China Ocean Engineering

, Volume 32, Issue 1, pp 90–98 | Cite as

Dynamic Positioning Capability Analysis for Marine Vessels Based on A DPCap Polar Plot Program

  • Lei Wang
  • Jian-min Yang
  • Sheng-wen Xu


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. DPCap analysis can help determine the maximum environmental forces, in which the DP system can counteract in given headings. The accuracy of the DPCap analysis is determined by the precise estimation of the environmental forces as well as the effectiveness of the thrust allocation logic. This paper is dedicated to developing an effective and efficient software program for the DPCap analysis for marine vessels. Estimation of the environmental forces can be obtained by model tests, hydrodynamic computation and empirical formulas. A quadratic programming method is adopted to allocate the total thrust on every thruster of the vessel. A detailed description of the thrust allocation logic of the software program is given. The effectiveness of the new program DPCap Polar Plot (DPCPP) was validated by a DPCap analysis for a supply vessel. The present study indicates that the developed program can be used in the DPCap analysis for marine vessels. Moreover, DPCap analysis considering the thruster failure mode might give guidance to the designers of vessels whose thrusters need to be safer.


DPCap analysis thrust allocation logic quadratic programming method 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. API, 1987. Analysis of Spread Mooring Systems for Floating Drilling Units, RP 2P-87, API.Google Scholar
  2. Børhaug, B., 2012. Experimental Validation of Dynamic Stationkeeping Capability Analysis: the Next Level DP Capability Analysis, MSc. Thesis, Norwegian University of Science and Technology, Trondheim.Google Scholar
  3. De Wit, C., 2009. Optimal Thrust Allocation Methods for Dynamic Positioning of Ships, MSc. Thesis, Delft University of Technology, Delft.Google Scholar
  4. Faltinsen, O.M., 1990. Sea Loads on Ships and Offshore Structures, Cambridge University Press, Cambridge.Google Scholar
  5. Faÿ, H., 1990. Dynamic Positioning Systems: Principles, Design and Applications. Technip, Paris.Google Scholar
  6. Gosman, A.D., 1999. Developments in CFD for industrial and environmental applications in wind engineering, Journal of Wind Engineering and Industrial Aerodynamics, 81(1-3), 21–39.CrossRefGoogle Scholar
  7. IMCA, 2000. Specification for DP Capability Plots, IMCA M140, International Marine Contractors Association.Google Scholar
  8. Johansen, T.A., Fossen, T.I. and Berge, S.P., 2004. Constrained nonlinear control allocation with singularity avoidance using sequential quadratic programming, IEEE Transactions on Control Systems Technology, 12(1), 211–216.CrossRefGoogle Scholar
  9. Kim, J.S., Hong, C.B., Lee, D.Y. and Ahn, S.M., 2009. Prediction of current load using computational fluid dynamics, Proceedings of the 28th International Conference on Ocean, Offshore and Arctic Engineering, American Society of Mechanical Engineers, Honolulu, Hawaii, USA.Google Scholar
  10. Leite, A.J.P., Aranha, J.A.P., Umeda, C. and De Conti, M.B., 1998. Current forces in tankers and bifurcation of equilibrium of turret systems: hydrodynamic model and experiments, Applied Ocean Research, 20(3), 145–156.CrossRefGoogle Scholar
  11. Mahfouz, A.B. and El-Tahan, H.W., 2006. On the use of the capability polar plots program for dynamic positioning systems for marine vessels, Ocean Engineering, 33(8-9), 1070–1089.CrossRefGoogle Scholar
  12. Molland, A.F. and Turnock, S.R., 2011. Marine Rudders and Control Surfaces: Principles, Data, Design and Applications, Butterworth-Heinemann, Oxford, UK.Google Scholar
  13. Morgan, M. J., 1978. Dynamic Positioning of Offshore Vessels, Petroleum Publishing Co., Tulsa, Oklahoma, USA.Google Scholar
  14. Newman, J.N., 1977. Marine Hydrodynamics, MIT Press, Cambridge, MA, USA.Google Scholar
  15. Pivano, L., Smogeli, Ø.N. and Vik, B., 2012. Dyncap–the next level dynamic DP capability analysis, Proceedings of the 2nd Marine Operations Specialty Symposium, MOSS, Singapore.Google Scholar
  16. Sørensen, A.J., 2011. A survey of dynamic positioning control systems, Annual Reviews in Control, 35(1), 123–136.CrossRefGoogle Scholar
  17. Sørensen, A.J. and Ronass, M., 2001. Mathematical modeling of dynamically positioned and thruster-assisted anchored marine vessels, in: El-Hawary, F. (ed.), The Ocean Engineering Handbook, CRC Press, Boca Raton.Google Scholar
  18. Vaz, G., Waals, O.J., Ottens, H., Fathi, F., Le Souëf, T. and Kiu K., 2009. Current affairs: Model tests, semi-empirical predictions and CFD computations for current coefficients of semi-submersibles, Proceedings of the 28th International Conference on Ocean, Offshore and Arctic Engineering, American Society of Mechanical Engineers, Honolulu, Hawaii, USA.Google Scholar
  19. Xu, S.W., Wang, X.F., Wang, L. and Meng, S., 2015a. Applying the bisection search method to search the maximum environmental conditions in dpcap analysis for marine vessels, International Journal of Offshore and Polar Engineering, 25(2), 104–111.Google Scholar
  20. Xu, S.W., Wang, X.F., Wang, L., Meng, S. and Li, B., 2015b. A thrust sensitivity analysis based on a synthesized positioning capability criterion in DPCap/DynCap analysis for marine vessels, Ocean Engineering, 108, 164–172.CrossRefGoogle Scholar
  21. Yadav, P., Kumar, R., Panda, S.K. and Chang, C.S., 2014. Optimal thrust allocation for semisubmersible oil rig platforms using improved harmony search algorithm, IEEE Journal of Oceanic Engineering, 39(3), 526–539.CrossRefGoogle Scholar
  22. Zhang, S., Wang, L., Yang, S.Z. and Yang, H., 2010. Numerical evaluation of wind loads on semi-submersible platform by CFD, Proceedings of the 29th International Conference on Ocean, Offshore and Arctic Engineering, American Society of Mechanical Engineers, Shanghai, China.Google Scholar

Copyright information

© Chinese Ocean Engineering Society and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.State Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghaiChina
  2. 2.Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE)ShanghaiChina

Personalised recommendations