Research On Control Method Of Load System Of Fin Stabilizer

The electro-hydraulic load simulator of fin stabilizer is a physical half-objective simulative system. Its function is to simulate, under laboratory conditions, different kinds of hydrodynamic force exerted on the fin stabilizer so as to detect technical performance index of the driving system of fin stabilizer. Thus the classical self-destructing all-objective experiment will be converted to half-objective forecasting experiment in laboratory to achieve the aims such as shortening lead time, saving developing funds, enhancing reliability and success proportion. Along with the development of sea national defense and ship industry, the electro-hydraulic load simulator of fin stabilizer with high performances is urgently demanded. Because the electro-hydraulic load simulator of fin stabilizer is a kind of typical passive electro-hydraulic force servo system, the large surplus force caused by strong disturbance of the fin stabilizer displacement seriously affects the static and dynamic performances of the electro-hydraulic load simulator. Now the key point is how to eliminate the surplus force and improve the static and dynamic performances of the electro-hydraulic load simulator.After synthesizing numerous related literatures and reference materials home and abroad, the development of domestic and oversea electro-hydraulic loading system is summarized, and the merit and shortcoming is analyzed. The studying direction is decided through comparing domestic products and overseas products.In the dissertation, the principle of surplus force is analyzed in detail. It can be seen from formula derivation that surplus force has characteristics of high-order differentiate. Eliminating disturbance of surplus forces is an avenue to enhance loading performance. It should find out position and influence of loading gradient by analyzing mathematical model. Hence, gain of disturbance channel can be decided by loading gradient. The disturbance of surplus force is main cause of influencing little loading gradients, and original factors of loading system also influence them.Two methods can eliminate surplus force at now . One method is to settle surplus force through system structure, the other is to compensate them by using control strategy, and that the latter is adopted in the dissertation. Because traditional PID method can't adapt system parameter' variation and adjust parameter changes in time, the internal model control is put forward that has finer track performance, stronger robust and can restraint surplus force unmeasured better.We go along with simulation researches on characteristics of surplus force with disturbance and without disturbance, its dynamic and static performance. Exerting internal model control strategy on electro-hydraulic load simulator is to improve control performance. The experiments calibrate measuring component of electro-hydraulic load simulator of fin stabilizer. It can be proved that control method is effective to enhance system performance of electro-hydraulic load simulator of fin stabilizer.