Active Control of Landing Gear Shock Absorber Characteristic Using Magnetoreological Fluids

2009 ◽  
Vol 154 ◽  
pp. 195-201
Author(s):  
Zbigniew Skorupka ◽  
R. Kajka ◽  
R. Harla ◽  
W. Kowalski ◽  
M. Parafiniak ◽  
...  
Keyword(s):  
Active Control ◽  
Smart Materials ◽  
Shock Absorber ◽  
New Technologies ◽  
Landing Gear

Smart materials are being used in much larger scale in mechanical solutions. Aviation usage of these materials seems to be natural because of interest in new technologies use in this industry. In this article authors discuss characteristics of magnetoreological fluids as a smart materials, examples of its industrial usage, requirements on landing gear characteristics, design and lab tests of model shock absorber in which MRF was used as damping fluid.

Adaptable pneumatic shock absorber

2018 ◽  
Vol 25 (3) ◽  
pp. 711-721 ◽  
Author(s):  
Rami Faraj ◽  
Cezary Graczykowski ◽  
Jan Holnicki-Szulc
Keyword(s):  
Active Control ◽  
Smart Materials ◽  
Shock Absorber ◽  
High Efficiency ◽  
Low Cost ◽  
Electronic System ◽  
Experimental Investigations ◽  
Adaptation Mechanism ◽  
Impact Absorption ◽  
Pneumatic Shock

Recent progress in the field of sensors, actuators, and smart materials allows the construction of more and more efficient controllable pneumatic dampers for shock absorption. Typically, such devices apply online semi-active control techniques, which utilize electromagnetic, piezoelectric, or magnetostrictive valves. As a result, they are characterized by a high efficiency of impact absorption, but simultaneously by a complicated construction and a specialized electronic system. The alternative solutions are semi-passive absorbers that ensure a similar performance by using a much simpler, low-cost construction and a less complicated adaptation mechanism. This paper introduces an adaptable semi-passive single-chamber pneumatic shock absorber, SOFT-DROP, which provides the optimal impact absorption and energy dissipation after a single reconfiguration performed at the beginning of the process. The high effectiveness of the proposed concept is proved in numerical and experimental investigations of the device. Moreover, the proposed semi-passive damper is also compared against already known pneumatic absorbers that utilize semi-active control methods. Ultimately, the device might be used in an airdrop system for delivery of light packages.

Active control of a non-linear landing gear system having oleo pneumatic shock absorber using robust linear quadratic regulator approach

2017 ◽  
Vol 232 (13) ◽  
pp. 2397-2411 ◽  
Author(s):  
Hakan Yazici ◽  
Mert Sever
Keyword(s):  
State Space ◽  
Active Control ◽  
Shock Absorber ◽  
Linear Quadratic Regulator ◽  
Landing Gear ◽  
Gear System ◽  
Superior Performance ◽  
Linear Quadratic ◽  
Non Linear ◽  
Pneumatic Shock

This paper deals with the active control of a non-linear active landing gear system equipped with oleo pneumatic shock absorber. Runway induced vibration can cause reduction of pilot’s capability of control the aircraft and results the safety problem before take-off and after landing. Moreover, passenger–crew comfort is adversely affected by vertical vibrations of the fuselage. The active landing gears equipped with oleo pneumatic shock absorber are highly non-linear systems. In this study, uncertain polytopic state space representation is developed by modelling the pneumatic shock absorber dynamics as a mechanical system with non-linear stiffness and damping properties. Then, linear matrix inequalities-based robust linear quadratic regulator controller having pole location constraints is designed, since the classical linear quadratic regulator control design is dealing with linearized state space models without considering the non-linearities and uncertainties. Thereafter, numerical simulation studies are carried out to analyse aircraft response during taxiing. Bump- and random-type runway irregularities are used with various runway class and wide range of longitudinal speed. Simulation results revealed that neglecting the non-linear dynamics associated with oleo pneumatic shock absorber results significant performance degradation. Consequently, it is demonstrated that proposed robust linear quadratic regulator controller has a superior performance in terms of passenger–crew comfort and operational safety when compared to classical linear quadratic regulator.

Characteristic Aircraft Landing Gear Thermo-Tribo-Mechanical Model

2012 ◽  
Author(s):  
Laurent Heirendt ◽  
Hugh H. T. Liu ◽  
Phillip Wang
Keyword(s):  
Mechanical Model ◽  
Structural Damage ◽  
Shock Absorber ◽  
Thermal Response ◽  
Landing Gear ◽  
Heat Sources ◽  
Sources And Sinks ◽  
Average Temperature ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

A methodology for studying the characteristic thermal response of a landing gear (LG) shock absorber is presented. Rough runways induce high loads on the shock absorber bearings and because of high relative sliding speeds of the shock absorber piston, heat is dissipated which is known to have led to structural damage. In this work, an overall model has been developed that is used to outline the characteristics of the thermal behavior and identify the heat sources and sinks in the landing gear shock absorber. The developed thermo-tribo-mechanical model (TTM model) is subdivided into four parts, all using simplified but representative equations. Emphasis is placed on developing a methodological framework and studying the evolution of the average temperature in the TZI (thermal zone of interest) while taxiing and taking-off.

scholarly journals Analysis of inertial amplification mechanism with smart spring-damper for attenuation of beam vibrations

2018 ◽  
Vol 157 ◽  
pp. 03002 ◽  
Author(s):  
Mateusz Barys ◽  
Robert Zalewski
Keyword(s):  
Complex Systems ◽  
Real Time ◽  
Active Control ◽  
Smart Materials ◽  
Low Frequency ◽  
Frequency Range ◽  
Longitudinal Vibrations ◽  
The Real ◽  
Resonance Frequencies ◽  
Amplification Mechanism

In this paper an inertial amplification mechanism with an embedded smart spring-damper device for attenuation of longitudinal vibrations in continuous structures is analyzed. The complex systems are the extension of the already investigated inertial mechanism, here additionally equipped with the vacuum controlled spring-damper device which shows features of smart materials. This allows the semi-active control to affect different frequency vibration ranges in the real time. The fea.tures of the basic inertia amplification mechanism are preserved as a possibility to generate two neighbouring anti-resonance frequencies between resonance peaks in the low frequency range.

Bayesian sensitivity analysis of flight parameters that affect main landing gear yield locations

2014 ◽  
Vol 118 (1210) ◽  
pp. 1481-1497 ◽  
Author(s):  
P. Sartor ◽  
K. Worden ◽  
R. K. Schmidt ◽  
D. A. Bond
Keyword(s):  
Sensitivity Analysis ◽  
Pitch Angle ◽  
Shock Absorber ◽  
Bending Moment ◽  
Landing Gear ◽  
Tube Bending ◽  
Vertical Descent ◽  
Margin Of Safety ◽  
Flight Parameters ◽  
The Individual

Abstract An aircraft and landing gear loads model was developed to assess the Margin of Safety (MS) in main landing gear components such as the main fitting, sliding tube and shock absorber upper diaphragm tube. Using a technique of Bayesian sensitivity analysis, a number of flight parameters were varied in the aircraft and landing gear loads model to gain an understanding of the sensitivity of the MS of the main landing gear components to the individual flight parameters in symmetric two-point landings. The significant flight parameters to the main fitting MS, sliding tube bending moment MS and shock absorber upper diaphragm tube MS include: longitudinal tyre-runway friction coefficient, aircraft vertical descent velocity, aircraft Euler pitch angle and aircraft mass. It was also shown that shock absorber servicing state and tyre pressure do not contribute significantly to the MS.

A Kind of Active Control Damping Shock Absorber

2014 ◽  
Vol 620 ◽  
pp. 511-515
Author(s):  
Han Song Yang ◽  
Peng Li ◽  
Li Zhi Gu ◽  
Hui Juan Guo
Keyword(s):  
Active Control ◽  
High Speed ◽  
Shock Absorber ◽  
Mechanical Energy ◽  
Control Variable ◽  
Suspension System ◽  
High Speed Train ◽  
Proportional Valve ◽  
The Road ◽  
Variable Damping

It is the main decrease press type used in high speed train of semi suspension system, as the parameter can not be regulated freely of the semi suspension system, to design a kind of damping shock absorber which with the sensitive and soft system are very important, this system which using of the Electro hydraulic proportional valve to regulation the safety valve, the guide valve and the damping force of shock absorber, get the recycle method of the hydraulic system from inner to outside, and also using the suspension active control variable damping shock absorber to detect the road, this device, in fact, by vibration, which let the valve move relation, turn the mechanical energy into hot and release outside, thus decrease the vibration. To design this variable damping shock absorber ,compared with the semi suspension system ,for it has the connect system and Electro hydraulic proportional valve, and with the road detectors, and various variable parameters, Which let the high speed train more stable and safety, overcome the short of parameter regulation for the semi-automatic suspension system.

Analytical Investigation on Elastodynamic Vibration Suppression of a Flexible Four-Bar Mechanism System Featuring a Smart Coupler Link and Multivariable Optimal Regulator

1997 ◽  
Author(s):  
Muhammad Sannah ◽  
Ahmad Smaili
Keyword(s):  
Active Control ◽  
Smart Materials ◽  
Vibration Suppression ◽  
Controller Design ◽  
Linear Quadratic Regulator ◽  
Piezoelectric Sensor ◽  
Analytical Investigation ◽  
Vibration Modes ◽  
Linear Quadratic ◽  
Luenberger Observer

Abstract This paper presents an analytical investigation on active control of the elastodynamic response of a four-bar (4R) mechanism system using “smart” materials featuring piezoelectric sensor/actuator (S/A) pairs and multivariable optimal control. The 4R mechanism consists of a flexible coupler link, relatively flexible follower link, and a relatively rigid crank. Two thin plate-type piezoceramic S/A pairs are bonded to the flanks of the coupler link at high strain locations corresponding to the first and second vibration modes. Based on the optimal multivariable control theory, a controller which consists of a linear quadratic regulator (LQR) and a Luenberger observer as a state estimator is designed and implemented. As the mechanism changes configuration, its modal characteristics are recalculated, and the controller is redesigned. The dynamic model used for the controller design includes the second and fourth vibration modes of the mechanism system. These modes are predominated by the first two bending modes of the mechanism’s coupler link. The results showed that while the proposed active control strategy is successful in reducing the amplitudes of vibrations about the quasistatic response, it has no effect on the quasistatic deflections due to steady state loading.

Sign in / Sign up

Export Citation Format

Share Document