Aircraft Landing Gears—The Past, Present and Future

1986 ◽  
Vol 200 (2) ◽  
pp. 75-92 ◽  
Author(s):  
D W Young
Keyword(s):  
Landing Gear ◽  
Future Developments ◽  
The Past ◽  
Aircraft Landing ◽  
Functional Efficiency ◽  
Landing Gears

This paper discusses landing gear basic requirements with a review of historic and current equipment designs, and concludes by pointing to possible future developments to improve functional efficiency.

scholarly journals Control of shimmy vibration in aircraft landing gears based on tensor product model transformation and twisting sliding mode algorithm

2018 ◽  
Vol 161 ◽  
pp. 02001 ◽  
Author(s):  
Suwat Kuntanapreeda
Keyword(s):  
Tensor Product ◽  
Model Transformation ◽  
Sliding Mode ◽  
Landing Gear ◽  
Common Phenomenon ◽  
Simulation Studies ◽  
Product Model ◽  
Robust Controller ◽  
Aircraft Landing ◽  
Landing Gears

Shimmy vibration is a common phenomenon in landing gear systems during either the take-off or landing of aircrafts. The shimmy vibration is undesirable since it can damage the landing gear and discomforts the pilots and passengers. In this work, tensor product model transformation (TPMT) and twisting sliding mode algorithm (TSMA) are utilized to design a robust controller for suppression of the shimmy vibration. The design has two steps. First, the TPMT is applied to determine the first part of the controller to suppress the vibration of the undisturbed system. After that, the TSMA is adopted to obtain another part of the controller to eliminate the remaining vibration caused by disturbances. By integrating these two parts, the proposed controller is obtained. Simulation studies are provided to demonstrate the effectiveness of the controller.

Monitoring of aircraft landing gear structure

2008 ◽  
Vol 112 (1131) ◽  
pp. 275-278 ◽  
Author(s):  
R. K. Schmidt
Keyword(s):  
Crack Detection ◽  
Landing Gear ◽  
Structural Monitoring ◽  
Monitoring Systems ◽  
Detection Techniques ◽  
Detection Systems ◽  
The Past ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Load Monitoring

Abstract Landing gear structure is developed predominantly using safe life design criteria. Health monitoring and structural prognosis techniques for landing gear cannot focus on crack detection; techniques for determining input loads and calculating damage or methods for directly measuring material damage must be employed. This paper will discuss Messier-Dowty’s research into structural monitoring over the past several years. Principally, direct damage detection systems and load monitoring systems will be discussed.

Friction analysis of aircraft landing gears due to landing impact

2021 ◽  
pp. 135065012110208
Author(s):  
Sanjay Baskaran ◽  
Sivakumar Sivaprakasam
Keyword(s):  
Degrees Of Freedom ◽  
Frictional Resistance ◽  
Landing Gear ◽  
Design Stage ◽  
Friction Forces ◽  
Six Degrees Of Freedom ◽  
Aircraft Landing ◽  
Landing Impact ◽  
Landing Gears ◽  
Friction Analysis

In this work, a six degrees of freedom heave-pitch mathematical model has been developed for an aircraft with main and nose oleo-pneumatic landing gear. Nonlinearities in stiffness, damping, and bending characteristics of landing gears and tires are incorporated in the model. Friction is an incidental and inevitable reaction that sticks along with the strut motion during the event of ground contact. The friction generated in the landing gear is the sum of the contribution from bearings and seals fitted in the landing gear. This study has focused on investigating the amount of frictional resistance gained by the struts while an aircraft is landing at various sink rates. The strut vertical forces, seal friction forces, and bearing friction forces generated in the main and nose landing gear during touchdown have been presented in this work. This preliminary estimation of friction forces for a range of sink rates aids the designer in developing optimal geometric or strut parameters in the design stage. This work also helps to calculate total landing loads for the certification of the landing gear.

scholarly journals A Multi-Step CNN-Based Estimation of Aircraft Landing Gear Angles

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8440
Author(s):  
Fuyang Li ◽  
Zhiguo Wu ◽  
Jingyu Li ◽  
Zhitong Lai ◽  
Botong Zhao ◽  
...  
Keyword(s):  
Vector Field ◽  
Target Detection ◽  
Landing Gear ◽  
Estimation Methods ◽  
Depth Information ◽  
Aircraft Landing ◽  
Key Points ◽  
Aircraft Landing Gear ◽  
Landing Gears ◽  
Rgb Image

This paper presents a method for measuring aircraft landing gear angles based on a monocular camera and the CAD aircraft model. Condition monitoring of the aircraft landing gear is a prerequisite for the safe landing of the aircraft. Traditional manual observation has an intense subjectivity. In recent years, target detection models dependent on deep learning and pose estimation methods relying on a single RGB image have made significant progress. Based on these advanced algorithms, this paper proposes a method for measuring the actual angles of landing gears in two-dimensional images. A single RGB image of an aircraft is inputted to the target detection module to obtain the key points of landing gears. The vector field network votes the key points of the fuselage after extraction and scale normalization of the pixels inside the aircraft prediction box. Knowing the pixel position of the key points and the constraints on the aircraft, the angle between the landing gear and fuselage plane can be calculated even without depth information. The vector field loss function is improved based on the distance between pixels and key points, and synthetic datasets of aircraft with different angle landing gears are created to verify the validity of the proposed algorithm. The experimental results show that the mean error of the proposed algorithm for the landing gears is less than 5 degrees on the light-varying dataset.

Fatigue Analysis for the Aircraft Landing Gear Connecting Parts

2013 ◽  
Vol 300-301 ◽  
pp. 870-873
Author(s):  
Ji Yan Li ◽  
Zhi Bing Yang
Keyword(s):  
Fatigue Life ◽  
Engineering Application ◽  
Simulation Method ◽  
Fatigue Analysis ◽  
Test Methods ◽  
Landing Gear ◽  
Theoretical Research ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Landing Gears

Landing gear is the critical component for aircrafts’ flight safety. According to the statistics, the accidents caused by the structure of landing gears and other structures relating to landing gears probably account for more than two thirds of the structural accidents. Fatigue failure is a key failure mode when the landing gears under the condition of alternating loads. Therefore it is very meaningful to develop the research on the fatigue life of the landing gears. The traditional fatigue analysis based on the test methods has many disadvantages, such as high cost and long test cycle. So a numerical simulation method was used to analyze the structural fatigue. Then the stress distribution and the fatigue life of the landing gear connecting parts under specific working conditions were studied. It turned out that the local fatigue performance of the component needed to be improved. The results have a certain value in engineering application and theoretical research, especially in improving the design level and working reliability of the aircraft landing gear.

The Evolution of Lead Extraction

2009 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Melanie Maytin ◽  
Laurence M Epstein ◽  
◽  
Keyword(s):  
Natural Selection ◽  
Lead Extraction ◽  
Significant Morbidity ◽  
Extraction Techniques ◽  
Extraction Technology ◽  
Device Management ◽  
Future Developments ◽  
The Past ◽  
New Methods ◽  
Life Threatening

Prior to the introduction of successful intravascular countertraction techniques, options for lead extraction were limited and dedicated tools were non-existent. The significant morbidity and mortality associated with these early extraction techniques limited their application to life-threatening situations such as infection and sepsis. The past 30 years have witnessed significant advances in lead extraction technology, resulting in safer and more efficacious techniques and tools. This evolution occurred out of necessity, similar to the pressure of natural selection weeding out the ineffective and highly morbid techniques while fostering the development of safe, successful and more simple methods. Future developments in lead extraction are likely to focus on new tools that will allow us to provide comprehensive device management and the design of new leads conceived to facilitate future extraction. With the development of these new methods and novel tools, the technique of lead extraction will continue to require operators that are well versed in several methods of extraction. Garnering new skills while remembering the lessons of the past will enable extraction technologies to advance without repeating previous mistakes.

EU-China Student and Academic Staff Mobility: Present Situation and Future Developments

2012 ◽  
Vol 1 (2) ◽  
pp. 282-300 ◽  
Author(s):  
Cécile Mathou ◽  
Jin Yan
Keyword(s):  
European Union ◽  
Qualitative Data ◽  
Academic Staff ◽  
Present Situation ◽  
Research Process ◽  
The European Union ◽  
Future Developments ◽  
The Past ◽  
Comprehensive Information

Abstract The objective of this study was to provide comprehensive information about student and academic staff mobility between the European Union (EU) and China as well as the main strategies and policies in place to promote mobility. Based on quantitative and qualitative data provided by national authorities and various stakeholders consulted throughout the research process, the study aimed at taking stock of the situation and identifying trends regarding EU-China learning mobility over the past ten years. It also aimed at drawing recommendations to improve current and future mobility actions between the two regions.

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