Specification for dp capability plots boat design net. For the latest guidance and information, please see. References 1 a guide to dp electrical power and control systems, imca m206, 2010, 2 dynamic positioning systems, rules for classification of ships, part 6, chapter 7, dnv, 2011. Director, commercial product quality management, gneroche 1 presentation outline. Assessment of station keeping capability of dynamic positioning vessels dnv gl as between vessels in case the same calculation method and environment are used for the vessels to be compared.
Capability plot in excel qi macros spc software for excel. Cpc special purpose vessel spv dynamic positioning duration. Capability plot in excel one of six charts created using qi macros capability suite create the same charts as minitabs capability sixpack for a fraction of the cost. Dynamic positioning capability analysis for marine. For more details of a specific plot, you can download the free trial of ncss 2019 by clicking here. Based on a vessel design we estimate external forces caused by wind, waves and current for every angle of attack.
Dpcap analysis can help determine the maximum environmental forces, in which the dp system can counteract in given headings. These capabilities are associated with the vessels dp class notations andor mission specific operational conditions. Hard copy dp capability plots relevant to the vessels areas of operations to be readily accessible to dpos at the dp control location. Barred zones for fully rotatable thrusters can limit the ultimate. Dnv gl dp capability standard clarity, consistency. For large samples, very likely, you will reject the normality assumption, though the underlying distribution may in fact be well modeled by the normal distribution. The thrust allocation algorithm implemented in the software is a quadratic.
If cp cpk the process is centered at the midpoint of the specification limits. Designcad 2d is an easy to learn cad applicationation. The calculation of a dynamic positioning capability plot for yachts in an early design stage american petroleum institute international marine contractors association american petroleum institute international marine contractors association. Results are displayed immediately to the user, and the application automatically generates a report. Like mentioned before the wave parameter are coupled to the wind speed. Dp capability analyses should be prepared for all dp vessels, regardless of dp equipment class. Jul 02, 2012 a dp capability plot is a polar plot that enables direct comparison of dp capability between a multiple operating modes of 1 ship or b between individual ships. This leads to a dp capability plot that provides a more realistic insight in the actual dp capability of the vessel in the dynamic environment. The calculation of a dynamic positioning capability plot for. Oct 19, 2010 hi firend im lookinf to findimca m 140 specification for dp capability plots could anyone help me. Position reference sensors, combined with wind sensors, motion sensors and gyrocompasses, provide information to the computer pertaining to the vessels position and the magnitude and direction of environmental forces affecting its position.
Dnv gl dp capability a new standard for assessment of the. A capability plot is just another way to visualize the capability of a process. Dynamic positioning capability analysis for marine vessels. The program calculates dp capability plots providing hull design, general arrangement, and thruster configuration. Dnvglst0111 assessment of station keeping capability of. The next level dp capability analysis dynamic positioning. This worst case failure is used in the consequence analysis. For example, if it is usual practice to always run the thrusters in a fixed mode then. Guidance is provided on dp capability plots in the abs guide for dynamic positioning systems and imca m140 rev 1, specification for dp capability plots. The position keeping capability of a dp vessel is determined with a dp capability analysis. Dynamic positioning capability analysis for marine vessels based. This level sets requirements for use of timedomain simulations and can be applied.
Dp capability level 1 will also be supported by a web based software application provided free of charge to the industry on the my dnv gl portal. Cp cpk pp ppk process capability analysis in excel. This promotes senselessly tight control limits, especially in cases where slight shifts in the process mean occur when an input parameter has been changed such as raw materials, setups, lots and so forth. The capability plot is located at the lower right corner of the betweenwithin capability sixpack report. Calculation of the dynamic positioning capability in time. The calculations use the beaufort wind scale as well as significant wave height, wave period and current speed data as input. Dynamic positioning dp is a computercontrolled system to automatically maintain a vessels position and heading by using its own propellers and thrusters. Process capability cpk and realtime spc software infinityqs.
Kongsberg maritime computer program statcap has been used for. Dp vessel and capability plot indicating the vessels station keeping ability. These plots are calculated from detailed information of the vessels hull and superstructure form and available thruster power. Capability plots of dynamic positioning in ice request pdf. Dp capability plots shall be generated for each level, and the result of the assessment is expressed as a dp capability number. Dp capability analyses are used to establish the maximum weather conditions in which a dp vessel can maintain its position and heading for a proposed thruster configuratioin. Static dp capability plot download scientific diagram. Dp capability plots are generated for each level, and the results of the assessment are expressed in a dp capability number with the format dp capabilitylx a, b, c, d. The betweenwithin interval represents the potential process tolerance and is calculated by six times the bw between and within standard deviation. Spc practitioners applying control charts to processes with high cpk 2. Dp operations guidance dynamic positioning committee. The blue line shows the maximum wind speed at which the dp system can maintain position and heading.
The application of dynamic positioning dp systems has been expanded significantly not only in the number of dp vessels, but also in the range of applications and the advancement of dp technologies. See on the left an example of the most used form to record a dp footprint. It provides an indication of station keeping ability in a common format. Online calculation tool for level 1, level 2 and level 2site dp capability assessments. This has been validated by the first formulation of capability plots in ice. Rules for classification and construction i ship technology. The capability plot is located at the lower right corner of the normal capability sixpack report. Below is a sample of many of the plots, charts, and graphs that can be produced in ncss statistical software. The statcap web service program provides customers with easy access to basic dp capability assessments.
The final remark is that the simple evaluating criteria for dp vessels are needed for showing the dp capability. Dp capability plots are generated for each level, and the results of. Compute capability indices if the process has an upper specification limit of 3. Access hundreds of 2d drafting and design tools through an intuitive interface to quickly and easily produce accurately scaled, precision designs. Example of a dp capability plot for level 1 including the intact condition and a combined plot for the worst case single failure wcsf condition karlsen et. Practical dp capability plot exercise oe44125 studeersnel. The capability plot is one of six charts created by qi macros capability suite.
The dp capability is characterised by the maximum wind speed for each wind direction. In order to address this variety and the needs of industry, abs undertook to develop an abs. The dp capability number indicates that the positionkeeping ability of the respective vessel can be maintained under the conditions defined for the respective capability level and all conditions. The portion of the distribution between the lower and upper bounds specified in specs is shaded in the plot. This section will teach you how to make a chart manually.
Dp abilities are naturally expected to be maximal when the ship is facing the ice drift with the bow or the stern. Dynamic positioning capability dpcap analysis is essential in the selection of thrusters, in their configuration, and during preliminary investigation of the positioning ability of a newly designed vessel dynamic positioning system. Dnv gl dp capability a new standard for assessment of. For each direction the maxiumum wind speed is differend because of the exposed length and shape of the vessel is not the same. Alternatively if model test data is not available, then a hydrodynamic computer program can provide the relevant forces. The traditional dp capability analysis dpcap as described in imca m140 is the current industrial standard for analyzing a vessels stationkeeping capability. The within interval represents the potential process tolerance and is calculated by six times the withinsubgroup standard deviation. A detailed description of the thrust allocation logic of the software program is. The dp capability number indicates that the positionkeeping ability of the respective vessel can be maintained under the conditions defined for the respective capability level and all conditions below, but not under the environmental conditions specified for the next higher dp capability number. The identified single failure mode in the dp system resulting in maximum effect on dp capability as determined through fmea study. Dp capability defines a dp vessels stationkeeping ability under given environmental and operational conditions. A uncapable process for potency assay cpk dp capability plot is a crucial tool developed to assess vessel ability to keep position and heading under certain environmental conditions. Dp capability plots should be calculated for the vessel. The capability analysis in figure 3 shows that with the lsl 37 and usl.
Rules i ship technology part 1 seagoing ships chapter 15 dynamic positioning systems section 1 general requirements and guidance. The type of measure you are plotting will decide what type of plot you choose to use. Dp capability level 1 will also be supported by a web based software. Specification for dp capability plots, imca m140, international. Process capability statistics for nonnormal distributions in r. How to construct a capability chartconstruct an spc chart using capchart software construct manually. Dp footprint verification is a common practice, well described in imca and mts guidelines, recommended by class see dnvrp 307 dp operation guidance, january 2011, paragraph 2. Dp capability analyses are used to establish the maximum weather conditions in which a dp vessel can maintain its position and heading for a proposed thruster. The results of the analyses are visualized in a polar plot, better known as a dp capability plot. Graphs for betweenwithin capability sixpack minitab.
Dp capability plots explained with examples offshore engineering. For example, if it is usual practice to always run the thrusters in a fixed mode then this has to be taken into account. In addition, the standard defines two dp capability assessment levels that allow the inclusion of sitespecific environmental data and external forces. Dp capability plot is a crucial tool developed to assess vessel ability to keep position and heading under certain environmental conditions. If cp and cpk are much greater than pp or ppk 33% greater, your process may not be stable enough to conduct a capability analysis. Download scientific diagram static dp capability plot from publication. This document contains a dp capability analysis for relume. Hence the results are presented in a dp capability plot which is exemplary shown in figure3. The construction of a capability chart is very straightforward. Process capability estimates and performance measures process capability ability of the process to realize a characteristic that will full l the requirements for that characteristic iso 255174 i. The program incorporates the thrust allocation algorithm used in the kpos dp system, to give realistic station keeping capability in the different scenarios analysed. Product quality management regulatory landscape and. In previous software releases, these values were properly displayed in the numeric view and dp operators were able to record and track footprint plot on their own forms as requested by the most of the dp operation manuals.
1225 1264 198 1089 381 966 85 51 1608 1563 1332 808 345 1136 448 1552 1073 1311 1559 252 646 1332 1523 1296 742 158 601 456 1311 213 1206 1586 771 905 964 108 1486 227 1184 770 773 758 15 1398