A. Wolski

Directions in the modernization of modern seaports

Growing trade and the globalization of production and consumption have contributed to the increased importance of seaports. Maritime transport of bulk cargo is competitive. The carriage of general cargo is also growing, mainly through the widespread use of containers. A particularly large growth in cargo throughput has taken place in seaports of developing countries. Maritime policy aims at improving the efficiency of sea transport in Europe and the world, while ensuring its long-term competitiveness. This can be achieved by the dissemination of technologies leading to increased productivity, minimizing negative environmental impacts and creating conditions for effective operations and integration of ports in transport chains.

A Comparison of the Least Squares with Kalman Filter Methods Used in Algorithms of Fusion with Dead Reckoning Navigation Data

Different calculation methods and configurations of navigation systems can be used in algorithms of navigational parameter fusion and estimation. The article presents a comparison of two methods of fusion of dead reckoning position with that from a positioning system. These are the least squares method and the Kalman filter. In both methods the minimization of the sum of squared measurement deviations is the optimization criterion. Both methods of navigation position parameter measurements fusion are illustrated using the data recorded during actual sea trials. With the same probabilistic model of dead reckoning navigation, the fusion of DR results with positioning data gives similar outcome. http://www.transnav.eu the International Journal on Marine Navigation and Safety of Sea Transportation Volume 11 Number 4 December 2017 DOI: 10.12716/1001.11.04.16

Determination of ship approach parameters in the polar coordinates system

Abstract An essential aspect of the safety of navigation is avoiding collisions with other vessels and natural or man made navigational obstructions. To solve this kind of problem the navigator relies on automatic anti-collision ARPA systems, or uses a geometric method and makes radar plots. In both cases radar measurements are made: bearing (or relative bearing) on the target position and distance, both naturally expressed in the polar coordinates system originating at the radar antenna. We first convert original measurements to an ortho-Cartesian coordinate system. Then we solve collision avoiding problems in rectangular planar coordinates, and the results are transformed to the polar coordinate system. This article presents a method for an analysis of a collision situation at sea performed directly in the polar coordinate system. This approach enables a simpler geometric interpretation of a collision situation

The Fusion of Point and Linear Objects in Navigation

There are great many human activities where problems dealt with are based on data from a number of sources or where there is a lack of certain data to solve a problem correctly. Such situations also occur in navigation, where it is necessary to combine data from diverse navigational devices with archival data, including images. This article discusses a problem of the fusion of position data from shipboard devices with those retrieved from a hydrographic data base, the data being of varying accuracy. These considerations are illustrated with examples of the fusion of shipboard measurements with the pier line (or another cartographic object).

Interval Analysis of Navigational Problems / Analiza Przedziałowa Zadań Nawigacyjnych

Abstract Algorithms of solutions to navigational problems usually comprise elements for numerical calculations. Apart from random errors, numerical errors of varying nature can be found in them. These errors are due to the level of precision of input data, the approximability of computing methods and errors generated by the computing very process itself in a computer. The latter category includes numerical precision (floating point of a numerical notation) and rounding off of numbers. These errors are analyzed as absolute and relative errors, rounding off errors and are regarded as random errors with a triangular distribution. Over the last decade or more the interval analysis of rounding off errors has been dynamically developing. Despite increased computing effort (costs), in some cases such analysis is necessary, particularly when we want to get a result of specific precision. It can be extended as an analysis of random errors with uniform distribution. Streszczenie Algorytmy rozwiązania zagadnień nawigacyjnych zazwyczaj zawierają elementy o obliczeń numerycznych. Występują więc w nich, oprócz błędów losowych, również błędy numeryczne o różnym charakterze. Błędy te wywołane są poziomem precyzji danych wejściowych, przybliżonością metod obliczeniowych oraz błędami generowanymi samym procesem obliczeniowym w komputerze. Do tych ostatnich należą precyzja numeryczna (reprezentacja zmiennopozycyjna) oraz zaokrąglenia. Błędy te analizujemy jako błędy bezwzględne, błędy względne, błędy zaokrągleń oraz traktuje się je jako błędy losowe o rozkładzie trójkątnym. W ostatnich kilkunastu latach dynamicznie rozwija się analiza przedziałowa błędów zaokrągleń. Pomimo zwiększone nakładu obliczeń (kosztów) jest ona w niektórych przypadkach niezbędna, szczególnie gdy chcemy otrzymać wynik o odpowiedniej precyzji. Można ją również rozszerzyć na analizę błędów losowych o rozkładzie jednostajnym.

Integration of the Short-Range Hyperbolic System Jemioluszka and DGPS

Integration of the Short-Range Hyperbolic System Jemioluszka and DGPS This article describes an algorithm of an integrated navigational system developed for the navigation and steering along a given trajectory by rescuesalvage ships operated by the Polish Navy. Due to strict requirements concerning the accuracy of measurements of navigational parameters of ships at slow speeds, inertial measurement units have been used, whilst the state variables in the algorithm include higher derivatives of the velocity vector. The algorithm has been verified by a simulation method and at sea trials on board a real ship. Integracja Hiperbolicznego Systemu Bliskiego Zasięgu Jemiołuszka Z DGPS W artykule przedstawiono opis algorytmu zintegrowanego systemu nawigacyjnego opracowanego dla potrzeb nawigacji i sterowania po trajektorii specjalistycznych okrętów wojennych. Ze względu na wysokie potrzeby dokładnościowe mierzonych parametrów nawigacyjnych na małych prędkościach, wykorzystano w systemie mierniki inercjalne, a w algorytmie jako zmienne stanu przyjęto również wyższe pochodne wektora prędkości. Algorytm zweryfikowano metodą symulacyjną oraz podczas prób morskich na obiekcie rzeczywistym.