Station-Keeping Trials in Ice: Test Scenarios

2018 ◽  
Author(s):  
Pavel Liferov ◽  
Nicolas Serre ◽  
Sofien Kerkeni ◽  
Robert Bridges ◽  
Fengwei Guo
Keyword(s):  
Measurement Data ◽  
Dynamic Positioning ◽  
Station Keeping ◽  
Operational Parameters ◽  
Drifting Ice ◽  
Test Scenarios ◽  
Insight Into

Station-keeping trials were undertaken in drifting ice in the Bay of Bothnia with two anchor handling supply vessels; Magne Viking and Tor Viking. This paper describes test scenarios which were performed with Magne Viking in moored, Dynamic Positioning and transit modes. An overview of the tests performed during the trials is presented, outlining the range of environmental and operational parameters. Examples of specific ice interaction scenarios are highlighted with illustrative measurement data providing observational insight into the performance and processes.

Station-Keeping Trials in Ice: Dynamic Positioning in Ice — Results and Learnings

2018 ◽  
Author(s):  
Sofien Kerkeni ◽  
Pavel Liferov ◽  
Nicolas Serré ◽  
Robert Bridges ◽  
Finn Jorgensen
Keyword(s):  
Full Scale ◽  
Control Algorithms ◽  
Dynamic Positioning ◽  
Station Keeping ◽  
Positioning Systems ◽  
Ice Conditions ◽  
Drifting Ice ◽  
External Loads

Dynamic Positioning Systems are used in numerous types of marine operations. Due to the important differences in the external loads acting on the vessel, standard DP systems may fail to perform in ice conditions. Moreover, specific principles and position keeping philosophies should be applied in ice covered waters. The objective of the paper is to elaborate on these aspects by presenting and analyzing full scale DP tests. These tests were a part of the station-keeping trials performed in March 2017 in drifting ice in the Bay of Bothnia. Control algorithms limitations of Standard DP Systems are presented, showing the necessity of new control principles. The importance of crew training is also demonstrated along with the approaches to keep position in ice.

Aspects of Importance Related to Arctic DP Operations

2012 ◽  
Author(s):  
Arne Gürtner ◽  
Bror Henrik Heier Baardson ◽  
Glenn-Ole Kaasa ◽  
Erik Lundin
Keyword(s):  
Boundary Conditions ◽  
New Technology ◽  
Open Water ◽  
The Arctic ◽  
Dynamic Positioning ◽  
Positioning Systems ◽  
Business Opportunities ◽  
New Business ◽  
Drifting Ice

International operators are seeking, investigating and pursuing new business opportunities in the Arctic. While operating in the Arctic, there will be a considerable need for vessels to keep their position during various operations which may include lifting, installation, crew change, evacuation, and maybe drilling. Opposed to open water, the drifting ice poses severe limitations as to how stationkeeping operations may be carried out. Dynamic positioning systems are currently developed aiding stationkeeping without mooring systems. There is a considerable need to enhance the open water DP systems for use in a new forcing environment. Essentially a new technology has to be developed with time. For that reason, considerable knowledge is required concerning current limitations and boundary conditions. This paper addresses some of the generic challenges related to DP operations in ice together with relevant learnings which are employed in mentioned DP enhancements.

Dynamic Positioning Observer Design Using Exogenous Kalman Filter

2019 ◽  
Author(s):  
Song An ◽  
Dengshuo Chen ◽  
Yong Bai
Keyword(s):  
Kalman Filter ◽  
Stability Property ◽  
Measurement Data ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Dynamic Positioning ◽  
Model Uncertainties ◽  
Process Noise ◽  
Second Stage ◽  
The Stability

Abstract Observer of a dynamic positioning (DP) system utilizes DP’s measurement data, to predict vessel’s velocities, positions, and unknown environmental forces on the vessel, as well as to handle model uncertainties and errors. Stability and optimality of a DP observer is important for overall DP performance. Nonlinear observer (NLO) designs usually take global asymptotic or exponential stability as the primary goal, and discard the noise. On the other hand, linearized Kalman filter (KF) algorithm, e.g. the extended Kalman filter (EKF), is optimal in minimizing the covariance of observer states by taking both measurement and process noise into account. The applied exogenous Kalman filter (XKF) algorithm in this paper, is a two-stage cascade of NLO and linearized KF, which uses the first-stage NLO estimated states as exogenous inputs for the second-stage linearized KF. XKF approach is proved to have both the stability property inherited from NLO and optimality from linearized KF. Stability and optimality of XKF based observer is studied through DP station-keeping numerical simulations.

Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements4

2009 ◽  
Vol 37 (4) ◽  
pp. 254-278 ◽  
Author(s):  
T. Freudenmann ◽  
H.-J. Unrau ◽  
M. El-Haji
Keyword(s):  
Experimental Determination ◽  
Test Bench ◽  
Measurement Data ◽  
Rolling Resistance ◽  
Surface Curvature ◽  
Operational Parameters ◽  
Combined Test ◽  
Modified Formula ◽  
New Formula

Abstract REFERENCE: Freudenmann, T., Unrau, H.-J., and El-Haji, M., "Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements," Tire Science and Technology, TSTCA, Vol. 37, No. 4, October - December 2009, pp. 254-278. Vehicle and tire manufacturers usually perform rolling resistance measurements on external drums with diameters of 1.71 or 2.0 m. The rolling resistance measured on these test benches is higher than the actual rolling resistance measured on a flat surface. This deviation is caused by the drums’ curvature. In 1979, S. K. Clark aimed to solve this problem by developing a formula, which converts the rolling resistance of a tire measured on a curved surface into the corresponding rolling resistance on a plane. This formula is still used today in ISO and SAE standards. To verify Clark’s universally accepted formula, a research project was initiated at the Universität Karlsruhe. A combined test bench that allows measurements on two external drums of different diameter and a continuous flat track with the same wheel suspension was built up and came into operation. The rolling resistances of six different tires on the three surfaces were measured under variation in operational parameters, such as tire load and inflation pressure. Comparison of converted values from measurements on external drums with flat track measurements showed the necessity for an upgrade of the existing formula. By conducting a multiple regression analysis, which took various tire properties and operational parameters into account, a modified formula was derived. Application of this new formula on the measurement data of the six tires as well as on further measurements showed excellent results.

Development and Validation of a Customizable DP System for a Full Bridge Real Time Simulator

2014 ◽  
Author(s):  
Asdrubal N. Queiroz Filho ◽  
Marcelo Zimbres ◽  
Eduardo A. Tannuri
Keyword(s):  
Real Time ◽  
Complete System ◽  
Dynamic Positioning ◽  
Station Keeping ◽  
Commercial System ◽  
System A ◽  
Important Requirement ◽  
Different Types ◽  
The One ◽  
Development And Validation

This paper presents the development and validation of a customizable Dynamic Positioning (DP) System for a real time full bridge simulator. The Maritime Waterway Simulator (SMH) was developed based on the code of the Numerical Offshore Tank (TPN) simulator. It is able to perform study of maneuvers feasibility and crew training. Many simulated operations such as oil offloading, pipe-laying, support to platforms or station keeping, require a DP system. In order to meet the demand for such a system, a complete system was developed with an important requirement in mind: The DP system of a full bridge simulator must be easily customizable for different types of vessels. In order to validate the developed DP system, a commercial DP system is used for comparison. DP operations with the vessel is conducted with both systems: the in house developed DP and the commercial one. The results obtained with the developed DP system are compared with the one obtained with the commercial system. This comparison demonstrates that the in-house DP system can indeed be used for simulating different types of DP vessels.

Insight into the Flow Within the Well Dock of a Mothership During Feeder Vessel Docking Manoeuvres

2020 ◽  
Vol 162 (A1) ◽  
Author(s):  
N T M Johnson ◽  
G J Macfarlane ◽  
J T Duffy ◽  
I Penesis ◽  
R J Ballantyne
Keyword(s):  
Measurement Techniques ◽  
Confined Water ◽  
Operational Parameters ◽  
Complex Flows ◽  
Sea Transport ◽  
Experimental Campaign ◽  
Feeder Vessel ◽  
Novel Concept ◽  
Optimum Solution ◽  
Insight Into

An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.

Temporary production at Xijiang field with a DP FPSO

2005 ◽  
Author(s):  
Hielke Brugts ◽  
Mireille Soeters ◽  
Max H. Krekel
Keyword(s):  
Dynamic Positioning ◽  
Production Operation ◽  
Station Keeping ◽  
Continue Production ◽  
Dry Dock ◽  
Cost Efficient ◽  
Temporary Production

The paper describes the successful mobilization of the FPSO Munin on the Xijiang field, offshore China, to continue production in the interval that the field’s permanent FPSO was in dry dock for maintenance. The project is unique in that the FPSO Munin relies solely on its Dynamic Positioning (DP) system for station keeping. The paper describes the background to the project and goes into detail on the challenges overcome in order to make it a success. By using the original riser system and by utilizing the FPSO Munin’s DP capability a fast and cost efficient mobilization was achieved that made the project worthwhile for all parties involved. The qualification of the DP system, the offshore installation and the production operation on Xijiang are described in detail. Other applications for DP production are addressed in order to demonstrate the potential of such operations.

Station-Keeping Trials in Ice: Ice and Metocean Conditions

2018 ◽  
Author(s):  
Sigurd Henrik Teigen ◽  
Joakim K. Lindvall ◽  
Ilija Samardzija ◽  
Roar I. Hansen
Keyword(s):  
Spatial Data ◽  
Ice Core ◽  
Ocean Current ◽  
Ice Thickness ◽  
Physical Parameters ◽  
Station Keeping ◽  
Sea Bed ◽  
Ice Drift ◽  
Ice Conditions ◽  
Drifting Ice

In March 2017, Statoil performed station-keeping trials in drifting ice in the Bay of Bothnia with the two anchor handling tug supply vessels Magne Viking and Tor Viking. During the trials observations of ice and metocean conditions were performed via a range of platforms and techniques. The purpose of the observations was to document the main physical parameters affecting the station-keeping vessel and ice management vessel, as well as giving tactical information on ice conditions and input to simultaneous numerical simulations. Measurements of meteorological parameters (wind speed, wind direction, air temperature, etc.) were done from the two vessels and supplemented with manual observations. Ice drift was independently measured by drifting ice trackers and ADCPs (also measuring ocean current) moored on the sea bed. Measurements of ice thickness were carried out with moored Ice Profiling Sensors (IPSs) and manual ice core samples, which were also analyzed for salinity and temperature profiles. The IPS ice thickness data was later processed together with the ice drift to provide 2D spatial data. The deepest ice ridge keels ranged from 5.4 m at the site with the most benign ice conditions to 10.9 m at the most severe site. Ridge frequency also increased from 2 ridges km−1 to 16 ridges km−1 at the most severe site (given a keel threshold of 3 m). In the present study, statistical summaries of the different time series collected at the sites of the station-keeping trials are presented, highlighting the variability in the ice conditions. Using the vessel tracks and overall drift of the broken channels, ice thickness and drift measurements are classified as being inside or outside the managed ice zone.

scholarly journals Application of omic technologies in cancer research

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Sarah Wagner ◽  
Graham R. Ball ◽  
A. Graham Pockley ◽  
Amanda K. Miles
Keyword(s):  
Cancer Research ◽  
Relevant Information ◽  
Dynamic Positioning ◽  
Data Handling ◽  
Therapeutic Approaches ◽  
Sample Throughput ◽  
Technological Developments ◽  
Insight Into ◽  
Complex Datasets

Understanding the biology of health and diseases such as cancer, generating insight into the triggers and potentiators of disease and the development of therapeutic approaches to counter and treat disease requires detailed interrogation of inherited genes, and the dynamic positioning of the transcriptome and proteome. In the last 10 years, significant technological developments and increases in sample throughput capabilities have led to a dramatic increase in the size and complexity of the datasets that can be generated. A key challenge now is to develop robust approaches for analysing and interpreting these, and converting data into biologically- and clinically-relevant information. Herein, we provide an overview of approaches for acquiring, integrating and interpreting complex datasets generated using multiple omic platforms, with a focus on the field of cancer research, and highlight key successful data handling and integration applications.

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