Thrust allocation algorithm with efficiency function dependent on the azimuth angle of the actuators

Author(s)

Arditti, F. ^[1] ; Souza, F. L. ^[1] ; Martins, T. C. ^[1] ; Tannuri, E. A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Mechatron Engn Dept, BR-05508010 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: OCEAN ENGINEERING; v. 105, p. 206-216, SEP 1 2015.
• Web of Science Citations: 1

Abstract

The Dynamic Positioning System is responsible for the station keeping of the vessel in a variety of offshore operations. The thrust allocation algorithm distributes the required forces among the available thrusters of the vessel accurately whilst optimizing the power consumption. Recent experimental studies and Computational Fluid Dynamics (CFD) simulations have shown that hydrodynamic interaction effects affect the thrust generation. Therefore, the allocation algorithm can be improved if these interactions are considered, using the thrusters efficiency functions in the formulation of the optimization problem. The result of this implementation is a nonlinear optimization problem, solved by a modified Sequential Quadratic Programming technique. The numerical simulations and experimental tests demonstrated a power reduction between 2% and 5% when the proposed thrust allocation algorithm is compared with a forbidden zone allocation (does not allow positioning the thrusters in directions with severe hydrodynamic interactions). The experimental results highlight the advantages of taking the hydrodynamic interactions into account in the thrust allocation algorithm. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 10/11903-3 - Thrust allocation algorithm for DP systems considering the interference between thrusters and thrust-hull
• Grantee: Felipe Arditti
• Support Opportunities: Scholarships in Brazil - Scientific Initiation