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.

Fuzzy PID control for landing gear based on magneto-rheological (MR) damper

Abstract: Landing gear of aircraft is the key component. The magneto-rheological (MR) damper applied to landing gear can ensure stability and safety during the process of takeoff, landing and rollout. Because of landing gear is a nonlinear, multivariate and multi-degree of freedom system. The traditional PID control can't obtain ideal control effects. Based on the advantages of fuzzy control theory do not need a precise mathematical model, fuzzy PID control is proposed in this paper by combining PID control and fuzzy control. The models of landing gear are simulated and analyzed under passive control, PID control and fuzzy PID control. The simulation results indicate that fuzzy PID control can effectively lower the amplitude of fuselage vibration acceleration and improve the ride quality and safety of aircraft. It has an important influence in the optimal control of the landing gear system.

Retractable auxiliary landing gear for aircraft

Abstract: This invention relates to new and useful improvements in the art of aeronautics and more particularly to improved landing gear for aircraft. The principal object of the present invention is to provide an auxiliary landing gear for aircraft to the end that in the event that something defective...

Digital Simulation of Flexible Aircraft Response to Symmetrical and Asymmetrical Runway Roughness

Abstract: : A method has been developed for determining the dynamic response of a flexible aircraft to runway roughness during takeoff or constant speed taxi. The equations that formulate the mathematical model have been programmed for a CDC 6600 digital computer and uses a Calcomp plotter for part of the program output. Three sets of runway elevation data are input to provide a forcing function at each landing gear. Three runway profiles measured at Washington National Airport, runway 36, were used to represent a typical commercial asymmetric profile. Three lines of profile were analytically generated to represent traversing a 1-cos dip at a 45 degree angle of approach. Several aircraft have been simulated with this program, each during a takeoff and a constant speed taxi. The data used to simulate the airplanes (McDonnell Douglas C-9A, Boeing 727-100, and an AMST) and the runway profile data used, are included in the appendix of this paper. Comparison of simulated results to limited experimental data was good. Peak vertical acceleration levels at the pilot's station were within 14%. The effect of the asymmetry of a profile on pilot's station vertical acceleration was significant providing the asymmetry of the profile was significant.

Spin-Up Studies of the Space Shuttle Orbiter Main Gear Tire

Abstract: One of the factors needed to describe the wear behavior of the Space Shuttle Orbiter main gear tires is their behavior during the spin-up process. An experimental investigation of tire spin-up processes was conducted at the NASA Langley Research Center's Aircraft Landing Dynamics Facility. During the investigation, the influence of various parameters such as forward speed and sink speed on tire spin-up forces were evaluated. A mathematical model was developed to estimate drag forces and spin-up times and is presented. The effect of prerotation was explored and is discussed. Also included is a means of determining the sink speed of the orbiter at touchdown based upon the appearance of the rubber deposits left on the runway during spinup.