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1

Determination of probabilities defining safety of a sea-going ship during performance of a transportation task in stormy weather conditions

Girtler J.

Journal of Polish CIMEEAC

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2017

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Vol. 12, no 1

21--30

EN

The paper presents the possibility of applying the theory of semi-Markov processes to determine the limiting distribution for the process of changes of technical states being reliability states of the systems of sea-going ships significantly affecting safety of such ships, which include main engine, propeller and steering gear. The distribution concerns the probabilities of occurrence of the said states defined for a long time of ship operation (t → ∞). The considered states are as follows: s0 – full ability state of the systems, i.e.: main engine, propeller and steering gear, s1 – inability state of the main engine, s2 – inability state of the propeller, s3 – inability state of the steering gear. Significance of the systems for safety of the ships at sea was demonstrated herein. General conditions for performing transportation tasks by the ships, with particular regard to stormy conditions, were also here described.

2

Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from collision of ships

Girtler J.

Polish Maritime Research

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2014

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nr 1

9--13

EN

In this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to determine the probability (P0) of correct execution of critical manoeuvres during ship’s entering and leaving the port as well as the probabilities Pj(j = 1, 2, 3, …, 7) of incorrect execution of critical manoeuvres by a ship, that leads to marine accidents. It was assumed that such accidents result from: ship’s grounding on port approaching fairway, collision with a ship on port approching fairway, collision with a pierhead during passing through port entrance, collision with a hydrotechnical structure during ship’s passing through port channels, collision with a port quay during coming alongside it and collision with a ship already moored to the quay. The probability (P0) was assumed a measure of safe execution of a critical manoeuvre. The probability characterizes possibility of avoiding any collision during ship’s entering and leaving the port. The probability Pa = 1 – P0 was assumed a measure of occurrence of a collsion and - consequently - marine accident. The probability Pa was interpreted as a sum of the probabilities Pj(j = 1, 2, 3, …, 7) of occurrence of all the selected events. In summing up the paper, attention was drawn to its merits which - in opinion of this author - are crucial for research on real process of accidents during entering the port and leaving it by sea-going ship in difficult navigation conditions.

3

Nowoczesne metody sterowania ruchem statku handlowego

Lisowski J., Gierusz W., Łebkowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2014

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Vol. 55, nr 8

9-11

PL

W pracy zaprezentowano wybrane systemy sterowania ruchem statku. Przedstawiono uwarunkowania sterowania statkiem przy małych prędkościach na akwenach ograniczonych. Opisano metody wyznaczania bezpiecznej trajektorii statku w sytuacji kolizyjnej. W końcowej części zaprezentowano metody weryfikacji systemów kierowania statkiem.

EN

The complex control systems destined to the sea-going ships are presented in the paper. The first one is used on the constrained areas like harbours and roads and is named precise steering system. Describes the method of determining a safe trajectory of the ship collision. In the final section presents a method of verification of the ship steering systems.

4

The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems

Girtler J.

Polish Maritime Research

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2013

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nr 4

18--24

EN

The article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability of faultless operation in time t was assumed the measure of system reliability. Operating situations of sea-going vessels were characterised, with special attention being paid to the fact that the loads of propulsion system components of these vessels are of random nature. These loads lead to damages which for this reason were also considered random events. It was also assumed that the damages provoke the appearance of states of inability of particular ship propulsion system components which means that these states are random events as well. The states of ability of a given ship propulsion system have been assumed to exist when all components of this system are in the state of ability. In case when at least one component is in the state of inability, the entire system is in the state of inability. Conditions were formulated for the reliability model of an arbitrary system to be able to be worked out in the form of the semi-Markov process. The need for the use of technical diagnostics in reliability examination of sea-going ship propulsion systems was indicated. In conclusions, certain qualities of the article were highlighted which are, in author’s opinion, of highest importance in reliability examination of sea-going ship propulsion systems.

5

Service margin - solution of the problem or a problem waiting for solution?

Stasiak J.

Polish Maritime Research

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2004

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S 1

29-33

EN

Subiect of the paper is the problem of predicting sea-going ship resistance and/or horsepower in real operating conditions. Attention is drawn first of all to the need and possibility of revising the very much outdated but still used "service margin" method, which consists in adding an arbitrary percentage margin to the value of resistance or horsepower, relatively precisely determined for the calm water conditions. A negative impact in this respect is shown of the generally used delivery-acceptance procedures, where particular importance is attached to the ship propulsion tests on the "measured mile". The need of revising the "service margins" is a consequence of an obvious need for most efficient ships from the technical as well as economic point of view. Secondly, it is a "must" of permanent improving the ship design quality - the adequacy and accuracy of design methods. The work presents the "wave service margin" coefficient models. It is assumed that they may contribute to the necessary rationalization of the procedure of real ship resistance and/or horsepower determination. The work is based on the results of resistance tests of a series of ships designed within the Baltecologicalship project. The tests were carried out in the Chair of Ship Theory and Design of the Faculty of Ocean Engineering and Ship Technology, Gdansk University of Technology.

6

Designing engine rooms of new generation ships realized within the framework of European research projects EUREKA - chosen questions

Girtler J.

Polish Maritime Research

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2004

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S 1

57-61

EN

Importance of reliability and safety in the operation phase of engine rooms has been proven. A concept of designing engine rooms taking into consideration their reliability, safety i of functioning as well as ecological features has been proposed. The need for as well as the main principles of carrying out empirical research in particular ship design stages have been introduced. Possibilities of the use of the semi-Markov theory in designing engine rooms have been justified. Possibilities of formulation and importance of hypothesis in scientific research related to engine rooms of sea going and inland ships depending on their particular specific features have been introduced. Examples of such hypothesis and their verification methods have been given. Possibilities of the use of semi-Markov processes in optimization of the ship operation have been signalled.

7

Procesy decyzyjne w sterowaniu statkiem morskim

Pietrzykowski Z.

Studia / Wyższa Szkoła Morska w Szczecinie

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2003

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nr 42

3-170

PL

W pracy rozpatrywano zagadnienia bezpiecznego sterowania statkiem morskim jako środkiem transportu. Zwiększająca się ilość dostępnych informacji oraz wzrost złożoności stosowanych systemów technicznych sprawiają, że zarządzanie informacją oraz podejmowanie na tej podstawie decyzji, zwłaszcza w przypadku sytuacji złożonych, np. awaryjnych, może przerastać możliwości decydentów. Jednym ze sposobów rozwiązania tego problemu jest tworzenie systemów wspomagania decyzji, opartych na nowoczesnych technikach i technologiach informatycznych. Rozwiązania wyznaczone przez te systemy powinny uwzględniać obowiązujące przepisy, zapewniać bezpieczne wykonanie manewru oraz być racjonalne. Oznacza to m.in. użycie kryteriów stosowanych i akcentowanych przez człowieka. Ma to istotne znaczenie z punktu widzenia wiarygodności systemu, a w konsekwencji stosowania go w praktyce. Podstawą do realizacji tego typu systemów jest analiza procesów decyzyjnych w sterowaniu statkiem morskim oraz opracowanie adekwatnych modeli, uwzględniających zarówno aspekt bezpieczeństwa żeglugi, jak i aspekt ekonomiczny. Zbiór zagadnień, omawianych w monografii, obejmuje: charakterystykę obszarów podejmowania decyzji na statku morskim; analizę statku jako obiektu sterowania z uwzględnieniem jego dynamiki i kinematyki; analizę uwarunkowań procesów związanych ze sterowaniem statkiem morskim; klasyfikację zagadnień podejmowania decyzji w warunkach niepewności; metody pozyskiwania i reprezentacji wiedzy ekspertów nawigatorów oraz jej wykorzystania w procesie sterowania statkiem; metody i kryteria oceny sytuacji nawigacyjnej; kryteria wyboru drogi oparte na regułach stosowanych w praktyce przez nawigatorów; problem wyboru drogi w zadaniu sterowania statkiem w ujęciu deskryptywnym i preskryptywnym; zadanie wyboru drogi jako zadanie optymalizacji jedno- i wieloetapowej w warunkach deterministycznych oraz w otoczeniu rozmytym; analizę procedur decyzyjnych. Na tej podstawie dokonano syntezy modeli procesów decyzyjnych sterowania statkiem morskim. Przeprowadzono badania symulacyjne sterowania statkiem z wykorzystaniem opracowanych procedur decyzyjnych oraz przedstawiono możliwości zastosowania zbudowanych modeli w nawigacyjnych systemach wspomagania decyzji. Opracowano koncepcję oraz zbudowano prototyp systemu komunikacji i kooperacji statków, oparty na technologii przetwarzania rozproszonego. Oryginalne modele i algorytmy obliczeniowe, wykorzystujące wiedzę nawigatorów, umożliwiają budowę systemu wspomagania decyzji nawigatora. Uwzględniają one zarówno bezpieczeństwo nawigacyjne, jak i aspekt ekonomiczny realizacji zadania transportowego. Zdaniem autora mogą znaleźć zastosowanie do budowy w pełni zautomatyzowanych systemów sterowania statkiem.

EN

This work deals with the subject of the control of a sea-going ship as a means of transport. The increasing amount of available information and a growing complexity of technical systems make the information management and making decisions too difficult for decision makers, especially in the case of complex situations, such as emergency ones. One of the methods to solve this problem is the development of decision support systems based on uptodate information technologies. Solutions defined by those systems should account for the regulations in force, provide for safe manoeuvres and be rational. Among others, this means the criteria used are to be those applied and accepted by human beings. This is very important if the system is to be reliable, consequently to be practically used. The implementation of such systems is based on the analysis of the decision processes in sea-going ship control as well as on the development of adequate models, which take into account both navigational safety and economic aspects. The problems this monograph deals with cover the following: characteristics of decision making areas on board a sea-going vessel; analysis of a ship as a control object, including object's dynamics and kinematics; analysis of conditions for processes involved in sea-going ship control; classification of problems of decision making in the conditions of uncertainty; methods of expert navigators' knowledge acquisition and representation and methods of its use in ship control process; methods and criteria for a navigational situation assessment; criteria for routing based on principles practically used by navigators; problem of routing in the task of ship control: descriptive and prescriptive approach; task of routing as a one-stage and multistage optimization task in the deterministic conditions and a fuzzy environment; analysis of decision procedures. On this basis a synthesis was made to combine models of sea-going ship control decision process models. Ship control simulation research was carried out using the decision procedures. Possible applications of the models in navigational decision support systems are presented. A concept of ship communication and cooperation was developed and its prototype was built. The prototype utilizes the technology of distributed processing. Original models and computing algorithms, using navigators' knowledge, enable the construction of a navigator's decision support system. They take into account navigational safety as well as economic aspect of the transport task execution. In the author's opinion the models and algorithms can be applied in designing fully automated ship control systems.