scholarly journals Collision Risk Assessment Based on Behaviour Analysis of Collision Avoidance Manoeuvre Using AIS Data

2016 ◽  
Vol 135 (0) ◽  
pp. 43-52
Author(s):  
Rina MIYAKE ◽  
Kazuhiko HASEGAWA ◽  
Junji FUKUTO
Keyword(s):  
Risk Assessment ◽  
Collision Avoidance ◽  
Collision Risk ◽  
Behaviour Analysis ◽  
Avoidance Manoeuvre

A Unified Measure Of Collision Risk Derived From The Concept Of A Ship Domain

2006 ◽  
Vol 59 (3) ◽  
pp. 477-490 ◽  
Author(s):  
Rafal Szlapczynski
Keyword(s):  
Risk Assessment ◽  
Collision Avoidance ◽  
Numerical Algorithms ◽  
Good Alternative ◽  
Collision Risk

The paper introduces a new measure of collision risk derived from the concept of a ship domain. Its simplicity and the fact that it takes into account the courses of both ships, makes it a good alternative to the commonly used term of the distance at the closest point of approach (DCPA). The measure being presented is flexible enough to be applied in combination with any given ship domain. Derivations of all the necessary equations for the Fuji domain have been presented in detail. Additionally, the paper contains numerical algorithms that are capable of determining value of the measure for any other ship domain. Based on these algorithms a generic method for determination of the necessary course alteration is developed. Also, an example of an already known formula for risk assessment, that may benefit from the measure, is provided. All of the algorithms, formulas and their derivations in the text are presented explicitly, so that they could be directly applied in any collision avoidance or VTS system.

An Intelligent Spatial Collision Risk Based on the Quaternion Ship Domain

2010 ◽  
Vol 63 (4) ◽  
pp. 733-749 ◽  
Author(s):  
Ning Wang
Keyword(s):  
Risk Assessment ◽  
Collision Avoidance ◽  
Domain Size ◽  
Domain Model ◽  
Fuzzy Information ◽  
Collision Risk ◽  
Factors Affecting ◽  
Practical Applications ◽  
Ship Manoeuvring ◽  
Simulation Results

In this paper, a novel ship domain model termed quaternion ship domain (QSD) is proposed. Unlike other ship domains, the proposed QSD is more dependable and more flexible for navigators to use to make decisions. The main characteristics are that: the domain size is determined by the quaternion including four radii, i.e. fore, aft, starboard and port, which sufficiently take factors affecting the domain (i.e. ship manoeuvring capability, speeds and courses, etc.) into account; and that the domain shape is modelled by another parameter which makes the QSD more flexible since the ship boundary could not only be linear or nonlinear, but also be thin or fat. In order to reasonably relate the proposed QSD to practical applications, i.e. collision risk assessment, collision avoidance and trajectory planning, etc., a fuzzy QSD (FQSD) has been developed by using fuzzy sets. As a result, fuzzy boundaries rather than crisp ones in the FQSD are more practical and more convenient for navigators to understand and judge since uncertainty and fuzzy information have been merged into the FQSD. Furthermore, concepts of longitudinal and lateral risk based on the FQSD have been introduced to estimate the spatial collision risk (SCR) for the ships encountered. Finally, several computer simulations have been conducted on various encounter situations and comparative studies with other ship domains have been comprehensively analyzed. Simulation results demonstrate that the proposed QSD is more effective and more flexible than other ship domains, and that the intelligent SCR based on the FQSD are reasonable and dependable.

Planning Emergency Manoeuvres

2008 ◽  
Vol 62 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Rafal Szlapczynski
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Real Time ◽  
Collision Avoidance ◽  
Support System ◽  
Visualization Tool ◽  
Collision Risk ◽  
The Real ◽  
Target Behaviour ◽  
Avoidance Manoeuvre

The paper addresses the issue of planning emergency manoeuvres and re-planning ship trajectories in case of unpredicted target behaviour. It introduces two methods. The first is responsible for monitoring other ships parameters, estimating the probability of illegal target behaviour and re-planning own trajectory in case of unpredicted events. The second is a visualization tool that enables the navigator to assess collision risk in an encounter situation and choose a collision avoidance manoeuvre if necessary. This tool is based on the Collision Threat Parameters Area display and offers new features: fuzzy sectors of forbidden speed and course values and the possibility to use any given ship domain. Both methods are fast enough to be applied in the real-time decision-support system.

scholarly journals Incorporation of Potential Fields and Motion Primitives for the Collision Avoidance of Unmanned Aircraft

2021 ◽  
Vol 11 (7) ◽  
pp. 3103
Author(s):  
Kyuman Lee ◽  
Daegyun Choi ◽  
Donghoon Kim
Keyword(s):  
Collision Avoidance ◽  
Search Algorithm ◽  
Unmanned Aircraft ◽  
Artificial Potential Field ◽  
Tree Search ◽  
Local Minima ◽  
Collision Risk ◽  
Motion Primitives ◽  
Multiple Uavs ◽  
Tree Search Algorithm

Collision avoidance (CA) using the artificial potential field (APF) usually faces several known issues such as local minima and dynamically infeasible problems, so unmanned aerial vehicles’ (UAVs) paths planned based on the APF are safe only in a certain environment. This research proposes a CA approach that combines the APF and motion primitives (MPs) to tackle the known problems associated with the APF. Since MPs solve for a locally optimal trajectory with respect to allocated time, the trajectory obtained by the MPs is verified as dynamically feasible. When a collision checker based on the k-d tree search algorithm detects collision risk on extracted sample points from the planned trajectory, generating re-planned path candidates to avoid obstacles is performed. After rejecting unsafe route candidates, one applies the APF to select the best route among the remaining safe-path candidates. To validate the proposed approach, we simulated two meaningful scenario cases—the presence of static obstacles situation with local minima and dynamic environments with multiple UAVs present. The simulation results show that the proposed approach provides smooth, efficient, and dynamically feasible pathing compared to the APF.

scholarly journals Navigation safety domain and collision risk index for decision support of collision avoidance of USVs

2021 ◽  
Vol 13 ◽  
pp. 340-350
Author(s):  
Jian Zhou ◽  
Feng Ding ◽  
Jiaxuan Yang ◽  
Zhengqiang Pei ◽  
Chenxu Wang ◽  
...  
Keyword(s):  
Decision Support ◽  
Collision Avoidance ◽  
Risk Index ◽  
Collision Risk ◽  
Navigation Safety
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