Study On Extraneous Force Compensation And Digital Control Algorithm Of Electro-Hydraulic Servo System

Electro-hydraulic servo system is widely used in various areas of national defense industry and national economy,with the fast response,high precision and powerful transmission.Cooperative control of electro-hydraulic servo system is a kind of important application among them.The principle of electro-hydraulic servo opposing cooperation control system is the same as the one of load simulator,which is the important ground experiment equipment for air vehicle design.The emphasis and difficulty of opposing cooperation control system is extraneous force.Electro-hydraulic servo opposing cooperation control system is made to be the research object.Based on digital control and its compensative technique of electro-hydraulic servo system, extraneous force is studied mainly as small force loaded.Domestic and foreign compensative methods of extraneous force are summarized. Electro-hydraulic force control scheme is comprehensively discussed.According to structure and motion feature of opposing cooperative control,the key problems of opposing cooperative control such as extraneous force are analyzed and provided firstly, and the main subjects and targets are drafted.Analytical and identifiable modeling methods are studied based on working principle and procedure of opposing cooperative control.Considering the nonlinear factors on the servo valve such as leakage of the cylinder and friction,power bond graph model is founded.Time domain,fi'equency domain and bond graph simulations of the position and force system are studied.Generating reasons of extraneous force are analyzed deeply,and characters of extraneous force are studied.Extraneous force and regulations are simulated and verified.Structure invariance compensation(SIC) method is the theoretical basis of extraneous force compensation.SIC calculates compensating flow according to speed of piston for extraneous force compensation in opposing cooperative control.Improved structure invariance compensation(ISIC) control scheme solves the uncertain factors in velocity estimation theoretically.ISIC compensates extraneous force effectively. Iterative learning ISIC is an intelligent ISIC control,which realizes the parameters optimization and tuning automatically for ISIC controller.Experiment results show modeling studies are correct,and Iterative learning ISIC compensates extraneous force effectively. Identifiable ZPETC algorithm is provided for position system of opposing cooperative control system.According to the results of system identification,dynamic compensation is designed in front of close loop.Identifiable ZPETC improves the dynamic performance of position system by zeros and poles cancellation.According to the request of digital controller,the controller based on principal-subordinate network topology structure including industry control computer and Ethernet is studied.The embedded operation system WinCE is adopted in the controller to improve the reliability of this control system.Matlab/RTW and VC++ mix-programmed technique is used to increase developing efficiency of control scheme. The control program implements the before-mentioned control schemes and achieves expectant results.