Wyniki wyszukiwania - Biblioteka Nauki

1

The problem of route determination in ship movement in a restricted area

100%

Pietrzykowski Z. , Magaj J.

Annual of Navigation

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2012

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tom No. 19, part 2

53--69

EN

This article focuses on the problem of determining a safe trajectory of a ship proceeding in a restricted area. An algorithm of trajectory choice has been developed, taking into account the parameters of the area, own ship, target ship and other vessels sailing in vicinity. The ship domain has been adopted as a safety criterion. The research results for selected test trials are presented and analyzed. The applicability of the proposed method of trajectory choice in real conditions is considered.

2

The automatic collision avoiding plan research of given way vessel in crossing situation

100%

Hu W. , He Y.

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2018

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tom S 2

12--16

EN

This paper aims to the computing model of quantitative elements in crossing situation based on the separating of different states about vessel’s meeting to study the automatic collision-avoiding plan of given way vessel in crossing situation. Following results are proved by simulations: The accuracy of hydrodynamic model is enough for studying and application for automatic collision-avoiding; computing model of quantitative elements by method of bisection is rapidly and reliably convergent during computing. The whole meeting process can be separated to several stages according to the quantitative elements in crossing situation. Different initial collision avoiding measures of given-way vessel in different stages produced as per rules and ordinary practice of seaman.

3

Ship domains in Traffic Separation Schemes

86%

Pietrzykowski Z. , Magaj J.

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tom nr 45 (117)

143--149

EN

Ship movement processes in selected Traffic Separations Schemes (TSS) of Southern Baltic Sea were analyzed. Ship domains in the analyzed water areas were calculated from Automatic Identification System (AIS) registered data. The purpose of investigation was identification of ship domain parameters taking into account different domain determination criteria. The results were compared and discussed. The conclusions were drawn.

4

A New Measure of Collision Risk Derived from the Concept of Ship Domain

86%

Szłapczyński R.

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tom nr 6 (78)

349-359

EN

The paper introduces a new measure of collision risk, derived from the concept of ship domain. The presented measure 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 the value of the measure for any other ship domain.

PL

Zaprezentowano nową miarę ryzyka kolizji dwóch statków wywiedzioną z koncepcji domeny statku. Miara ta jest elastyczna, tzn. można korzystać z niej w powiązaniu z dowolną zadaną domeną statku. Szczegółowo przedstawiono wyprowadzenia wszystkich niezbędnych wzorów w przypadku zastosowania modelu domeny Fuji. Dodatkowo zamieszczono algorytmy rozwiązań numerycznych, znajdujących wartość miary dla dowolnej zadanej domeny

5

Unmanned ship simulation with real-time dynamic risk index

86%

Brake M. C. t. , Iperen E. W. H. v. , Looije D. , Koldenhof Y.

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tom nr 43 (115)

48--54

EN

Currently there is growing interest in unmanned shipping. In the case of unmanned ‘autonomous’ shipping, navigation is automated by on-board decision-making systems. Important motives for unmanned ships include the shortage of skilled mariners, the facilitation of slow steaming strategies, efficiency improvements in confined shipping areas, and increased safety. The aim of the present research is to simulate an unmanned ship through an Automatic Identification System (AIS) based traffic situation. In order to do this, the Maritime Research Institute Netherlands (MARIN) will use the existing simulation technology Dolphin, implement a new tool to read AIS data, simulate a large amount of ships, and develop an auto-captain. The real-time dynamic risk index developed by MARIN will be integrated in Dolphin, to monitor nautical safety of all ships with focus on the unmanned ship. The simulated unmanned ship will navigate according to the International Regulations for Preventing Collisions at Sea (COLREGS). In more complex situations, the auto-captain may use a dedicated decision support tool to find a more efficient solution to pass safely. This approach will be analysed using the real-time dynamic risk index, which will be updated based on latest insights. This paper will discuss the latest development and plans in the unmanned ship simulation project.

6

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

72%

Pietrzykowski Z. , Magaj J.

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tom 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.

7

Domena statku w identyfikacji incydentów w systemach rozgraniczenia ruchu

72%

Pietrzykowski Z. , Magaj J.

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tom z. 114

279--290

PL

Systemy rozgraniczenia ruchu są ustanawiane na podejściach do portów i trasach żeglugowych, charakteryzujących się dużą intensywnością ruchu statków. Porządkują ruch statków poprzez rozdzielenie strumieni ruchu. Ograniczają powstawanie sytuacji niebezpiecznych, ale ich nie eliminują. Część z tych sytuacji może prowadzić do incydentów a nawet do wypadków - kolizji. O ile wypadki nawigacyjne są dokumentowane, to brak jest danych dotyczących wystąpienia sytuacji niebezpiecznych oraz incydentów. Wynika to m.in. z trudności w zdefiniowaniu odpowiednich kryteriów. Identyfikacja sytuacji niebezpiecznych i incydentów może przyczynić się do ograniczenia liczby wypadków poprzez sygnalizowanie tych sytuacji nawigatorowi lub operatorowi VTS - tryb online - lub wskazanie obszarów, na których występują najczęściej - tryb offline. Zaproponowano dwuetapową metodę identyfikacji incydentów z wykorzystaniem kryterium domeny statku. Przedstawiono wyniki badań identyfikacji incydentów nawigacyjnych w wybranym TSS.

EN

Traffic Separation Schemes are established in port approaches and freąuently used shipping routes, characteristic of high intensity of vessel traffic. They organize the traffic by separating vessel flows. These systems reduce the occurrence of dangerous situations, but do not eliminate them completely. Some of these situations may lead to incidents, near-misses, even accidents, i.e. collisions. While marine accidents are documented, data on the occurrence of dangerous situations, near-misses or incidents are not, due to difficulties in defining relevant criteria. The identification of dangerous situations and incidents may contribute to the reduction of accident frequency by online signaling these situations to the navigator or VTS operator, or indicating areas of largest occurrence (offline). The proposed two-stage incident identification is based on the criterion of ship domain, and the results illustrate research on the identification of navigational incidents in a selected TSS.

8

Towards the assessment of critical area in a collision encounter accounting for stability conditions of a ship

72%

Krata P. , Montewka J. , Hinz T.

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tom z. 114

169--178

EN

The rules of road, called COLREGS provide guidelines for navigators onboard ships involved in collision encounter at navigable waters. Specific roles for stand-on and give-a-way vessels are assigned, depending on the phase of the encounter. In this paper we extend further our earlier work on the definition of the boundaries for the third phase of the encounter. The latter is referred to as critical area for an escape maneuver of a stand-on ship, in the situation where the give-way vessel does not take an action. This area is determined with the use of a state-of-the-art, six degree-of-freedom hydrodynamic model of ship motion. Series of simulations are conducted for a specific type of encountering ships applying various rudder angles to perform collision evasive maneuvers. Varying rudder angles reflect the fact, that hard-to-side command cannot always be executed, due to stability conditions of a ship. As a result we obtained a set of areas of various size, depending on the rudder angle used to perform evasive action for the predefined ship loading conditions related to her transverse stability characteristics. These demarcate the boundaries of the third phase of encounter for the standon ship, where other ships on collision courses must not enter. Otherwise a collision cannot be avoided by an action of one ship alone or the ship would have to turn too vigorously causing actual stability related threat.

PL

Prawidła prawa drogi dla statków nawigujących na morzu wynikające z konwencji COLREGS określają wzajemne obowiązki statków. W szczególności w sytuacji przecinania się kursów statków idącychn na zderzenie przypisywane są im obowiązki związane z ustąpieniem drogi oraz z utrzymaniem kursu i prędkości. Obowiązki te są jednak uzależnione od fazy spotkania. W artykule rozwinięte zostały wcześniejsze prace dotyczące określania krytycznego obszaru związanego z trzecią fazą spotkania, gdy statek uprzednio zobowiązany do utrzymania kursu i prędkości jest już zobligowany do podjęcia własnego manewru z powodu nie wykonania swego obowiązku przez statek zobowiązany do ustąpienia drogi. Kształt obszaru krytycznego wynika zarówno z rozmiarów statków, ich właściwości manewrowych, ale także z parametrów statecznościowych, co stanowi nowość w stosunku do dotychczasowego ujęcia zagadnienia. Wykorzystano zaawansowany hybrydowy model hydrodynamiczny określający w toku licznych symulacji ruch statku w sześciu stopniach swobody dla manewru antykolizyjnego wykonanego przy różnych wychyleniach steru. Nie zawsze bowiem wyłożenie steru na burtę jest dopuszczalne z punktu widzenia stateczności i wywoływanego przechyłu. W rezultacie wyznaczono granice obszaru krytycznego dla pełnego zakresu wychyleń steru. Niedopuszczalne jest zbliżenie powodujące wejście statku w obszar krytycznych, gdyż niemożliwe stanie się wówczas uniknięcie zderzenia własnym manewrem bądź przekroczona zostanie krytyczna wartość kąta przechyłu, co jest niebezpieczne dla statku, pasażerów i przewożonego ładunku.

9

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

72%

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

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tom 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.

10

Assessment of a critical area for a give-way ship in a collision encounter

72%

Krata P. , Montewka J.

Archives of Transport

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2015

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tom Vol. 34, iss. 2

51--60

EN

Evasive action in ship-ship encounter has to be carried out on time and in line with the international convention on collision regulation – COLREG. The convention not only includes a set of rules defining types of relations between encountering ships but also indicates appropriate action to be taken in a given encounter. One of such encounters is crossing, where, in case of a collision situation, a give-way ship has to take an appropriate action in due time. However, a stand-on vessel is also given an opportunity to manoeuver, if it is made clear to her that the other ship is not fulfilling her obligations. However, it is difficult to specify, at which point in time in the course of an encounter, the stand-on ship has to take an action in order to avoid collision. It is understandable, as this parameter depends on numerous factors, both endogenous (e.g. ship characteristics, her maneuverability), and exogenous (e.g. type of encounter, weather conditions). Therefore in this paper we make an attempt towards the definition of the critical area for a maneuver of a stand-on ship, in the situation where the give-way vessel does not take an action. This is determined with the use of a hydrodynamic model of ship motion, and series of simulations conducted for several types of encountering ships under various conditions. Once determined, the critical area demarcates the no-go area around the own ship, where any other ships on collision courses must not enter. Otherwise a collision cannot be avoided by an action of one ship alone.