Research On Simulation Of Semi-Active Control For Aircraft Landing Gears During Landing Process

Landing gear is one of the important equipments in the aircraft structure, it can influence the aircraft during the process of takeoff, landing and taxiing. There are three control methods of aircraft landing gear: passive control, active control and semi-active control. The research and discussion presented in this paper are semi-active control technology applied on the aircraft landing gear.In this paper, dynamic analysis for landing gear landing is conducted for a large transportation aircraft, and dynamic equation of landing gear during landing process was established. The mathematical model and dynamic simulation of landing gear was established in the software ADAMS. From the simulation, we can get some parameter curves of landing gear. By analyzing these curves and the methods with two-masses model, the linear state equation of landing gear during landing process was established. According to the modern control theory, the stability and controllability of passive control landing gear were analyzed and the process of landing was simulated trough the simulation soft MATLAB. Simulation shows: the linear model can explain the characteristic of the passive control landing gear.The development of semi-active control technology and the equipment: magnetorhelogical fluids damps based in this technology were introduced. The discussion presented in this paper is this equipment applied on the aircraft landing gear. The semi-active controller was designed on landing gear system and the control algorithm is pole configuration, optimal control and BP neural network control. The semi-active control landing gear model was simulated trough the Simulation soft MATLAB and the simulation results were in contrast with the results of passive control model. The contrast curves show: in the semi-active control landing gear system the impact load and vibration can be reduced, the vibration time and extent were also reduced. The aircraft can reach the stability state in few seconds and the security and comfort of aircraft landing process were improved.