| A ship on sail is usually affected by various kinds of disturbance e.g. currents and waves. Thus sway motions are inevitable for the ship among which the influence of roll motion is the biggest. Fin stabilizers are the most applied widely traditional anti-roll equipments. However for the limit of the principles traditional anti-roll fin only can work normally on ships at high speed which cannot reduce roll motion effectively when ships are navigating at zero speed. In order to solve this problem effectively, researchers propose the conception of fin stabilizer at zero speed. Now the devices used practically have been designed successfully on the base of the theory. However, there are still inherent bad shortcomings. Among these problems the insufficient lift is the most difficult. The concept of transformative fin is creatively proposed by Ship Control Engineering Lab of HEU. The results of aeronautics are the reference. When the fin surface is rotating, transformative fin can generate enough lift..The development of anti-roll fin at zero speed is summarized at first in this paper, and then the working principle of transmutative fin stabilizer is analyzed. The numerical value of lift has a great effect on the anti-roll performance of transmutative fin. So the reasonable analysis of existed lift models is the point. Afterwards the thesis elaborates the structure and work mode of fin stabilizer.At present most designs of fin stabilizer controllers are based on Single-Chip Microcomputer and industrial PC. SCM's integration degree is low and its stability is poor, whereas the cost of the industrial PC is high. This scheme introduced currently broadly applied embedded system to the design of the new transmutative fin. The special embedded system is based on the microprocessor S3C2440(ARM920T) and the software is developed with Embedded Linux. We thoroughly analyze the hardware constitute of the platform, the system structure of S3C2440 processor, the composition and function of various modules. Next the circuit chart was given and we designed the power circuit, reset circuit and clock circuit. We built the embedded Linux cross-compiling environment and analyzed the principle of Linux core. Next we transplanted Linux into the platform. We researched system's graphic interface adopted QT technology and implemented driver programs such as ADC and LCD display driver.Traditional PID controller has outstanding advantage of simple structure, realizing simple and rude well, but the PID parameter usually needs to be settled by the experienced researchers. Actually the PID controller often cannot work well because of bad adjusting. In this paper we realized pair of parametric PID adjusting based on Genetic Algorithm. We built fitness function composing corresponding to performance index, so we can realize changing parametric adjusting process into optimization process. The results of simulation indicate that the control system based on Genetic Algorithm has a better performance in the optimization of parameters in complex system. Compared with the conventional method the system in this scheme has a better advantage in power and work efficency. The designed embedded controller of transmutative fin has a good performance-price ratio, a high integration density and has a friendly interface with strong anti-jamming capability and high real-time performance. |
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