmental consequences to individuals and societies. The previous studies focused on the ship-bridge collision mainly concentrated on passive anti-collision, such as strengthening the bridge structure or...

Distributed Conflict Resolution at High Traffic Densities with Reinforcement Learning

Future operations involving drones are expected to result in traffic densities that are orders of magnitude higher than any observed in manned aviation. Current geometric conflict resolution (CR) methods have proven to be very efficient at relatively moderate densities. However, at higher densities, performance is hindered by the...

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...

Seasonal Variability of Aircraft Trajectories reducing NOx-climate Impacts under a Multitude of Weather Patterns

Air traffic contributes to global warming through CO2 and non-CO2 effects, including the impact of NOx emissions on atmospheric ozone and methane, formation of contrails, and changes in the amount of stratospheric water vapour. The climate impact of non-CO2 effects is highly dependent on the background atmospheric conditions at the time and...

Velocity Obstacle Based Conflict Avoidance in Urban Environment with Variable Speed Limit

Current investigations into urban aerial mobility, as well as the continuing growth of global air transportation, have renewed interest in conflict detection and resolution (CD&R) methods. The use of drones for applications such as package delivery, would result in traffic densities that are orders of magnitude higher than those currently...

Limitations of Conflict Prevention and Resolution in Constrained Very Low-Level Urban Airspace

Road traffic delay and urban overcrowding are increasing rapidly all over the world. As a result, several companies have proposed the use of small unmanned aerial vehicles (sUAVs) as an alternative to road-based transportation. These small autonomous drones are expected to operate within a thin airspace band (Very Low Level) in high traffic...

Path planning for autonomous ships: A hybrid approach based on improved apf and modified vo methods

In this research, a hybrid approach for path planning of autonomous ships that generates both global and local paths, respectively, is proposed. The global path is obtained via an improved artificial potential field (APF) method, which makes up for the shortcoming that the typical APF method easily falls into a local minimum. A modified...

Probabilistic Risk Analysis for Ship Collision-Theory and Application for Conventional and Autonomous Ships

Maritime transportation has been one of the major contributors to the global trade and economy. Accidents, however, have been continuously posing risks to individuals and societies in terms of loss of human life, economic and environmental consequences, etc. This thesis paid particular attention to the probabilistic risk analysis of ship...

Review of conflict resolution methods for manned and unmanned aviation

Current investigations into urban aerial mobility, as well as the continuing growth of global air transportation, have renewed interest in Conflict Detection and Resolution (CD&R) methods. With the new applications of drones, and the implications of a profoundly different urban airspace, new demands are placed on such algorithms, further...

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...

Collision risk measure for triggering evasive actions of maritime autonomous surface ships

Collision risk assessment is essential for supporting collision avoidance, which is the core of various collision alert/avoidance systems. One main task of the systems is setting off alarms for taking evasive actions. The alarms need to be triggered before the conflict has no collision-free solution. However, most of existing collision risk...

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...

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...

Conformal automation for air traffic control using convolutional neural networks

Lack of trust has been identified as an obstacle in the introduction of workload-alleviating automation in air traffic control. The work presented in this paper describes a concept to generate individual-sensitive resolution advisories for air traffic conflicts, with the aim of increasing acceptance by adapting advisories to different...

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...

Analysis of Conflict Resolution Methods for Manned and Unmanned Aviation Using Fast-Time Simulations

In the coming years, aviation will have to cope with an increase in the number of aircraft, and of drones purchased in the open market. The human intervention of Air Traffic Management (ATM) will be overburden with guaranteeing flight safety with hundreds of manned aircraft and Unmanned Aerial Vehicles (UAVs) operating simultaneously. Conflict...

Time-Varying Risk Measurement for Ship Collision Prevention

We propose an innovative time-varying collision risk (TCR) measurement for ship collision prevention in this article. The proposed measurement considers the level of danger of the approaching ships and the capability of a ship to prevent collisions. We define the TCR as the probability of the overlap of ships’ positions in the future, given...

Autonomous Conflict Detection and Resolution for Unmanned Aerial Vehicles: On integration into the Airspace System

In the last decade, the commercial values of Unmanned Aerial Vehicles (UAV), defined as devices that are capable of sustainable flights in the atmosphere that do not require to have a human (pilot) on-board, become widely recognized thanks to the advancement of technology in materials, sensors, computation, and telemetry. As UAVs are becoming...