Aircraft Guidance Research Articles

Proposed System for Securing Aircraft Guidance Commands

This paper introduces a system for transmitting the aircraft guidance command over a narrow band communication channel in a secured way. The paper takes into account the noise, which exists in the guidance center. The proposed system is based on speech recognition and consists of two modules; one on the ground and the other is on the onboard. Guidance command words are modeled using Hidden Markov Modeling (HMM) and stored in the onboard module. During operation the input guidance word is processed and transmitted in a coded form from the ground module to the aircraft. The onboard module recognizes the words using HMM speech recognizer. The feature extraction technique used in this work is the Perceptual Linear Predictive (PLP) coding, which shows good immunity to noise. The performance measure is the recognition accuracy at different SNRs, as well as the achieved compression ratio of the transmitted message.

Fault-Tolerant Flight Control Using One Aerodynamic Control Surface

This paper considers a statically stable unmanned aircraft that is equipped with only two aerodynamic control surfaces (called elevons) and one tractor-type propeller. A fault in either of the elevons must, therefore, be managed using only the other elevon and the throttle. Because the fault results in an underactuated aircraft, the reconfiguration possibilities are limited. This paper proposes a strategy of using the throttle for total energy control and the single operable elevon for lateral control. This paper then develops a fault-tolerant controller based on this strategy and demonstrates, via multiple flight tests, the autonomous guidance and final approach of this unmanned aircraft in the presence of a stuck elevon fault. The results indicate that it may be possible to control other aerial bodies, including larger aircraft, using one aerodynamic control surface.

Flowfield Reconstruction Method Using Artificial Neural Network

Multidimensional aerodynamic database development has become more and more important for the design, control, and guidance of modern aircraft. To relieve the curse of the dimensionality, a novel flowfield reconstruction method based on an artificial neural network is proposed. The idea is to design a simplified problem that is related to the target problem. Then, the map from the simplified problem to the target problem is built using an artificial neural network. Finally, the target problem can be predicted efficiently through solving the simplified problem instead. Examples of the efficiency of this approach include two-dimensional viscous nozzle flows, an inviscid M6 wing flow, a viscous hypersonic flow of a complex configuration, and an unsteady two-dimensional Riemann problem to evaluate the performance of the proposed method. A Gaussian process model is also incorporated for a comparative study. With an artificial neural network of moderate complexity, the solution of the target problem can be generated with good accuracy. Among other observations, it is found that shocks can be predicted well with sharp resolution for steady and unsteady cases. Overall, using a simplified problem that accounts for all the interested parameters as inputs tends to be more reliable than using input parameters.

Nonvisible satellite estimation algorithm for improved uav navigation in mountainous regions

Global Navigation Satellite System (GNSS) is one of the most used technologies around the world for navigation. This technology is integrated in aircraft, ship, and submarine guidance systems; it is available in cell phones and cars, and also used to monitor Earth surface movements. The system accuracy spans from a range of a few centimeters up to meters. This variation is related to different sources of error such as the receiver clock error, Earth's ionospheric and tropospheric signal delay [1], or multipath effect in semiobstructed areas. If the surrounding objects have highly reflective surfaces, the error magnitude might surge to several hundred meters due to multiple reflections that the signal experiences before reaching the receiving antenna. A further source of error is present when the same signal is received more than once. As the present work is focused only on the effect of nonvisible satellites, multipath effect is not further investigated.

A method of atmospheric corrosion prediction for aircraft structure

A simulation prediction system, test pieces → flat test pieces → structural parts, for the atmospheric corrosion of aircraft is proposed to provide guidance for aircraft anti‐corrosion material selection and outfield maintenance. Based on the shell current distribution, a COMSOL corrosion simulation prediction model was constructed and applied to three types of test parts. The correctness of simulation principle is verified by comparing the galvanic current of simulation and test on each electrode surface of multi‐electrode system. Comparing the simulated potential distribution at 100 µm electrolyte layer with the corrosion morphology after 12 wet–dry corrosion periods, it is found that simulation and test are in good agreement. It is also proved that the 100 µm static liquid film can reflect the corrosion of this kind of wet–dry cycle. Comparing the corrosion depths of different periods at three different points and the simulated corrosion depth with time, it is found that the corrosion depth of the first four periods was larger than the simulated depth, which was less than the simulated value after four periods. The model was applied to the local structural parts of aircraft. Then, corrosion position and corrosion area were predicted. The results were compared with the accelerated test results to verify the accuracy of the model's prediction of structural parts. At the same time, the corrosion depth of the structural parts was also predicted.

Multiple fault diagnosis using factored evolutionary algorithms

When supporting commercial or defense systems such as aircraft avionics, guidance and control, electronic warfare, or propulsion systems, a perennial challenge is providing effective test and strategies to minimize downtime, thereby maximizing system availability. One can argue that one of the most effective ways to maximize downtime is to be able to detect and isolate as many faults that either exist or are emerging in a system at one time as possible. This is referred to as the multiplefault diagnosis problem, and it is a problem that is known to be computationally intractable (i.e., NP-complete) [1]. While several tools have been developed over the years to assist in addressing the multiple-fault problem, considerable work remains to provide the best possible given the information collected through observations, gripes, test results, and historical data. Recently, a new model for evolutionary computation has been developed called the Factored Evolutionary Algorithm (FEA) [2]. In FEA, a target optimization problem is broken down into subproblems that exhibit some kind of overlap. Then the optimization algorithm of choice (e.g., simulated annealing, genetic algorithm, particle swarm optimization) is applied to each of the subproblems, and the subproblems periodically share information with neighboring subproblems along the points of overlap.

Система управления летательного аппарата на основе априорной информации о положении цели

Система управления летательного аппарата на основе априорной информации о положении цели

ANALISIS BEBAN KERJA MENTAL PADA OPERATOR AIR TRAFFIC CONTROLLER (ATC) DENGAN METODE SUBJEKTIF DAN OBJEKTIF (STUDI KASUS : AIRNAV BANDAR UDARA XYZ)

An Air Traffic Controller (ATC) operator is required to always concentrate on monitoring navigation, radiation as well as supervising and implementing aircraft guidance. Obviously such work can lead to a mental workload on the worker. Based on these problems, it is necessary to do a research on the analysis of mental workload on the operator ATC at XYZ Airport. Measurement of mental workload can be done in two ways: subjective measurement and objective measurement. Subjective measurements of the mental workload can be done with NASA-TLX method. While the objective measurement can be done by doing the measurement physiologically such as through the heart rate. The results showed that the metal workload of ATY operator of XYZ Airport was in high category and very high base on subjective measurement. Performance level is the dominant factor causing high mental work load perceived by ATC operator. While based on the objective measurement found that the mental workload of ATC operators are in the medium category.

High Fidelity Modeling Method of High Performance Electromechanical Actuator

The accuracy of high performance electromechanical actuator(EMA) system model has important influence on the simulation accuracy of aircraft guidance and control loop. Aiming at solving the deficiency in the reflection of EMA characteristics using traditional second-order model, a high-fidelity global coupling modular structure modeling method is proposed. Based on the analysis of the modeling process, high-fidelity modeling research is conducted on "BLDCM/ball screw/fork" type EMA systems. The structure of high fidelity model is investigated, and modeling methods of nonlinear factors such as servo motor, transmission ratio, mechanical inertia and transmission flexibility in the system are examined in detail. Simulation results based on simulink platform show that the high fidelity model established by this method is highly consistent with the actual system performance of the input-output characteristics and the internal state characteristics, ensuring the authenticity of the system model, which plays an important effect on improving the simulation accuracy of the aircraft guidance and control loop.

Cooperative Intercept Guidance of Multiple Aircraft with a Lure Role Included

When threatened by a pursuer, an evading aircraft launches two defenders to accomplish a cooperative evasion, constituting a four-aircraft interception engagement. Under the assumption that the pursuing aircraft adopts the augmented proportional guidance law and first-order dynamics, a cooperative intercept mathematical model with an intercept angle constraint is established, allowing for the cooperative maneuvering of the evader. Based on the differential linear matrix inequality (DLMI), a controller design method of input and output finite time stability (IO-FTS) is proposed and applied to the aircraft’s cooperative intercept scenario. A cooperation performance analysis is carried out for two cases: (1) two defenders intercept the pursuer with various intercept angle constraints, and (2) the evader acts in a lure role to cooperate with two defenders. The simulation results indicate that the proposed method of controller design has the ability to guarantee that the two defenders intercept the pursuer at the preassigned intercept angles. The cooperative intercept scenario with a lure role is shown to be a very effective method for reducing the maximum required acceleration for defenders, which confirms the availability and advantage of cooperation. The strong adaptability and robustness of the cooperative guidance law with respect to various initial launch conditions is also verified.

Datalink security in the L-band digital aeronautical communications system (LDACS) for air traffic management

Today's very high-frequency (VHF) voice-based air–ground communication system for tactical aircraft guidance is suffering from the VHF band's increasing saturation in high-density areas [1]. The air–ground1 communication infrastructure is therefore undergoing modernization to ensure the sustainable growth of the European air transportation system in the coming decades [2], [3]. One major goal of this effort is the introduction of computerized air traffic management applications and new digital communication links between aircraft and ground systems.

Aircraft Dynamics Model Augmentation for RPAS Navigation and Guidance

An Aircraft Dynamics Model (ADM) augmentation scheme for Remotely Piloted Aircraft System (RPAS) navigation and guidance is presented. The proposed ADM virtual sensor is employed in the RPAS navigation system to enhance continuity and accuracy of positioning data in case of Global Navigation Satellite System (GNSS) data degradations/losses, and to improve attitude estimation by vision based sensors and Micro-Electromechanical System Inertial Measurement Unit (MEMS-IMU) sensors. The ADM virtual sensor is essentially a knowledge-based module that predicts RPAS flight dynamics (aircraft trajectory and attitude motion) by employing a rigid body 6-Degree of Freedom (6-DoF) model. Two possible schemes are studied for integration of the ADM module in the aircraft navigation system employing an Extended Kalman Filter (EKF) and an Unscented Kalman Filter (UKF). Additionally, the synergy between the navigation systems and an Avionics-Based Integrity Augmentation (ABIA) module is examined and a sensor-switching framework is proposed to maintain the Required Navigation Performance (RNP) in the event of single and multiple sensor degradations. The ADM performance is assessed through simulation of an RPAS in representative fight operations. Sensitivity analysis of the errors caused by perturbations in the input parameters of the aircraft dynamics is performed to demonstrate the robustness of the proposed approach. Results confirm that the ADM virtual sensor provides improved performance in terms of data accuracy/continuity, and an extension of solution validity time, especially when pre-filtered and employed in conjunction with a UKF.

Fuzzy Behavior-Based Online Command Generation for Unmanned Aircraft Guidance in Rough Terrain Environments

AbstractThis research is aimed at developing an efficient online path planner for unmanned air vehicle guidance in completely unknown three-dimensional (3D) rough terrain environments. A novel algo...

Towards 4D Trajectory Tracking for Transport Aircraft

This paper presents a new approach to perform 4D trajectory tracking for transportation aircraft. As current systems are extensions of 3D guidance with overfly time constraints at some given points and no general control framework has been developed for 4D guidance of a transport aircraft; the main goal of the proposed approach is to introduce a new method based on the inversion of the flight dynamics while avoiding numerical issues. A six degree of freedom model for a wide body transportation aircraft was developed in Matlab to provide a numerical simulation of the proposed approach, showing satisfying results.

Использование виртуальной глиссады для вычисления отклонений летательного аппарата на конечном участке посадки

Objective: The development of a calculation method of aircraft guidance parameters (linear and angular deflection from a synthetic glide path) by means of global satellite navigation system signals. As opposed to the existing methods, it is suggested to use an inclined plane, containing a glide slope line, as a base surface for vertical guidance. Methods: An experimental research was carried out, based on the suggested method of deflections’ calculation, as well as the comparison of results was fulfilled with identification of guidance parameters’ data by means of the existing methods. Results: It is shown that the results of calculating deflections from a glide path by means of the developed method and those methods, which are currently applied in transport planes landing, are practically the same. Practical importance: Application of the given method of calculating aircraft deflections from a glide path will make it possible to simplify significantly the deployment of the ground segment of landing system in airports, which in its turn will give the opportunity to equip regional airdromes of the third and the forth class, which are currently equipped with imprecise approach systems (compass locators or, the so-called, VOR) or have no radio-navigation aids, with satellite systems of precision approach. Satellite landing system implementation will allow aircraft crews, provided with proper airborne equipment, to pass, in case of need, from a contact fly to an instrumental fly conducted under flight rules. The above mentioned will reduce airdromes meteorological minimum, which in its turn will cause the decrease in the number of non-flying days and increase the efficiency of airdromes and fleet exploitation. One more advantage of satellite landing system application is the fact that it allows students to work out the procedure of approach on instrument landing system.

Синтез оптимальных алгоритмов наведения летательных аппаратов на групповую воздушную цель

Синтез оптимальных алгоритмов наведения летательных аппаратов на групповую воздушную цель

Математическая модель процесса поражения летательного аппарата управляемыми ракетами с оптико-электронными системами наведения матричного типа

Математическая модель процесса поражения летательного аппарата управляемыми ракетами с оптико-электронными системами наведения матричного типа

連続変化を用いた単機の最適解による最短時間編隊形成問題の解法

This paper presents a method to derive a minimum-time formation guidance of fixed-wing aircraft which is based on optimal solutions of single aircraft. This problem is conventionally formulated by treating the aircraft as one group which means centralized control. Moreover, the computational time is increased rapidly as the number of aircraft is increased. On the other hand, it is solved by each aircraft with small communication in the proposed method. Further the computational time is not sensitive to the number of aircraft by using homotopy method. Numerical results show almost no difference about the time for the minimum-time formation and the effectiveness of the computational time.

Predictive control of aircraft control systems for maneuverable target

A new aircraft guidance law utilizing predictive control algorithm is proposed. Compared with extended proportional navigation guidance law, this guidance law is designed specifically for using against a maneuverable target. It can track the target maneuver effectively. Uncertainty in the predicted target's future maneuvering is handled by constructing a stochastic predictive cost function and utilizing the stochastic minimum principle to deduce a predictive control algorithm. The guidance law is established by adopting the continuous approximation method into the continuous predictive control algorithm. The simulation results demonstrate that the stochastic predictive guidance law has the ability of trajectory prediction. Compared with the PID proportional navigation guidance law, the stochastic predictive guidance law has smaller overload and can intercept the maneuvering target more effectively.

Route Guidance for Satisfying Temporal Logic Specifications on Aircraft Motion

A new technique for aircraft route guidance subject to linear temporal logic specifications is presented. The proposed approach is based on workspace partitioning, and it relies on the idea of so-called lifted graphs. Briefly, edges in a lifted graph are successions of adjacent edges in the topological graph associated with the workspace partition. Edges of the lifted graph are associated with certain reachability properties of the aircraft model. The main result of this paper is the precise characterization of acceptable routes (namely, sequences of cells) that are guaranteed to be traversable by admissible state trajectories of the aircraft model while satisfying the given linear temporal logic specifications. The proposed approach incorporates nonholonomic kinematic constraints, does not require complete controllability in the presence of workspace constraints, and does not require linearization of the aircraft model. Numerical methods to implement the proposed route-planning algorithm are discussed. The proposed algorithm is illustrated with numerical simulation examples that reflect the practical significance of linear temporal logic specifications in aircraft guidance.