Control Algorithm Research Of Dynamic Positioning And Tracking System For Trailing Suction Hopper Dredger

Trailing suction hopper dredger required keeping at the fixed zone or navigation with apredefined track while dredging at sea, all these functions should guaranteed by a goodperformance Dynamic Positioning system. With the deepening of deep-sea operation, thestrict indicators of dynamic positioning technology for Trailing suction hopper dredger areincreasing improved. This issue is a major technology achievement conversion project ofJiangsu province, here have a research on Dynamic Positioning or Tracking systemcontroller design, combined with the application of actual project based on Trailing suctionhopper dredger. This thesis contains the following parts:Towards the rain-bowing mode of Dynamic Positioning, constructed the DP lowfrequency model for TSHD while the speed of the hull near to zero. During the processintroduced the compensation method of anti-resistance while rain-bowing operation. ForDT-dredging and DT-navigation mode under a certain speed, established the DT lowfrequency motion model, analyzed the hull resistance and the rake arm drag force whichgenerated by the process while dredging, also established the calculation model. Meantime,in order to meet the needs of controller design, the model of wind, wave and current andother environmental interference were constructed.Towards the DP controller for TSHD, here used the PID algorithm as the main controlalgorithm. As the PID control algorithm is still widely used in ship control systems, and issuitable for low-frequency motion control, also the three degrees of freedom of TSHDmotion can be decoupled into three independent parts to analysis. So in the thesis designedthree independent controllers based on PID algorithm. Moreover, compiles the programunder the circumstance of MATLAB to see the effect of the corresponding controller.Simulation results show that the incremental digital PID control algorithm has a goodcontrol effect, well done on Trailing suction hopper dredger for fixed positioning control, tomeet operational needs.Towards the DT-dredging mode, according to the deviation of the cross-error, in orderto control hull followed a predefined path, here used sub-control strategies which combinedwith conventional control strategies and line of sight (LOS) control strategy. Furthermore,the draft of the hull is changing during dredging process, the system model parameters also are changing constantly, so the full uncertainties should be taking into account in the designof DT controller. So the fuzzy PID control algorithm is used as a practical applicationmethod. After a careful summary and analysis of ship based on staff experience, to developappropriate fuzzy control rules, combined with the sub-control design ideas to design theDT controller. In addition, the use of fuzzy toolbox in MATLAB to do simulation ofdifferent operation conditions and analysis the actual control effects duringdredging. Simulation results show that sub-control strategy with fuzzy PID controlalgorithm can obtain better system dynamic performance, more importantly, to improvedredging accuracy, has the actual project value.