11 research outputs found

    Multi criteria route selection with custom domain shape

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    The paper describes a multi criteria vessel route selection system designed to support VTS systems. The system is comprised of three cooperating modules: simulation, collision risk estimation and multi criteria decision making. Given the set of alternative routes, the initial and goal positions and velocities of own and target ships the output of the system is a ranking of all considered routes. This ranking enables the VTS operator to produce a proper route recommendation which is then sent to the navigators. The additional advantage of the system described here is its ability to support custom shape of ship domain

    Evolutionary sets of cooperating ship trajectories : COLREGS compliance

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    The paper presents a newly designed improvement to the method of solving multi-ship encounter situations. In general, the method combines some of the assumptions of game theory with evolutionary programming and aims to find optimal set of cooperating trajectories of all ships involved in an encounter situation. The improvement presented here is a new way of modelling some of the COLREGS rules. Due to this change, the method is now able to find solutions, which are more compliant with COLREGS, more intuitive and consequently – safer from the navigator’s point of view

    Adopted isochrones method improving ship safety in weather routing with evolutionary approach

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    The paper is focused on adaptation of an isochrones method necessary for application to a weather routing system with evolutionary approach. Authors propose an adaptation of the isochrones method with area partitioning assuring that the route found by the adopted method would not cross land. In result, when applied to a weather routing system with evolutionary approach, this proposal facilitates creation of initial population, resulting with routes of reduced collision risk and low costs of passage

    CUSTOMIZED CROSSOVER IN EVOLUTIONARY SETS OF SAFE SHIP TRAJECTORIES

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    The paper presents selected aspects of evolutionary sets of safe ship trajectories—a method which applies evolutionary algorithms and some of the assumptions of game theory to solving ship encounter situations. For given positions and motion parameters of the ships, the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The method works in real time and the solutions must be returned within one minute, which enforces speeding up the optimisation process. During the development of the method the authors tested various problem-dedicated crossover operators to obtain the best performance. The results of that research are given here. The paper includes a detailed description of these operators as well as statistical simulation results and examples of experiment results

    A Simulative Comparison of Ship Domains and Their Polygonal Approximations

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    The paper investigates the impact of a precise ship domain shape on the size of collision avoidance manoeuvres. The considered collision avoidance manoeuvres include both course and speed alterations. Various ship domains are compared with their polygonal approximations, which vary in the number of points of a domain contour and placement of these points. The best of all considered approximations is determined in the course of simulation experiments performed for head-on, crossing and overtaking situations. The chosen number and placement of contour points combine precision of domain approximation with reasonable computational time

    Review of Weather Forecast Services for Ship Routing Purposes

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    Weather data is nowadays used in a variety of navigational and ocean engineering research problems: from the obvious ones like voyage planning and routing of sea-going vessels, through the analysis of stability-related phenomena, to detailed modelling of ships’ manoeuvrability for collision avoidance purposes. Apart from that, weather forecasts are essential for passenger cruises and fishing vessels that want to avoid the risk associated with severe hydro-meteorological conditions. Currently, there is a wide array of services that offer weather predictions. These services include the original sources – services that make use of their own infrastructure and research models – as well as those that further postprocess the data obtained from the original sources. The existing services also differ in their update frequency, area coverage, geographical resolution, natural phenomena taken into account and finally – output file formats. In the course of the ROUTING project, primarily addressing ship weather routing accounting for changeable weather conditions, the necessity arose to prepare a report on the state-of-the-art in numerical weather prediction (NWP) modelling. Based on the report, this paper offers a thorough review of the existing weather services and detailed information on how to access the data offered by these services. While this review has been done with transoceanic ship routing in mind, hopefully it will also be useful for a number of other applications, including the already mentioned collision avoidance solutions

    Review of weather forecast services for ship routing purposes

    No full text
    Weather data is nowadays used in a variety of navigational and ocean engineering research problems: from the obvious ones like voyage planning and routing of sea-going vessels, through the analysis of stability-related phenomena, to detailed modelling of ships’ manoeuvrability for collision avoidance purposes. Apart from that, weather forecasts are essential for passenger cruises and fishing vessels that want to avoid the risk associated with severe hydro-meteorological conditions. Currently, there is a wide array of services that offer weather predictions. These services include the original sources – services that make use of their own infrastructure and research models – as well as those that further postprocess the data obtained from the original sources. The existing services also differ in their update frequency, area coverage, geographical resolution, natural phenomena taken into account and finally – output file formats. In the course of the ROUTING project, primarily addressing ship weather routing accounting for changeable weather conditions, the necessity arose to prepare a report on the state-of-the-art in numerical weather prediction (NWP) modelling. Based on the report, this paper offers a thorough review of the existing weather services and detailed information on how to access the data offered by these services. While this review has been done with transoceanic ship routing in mind, hopefully it will also be useful for a number of other applications, including the already mentioned collision avoidance solutions

    Multi-Criteria Optimisation of Liquid Cargo Transport According to Linguistic Approach to the Route Selection Task

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    The main aim of the paper is to present the possibility of use of the multi-criteria optimization method Analytical Hierarchy Process (AHP) to liquid cargo transportation by sea. Finding the optimal solution is not simple. There are many factors influencing the shipping process. In the case of liquid cargo, the most important thing is the safety of the crew, ship, and environment. Therefore, the Mathematical Theory of Evidence is introduced and used to determine the optimal path in terms of time and safety of transport. Moreover, the details of liquid cargo transport process are described with particular attention to ship to ship operations. Besides, the basic concept of the AHP method, steps of the algorithm are introduced. Finally, the multicriteria optimization of the transport of the liquid cargo from the Persian Gulf to Port of Gdansk is done. It is based on the experts’ opinions
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