Research On Control Of MR Damper Based On Dynamics

As well-known, on account of runway irregularity factor, great impact load will give to aircraft during taxiing, the buffering of these load is mainly accomplished by the aircraft landing gear tires and landing gear shock absorber, and shock absorber plays a role of leading buffer effect. So aircraft landing gear shock absorber's damping performance directly affects the safety of the plane and comfort for passengers. At present, the civil aircraft landing gear shock absorber mainly adopts the traditional olec-pneumatic type, but this kind of shock absorber isn't fast enough to make real time control when great changes have taken place in external load. For the reason, the main research content goes to the following several aspects:Firstly, consulted the MR damper relevant literature and then summarized a series of model that are put forward by the experts in this field and divided these molds into three types:pseudo statics model, parametric model and nonparametric model and then got the analytic comparison between the advantages and disadvantages of each model and its feasibility in this paper.After that, combined with a kind of MR damper that designed by the research group and then do dynamic damping experiment in vibration test platform, it is concluded that the required output dates of force, acceleration, velocity, displacement and so on, combined with these data, adopted least squares identify several feasible model parameters and the various parameters is obtained respectively with the magnetic induction intensity(this paper converted into current) polynomial equation. At the same time, comparing the identification model curve with the experimental data curve in MATLAB software, comparison results show that a high degree of alignment between them.Then, analyzes the principle of aircraft landing gear shock and then put forward the hypothesis and established two degree of freedom gear system model and consult the aircraft model related material to determine the value of the known data. Compared the advantages and disadvantages, the feasibility and practicability of each control algorithm, selected the skyhook control algorithm as the MR damper semi-active control algorithmsn in this paper,considered to the landing gear smoothness and tire longitudinal throbbing Bode diagram of frequency characteristics determine the damping control coefficient of this algorithm, Thenaccording to the differential equation of control system model, the control thoughts, damping control coefficient and the equation of between identify the dynamic model parameters and the current, then set up the Simulink simulation platform and simulated. Compared with the passive control without control algorithm, the simulation results show that this control can effectively reduce the amplitude of the MR damper's displacement, velocity, acceleration and the maximum value all within the scope of the airplane landing gear shock absorber performance design requirements.Finally, get the actual throttling damping force of the oil hole based on the oil interpolation optimization under the pinhole sectional area curve then put it into the MATLAB/Simulink damping force input box according to the requirements of trip generation and got the real situation of the magnetorheological damper displacement, velocity and acceleration output value then comparing the sky-hook control output parameter values with the same incentives, the result showed that sky-hook control effect is superior to the passive control of this situation.