摘 要

耙吸挖泥船海上作業(yè)要求保持在特定區(qū)域或者按照預(yù)定軌跡航行，這些工作需要有性能良好的動力定位系統(tǒng)來保證。隨著耙吸挖泥船深海作業(yè)的不斷深入，對動力定位技術(shù)的指標要求也越來越嚴格。本課題是江蘇省科技廳重大成果轉(zhuǎn)化項目，文中以某大型耙吸挖泥船為研究背景，結(jié)合實際工程應(yīng)用針對耙吸挖泥船定點定位（DP）和動態(tài)循跡（DT）兩種功能下控制器設(shè)計進行探討和研究，論文主要包括以下幾個方面的工作：
針對耙吸挖泥船DP-艏噴工作模式在零航速下建立DP低頻運動模型，模型建立過程中詳細闡述了艏噴作業(yè)產(chǎn)生的反推力的補償方法。針對DT-疏浚和DT-航行工作模式在一定航速下建立DT低頻運動模型，在循跡過程中分析船體阻力以及疏浚作業(yè)時耙臂產(chǎn)生的拖曳力，并建立其計算模型。同時為滿足控制器設(shè)計需要，建立了風(fēng)浪流等環(huán)境干擾力模型。
針對耙吸挖泥船DP控制器設(shè)計，結(jié)合工程應(yīng)用，采用增量式數(shù)字PID控制算法。由于PID控制算法目前還廣泛應(yīng)用于船舶控制系統(tǒng)中，并且適合低頻運動控制，在零航速情況下，各自由度方向可以解耦進行分析。文中依據(jù)PID控制算法思想對耙吸挖泥船三個自由度設(shè)計獨立的控制器，并且編寫MATLAB程序仿真平移作業(yè)時的定位效果。仿真效果表明：采用增量式數(shù)字PID控制算法具有良好的控制效果，可以很好的對耙吸挖泥船進行定點定位控制，能夠滿足實際作業(yè)需要。
針對耙吸挖泥船DT-疏浚模式，結(jié)合常規(guī)航跡控制策略和“視線”（LOS）控制策略，根據(jù)偏差大小范圍采用分區(qū)控制策略對航跡控制進行分析。同時考慮到在疏浚過程中變吃水情況，系統(tǒng)模型參數(shù)處于不斷變化狀態(tài)，因此在DT-控制器設(shè)計部分充分考慮模型的不確定性因素，運用模糊PID控制算法作為實際工程應(yīng)用方法。在認真總結(jié)和分析實船工作人員經(jīng)驗的基礎(chǔ)之上，制定相應(yīng)模糊控制規(guī)則，結(jié)合分區(qū)控制思想設(shè)計DT控制器。此外，采用MATLAB中模糊工具箱和Simulink對DT疏浚工作模式在不同工況下對比分析實際控制效果。仿真結(jié)果顯示：在分區(qū)控制策略下結(jié)合模糊PID控制算法，能夠獲得更好的系統(tǒng)動態(tài)性能，更重要的是能夠提高疏浚精度，具有實際工程價值。

關(guān)鍵詞 耙吸挖泥船；動力定位系統(tǒng)；PID算法；變吃水；模糊PID




Abstract

Trailing suction hopper dredger required keeping at the fixed zone or navigation with a predefined track while dredging at sea, all these functions should guaranteed by a good performance Dynamic Positioning system. With the deepening of deep-sea operation, the strict indicators of dynamic positioning technology for Trailing suction hopper dredger are increasing improved. This issue is a major technology achievement conversion project of Jiangsu province, here have a research on Dynamic Positioning or Tracking system controller design, combined with the application of actual project based on Trailing suction hopper dredger. This thesis contains the following parts:
Towards the rain-bowing mode of Dynamic Positioning, constructed the DP low frequency model for TSHD while the speed of the hull near to zero. During the process introduced the compensation method of anti-resistance while rain-bowing operation. For DT-dredging and DT-navigation mode under a certain speed, established the DT low frequency motion model, analyzed the hull resistance and the rake arm drag force which generated 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 and other environmental interference were constructed.
Towards the DP controller for TSHD, here used the PID algorithm as the main control algorithm. As the PID control algorithm is still widely used in ship control systems, and is suitable for low-frequency motion control, also the three degrees of freedom of TSHD motion can be decoupled into three independent parts to analysis. So in the thesis designed three independent controllers based on PID algorithm. Moreover, compiles the program under the circumstance of MATLAB to see the effect of the corresponding controller. Simulation results show that the incremental digital PID control algorithm has a good control effect, well done on Trailing suction hopper dredger for fixed positioning control, to meet operational needs.
Towards the DT-dredging mode, according to the deviation of the cross-error, in order to control hull followed a predefined path, here used sub-control strategies which combined with 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 design of DT controller. So the fuzzy PID control algorithm is used as a practical application method. After a careful summary and analysis of ship based on staff experience, to develop appropriate fuzzy control rules, combined with the sub-control design ideas to design the DT controller. In addition, the use of fuzzy toolbox in MATLAB to do simulation of different operation conditions and analysis the actual control effects during dredging. Simulation results show that sub-control strategy with fuzzy PID control algorithm can obtain better system dynamic performance, more importantly, to improve dredging accuracy, has the actual project value.

Keywords Trailing..