?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F583%2F&rft.title=Thruster+Allocation+for+Dynamical+Positioning&rft.creator=Poppe%2C+K&rft.creator=Bouwe+van+den+Berg%2C+J&rft.creator=Blank%2C+E&rft.subject=Environment&rft.subject=Energy+and+utilities&rft.subject=Discrete&rft.subject=Transport+and+Automotive&rft.description=Positioning+a+vessel+at+a+fixed+position+in+deep+water+is+of+great+importance+when+working+offshore.+In+recent+years+a+Dynamical+Positioning+(DP)+system+was+developed+at+Marin+%5B2%5D.+After+the+measurement+of+the+current+position+and+external+forces+(like+waves%2C+wind+etc.)%2C+each+thruster+of+the+vessel+is+actively+controlled+to+hold+the+desired+location.%0D%0AIn+this+paper+we+focus+on+the+allocation+process+to+determine+the+settings+for+each+thruster+that+results+in+the+minimal+total+power+and+thus+fuel+consumption.+The+mathematical+formulation+of+this+situation+leads+to+a+nonlinear+optimization+problem+with+equality+and+inequality+constraints%2C+which+can+be+solved+by+applying+Lagrange+multipliers.%0D%0AWe+give+three+approaches%3A+first+of+all%2C+the+full+problem+was+solved+using+the+MATLAB+fmincon+routine+with+the+solution+from+the+linearised+problem+as+a+starting+point.+This+implementation%2C+with+robust+handling+of+the+situations+where+the+thrusters+are+overloaded%2C+lead+to+promising+results%3A+an+average+reduction+in+fuel+consumption+of+approximately+two+percent.+However%2C+further+analysis+proved+useful.+A+second+approach+changes+the+set+of+variables+and+so+reduces+the+number+of+equations.+The+third+and+last+approach+solves+the+Lagrange+equations+with+an+iterative+method+on+the+linearized+Lagrange+problem.&rft.date=2010&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F583%2F1%2FAmst103.pdf&rft.identifier=++Poppe%2C+K+and+Bouwe+van+den+Berg%2C+J+and+Blank%2C+E++(2010)+Thruster+Allocation+for+Dynamical+Positioning.++%5BStudy+Group+Report%5D+++++