Research On The P-Q Servo-Valve Controlled Electro-hydraulic Load Simulator Of Fin Stabilized

The electro-hydraulic load simulator of fin stabilizer is an equipment simulating water'power exerted on the fin stabilizer. Its function is to simulate different water'movement forces exerted on the fin stabilizer on different position so as to detect technical performance index of the driving system of fin stabilizer and 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 afects 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 and simplifies it. Theory analysis on control perpormance and relation to find out between structure parameter and control parameter provide theory base for improving control performance of the electro-hydraulic load simulator of fin stabilizer. Considering the static and dynamic performances of power elements, the mechanism and characteristics of surplus force is opened out. Analyzing effect factor of the surplus force and effecet function of surplus force on control performance seek for approach of overcoming surplus force and improving control performance.Driving elements of fin stabilizer are designed and the simulation about static dynamic 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 and loading gradient is analyzed. Using Structure Unchangeable Principle, control link is designed to eliminate surplus force and to improve the control performance of loading system.This dissertation put forward the scheme that P—Q servo valve control load simulator .Compared with flow servo valve. This control scheme has characteristic itself. It provides new method for the design of the electro-hydraulic load simulator of fin stabilizer.This dissertation adopts PID controller to control loading system controled by P-Q servo valve, and designs compensator with utilizing Structure Unchangeable Principle so as to compensate surplus flow and strain disturbance of surplus force and improve performance of the electro-hydraulic load simulator. Simulation indicate loading system controlled by P-Q servo valve ,under adjusting by PI adjustor and compensate surplus flow by compensator ,can obtain effective loading effect.