Study On Structural Optimization Of Aircraft Rudder Electro-hydraulic Load Simulator

The aircraft rudder electro-hydraulic load simulator is used as the main equipment for surface semi-physical simulation.The function of the simulator is to quickly and accurately reproduce the force load of the rudder during the flight of the aircraft.So that the static and dynamic technical indicators of the rudder can be checked and tested.The aircraft rudder electro-hydraulic load simulator is a passive servo loading system that uses electro-hydraulic integration technology.The passive motion of the loading system following the rudder will cause surplus force interference to the system,which will seriously affect the loading performance of the system.Therefore,research on the method of suppressing surplus force has an effect on improving the loading accuracy of the electromechanical fluid simulator of the aircraft rudder.Based on the current research status of aircraft servo electro-hydraulic load simulator at home and abroad,this paper first analyzes the structural composition and working principle of the electro-hydraulic load simulators,and establishes the mathematical model of the loading system.By analyzing the mechanism and characteristics of the surplus force,it was clarified that the main factors influencing the electro-hydraulic load simulator were the rigidity of the connecting mechanism,the internal cushioning performance of the hydraulic cylinder of the loading system,and the flow pressure variation of the two chambers of the hydraulic cylinder.The struct ural optimization design of electromechanical hydraulic load simulator provides a theoretical basis.Then,with the purpose of suppressing the interference of the surplus force,a variable-stiffness cylindrical coil spring is designed as a connection device,and the system can perform variable stiffness loading under different loading gradients.The hydraulic cylinder buffer mechanism is designed to improve the cushioning performance of the hydraulic cylinder.The compensation valve is designed in parallel with the loading servo valve to control the hydraulic cylinder,eliminating forced flow in the two chambers of the hydraulic cylinder during the loading process.Simulation experiments verify the feasibility and effectiveness of the structural compensation method to suppress the surplus force of the aircraft rudder electro-hydraulic load simulator.Finally,according to the designed structure of the simulator,the control structure and corresponding algorithm are designed by using CMAC neural network algorithm.Solved the problem of self-adaptiveness of the electro-hydraulic load simulator in the case of large changes in the frequency,amplitude,and loading gradient of the servo.