Aircraft Automatic Landing Research Articles

Adaptive fuzzy fault-tolerant controller for aircraft autolanding under failures

This paper presents an adaptive fuzzy control strategy for an aircraft automatic landing problem under the failures of stuck control surfaces and severe winds. The strategy incorporates a dynamic fuzzy system called sequential adaptive fuzzy inference system (SAFIS) and it augments an existing conventional controller called baseline trajectory following controller (BTFC). SAFIS is an online learning fuzzy system in which the rules are added or deleted based on the input data. Also, SAFIS incorporates an online scheme for parameter update of the membership functions. BTFC has been designed using classical control methods under normal operating conditions with winds. For this study, the following fault scenarios have been considered: 1) single fault of either aileron or elevator stuck at certain deflections, and 2) double fault cases where one aileron and one elevator at the same or opposite direction are stuck at different deflections. Simulation studies indicate that the BTFC is unable to handle these failures. Recently, Abhay et al. have proposed a neural-based scheme to augment the BTFC and its performance has been shown to be superior. However, even in this neural scheme there are gaps in the fault cases where performance specifications are not met. In this paper, results show that the SAFIS-aided BTFC improves the fault-tolerant capabilities compared with BTFC and also the earlier neural-aided BTFC performance in filling up the gaps observed earlier.

ファジィ制御による自動着陸の制御則

The effectiveness of fuzzy logic control law for automatic landing of aircraft, which cover both of control to lead aircraft from level flight at an altitude of 500m to the flight on the glide-path course near the runway and control for the aircraft to land smoothly on a runway, was studied. The control law of the automatic landing was designed to match the design goals of leading from the horizontal flight to the flight on the glide-path course quickly and smoothly and of landing smoothly on a runway. Because there is the ground effect at landing, design of control law and evaluation of control performance were done in consideration of the ground effect. As a result, it was confirmed that the design objective was achieved. Even if the characteristics of the plant changes greatly, this control law was able to maintain the control performance. Moreover, it was confirmed to be able to land safely when there was air turbulence. This paper shows that fuzzy logic control is an effective and flexible method when applied to control law for automatic landing and the design method of control law using fuzzy logic control was obtained.

Fuzzy modelling control for aircraft automatic landing system

Aircraft landing control based on fuzzy modelling networks is presented. The proposed scheme uses a fuzzy controller combined with a linearized inverse aircraft model. A multi-layered fuzzy neural network is used as the controller, providing the control signals at each stage of the aircraft-landing phase. The algorithm used to train the network is the Backpropagation Through Time. The linearized inverse aircraft model provides the error signals that will be used to back-propagate through the controller at each stage. The objective of this study is to improve the performance of conventional automatic landing systems. The simulation results are described for the automatic landing system of a commercial aeroplane. Tracking performance and robustness are demonstrated through software simulations. Simulation results show that the fuzzy controller can successfully expand the safety envelope to include more hostile environments such as severe turbulence.

Development of Navigation Algorithm Architecture for Automatic Landing Based on Landmarks Image Processing

This paper discusses navigation algorithm architecture for estimating aircraft position and attitude during approach and landing using landmarks image processing of the Earth. In general, automatic landing can be realized with the help of high accuracy real-time estimation of aircraft position and attitude. In the proposed algorithm, the reference images of the Earth surface saved in the onboard memory are matched with the current images captured from onboard electro-optical camera. The matching information is used for INS correction by means of the Kalman filter with a radio altimeter. For application of this algorithm architecture, image matching algorithm and decision of more informative reference images for improvement in matching efficiency have been studied. The results indicate that it is possible to use the proposed navigation algorithm for aircraft automatic landing without the use of ground equipment.

Automatic aircraft landing using interferometric inverse synthetic aperture radar imaging

This paper presents an interferometric processing of an aircraft's monostatic and bistatic inverse synthetic aperture radar (ISAR) signatures for automatic landing. The aircraft's squint angle in this ISAR imaging problem is near 90 degrees . We show that this extreme squint angle does not pose any problem for the ISAR Fourier-based (wavefront) reconstruction algorithm. In fact, the aircraft can be imaged accurately, and without any erroneous shifts in the cross-range domain, within the imposed theoretical resolution. Moreover, the algorithm is accurate enough such that one can utilize the phase of the ISAR monostatic and bistatic measurements for interferometric processing. The resultant interferometric ISAR image is used to detect undesirable rotations in the aircraft's orientation.

Design of an autoland controller for an F-14 aircraft using H-infinity synthesis

Our purpose is to present the results of a design effort to incorporate direct lift control into the F-14 aircraft automatic carrier landing system. This was accomplished using a new design methodology whereby typical single input/single output design specifications were translated into the weighting functions of an T^oo output-feedback synthesis problem. Next, robustness of the Tioo controller was analyzed using the structured singular value concept (JJL). A simplified uncertainty model for air vehicles based on flight test data was developed for this analysis. Finally, the resulting controller was successfully validated on the nonlinear simulation.

Adaptive critic designs: A case study for neurocontrol

For the first time, different adaptive critic designs (ACDs), a conventional proportional integral derivative (PID) regulator and backpropagation of utility are compared for the same control problem—automatic aircraft landing. The original problem proved to contain little challenge since various conventional and neural network techniques had solved it very well. After the problem had been made much more difficult by a change of parameters, increasingly better performance was observed by going from the simplest ACD to more sophisticated designs, dual heuristic programming having been ranked best of all. This case study is of use in general intelligent control problems for it provides an example of the capabilities of different adaptive critic designs.

Stabilization of an inverted pendulum by a high-speed fuzzy logic controller hardware system

A high-speed fuzzy controller hardware system employing Min-Max operations is presented. It has fifteen control rule boards and one defuzzifier. Grades of membership are represented with 0 V ∼ 5 V corresponding to 0.0 ∼ 1.0. This fuzzy controller facilitates approximate reasoning at 1 000 000 FIPS (fuzzy inferences per second) and is able to be used for various purposes by programming on each control rule board. It handles fuzzy linguistic information of the form NL (negative large), NM (negative medium), NS (negative small), ZR (approximately zero), PS (positive small), PM (positive medium), PL (positive large) and NG (negation). This fuzzy controller hardware system makes an inverted pendulum stand on a vehicle by using seven control rules. Two pendulums (5 mm diameter, 15 cm length, 3.5 g weight; respectively 10 mm, 50 cm, and 50 g) can be stabilized by the same rule set. It is much easier to produce control rules than to solve the nonlinear differential equations representing the dynamics of an inverted pendulum. This fuzzy controller hardware system can be applied to attitude control of a space booster rocket and satellite, an automatic aircraft landing system, pattern recognition, stabilization of nuclear fuel rods in a reactor, an intelligent sensor, and many other applications which need swift approximate reasoning.

Aircraft Automatic Landing Systems Using GPS

abstractThis paper is based on a presentation made at the IAIN International Navigation Congress held in Sydney, Australia, in February 1988.The global positioning system (GPS) offers a new opportunity for the automation of aircraft landing systems. The position and velocity measurements provided by a state-of-the-art GPS receiver using the C/A code and working in a normal or differential mode (D-GPS) and aided by one or two ground-based PseudoLites (PLS), may be able to satisfy the landing accuracy requirements of the FA A.This paper describes the design and simulation of an aircraft automatic landing system. Aircraft position and velocity are assumed to be measured using a (carrier-tracking) GPS receiver. The hypothesized capability is based on measurements taken at Stanford and elsewhere, using the Trimble 4000SX, five-channel receiver in an integrated-doppler-aiding mode. For some of the autopilot designs, either ground-based GPS transmitters (pseudolites) or a radar altimeter have also been incorporated.Included in the landing simulations are wind shears and a gust model, creating realistic landing situations. The performances of the lateral and vertical displacements are presented with their 1σ r.m.s. estimation errors during the glide-slope and flare phases. Included are different wind conditions, GPS configurations and controllers. The results are compared with the FAA requirements for various categories of automatic landing systems.

Observers as Noise Filters in an Automatic Aircraft Landing System

Observers as Noise Filters in an Automatic Aircraft Landing System

Aircraft Automatic Landing

NAVIGATIONVolume 27, Issue 1 p. 23-29 Aircraft Automatic Landing J. A. MCDONALD, J. A. MCDONALD Group Capt.Search for more papers by this author J. A. MCDONALD, J. A. MCDONALD Group Capt.Search for more papers by this author First published: Spring 1980 https://doi.org/10.1002/j.2161-4296.1980.tb01396.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume27, Issue1Spring 1980Pages 23-29 RelatedInformation

The automatic landing of aircraft independently of the weather

This lecture, delivered on 8th November 1962 to the Club der Luftfahrt in Bonn, is an account of blind landing prepared with the aim of interesting a non-specialist audience in this and other British developments.

Terminal control system applications

This paper describes a synthesis procedure for terminal control systems. The synthesis procedure is illustrated by application to the design of an aircraft automatic landing system. A simplified model for the landing aircraft is chosen and justified. The prediction equations for this model are discussed. Using the prediction equations, a two-condition terminal controller, which controls the altitude and altitude rate at time of touchdown to the desired values, is developed. The terminal control landing system developed is simplified by combining feedback loops in a straightforward fashion to arrive at a practical mechanization. A stability analysis of the simplified terminal controller, considered as a servo with time variable gains and time constants, is presented. The results of extensive analog computer simulation and flight test of the terminal control landing system developed in this paper are reviewed. It is shown that the synthesis procedures developed in this paper result in a system which can be implemented by state-of-art hardware to land aircraft successfully.

Multicondition Terminal Control Systems for Aircraft

A method is presented for synthesizing a type of control system applicable to automatic landing of aircraft and designated as a multicondition terminal control system. This closed-loop control system is designed to cause the response of a controlled member to meet several independently specified conditions at a particular instant of time. The desired values of altitude and altitude rate at touchdown typify such conditions. Because the S3^stem operates to shape the response at one time only, it is suitable for use with controlled members that have oscillatory or divergent responses to forcing inputs.

Fully automatic aircraft landing approach

Fully automatic aircraft landing approach

An Automatic Landing System

The concept, theory, implementation, and test results of the Bell Aircraft Automatic Landing System are presented. The system, which requires no additional airborne electronics equipment in land-based aircraft carrying an ILAS receiver and coupler, employs a precise ground-based radar and command computer. The major source of error of this closed-loop system is turbulence, while performance is limited chiefly by aircraft and autopilot properties. Flight-test results covering over 2000 automatic touchdowns and a variety of propeller and jet aircraft are presented for vertical and lateral degrees of freedom.