scholarly journals Experimental Validation for the Performance of MR Damper Aircraft Landing Gear

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 272
Author(s):  
Bang-Hyun Jo ◽  
Dae-Sung Jang ◽  
Jai-Hyuk Hwang ◽  
Yong-Hoon Choi

The landing gear of an aircraft serves to mitigate the vibration and impact forces transmitted from the ground to the fuselage. This paper addresses magneto-rheological (MR) damper landing gear, which provides high shock absorption efficiency and excellent stability in various landing conditions by adjusting the damping force using external magnetic field intensity. The performance and stability of an MR damper was verified through numerical simulations and drop tests that satisfied aviation regulations for aircraft landing gear. In this study, a prototype MR damper landing gear, a drop test jig, and a two-degree-of-freedom model were developed to verify the performance of the MR damper, with real-time control, for light aircraft landing gear. Two semi-active control algorithms, skyhook control and hybrid control, were applied to the MR damper landing gear. The drop tests were carried out under multiple conditions, and the results were compared with numerical simulations based on the mathematical model. It was experimentally verified that as the shock absorption efficiency increased, the landing gear’s cushioning performance significantly improved by 17.9% over the efficiency achieved with existing passive damping.

2021 ◽  
Vol 12 (1) ◽  
pp. 400
Author(s):  
Quoc-Viet Luong ◽  
Bang-Hyun Jo ◽  
Jai-Hyuk Hwang ◽  
Dae-Sung Jang

This paper adopts an intelligent controller based on supervised neural network control for a magnetorheological (MR) damper in an aircraft landing gear. An MR damper is a device capable of adjusting the damping force by changing the magnetic field generated in electric coils. Applying an MR damper to the landing gears of an aircraft could minimize the impact at landing and increase the impact absorption efficiency. Various techniques proposed for controlling the MR damper in aircraft landing gears require information on the damper force or the mass of the aircraft to determine optimal parameters and control commands. This information is obtained by estimation with a model in a practical operating environment, and the accompanying inaccuracies cause performance degradation. Machine learning-based controllers have also been proposed to address model dependency but require a large number of drop test data. Unlike simulations, which can conduct a large number of virtual drop tests, the cost and time are limited in the actual experimental environment. Therefore, a neural network controller with supervised learning is proposed in this paper to simulate the behavior of a proven controller only with system states. The experimental data generated by applying the hybrid controller with the exact mass and force information, which has demonstrated high performance among the existing techniques, are set as the target for supervised learning. To verify the effectiveness of the proposed controller, drop test experiments using the intelligent controller and the hybrid controller with and without exact information about aircraft mass and force are executed. The experimental results from the drop tests of a landing gear show that the proposed controller maintains superior performance to the hybrid controller without using explicit damper models or any information on the aircraft mass or strut force.


2020 ◽  
Vol 10 (17) ◽  
pp. 5962 ◽  
Author(s):  
Quoc Viet Luong ◽  
Dae-Sung Jang ◽  
Jai-Hyuk Hwang

A typical oleo-pneumatic shock-absorbing strut (classic traditional passive damper) in aircraft landing gear has a metering pin extending through the orifice, which can vary the orifice area with the compression and extension of the damper strut. Because the metering pin is designed in a single landing condition, the traditional passive damper cannot adjust its damping force in multiple landing conditions. Magnetorheological (MR) dampers have been receiving significant attention as an alternative to traditional passive dampers. An MR damper, which is a typical semi-active suspension system, can control the damping force created by MR fluid under the magnetic field. Thus, it can be controlled by electric current. This paper adopts a neural network controller trained by two different methods, which are genetic algorithm and policy gradient estimation, for aircraft landing gear with an MR damper that considers different landing scenarios. The controller learns from a large number of trials, and accordingly, the main advantage is that it runs autonomously without requiring system knowledge. Moreover, comparative numerical simulations are executed with a passive damper and adaptive hybrid controller under various aircraft masses and sink speeds for verifying the effectiveness of the proposed controller. The main simulation results show that the proposed controller exhibits comparable performance to the adaptive hybrid controller without any needs for the online estimation of landing conditions.


2019 ◽  
Vol 894 ◽  
pp. 29-33
Author(s):  
Luong Quoc Viet ◽  
Jai Hyuk Hwang

The magnetorheological (MR) damper is the newest approach to replace the traditional passive damper which cannot change their dynamics in response to different operating conditions of the aircraft landing gear. This paper presents the simulation study of a semi-active controller for a landing gear equipped MR damper. Furthermore, a new method combined skyhook control with force control, called hybrid control, is developed to improve the performance of the MR damper landing gear. Finally, the numerical simulation result of the landing gear using SIMSCAPE-Simulink is discussed.


2014 ◽  
Vol 665 ◽  
pp. 601-606
Author(s):  
Xiao Chuan Liu ◽  
Shi Xing Zhu ◽  
Yong Gang Yang

The structure of a shock absorber based on magnetorheological (MR) damper with a metering pin is proposed, and structure of the magnetic circuit of MR damper is optimized. By drop tests, the damping characteristics of the shock absorber and damping effect are tested. The experimental results show that the shock absorber has the characteristic of a wide damping force adjustment range and lower energy dissipation. The maximum vertical load and shock absorber piston displacement can be changed at same drop height by changing the current. It has also been proved that shock absorber based on MR damper is better than conventional oleo-pneumatic shock absorber on adjustment of damping force.


2015 ◽  
Vol 63 (3) ◽  
pp. 745-757 ◽  
Author(s):  
W. Krason ◽  
J. Malachowski

Abstract Dynamic analyses of a transport aircraft landing gear are conducted to determine the effort of such a complex system and provide capabilities to predict their behaviour under hazardous conditions. This kind of investigation with the use of numerical methods implementation is much easier and less expensive than stand tests. Various 3D models of the landing gear part are defined for the multistage static FE analysis. A complete system of the main landing gear was mapped as a deformable 3D numerical model for dynamic analysis with the use of LS-Dyna code. In this 3D deformable FE model, developed in a drop test simulation, the following matters were taken into consideration: contact problems between collaborating elements, the phenomena of energy absorption by a gas-liquid damper placed in the landing gear and the response of the landing gear during the touchdown of a flexible wheel with the ground. The results of numerical analyses for the selected drop tests and the results from the experiments carried out on a real landing gear were used for verification of FE models and a methodology of the landing gear dynamics analysis. The results obtained from the various simulations of the touchdown have proved the effectiveness of the 3D numerical model and how many problems can be solved in the course of only one numerical run, e.g. geometric and material nonlinearities, a question of contact between the mating components, investigation of the landing gear kinematics, investigation of the energy dissipation problem in the whole system and the stresses influence on the structure behaviour, which can appear in some elements due to overload.


2014 ◽  
Vol 61 (2) ◽  
pp. 287-304 ◽  
Author(s):  
Romeo Di Leo ◽  
Angelo De Fenza ◽  
Marco Barile ◽  
Leonardo Lecce

Abstract This work deals with the effectiveness of a multi-body approach for the study of the dynamic behavior of a fixed landing gear, especially the research project concerns the drop tests of the AP.68 TP-300 aircraft. First, the Digital Mock-up of the of landing gear system in a C.A.D. software has been created, then the experimental structural stiffness of the leaf spring has been validated using the FEM tools MSC. Patran/Nastran. Finally, the entire model has been imported in MSC.ADAMS environment and, according to the certifying regulations, several multi-body simulations have been performed varying the heights of fall and the weights of the system. The results have shown a good correlation between numerical and experimental tests, thus demonstrating the potential of a multi-body approach. Future development of the present activity will probably be an application of the methodology, herein validated, to other cases for a more extensive validation of its predictive power and development of virtual certification procedures.


2011 ◽  
Vol 383-390 ◽  
pp. 2426-2429 ◽  
Author(s):  
Shen Shou Li ◽  
Xiao Ming Liu ◽  
Zhong Gan Zhu ◽  
Fang Yang

by the MSC Adams / Aircraft software features, setting pillar-type landing gear as the prototype, and using ADAMS software modules prior to the establishment of a certain type of aircraft landing gear model, then calculate the air buffer spring force oil, damping force and the structural constraints force curve based on dynamics model, At the end of paper we will analyze the model drop-test results. The results proved that we used this method was feasible.


Sign in / Sign up

Export Citation Format

Share Document