Research On The Working Condition Simulation System Of Reciprocating Sealing For Aircraft Actuators

As a key component of aircraft hydraulic system,the actuator has a direct impact on the efficiency and safety of the aircraft.Therefore,it is of great importance to study the reciprocating sealing performance of the aircraft actuator.In this paper,the characteristics of the working condition simulation system for aircraft actuators are analyzed,and the mathematic models of the pressure impulse system,the dynamic model of multi-cylinder synchronous motion and thermodynamics model are established to realize the three conditions,high pressure,wide temperature and variable load respectively.Corresponding to the requirements of the three subsystems,various controllers are developed,and simulation and experimental study is carried out.The research mainly includes the following parts:Chapter 1:Introduction.The research background of the reciprocating sealing test system for aircraft actuators is introduced,and the research status at home and abroad is presented.The characteristics and key technologies of the simulation system of the three working conditions are analyzed,and then the research objectives and significance are pointed out.Chapter2:Characteristic analysis of the pressure pulse simulation system.The composition and principle of the pressure impulse simulation system are introduced,and the mathematical model including the pump source is established.In order to guarantee the transient and steady state performance of the pressure impulse,a sliding mode PID hybrid controller based on fuzzy switching is proposed and developed.Simulation and experimental results show that the sliding mode PID hybrid controller based on fuzzy switching is more effective than the fuzzy PID controller and the conventional PID controller,and its ITAE index is reduced by more than 200%,and the waveform adaptive ability is stronger.Chapter3:Multi-cylinder synchronization analysis of the load simulation system.The principle of the load simulation system is introduced.The dynamic model of the load is established by considering the Stribeck characteristics of the friction force,and the experimental identification method of the friction model parameters is put forward.Aiming at the obvious characteristic of one servo valve controlling parallel multi-cylinders,the factors influencing the multi-cylinder synchronization are analyzed.In order to reduce the synchronization error of multi-cylinders,a synchronization controller based on bias coupling is developed.Simulation and experimental results show that the synchronization control based on deviation coupling can effectively reduce the synchronization error of "one valve controlling multi-cylinders".Chapter4:Thermal characteristics analysis of the temperature simulation system.The composition of the temperature simulation system is introduced.The thermodynamic model of the system is established by the control volume method,and the thermal characteristics of the hydraulic components of the system are analyzed.In order to ensure the steady state precision and the dynamic tracking effect of the oil temperature of the system,an intelligent temperature controller based on double-controller is designed.Simulation and experimental results show that the temperature controller based on double-controller can reduce the overshoot of temperature effectively and make the temperature stable quickly,The steady state error is within±1?.Chapter5:Summary and prospect.The research progress and results of the working condition simulation system of the reciprocating sealing for aircraft actuator are summarized,and the direction and development of the future research work is proposed.