scholarly journals A Supervised Neural Network Control for Magnetorheological Damper in an Aircraft Landing Gear

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.


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.


Algorithms ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 97
Author(s):  
Song Zheng ◽  
Chao Bi ◽  
Yilin Song

This paper presents a novel diagonal recurrent neural network hybrid controller based on the shared memory of real-time database structure. The controller uses Data Engine (DE) technology, through the establishment of a unified and standardized software architecture and real-time database in different control stations, effectively solves many problems caused by technical standard, communication protocol, and programming language in actual industrial application: the advanced control algorithm and control system co-debugging difficulties, algorithm implementation and update inefficiency, and high development and operation and maintenance costs effectively fill the current technical gap. More importantly, the control algorithm development uses a unified visual graphics configuration programming environment, effectively solving the problem of integrated control of heterogeneous devices; and has the advantages of intuitive configuration and transparent data processing process, reducing the difficulty of the advanced control algorithms debugging in engineering applications. In this paper, the application of a neural network hybrid controller based on DE in motor speed measurement and control system shows that the system has excellent control characteristics and anti-disturbance ability, and provides an integrated method for neural network control algorithm in a practical industrial control system, which is the major contribution of this article.


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.


Author(s):  
S. Bhasin ◽  
K. Dupree ◽  
P. M. Patre ◽  
W. E. Dixon

The objective in this paper is to control a robot as it transitions from a non-contact to a contact state with an unactuated viscoelastic mass-spring system such that the mass-spring is regulated to a desired final position. A nonlinear Hunt-Crossley model, which is physically consistent with the real behavior of the system at contact, is used to represent the viscoelastic contact dynamics. A Neural Network feedforward term is used in the controller to estimate the environment uncertainties, which are not linear-in-parameters. The NN Lyapunov based controller is shown to guarantee uniformly ultimately bounded regulation of the system despite parametric and nonparametric uncertainties in the robot and the viscoelastic environment respectively. The proposed controller only depends on the position and velocity terms, and hence, obviates the need for measuring the impact force and acceleration. Further, the controller is continuous, and can be used for both non-contact and contact conditions.


2013 ◽  
Vol 567 ◽  
pp. 169-173
Author(s):  
Hong Feng Wang ◽  
W.W. Song ◽  
J.L. Wang ◽  
Dun Wen Zuo ◽  
X.L. Duan

Analysis about the cause of the main failure and the forces of the main welding outer cylinder of the recent large aircraft landing gear were given. The impact load for main welding outer cylinder in the process of the taking off and landing was calculated of 580MPa. Finite element model of the main welding outer cylinder was then established and the influence of the impact loading to the main welding outer cylinder was analyzed. The results showed that crack was most likely take place on the top of the outer cylinder, and then on the two welds. The crack expanded in an S shape. This study could provide an important basis for the safety of the aircraft landing gear inspection and service life prediction.


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.


2020 ◽  
Vol 8 (5) ◽  
pp. 4265-4269

In this study a typical Aircraft Landing Gear with shock absorber was modeled a Mass-Spring-Damper System. Basic components of the system were explained. The equations of the model was presented. Aircraft Landing Gear was also modeled in Matlab/Simulink for a given set of aircraft parameters. A case study for an Aircraft Landing Gear was solved and results were presented. Results included the variation of spring (k1 and k2 ) and damping coefficient (b) in a given interval to show their effects on the impact force and displacement of landing gear as main outputs to consider. Effect of damping coefficient (b) on impact force was found to be highest (3.76%), spring coefficient (k1 ) effect is moderate (2.29%), and spring coefficient (k2 ) is lower (0.97%), for a change of ±10% of coefficients.


2011 ◽  
Vol 311-313 ◽  
pp. 2457-2460
Author(s):  
Ji Hong Liu ◽  
Ying Zhong Pang ◽  
Yu Ming Zhu

Modern products become more and more complex, the modeling and simulation of them are carried out with different software on heterogeneous platforms, which always caused the heterogeneous data, separated disciplines and cannot obtain the result of unified model correctly. Therefore, a Modelica-based modeling and simulation method for aircraft landing gear is proposed. The landing gear library based on Modelica was established. The unified physical model of landing gear which is composed of structural, thermodynamics and hydromechanics disciplines is constructed. The aircraft landing process, the track of retraction mechanism and the impact work amount of the shock absorber are obtained through multi-domain unified simulation, which provides references for deisgners.


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