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Landing gear

About: Landing gear is a research topic. Over the lifetime, 3403 publications have been published within this topic receiving 25370 citations. The topic is also known as: landing gear & gear.


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Proceedings ArticleDOI
12 Jun 2018
TL;DR: A previously designed dynamic model of the landing gear is extended with the experimental characterization of the hydraulic braking system, and a test-rig is setup, which allows testing the contact between wheel and ground with a flywheel.
Abstract: Aircraft control systems are in general difficult to test in their final deployment phases, as flight time has very high costs and entails possible dangerous working conditions. Thus, coming to test flights with control algorithms that have been thoroughly tested beforehand is paramount. As far an anti-skid control is concerned, the industrial practice is to have the anti-skid controller embedded in the landing gear, so that the initial test bench for controller design is a rig comprising all or parts of the landing gear system. In this work, we extend a previously designed dynamic model of the landing gear with the experimental characterization of the hydraulic braking system. Then, a test-rig is setup, which allows testing the contact between wheel and ground with a flywheel. Open-loop experiments to tune the simulator are conducted, and a final validation of the simulation model against experimental data is carried out.

10 citations

Journal ArticleDOI
10 Aug 2020
TL;DR: A LocoGear, a novel algorithm for locomotion of UAV equipped with the robotic landing gear, is proposed based on feedforward control that proves the capability of landing gear to move along the desired trajectory.
Abstract: Nowadays, there are few unmanned aerial vehicles (UAVs) that are capable of landing on uneven surfaces or moving on the complex ground. A drone having both of these functionalities can significantly improve its performance in accomplishing difficult tasks, such as monitoring and exploring various types of terrain, searching for survivors, and delivering medical aid or repair kits in an unstructured dynamic environment, e.g., rescue operation following an earthquake. This article presents a motion analysis of the gait of an adaptive landing platform for multicopters. This landing gear has four robotic legs facilitated with torque sensors in the knee joints. Though it had been developed to provide adaptive landing on uneven surfaces, we decided to exploit the system for terrain locomotion purposes. For this purpose, we have analyzed the center of mass trajectory to evaluate the possible trajectory of the robot. Based on the result of this experimental analysis, we propose a LocoGear, a novel algorithm for locomotion of UAV equipped with the robotic landing gear. The servomotor torques were estimated using Lagrangian dynamic formulation and kinetostatic methods. We conducted experiments to verify the LocoGear approach based on feedforward control that proves the capability of landing gear to move along the desired trajectory. We achieved the robot motion along the straight line with the standard deviation of length in each step of 9.8 mm and standard deviation in yaw of 9°.

10 citations

Patent
09 Jun 1988
TL;DR: In this paper, an aerial aircraft carrier is disclosed having a first and a second shuttlecraft that have a cantilever fluselage extending between the first and second, with control surfaces for stabilizing an aircraft (a payload) that is secured in a mount assembly.
Abstract: An aerial aircraft carrier is disclosed having a first and a second shuttlecraft that have a cantilever fluselage extending between the first and second shuttlecraft. The cantilever fuselage is disposed at both ends within a fuselage housing that depends from the under-carriage of the first (lead) and second (aft) shuttlecraft, the cantilever fuselage forming a longitudinal member therebetween. A means for elevating a plurality of aerodynamically stable platforms, (wing assemblies), is affixed to the cantilever fuselage. The wing assemblies each have a wing span member attached thereto, with control surfaces, for stabilizing an aircraft (a payload) that is secured in a mount assembly. An aircraft landing in the mount assembly is secured by an application of negative air pressure against a landing gear pod of the aircraft, and as the aircraft is adhered to a pair of mount elements, by evacuation of air, forming a suction seal peripheral to the environmental surfaces of the landing pod, the wing span members aerodynamically stabilize the weight of the aircraft on the wing assembly platforms. The pilot of the retrieved aircraft then feathers the rotors to his/her aircraft, the weight thereof being primarily supported by the aerodynamic lift of the wing span members. The aircraft is then retrieved in flight, aerodynamically stabilized and can be serviced while in flight. A reverse sequence allows the secured aircraft to be launched from the carrier apparatus.

10 citations

01 Jan 2004
TL;DR: In this paper, a simulation of such an unstable and complex phenomenon during aircraft ground maneuvers is done to detect vibrations in aircraft landing gear, based on work done in cooperation between DLR and Liebherr Aerospace.
Abstract: In a variety of mechanical systems friction induced vibrations are a major concern. The aircraft landing gear is by nature a complex multi-degree-of-freedom dynamic system. It may encounter various vibration modes which can be induced by brake frictional characteristics and design features. These brake induced oscillations can lead to very high loads in the landing gear and brake structure which may result in passenger discomfort and sometimes in component failure. Along with the serious fore and aft oscillations of a landing gear, often referred to as gear walk, chatter, squeal, shimmy and other vibrations in aircraft landing systems are not only annoying and disconcerting but can also affect the stability of the plane during take-off, landing, and rolling. In this paper, simulation of such an unstable and complex phenomenon during aircraft ground maneuvers is done to detect vibrations in aircraft landing gear. A commercial multibody simulation tool SIMPACK is used for this purpose. The article is based on work done in cooperation between DLR and Liebherr Aerospace.

10 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202353
2022135
2021101
2020116
2019199
2018190