Research On Electro-hydraulic Servo Simulation Loading System Of Aircraft Landing Gear

The electro-hydraulic servo loading system of aircraft landing gear is used to simulate the aerodynamic loads on the landing gear during takeoff and landing of the aircraft to test the performance of the airborne system when it receives the air loads.It is an important part of the aircraft ground simulation test bench.This paper introduces the development and research status of electro-hydraulic servo loading system,and the research status of research methods to reduce surplus torque.First of all,this paper mainly studies some problems in the mechanism part of the loading system,including the selection of loading points for the front support,the design and verification of the loading rocker arm,and the layout of the mechanism part of the loading system.The hydraulic part is also introduced,including the selection of components,the design of hydraulic schematics and other issues.Secondly,the loading circuit is simulated and analyzed in AMESim.The simulation model of loading system and carrying system is established in AMESim,and the causes and influencing factors of the surplus torque are analyzed.The loading effect of the system under PID control is studied.Then,based on the principle of structural invariance,the speed-dependent feed-forward compensation is added to the loading system control signal to reduce the excess force.The simulation results in AMESim show that the control effect is improved to some extent.Finally,combined with the simulation results of AMESim and the Fourier series expansion theorem,the frequency of the surplus torque generated by the loading system is analyzed,and the PID+speed feed-forward method is improved.The joint simulation model of AMESim and MATLAB is established.The PID + modified feed-forward method is applied to the loading system.The experimental results are verified by the pair of top cylinders test platform in the hydraulic laboratory of Yanshan University.The experimental results are in agreement with the simulation results,indicating that the model study is correct,and the modified speed feed-forward + PID control can effectively reduce the surplus torque.