Song Lin Yang

Optimizing-Computation of Controlling Parameters of Intelligent Propulsion System of a Hydrofoil Sliding Craft Propelled by Adjustable-Pitch Screw

In this paper, VC++ serves as a workspace to establish the features of speediness and navigation speed controlling. A mathematical model of intelligent propulsion system of an adjustable-pitch-screw-propelled hydrofoil sliding craft was built up, and then applied the fuzzy-genetic algorithm (FGA), to program the optimizing-computing process of the best combination of the controlling parameters of the system. The optimizing result indicates that FGA is capable of optimizing-computing the model quite well, Since not only all the equation restriction conditions are satisfied at a degree of more than 99.99%, but also the in equation restriction conditions are also wholly satisfied, this method is good at dealing with the restriction condition and this program can also be used to primarily optimizing-design and analyze the system.

The FUZZY-D-P-GA of Navigation Performance and Structure Characteristic of Ships

The authors built up a new algorithm called FUZZY-D-P-GA which was based on the fuzzy optimization, the genetic algorithm, delicate variables’ segments thinking & parallel principle. Meanwhile, they also succeed in applying this composite method on the synthetically optimization of navigation performance and structure characteristic of ships. Through a large number of calculation, the results showed that this kind of algorithm had high efficiency and it was also reliable.

Optimization of Synthetical Fundamental Mechanics Properties of the High-Speed Monohull Vessel and its Method

Based on a kind of typical high speed monohull vessel, the paper discusses an integrate optimization’s method of Synthetical Fundamental Mechanics Characteristic with the materials of some ships and some relevant experience expressions. The authors use the weighted sum of rapidity, sea-keeping ability and maneuverability as the sub-objective function of ship performances; use the weighted sum of static and dynamic properties as the sub-objective function of structural mechanics properties; The weighted sum of these 2 sub-objective functions is just the general objective function. Stability, buoyancy and some other characteristics as well as limits of design variables form the constraint conditions. The mathematic model shows that the synthetical optimization of mechanics properties for ships involves at least 49 design variables, 9 equation constraints and 5 inequality constrains. Evidently, it’s a very complicated engineering optimization. The data was gained after this algorithm(DP- genetic chaos algorithms) had applied to optimize integrate the performance of navigational performance and structure characteristic by VC++, quantities of computation results of different solving methods show that compared with other methods such as GA, chaos algorithm and their parallel algorithms, this complex algorithm can overcome GA’s premature convergence and is reliable and efficient. Above all, the software is programmed. Using this software can conveniently get the possibility distributing function of integrate optimum navigation performance of each design variables, and can provide the condition to integrate evaluation of the ship design project and the integrate decision-making of ship parameters.

Primary Research on Trimaran Unmanned Vessels

Unmanned surface vessel (USV) which is an unmanned and intelligent platform which relied on remote control or autonomous navigation. Compared with conventional surface vessels, USV has many merits such as variegated function, flexibility of operations, zero injury and network information center. Trimaran is a kind of high-speed-crafts, and has broad application for military and civilian market. Here, we develop and design a modular platform of Trimaran unmanned vessels, an unmanned vessels model data acquisition and analysis system. Through the model test of maneuverability and rolling, we validated the feasibility that Trimaran unmanned vessel model test data apply to identify ship rolling motion and maneuverability motion.

Model-Based Synthetical Optimization Analysis on Navigation Performance of Unmanned Surface Vehicle

Unmanned Surface Vehicle (USV) has very complex forces and states when sailing at sea. While the optimization of USV via regression equations usually has a lower precision. Rapidity and seakeeping tests have been conducted based on a USV model of JUST. The rapidity test is mainly ship model resistance test and the seakeeping tests include wave added resistance test, hydrostatic pitching test, pitching and heaving test under the wave. Response surfaces fitting vectors of rough water resistance, pitching significant value, heaving significant value is established while using VC++ language to write second-order response surface fitting programs after dimensionless conversion of test data. Mathematical model of USV navigation performance synthetical optimization is proposed, including systems of rapidity, maneuverability and seakeeping. A layered parallel genetic algorithm (L-P-GA) optimization program is written in VC++ language, which can optimize a variety of conditions with different design speed and displacements. The results indicate that the optimization method has a higher precision and it can provide an opportunity to optimize the navigation performance of USV effectively.

Comprehensive Evaluation of the Designing Scheme of AUV Platform Performance by AHP Method

This paper divides the platform performance into three different aspects: general characteristics, hull property and concealment performance, from which we fully study the various factor index involved, use the AHP to build an integrated-assessed mathematic model of hierarchy of good distinct and structure of high efficiency and calculate the weight assessment indicator of each hierarchy. This paper uses AHP to build the general objective function of the designing scheme of platform property. By the statistical analysis of the tip of various property indexes of mass hull property data, we choose the corresponding subordinating degree functions in the fuzzy mathematic field to determine the appropriate subjection function, calculate the relevant degree of membership, and finally conduct the integrated assessment of mathematic model of the design of AUV platform performance system. We use C# language in the developing environment of VS2010 to develop the fuzzy-comprehensive-assessment software system of the designing scheme of AUV platform, and, we also use the software to analysis the systematic reliability of this scheme by living example. Through this work, we could offer a scientific and rational theory of technology for the support of underwater unmanned vehicle research department.

ANALYSIS ON THE ROLLING MOTION MODE OF NEW FLOATING OBJECTS COLLECTING TRIMARAN

In this article,to make this new trimaran work better,the author made an experimental research on the rolling motion mode of the new trimaran under different drafts,using MTi Micro AHRS System to measure the free damping angular velocity curve.And with system identification based on optimization,the author conducted the identification of rolling motion mode,which verified the feasibility of this method.Using optimization calculation and Genetic Algorithm,the author obtained the rolling motion differential equation of the ship model under different drafts.Furthermore,the author investigated the variation of hydrodynamic coefficients.The research method and results could give technical support to indepth research and designing and development of the rolling motion of this kind of trimaran.

Simulation of Viscous Flow around Surface Ship Using ANSYS-Fluent CFD Code

In this paper, numerical simulations have been carried out to determine the incompressible free surface flow around a Wigley hull form for which experimental results are available. A commercial viscous flow finite volume code using the two-phase Eulerian-Eulerian fluid approach has been used in this study. The simulation conditions are the ones for which experimental results exist. The shear stress transport (SST) turbulence model has been used in the viscous flow code. A structured grid was used with the viscous flow code for meshing the computational domain. The results compare well with the available experimental data, which make their complementary application useful for determining the total ship resistance.

System Identification of Unmanned Planning Boat Rolling Motion Mode

In this paper, the author took an unmanned planning boat as the object of study and carried out a series of rolling decay ship model test by changing the draft. The author established nine kinds of mathematical model of rolling decay motion model system identification by using different damping and righting moment and established the optimization calculation of the objective function based on the principle of system identification. Then the author adapted the genetic algorithm of system identification program which is based on the Visual Basic 6.0 and got 15 kinds of identification programs. By doing research on the first three cycles of the series of rolling angular velocity curve and identifying respectively the resulting 15 kinds of identification programs, the author confirmed the feasibility of the adapted program. Comparing different drafts and the initial roll angle identification results, the author found a reasonable hydrostatic roll motion equation of the unmanned planning boat in the case of different drafts and the initial roll angle, and made a preliminary analysis.

Preliminary Study on Maneuvering Motion Pattern of Unmanned Composite Trimaran Ship Model

The composite trimaran is characterized by adding the hydrofoils with different aspect ration in the main hull and sides of the conventional trimaran hull. Regarding the programmable automatic controller as the core, the paper designed the unmanned intelligent control system of the composite trimaran ship model, used VB.NET language to design the maneuverability simulation platform on MMG. And designed six rudder blades with different aspect ratio, and carried out a series of manipulation turning tests of the ship model under different speed and rudder angle. Through comparing with experimental data and the simulation results, it has verified the reliability of the simulation platform. Then with the system identification methods, the paper has discussed the aspect ratio of the rudder which has influence on the manipulation rotary motion of the composite trimaran ship model, and the manipulation rotary performance of the composite trimaran ship model in different speed and rudder angle.