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1

Graphical tools to facilitate the selection of manoeuvres to avoid collision

Vagushchenko L., Vagushchenko A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 3

625--633

EN

Graphical tools have been proposed to facilitate the selection, evaluation, and correction of anticollision actions in situations with moving and stationary obstacles, assuming that such situations are not extreme or ordinary with sailing vessels and that the target movement parameters are constant or their upcoming change is known. The choice of evasive combined Z‐manoeuvre (both course and speed change at one point and return to the original values of these parameters at another point) and one combined action (both course and speed alteration at the selected point) were considered. The graphical tools developed contain diagrams, showing eight zones of actions, and special marks of targets at the moment of their closest approach to the own ship. In view of the COLREG and good seamanship, these zones were arranged in order of application priority. The results of the enumeration of a representative discrete set of possible manoeuvre variants were used to construct the diagrams.

2

Development of evaluation procedures for watchkeeping officers using bridge simulator

Solmaz M. S., Özsever B., Güllü A., Meşe C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2020

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Vol. 14. no. 3

565--571

EN

A comprehensive assessment of watchkeeping officers should be considered as a preventive measure in terms of safety of navigation. Watchkeeping officers are assigned after passing exams of state authorities and various evaluation procedures of companies. However, they are not subjected to comprehensive evaluations with practical implementations. Therefore, this study aims to develop effective use of simulators in terms of comprehensive evaluation of watchkeeping officers. In this study, simulation was designed with Goal-Directed Task Analysis (GDTA) technique to indicate important points on the situations watchkeeping officers face in navigation. 3 parameters were determined for difficulty adjustment; visibility, traffic density, geography. At the last phase of this study, performance evaluation method was prepared for performance evaluation of watchkeeping officer and scenario was evaluated for comprehensiveness by oceangoing masters. Hereby, the developed performance evaluation method for navigation can be used to generate more reliable method to evaluate the officers’ competence of technical skills.

3

The effect of high ship speed ratio on collision avoidance behavior of COLREGS

Wang X. H., Li L., Chen G.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 2

319--323

EN

The speed ratio is an important factor that must be considered when two vessels will course change to avoid collision. In the process of the research on Personifying Intelligent Decision-making for Vessel Collision Avoidance (short for PIDVCA), it is found that the effect of collision avoidance based on the existing “International Regulations for Prevention Collision at sea” (short for COLREGS) is greatly affected by the high speed ratio (k=Vt/V0≥1.5). Through the analysis on the geometric change law of two vessels’ relative motion in Open waters, the effects of the responsibility for the ship collision avoidance under the COLREGS and special case for high-speed ratio is discussed. According to the collision avoidance measures taken for two vessels encounter situation, some reasonable suggestions are put forward and the simulation experiments that based on ship's intelligent collision avoidance simulation platform are given to support the idea.

4

Ship collision avoidance decision model and simulation based on collision circle

Zhang J., Hu Q., Liao B.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 2

325--334

EN

In order to give consideration to both comprehensive evaluation and efficient decision-making in collision avoidance decision-making process, a collision avoidance decision-making model based on collision circle is proposed by introducing the concept of collision circle. Firstly, the factors causing ship collision are analyzed. Secondly, the static and dynamic characteristics of collision circles are analyzed and summarized by using collision circle simulation cases. Thirdly, based on the static characteristics, a reasonably distributed collision avoidance decision model of (Possible Point of Collision,PPC) was established. Finally, the spatial data operations core algorithm (Java Topology Suite, JTS) is used for logical operation and visualization, so as to realize the ship collision avoidance evaluation and decision. The decision model was used to verify the accident scenario of "SANCHI", and the results showed that the obtained collision avoidance scheme was reasonable and in line with the "International Regulations for Preventing Collisions at Sea" and safety requirements, thus providing a reference for maritime operators to avoid collisions between ships.

5

Neuroevolutionary approach to COLREGs ship maneuvers

Łącki M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13. no. 4

745--750

EN

The paper describes the usage of neuroevolutionary method in collision avoidance of two power-driven vessels approaching each other regarding COLREGs rules. This may be also be seen as the ship handling system that simulates a learning process of a group of artificial helmsmen - autonomous control units, created with artificial neural networks. The helmsman observes an environment by its input signals and according to assigned CORLEGs rule, he calculates the values of required parameters of maneuvers (propellers rpm and rudder deflection) in a collision avoidance situation. In neuroevolution such units are treated as individuals in population of artificial neural networks, which through environmental sensing and evolutionary algorithms learn to perform given task safely and efficiently. The main task of this project is to evolve a population of helmsmen which is able to effectively implement chosen rule: crossing or overtaking.

6

Multi-criteria optimization of multi-step matrix game in collision avoidance of ships

Lisowski J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 1

125--131

EN

This research article formulates a mathematical model of the matrix game of the safe ship control process containing: state variables and control, collision risk definition and the form of a collision risk matrix. Multicriteria optimization of the matrix game was introduced, leading to non-cooperative and cooperative game control algorithms and non-game control. Simulation safe trajectories of own ship for various types of control were compared to the example of the real situation at sea.

7

Maritime Autonomous Surface Ships (MASS) and the COLREGS: Do we need quantified rules or is “the ordinary practice of seamen” specific enough?

Porathe T.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 3

511--517

EN

Maritime Autonomous Surface Ships (MASS) is currently on the agenda in several countries and also in the IMO. In Norway a 120 TEU container feeder is being build and will start sailing autonomously in 2022. The challenge is huge. One question is whether or not the present, quantitative, collision regulations needs to be updated to rules where expressions as “early” and “substantial” are quantified? Or if ships can sail autonomously under the present rules? Another question is if MASS should be marked to signal that the ship is in autonomous mode? Or if it is enough that she follows COLREGS? This discussion paper will take a closer look at these questions and advocate automation transparency, meaning that the behavior of an autonomous vessel has to make sense and be understandable to human operators on other manned ships and crafts.

8

DSSA+: distributed collision avoidance algorithm in an environment where both course and speed changes are allowed

Hirayama K., Miyake K., Shiotani T., Okimoto T.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 1

117--123

EN

Distributed Stochastic Search Algorithm (DSSA) is one of state-of-the-art distributed algorithms for the ship collision avoidance problem. In DSSA, whenever a ship encounters with any number of other ships (neighboring ships), she will select her course with a minimum cost after coordinating their decisions with her neighboring ships. The original DSSA assumes that ships can change only their courses while keeping their speed considering kinematic properties of ships in general. However, considering future possibilities to address more complex situations that may cause ship collision or to deal with collision of other vehicles (such as mobile robots or drones), the options of speed changes are necessary for DSSA to make itself more flexible and extensive. In this paper, we present DSSA+, as a generalization of DSSA, in which speed change are naturally incorporated as decision variables in the original DSSA. Experimental evaluations are provided to show how powerful this generalization is.

9

Difficulties in understanding the COLREGs among the students from different systems of education for seafarers

Ivanišević D., Gundić A., Mohović D.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13. no. 4

869--873

EN

The paper shows the results of the research conducted in order to analyse the differences in understanding the International Regulations for Preventing Collisions at Sea among the students in countries practising two different systems of education for seafarers: the so-called “sandwich system” and the continuing system. Methods of learning as well as their effect on understanding the International Regulations for Preventing Collisions at Sea and students’ opinions on efficient methods of learning have also been analysed. Furthermore, the problems the teachers are facing have been identified. Measures for the improvement of the system have been proposed as well.

10

Development of automatic collision avoidance system and quantitative evaluation of the manoeuvring results

Nakamura S., Okada N.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13, no. 1

133--141

EN

The automatic collision avoidance system introduced in this paper is a system constantly calculating optimal manoeuvring method from the risk and economic preference in the ship manoeuvring space where the course change and the deceleration are performed. The authors also propose a system that quantitatively evaluates the collision avoidance manoeuvring results. Based on the evaluation results of this system, the authors are setting parameters so that ship manoeuvring that does not give anxiety to target ships to be avoided is also realized in automatic collision avoidance manoeuvring. In addition, comparison between the manoeuvring results of the automatic collision avoidance system and the veteran captain's manoeuvring results was quantitatively compared by the proposed evaluation system. Verification experiments were successfully conducted to verify the effectiveness of the proposed automatic collision avoidance system on the actual ship navigating in congested waters.

11

Certifying navigational skills: A video-based study on assessments in simulated environments

Sellberg C., Lindmark O., Lundin M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13. no. 4

881--886

EN

In Maritime Education and Training (MET) where students are trained for professions with high standards of safety, the use of simulators is taken to provide opportunities for safe and cost-effective training. Although the use of simulators for training and certifying technical proficiency and so-called non-technical skills is well established and regulated by international standards, previous research suggests that simulator-based assessment has been poorly implemented in the MET system. Now the challenge is to contribute with knowledge about how to conduct consistent, unbiased, and transparent assessments of navigational skills and competencies. However, in current research it is not evident how training of non-technical skills in simulated environments should be assessed. The aim of this study is to explore the pedagogical challenges instructors face when assessing students’ navigational skills and competencies in a simulated environment. The study is based on video-recorded data from the certification part in a navigation course for second year master mariner students. A situated approach to cognition and learning is employed to analyze the co-construction of assessment in the simulated exercises by means of instructors’ questions and students’ answers. Results reveal an assessment practice where the students are still developing their navigational skills with instructional support from examiners whilst being certified on using Radar equipment in accordance to COLREG.

12

Cooperative and non-cooperative game control strategies of the ship in collision situation

Lisowski J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2018

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Vol. 12, no. 1

83--91

EN

The paper introduces the positional cooperative and non-cooperative game of a greater number of met ships for the description of the process considered as well as for the synthesis of optimal control strategies of the own ship in collision situation. The approximated mathematical model of differential game in the form of triple linear programming problem is used for the synthesis of safe ship trajectory as a multistage process decision. The considerations have been illustrated an example of program computer simulation to determine the safe ship trajectories in situation of passing a many of the ships encountered.

13

Codifying Good Seamanship into Machine Executable Rules

Salter I. R.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2018

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Vol. 12, no. 2

329--334

EN

Enabling unmanned surface vessels to comply with the collisions regulations is one of the most interesting challenges facing the shipping industry. The “Machine Executable Collision Regulations for Marine Autonomous Systems” (MAXCMAS project aims to develop a comprehensive capability and demonstrate satisfactory execution of marine ‘rules of the road’ by autonomous vessels. This is an Industry-academia Research and Technology (R&T) collaboration with Innovate UK part-funding including a contribution from the Defence Science and Technology Laboratory (Dstl). The project partners include Rolls-Royce, ATLAS ELEKTRONIC UK Ltd, Lloyd’s Register EMEA, Queen’s University of Belfast and Warsash Maritime Academy. This paper discusses how the regulations that have been written by humans for human consumption were portrayed to the researchers by the Master Mariner to enable the generation of intelligent MAXCMAS algorithms.

14

The choice of the maneuver of the vessel’s passing considering the coordination’s system of the interactive vessels and their dynamic characteristics

Volkov Y., Pyatakov E., Kalinichenko Y.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 1

79--82

EN

The maneuver of the altering course of the vessel is a more preferable to avoid a collision. Due to that the calculation of the parameters of the avoidance maneuver should be done considering the dynamic characteristics of the vessel in maneuvering. The paper analyzes the dynamic models of the vessel rotation motion in order to select more appropriate one for the calculation of avoidance maneuver of the vessel applying the altering of the course.

15

Ship domain model for multi-ship collision avoidance decision-making with COLREGs based on artificial potential field

Wang T.F., Yan X.P., Wang Y., Wu Q.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 1

85--92

EN

A multi-ship collision avoidance decision-making and path planning formulation is studied in a distributed way. This paper proposes a complete set of solutions for multi-ship collision avoidance in intelligent navigation, by using a top-to-bottom organization to structure the system. The system is designed with two layers: the collision avoidance decision-making and the path planning. Under the general requirements of the International Regulations for Preventing Collisions at Sea (COLREGs), the performance of distributed path planning decision-making for anti-collision is analyzed for both give-way and stand-on ships situations, including the emergency actions taken by the stand-on ship in case of the give-way ship’s fault of collision avoidance measures. The Artificial Potential Field method(APF) is used for the path planning in details. The developed APF method combined with the model of ship domain takes the target ships’ speed and course in-to account, so that it can judge the moving characteristics of obstacles more accurately. Simulation results indicate that the system proposed can work effectiveness.

16

Ship domain as a safety criterion in a precautionary area of traffic separation scheme

Pietrzykowski Z., Magaj J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 1

93--98

EN

The ship domain is one of the criteria for navigational safety assessment. It is particularly important in restricted areas with high intensity traffic, where the criteria of closest point of approach (CPA) and time to CPA are difficult to apply. This research continues to examine ship domains in Traffic Separation Schemes (TSS). We have analyzed precautionary areas established within TSSs in connection with changed arrangements of vessel traffic. Besides, we have defined ship domains in a precautionary area of a specific TSS, and compared them to domains of vessels proceeding along traffic lanes.

17

New system for improving navigation standards (Totem Plus)

Rahav A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 3

409--412

EN

EDA is a tool for auditing vessel’s performance that helps installing strict safety navigation standards on ships. The practice of investigating every near-miss event is common in aviation, but unheard of in the maritime industry. At the same time, major accidents attributed to human errors are increasing, including collisions and groundings that cost lives, pollute the seas and lose property. The idea of EDA, short for E-navigation Data Audit, is simple: analyze the navigational data from VDR and/or ECDIS, find the events that should not have happened (“near misses”), and instruct your ships that it is not the standard you want on your vessels. EDA allows remote auditing on how the bridge team is performing and how the ship is handled, as required by ISM but seldom done. A pilot project for the EDA was carried out during 6 months. The first data showed 18 events of close proximity (“Near-collision”); 4 of them showed severe violation of the International Regulations for Preventing Collisions at Sea (COLREG, 1972). As expected, after sending the EDA first report to the ship, NO such events were found in the next 5 months of the pilot project.

18

Multi-criteria ACO-based algorithm for ship’s trajectory planning

Lazarowska A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 1

31--36

EN

The paper presents a new approach for solving a path planning problem for ships in the environment with static and dynamic obstacles. The algorithm utilizes a heuristic method, classified to the group of Swarm Intelligence approaches, called the Ant Colony Optimization. The method is inspired by a collective behaviour of ant colonies. A group of agents - artificial ants searches through the solution space in order to find a safe, optimal trajectory for a ship. The problem is considered as a multi-criteria optimization task. The criteria taken into account during problem solving are: path safety, path length, the International Regulations for Preventing Collisions at Sea (COLREGs) compliance and path smoothness. The paper includes the description of the new multi-criteria ACO-based algorithm along with the presentation and discussion of simulation tests results.

19

Heuristic Method of Safe Manoeuvre Selection Based on Collision Threat Parameters Areas

Szlapczynska J., Szlapczynski R.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 4

591--596

EN

This paper is a continuation of papers dedicated to a radar-based CTPA (Collision Threat Parameters Area) display designed to support safe manoeuvre selection. The display visualizes all the ships in an encounter and presents situational overview from the own ship's point of view. It calculates and displays information on unsafe or unrealistic own ship's course & speed allowing a user to select a safe manoeuvre. So far only the manual selection was possible, thus the paper aims at presenting a heuristic approach towards the manoeuvre selection when using the display.

20

Study Reliability of the Information About the CPA and TCPA Indicated by the Ship's AIS

Wawruch R.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2016

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Vol. 10, no. 3

417--424

EN

According to the IMO recommendation when the target data from AIS and radar tracking are both available and the association criteria are fulfilled such that the AIS and radar information are considered as for one physical target, then as a default condition in radar equipment, the AIS target symbol and the alphanumerical AIS target data should be automatically selected and displayed only. The article presents research conducted in real conditions on the reliability of information presented by the ship's AIS about the passing distance with the other vessel equipped with AIS and time to pass it by comparing data from the AIS with that presented by ARPA.