Wyniki wyszukiwania - BazTech

1

Classification of parametric rolling for seagoing ships and percentage distribution for multiple sea state parameters

Chhoeung S., Hahn A.

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

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2022

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Vol. 16 No. 4

769--777

EN

In this paper, parametric rolling is divided into 5 heavy grades, establishing a classification for parametric rolling. This is achieved by a multi-parameter application in the simulations. For this purpose, parametric rolling, established criteria and the state of the art are considered and the results are summarized. Based on this, parametric rolling is successfully simulated using discrete simulation in MARIN [1]. Five heavy grades are introduced so different classes of parametric rolling can be distinguished. Furthermore, dependencies and probabilities for the occurrence of parametric roles in relation to the see are determined numerically. This will later be used in an assistance system on board ships to compute the prediction of parametric roll using an AI.

2

Mobile bridge - a portable design siimulator for ship bridge interfaces

Stratmann T.C., Gruenefeld U., Hahn A., Boll S., Stratmann J., Schweigert S.

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

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2018

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Vol. 12, no. 4

763--768

EN

Developing new software components for ship bridges is challenging. Mostly due to high costs of testing these components in realistic environments. To reduce these costs the development process is divided into different stages. Whereas, the final test on a real ship bridge is the last step in this process. However, by dividing the development process into different stages new components have to be adapted to each stage individually. To improve the process we propose a mobile ship bridge system to fully support the development process from lab studies to tests in realistic environments. Our system allows developing new software components in the lab and setting it up on a ship bridge without interfering with the vesselʹs navigational systems. Therefore it is linked to a NaviBox to get necessary information such as GPS, AIS, compass, and radar information. Our system is embedded in LABSKAUS, a test bed for the safety assessment of new e‐Navigation systems.

3

Investigations on Container Ship Berthing from the Pilot’s Perspective: Accident Analysis, Ethnographic Study, and Online Survey

Gruenefeld U., Stratmann T.C., Brueck Y., Hahn A., Boll S., Heuten W.

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

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2018

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Vol. 12, no. 3

493--498

EN

In recent years, container ships have had to transport more and more goods due to constantly growing demand. Therefore, the container ships for carrying these goods are growing in size, while the harbors fall short in adapting to these changes. As a result, the berthing of these container ships in harbors has become more challenging for harbor pilots. In this work, we identify problems and risks with which pilots are confronted during the berthing process. First, we analyzed approximately 1500 accident reports from six different transportation safety authorities and identified their major causes. Second, we conducted an ethnographic study with harbor pilots in Hamburg to observe their actions. Third, we gained more specific insights on pilots environments and communications through an online survey of 30 harbor pilots from different European countries. We conclude our work with recommendations on how to reduce problems and risks during berthing of container vessels.

4

Parameter identification of ship maneuvering models using recursive least square method based on support vector machines

Zhu M., Hahn A., Wen Y., Bolles 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

23--29

EN

Determination of ship maneuvering models is a tough task of ship maneuverability prediction. Among several prime approaches of estimating ship maneuvering models, system identification combined with the full-scale or free- running model test is preferred. In this contribution, real-time system identification programs using recursive identification method, such as the recursive least square method (RLS), are exerted for on-line identification of ship maneuvering models. However, this method seriously depends on the objects of study and initial values of identified parameters. To overcome this, an intelligent technology, i.e., support vector machines (SVM), is firstly used to estimate initial values of the identified parameters with finite samples. As real measured motion data of the Mariner class ship always involve noise from sensors and external disturbances, the zigzag simulation test data include a substantial quantity of Gaussian white noise. Wavelet method and empirical mode decomposition (EMD) are used to filter the data corrupted by noise, respectively. The choice of the sample number for SVM to decide initial values of identified parameters is extensively discussed and analyzed. With de-noised motion data as input-output training samples, parameters of ship maneuvering models are estimated using RLS and SVM-RLS, respectively. The comparison between identification results and true values of parameters demonstrates that both the identified ship maneuvering models from RLS and SVM-RLS have reasonable agreements with simulated motions of the ship, and the increment of the sample for SVM positively affects the identification results. Furthermore, SVM-RLS using data de-noised by EMD shows the highest accuracy and best convergence.

5

Virtual test bed for maritime safety assessment

Hahn A., Gollücke V., Buschmann C., Schweigert S.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2015

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nr 44 (116)

116--122

EN

“Safe voyage from berth to berth”: This is the goal of all e-Navigation strains driven by new technologies, new infrastructures, and new organizational structures on bridge, on shore, as well as in the cloud. To facilitate these efforts suitable engineering and safety/risk assessment methods are required. Understanding maritime transportation as a sociotechnical system allows the usage of system-engineering methods. Simulation-based test beds for verification and validation (V +V) of e-Navigation technologies are important methods to obtain functional safety and reliability. The modeling and simulation toolset HAGGIS is a cosimulation system for the evaluation of e-Navigation concepts and systems. It provides a maritime traffic simulator and a physical world (n-body) simulator and services for finding rare events of failures. HAGGIS is accompanied by the physical test bed LABSKAUS, which implements a reference port and waterways. This paper describes an integrated and seamless approach for developing new e-Navigation technologies starting with virtual simulation-based safety assessment and ending in physical real-world demonstrations. It gives an overview of the actual test bed and introduces requirements, concepts and elements of HAGGIS and LABSKAUS, which are joined in the e-Maritime Integrated Reference Platform (eMIR) test bed.

6

Improving maritime traffic safety by applying routes exchange and automatic relevant radar data exchange

Salous M., Müller H., Bolles A., Hahn A.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2015

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nr 44 (116)

90--98

EN

The e-navigation strategy of the International Maritime Organization (IMO) aims to improve the safety of maritime traffic by increasing cooperation between several maritime stakeholders. The COSINUS (Bolles et al., 2014) project contributes to such a strategy by enabling an automated data exchange (observations, routes and maneuver plans) between ship-side and shore-side navigational systems, developing useful sensor fusion applications upon the new information available from data exchange and introducing new Human Machine Interfaces (HMIs) to support the users of navigation systems. The project shows potential for improvement in maritime traffic safety by ensuring continuous awareness to all participants involved through sensor fusion applications, i.e. by providing all participants (mobile and stationary navigation systems) with a complete view at all times. These applications include detection of critical situations like radar shadowing areas, early and accurate prediction of potential collisions or closest point of approach (CPA) based on the exchanged routes, and improving the accuracy of radars by ensuring high quality data for obstructed or far away routes. The new HMI concepts introduced within the COSINUS project aim at highlighting critical maritime traffic situations. Thus, the users of such navigation systems supported with COSINUS facilities can easily detect such critical situations and react efficiently to avoid collisions, possible crowded areas and inefficient routes.

7

Trajectory Planning with Negotiation for Maritime Collision Avoidance

Hornauer S., Hahn A., Blaich M., Reuter J.

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

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2015

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Vol. 9, no. 3

335--341

EN

The problem of vessel collisions or near-collision situations on sea, often caused by human error due to incomplete or overwhelming information, is becoming more and more important with rising maritime traffic. Approaches to supply navigators and Vessel Traffic Services with expert knowledge and suggest trajectories for all vessels to avoid collisions, are often aimed at situations where a single planner guides all vessels with perfect information. In contrast, we suggest a two-part procedure which plans trajectories using a specialised A* and negotiates trajectories until a solution is found, which is acceptable for all vessels. The solution obeys collision avoidance rules, includes a dynamic model of all vessels and negotiates trajectories to optimise globally without a global planner and extensive information disclosure. The procedure combines all components necessary to solve a multi-vessel encounter and is tested currently in simulation and on several test beds. The first results show a fast converging optimisation process which after a few negotiation rounds already produce feasible, collision free trajectories.

8

Certainty against flexibility – the concept of frozen horizon – chances, problems and solutions

Hahn A.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2014

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nr 84

48--55

EN

This scientific article is about the complexity of supply chains, the problematic of fixed order points and the potential of regulated agreements between the Original Equipment Manufacturer and its Suppliers. There are two different perspectives. On the one hand, the OEM tries to be as flexible as possible, whereas the supplier needs a clear certainty about future orders. To be competitive on the current market, it is not enough just to improve the internal processes of a specific company, but rather the whole supply chain has to be optimized. Consequently, one main point has to be focused within the supply chain – certainty against flexibility. With the implementation of individual contracts between every direct cooperating business, the frozen horizon could help to avoid the arising waste by the bullwhip effect which is exclusively attributable to the uncertainty of the supplier. The OEM has to realize that a reduction of its own flexibility and control leads to a tremendous optimization of the entire supply chain and thus to a better position in the market as well.

9

Metodyka pomiarów i oprogramowanie do analiz obrazów termograficznych i cyfrowych

Balzam E., Hahn A., Sokołowski A.

Prace Naukowe Katedry Budowy Maszyn / Politechnika Śląska

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2007

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nr 1

97-108

PL

W artykule przedstawiono wyniki badań w ramach, których zweryfikowano możliwość zastosowania technik przetwarzania obrazów cyfrowych, a zwłaszcza metod detekcji krawędzi w diagnostyce obrabiarek. Nadrzędnym celem było zaproponowanie koncepcji metodyki badań pola temperatur obrabiarek z zastosowaniem skanera termograficznego oraz wykonanie oprogramowania komputerowego wspomagającego analizę obrazu termograficznego ze szczególnym zwróceniem uwagi na problem emisyjności powierzchni oraz sposobami jej korekcji.

EN

The general goal of the presented research is to develop methodology for machine tool temperature field measurement and analysis. For digital and thermograph images processing, new software has been elaborated. In the paper, a problem of temperature determination based on thermographs recorded with thermo-scanner is analysed, mainly. Such determination requires identifying emissivity factors of considered surfaces, first of all. In order to perform such operation, the surfaces (or elements) should be marked on the thermographs. It is proposed to apply image-processing techniques for detecting the edges of surfaces that can differ in terms of emissivity factors. The tests of selected image processing methods were worked out with Matlab "Image Processing" toolbox and LabView "Vision" toolbox. The conducted research pointed at necessity of proper fixing of markers on tested object. In higher temperature, markers can easy move on vertical and sloped surfaces. Selected solutions and discussion of the obtained results are shown in the paper, as well.