Effects of magnetic core parameters on landing stability and efficiency of magnetorheological damper-based landing gear system

2019 ◽  
Vol 31 (2) ◽  
pp. 198-208 ◽  
Author(s):  
Chulhee Han ◽  
Bo-Gyu Kim ◽  
Byung-Hyuk Kang ◽  
Seung-Bok Choi
Keyword(s):  
Equations Of Motion ◽  
Magnetic Core ◽  
Landing Gear ◽  
Gear System ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Damping Force ◽  
Magnetic Circuits ◽  
Aircraft Landing ◽  
New Type

In this research, a new type of magnetorheological damper for a small-sized aircraft landing gear system is proposed and its performance is evaluated with respect to design parameters of the magnetic core. As a first step, a new configuration of magnetorheological damper for the landing gear system, which consists of orifices, recoil valve, and magnetic circuits, is introduced with working principles. After formulating the governing equations of motion, six different models of magnetorheological damper featuring different number of magnetic core and different pole length are chosen to investigate both the landing stability and the efficiency. Subsequently, the distribution of the magnetic field intensity of each model is analyzed through the finite element method, followed by the calculation of the field-dependent damping force to be used for the landing simulation, which is undertaken by adopting the dynamic model of a half airplane landing gear system. In order to identify the significance of the magnetic core parameters, the landing stability is judged from the sign of the minimum force and the landing efficiency is determined from the energy dissipation during the vertical drop motion.

scholarly journals Intelligent Control Based on a Neural Network for Aircraft Landing Gear with a Magnetorheological Damper in Different Landing Scenarios

2020 ◽  
Vol 10 (17) ◽  
pp. 5962 ◽  
Author(s):  
Quoc Viet Luong ◽  
Dae-Sung Jang ◽  
Jai-Hyuk Hwang
Keyword(s):  
Neural Network ◽  
Mr Damper ◽  
Landing Gear ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Hybrid Controller ◽  
Aircraft Landing ◽  
Neural Network Controller ◽  
Passive Damper ◽  
Aircraft Landing Gear

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.

A Semi-Active Controller for an Aircraft Landing Gear Equipped with Magnetorheological Damper

2019 ◽  
Vol 894 ◽  
pp. 29-33
Author(s):  
Luong Quoc Viet ◽  
Jai Hyuk Hwang
Keyword(s):  
Numerical Simulation ◽  
Force Control ◽  
Hybrid Control ◽  
Mr Damper ◽  
Landing Gear ◽  
Operating Conditions ◽  
Magnetorheological Damper ◽  
Numerical Simulation Result ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

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.

Research on the Dynamic Performance and Mechanical Model of the Single Rod MRD without Accumulator

2011 ◽  
Vol 295-297 ◽  
pp. 2120-2124
Author(s):  
Jian Guo Du ◽  
Wan Hua Li ◽  
Yong Sheng He ◽  
Xue Li Lv
Keyword(s):  
Energy Absorption ◽  
Mechanical Model ◽  
Dynamic Performance ◽  
Magnetorheological Damper ◽  
Excitation Current ◽  
Damping Force ◽  
New Type ◽  
Working Status ◽  
Comparison Of The Results

In this paper, the dynamic performance of the single rod magnetorheological damper (MRD) without accumulator in different working status is researched, which is a new type of MRD developed by us to apply in the environment of explosion and shock. It is concluded that there is no offset force in the new MRD. The maximum damping force and energy absorption capability increase non-linearly with the excitation current and piston’s velocity. The mechanical model of this type MRD is proposed. By comparison of the results of tests with simulation, it is proved that the mechanical model proposed in this paper can simulate the dynamic performance of the new MRD accurately.

Computer Simulation of Dynamical Behavior of Self-Propelled Gurney

1993 ◽  
Author(s):  
Wieslaw M. Szydlowski ◽  
Srinivas Sastry
Keyword(s):  
Computer Simulation ◽  
Equations Of Motion ◽  
Dynamical Behavior ◽  
Design Parameters ◽  
Dynamical Response ◽  
Straight Path ◽  
Main Disadvantage ◽  
Oscillatory Response ◽  
New Type ◽  
Difficult Part

Abstract The conventional gurneys used in hospitals to move patients from room to room have one main disadvantage: they are difficult to control. A typical gurney has a form of an oblong table moving on four castor wheels. The vehicle is difficult to maneuver, especially on corridor turns, and usually requires two operators — each at one end. Dr. J. Bleicher from the St. Joseph’s Hospital in Omaha, Nebraska suggested a new type of a self-propelled gurney which would be a cross-breed of a motorized wheelchair and a gurney. A new type of a gurney would have two additional wheels in the center of the gurney, each connected to a separate DC motor. The torques developed by the motors would be controlled by one operator using a joystick. Applying opposite torques to the controlled wheels would rotate a stationary gurney in place, or would curve the path of a moving gurney. The position of two additional wheels can be changed, so that the gurney can move sideways, translate in chosen direction or move along a curvelinear path. The work presented in the paper contains an analysis of the dynamics of such a gurney. A mathematical model of the vehicle was developed to check how much effort is needed on the part of the operator in straight path motion and during negotiating a corner. The most difficult part of the modelling was a proper description of forces and torques exerted by the ground on the wheels. The differential equations of motion of the gurney have been numerically integrated, and the dynamical response of the vehicle studied. The results of the computer simulation show a transient oscillatory response of the castor wheels (shimmying) which can be controlled by a proper choice of design parameters of the vehicle.

scholarly journals Thermodynamic Behaviors of a Kind of Self-Decoupling Magnetorheological Damper

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guojun Yu ◽  
Chengbin Du ◽  
Tiger Sun
Keyword(s):  
Theoretical Model ◽  
Heat Dissipation ◽  
Performance Test ◽  
Design Method ◽  
Constraint Equation ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Test Results ◽  
Damping Force ◽  
Conservation Of Energy

A theoretical model of temperature change on a kind of self-decoupling magnetorheological (SDMR) damper was established based on conservation of energy, and the constraint equation for structural design parameters of the SDMR damper was improved to satisfy heat dissipation requirements in this work. According to the theoretical model and improved constraint equation, the main structure parameters of SDMR damper were obtained and the damper was tested. The temperature performance test results indicate that the rising temperature makes the damping force decline, and the main affection factors of temperature variation are excitation methods and input current. The results also show that the improved constraint equation and design method introduced are correct and efficient in the engineering.

Damping force characteristics of electrorheological shock absorbers with different electrode designs

2010 ◽  
Vol 224 (2) ◽  
pp. 293-304 ◽  
Author(s):  
Y-M Han ◽  
M-S Seong ◽  
S-B Choi ◽  
N M Wereley
Keyword(s):  
Shock Absorber ◽  
Equations Of Motion ◽  
Design Parameters ◽  
Damping Force ◽  
Passenger Vehicles ◽  
Shock Absorbers ◽  
Car Suspension ◽  
Field Dependent ◽  
The Time Domain ◽  
Er Fluid

This article presents the effect of electrode design parameters on the damping force of an electrorheological (ER) shock absorber for passenger vehicles. As a first step, an ER fluid is synthesized by dispersing arabic gum particles into non-conducting oil, and its field-dependent Bingham characteristics are experimentally evaluated. The Bingham model of the ER fluid is then formulated and incorporated with the governing equations of motion of the ER shock absorber. Subsequently, several ER shock absorbers are designed and manufactured with various electrode designs, which have three different electrode gaps, lengths, and materials, respectively. The field-dependent damping force of the manufactured shock absorbers is demonstrated in the time domain and compared with simulation results. In addition, the vibration control performance of a quarter-car suspension system is presented and compared with different electrode gaps and lengths.

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