Research On The Electro-hydraulic Load Simulator Of Fin Stabilizer

The electro-hydraulic load simulator of fin stabilizer is 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 this dissertation, the author builds up mathematical model of the electro-hydraulic load simulator of fin stabilizer, obtaining the mechanism and characteristics of surplus force through analyzing the mathematical model of the electro-hydraulic load simulator. The conclusion is obtained that the surplus force is influenced by speed and acceleration of the electro-hydraulic load simulator.Driving elements of fin stabilizer are designed and the simulation about characteristics of surplus force, loading system with or without disturbance, static or dynamic state is done. The relationship between the dynamic characteristics of servo valve and loading system' s control performance, loading gradient and loading system' s control performance is analyzed. Using structure invariance principle,control link is designed to eliminate surplus force and to improve the control performance of loading system.This dissertation put forward a new control scheme to improve the control performance of load simulator . This control scheme which can bring the merit of the two kinds of servo valves into full play, use a pressure servo valve and a flow servo valve to control loading system. Compared with the other control scheme with loading platform controlled by single pressure servo valve, this control scheme has more merit and is a new method for the design of the electro-hydraulic load simulator of fin stabilizer. The experimental system is build up in this dissertation, by which we proceed the experimental research aiming at two structure schemes which are electro-hydraulic load simulator controlled by single pressure servo valve control and loading platform controlled by pressure and flow servo valves separately. It receives static and dynamic performances of fin stabilizer, which can prove that the methods advanced in this dissertation is effective for improving the comprehensive control performances of the electro-hydraulic load simulator . From the methods improving the control performance of the electro-hydraulic load simulator of fin stabilizer, we can draw the conclusions that these methods are fit for the rest passive loading system.