Application Of Nonlinear And Delayed Feedback Control Theory On Landing Gear Structure

In the present paper,nonlinear vibration theory and time-delay active control theory are applied to design the nonlinear vibration suppression damper and active vibration control module of the landing gear structure.Firstly,the development of the landing gear structure is reviewed.The layout of landing gear structure and present problems are summarized.Correspondingly,the motivation of the present paper,research contents and innovation points are elaborated.The theoretical methods of this paper are introduced.Secondly,the unified model of the landing gear structure model is simplified and generalized.The single resonance and composite resonance laws of the model are obtained.The theoretical analysis is carried out to study the influence of the physical parameters of each small parameter on the stability of steady state motion.In addition,a method for system stability determination and calculation of time-delay stability interval is obtained.Then,the effects of different combinations of small physical parameters in the stability interval on the amplitude of the system are studied when the external excitation exists.For the case of 1:5 internal resonance,a nonlinear system landing gear model is designed to investigated the effect of time delay feedback gain coefficient and time delay on the damping in linear time-delay term.For the case of1:3 internal resonance,a nonlinear system landing gear model is designed to study the effects of combinations of time-delay orders and multiple time-delay terms on damping in general time-delay terms.The theoretical derivation and conclusions in the paper are verified by approximate analytical calculation and numerical simulation of MATHEMATICA software,which compared with WINPP software.The results of theoretical and numerical simulation are agree with well.