In order to deal with the chattering of rudder angle and the problem of non-convex attainable thrust regions,introduce the concept of dynamic attainable region for each thruster and rudder to limit the thruster rotati...In order to deal with the chattering of rudder angle and the problem of non-convex attainable thrust regions,introduce the concept of dynamic attainable region for each thruster and rudder to limit the thruster rotational speed and the rudder angle,and decompose the thrust allocation optimization problem into several optimization sub-problems.The optimization sub-problems were solved by particle swarm optimization(PSO) algorithm.Simulation studies with comparisons on a model ship were carried out to illustrate the effectiveness of the proposed thrust allocation optimization method.展开更多
This article presents a method named pseudo-inverse to solve the optimal thrust allocation of dynamic positioning (DP) system,proposes to optimally determine the azimuth angle of thrusters instead of man-control or se...This article presents a method named pseudo-inverse to solve the optimal thrust allocation of dynamic positioning (DP) system,proposes to optimally determine the azimuth angle of thrusters instead of man-control or semi-auto control,and combines with the pseudo-inverse methods to get the optimal solutions for dynamic positioning control system.It is able to greatly reduce the risk of manual mode.Three different kinds of modes are proposed and detailedly illuminated,and can be used to solve much more complex nonlinear constraint problems,such as typical forbidden vector boundary.Several illustrative examples are provided to demonstrate the effectiveness and correctness of the proposed thrust allocation modes.展开更多
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 pos...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.展开更多
基金National Natural Science Foundations of China(Nos.51579026,51079013)Program for Excellent Talents in Universities of Liaoning,China(No.LR2015007)+1 种基金Project of Resource and Social Security of Ministry of Human Province,ChinaFundamental Research Funds for the Central Universities,China(No.3132016020)
文摘In order to deal with the chattering of rudder angle and the problem of non-convex attainable thrust regions,introduce the concept of dynamic attainable region for each thruster and rudder to limit the thruster rotational speed and the rudder angle,and decompose the thrust allocation optimization problem into several optimization sub-problems.The optimization sub-problems were solved by particle swarm optimization(PSO) algorithm.Simulation studies with comparisons on a model ship were carried out to illustrate the effectiveness of the proposed thrust allocation optimization method.
基金the National High Technology Research and Development Program (863) of China(No. 2008AA09Z315)
文摘This article presents a method named pseudo-inverse to solve the optimal thrust allocation of dynamic positioning (DP) system,proposes to optimally determine the azimuth angle of thrusters instead of man-control or semi-auto control,and combines with the pseudo-inverse methods to get the optimal solutions for dynamic positioning control system.It is able to greatly reduce the risk of manual mode.Three different kinds of modes are proposed and detailedly illuminated,and can be used to solve much more complex nonlinear constraint problems,such as typical forbidden vector boundary.Several illustrative examples are provided to demonstrate the effectiveness and correctness of the proposed thrust allocation modes.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51179103 and51709170)the 7th Generation Ultra Deep Water Drilling Unit Innovation Project and the Shanghai Sailing Program(Grant No.17YF1409700)
文摘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.
