Dynamic Characteristics Of Aircraft Research Articles

Distributed rotorcraft coupling modal parameters influence analysis

In order to explore the influence mechanism of different parameters on Multi-rotor aircraft dynamic characteristics, Hamilton principle and the theory of medium deformation beam were used to derive the rotors/nacelle/wing coupling structure dynamic equation, and a solution method suitable for the analysis of coupled modal was established. By using literature as an example calculate rotor and wing modal, the error is less than 5% compared with the experimental results in the literature, indicating that the coupling model in this paper is accurate and effective. On this basis, the influences of, nacelle offset, rotor collective pitch, blade center of mass on the coupling modal are studied.

Innovating aircraft control systems with the use of artificial intelligence and electronics

AbstractDespite all the research being done in an attempt to bridge the gap between control systems and artificial intelligence, there is still an immense risk of failure and instability that exists. One particular application that this research will look into and expand on is aircraft control mechanisms. This article will examine the existing uncertainties within these systems that could be suspected as the cause of failure in the artificial control operation of an aircraft. This study will act as a further extension of research on the feedback linearization of an aircraft's control architecture using adaptive neural networks to decrease the probability of an uncontrolled error resulting from the nonlinearity of the aircraft's dynamic characteristics. The stability of previously implemented mechanisms to control aircraft systems will also be investigated. This research will require a thorough approach and understanding of various possible areas of malfunction and instability caused by multiple factors, including, external interferences and inefficiencies that accumulate within the controller that can mislead or cause an undesirable effect on the system. Examining similar areas where this study may be used for further research, while also discussing opportunities to apply these procedures to relatable applications will be analyzed, as it is of key importance for the progression of this technology.

Design of aircraft flight performance analysis and simulation software

Considering design of flight control system in the early stage of aircraft design is the development trend of aircraft design, which improves the design quality and reduces the cost, and the analysis of aircraft dynamic characteristics is its foundation. The aircraft flight performance analysis and simulation software is designed and developed by C++ language according to the flight dynamics principle of fixed-wing aircraft with conventional layout, combined with control law and simulation algorithm, which can be used to analyze the stability of aircraft, estimate the flight performance, preliminarily design the flight control system and carry out real-time flight simulation. The numerical example shows that the software can accurately analyze and calculate the flight performance of the aircraft, and achieve good attitude maintenance and maneuver control in the simulation. The comparison of results verifies the accuracy of the software.

Development of equivalent model of external fuel tank assembly for dynamic characteristics analysis of aircraft

Aircraft are frequently equipped with various external stores for mission performance. Because these external stores may cause structural instability of the aircraft, an evaluation of the interactions between the aircraft and the external stores is required. For this purpose, an analysis of the characteristics of the aircraft dynamics reflecting an external store was performed. The finite element model used for the analysis of these characteristics should be able to simulate the dynamic characteristics of the component as accurately as possible, while using a minimum of nodes and elements. In this study, an equivalent model for dynamic characteristics analysis of an external fuel tank and installation pylon was constructed using MSC Patran/Nastran. The validity of an equivalent model of each component was confirmed by comparison with the modes of the full-scale model. Then, each component was assembled with connecting member and the modal analysis of the equivalent model assembly was performed to verify that the basic modes required for the analysis of aircraft dynamic characteristics can be well extracted. Finally, it was confirmed that the newly developed equivalent model assembly could be used for aircraft dynamics characteristics analysis through the equilibrium check by comparing to the modes of the full-scale model.

Parameter setting of pilot behavioral dynamic model in aircraft control loop

Subject of Research. The paper considers a flight control system for the longitudinal movement of an aircraft with a human-pilot in a closed loop. Computer simulation setting of the selected pilot behavioral model is carried out in the compensatory tracking mode. The parameters correspond to the optimal behavior of the pilot providing the best aircraft dynamic characteristics. Method. Padé approximation was used when creating a computer program for calculations.Frequency and optimal methods, and handling qualities scale were used for quality assessment of the control system dynamic properties. Main Results. Numerical values of the pilot behavior model parameters are found on the example of a normal aerodynamic scheme, in which the elevator serves as an element of the tail unit. The numerical values estimation of the pilot model parameters is performed. The simulation results are given. Practical Relevance. The proposed approach to the pilot behavior simulating process during piloting simplifies, accelerates, and reduces the cost of an aircraft test program. Software simulation can be used at the test stage and before tests on flight simulators and will give the possibility to identify unsatisfactory handling characteristics of the aircraft and its control system and quickly correct them.

Amphibious airplane for underwater observation: Conceptual design

This paper aims at presenting the conceptual design of an amphibious airplane for underwater observation in the territory of Japan. Taking into account the specificity of this type of vehicles, particular attention should be paid to the analysis of aerodynamic and dynamic characteristics of aircraft. In order to cope up with this topic, commercial tools have been exploited (such as ANSYS Fluent for wing aerodynamics analysis) as well as the home-built software PANUKL package for aerodynamic analysis of the entire airplane and simulation and dynamic stability analysis for dynamic analysis. Special attention was given to the priorities resulting from understanding the characteristics of the Japanese client.

Evaluation of the Dynamic Characteristics of Aircraft during Landing in Crosswinds

Abstract This article summarizes the results of aircraft lateral drift parameter estimation. The lateral drift of an aircraft may occur in extreme and dangerous situations when the aircraft lands in crosswind conditions. Such a situation is developing with great dynamics in a small period of time. Within seconds, the aircraft can drastically change the flight path or position. The article highlights the results obtained in a calculation made during the flight phase of the aircraft landing in crosswind.

Hybrid Lateral Aerodynamic Modeling Based on WNN and Kernel Principal Components Feature Extraction

In order to better describe the dynamic characteristics of aircraft through aerodynamic modeling, a Wavelet Neural Network (WNN) aerodynamic modeling method based on Kernel Principal Components Analysis (KPCA) is proposed. Firstly, the training samples are used to execute KPCA for extracting basic features of samples, and then using the extracted basic features, WNN aerodynamic model was established. The simulation result shows that, the modeling ability of the method proposed is better than that of another 3 methods. It can easily determine of model parameters. This enables it to be effective and feasible to establish the aerodynamic modeling for aircraft.

Research on Technology of Thrust Asymmetry Lateral Compensation for Large Aircraft

Thrust asymmetry is dangerous for aircraft, especially in the phases of approach and landing. This paper proposes a new technology to compensate the thrust asymmetry in lateral of large aircraft. The dynamic characteristics of aircraft with asymmetric thrust are firstly analyzed in the paper. Then, the controllability conditions and balanced flight attitude in the case of thrust asymmetry are studied. Based on the mathematic model of Airbus 300, a thrust asymmetry lateral compensator is designed for the phases of approach and landing to ensure the safety of approach and landing. Numerical simulation results show that the designed compensator (control law) can compensate the asymmetric thrust very well.

Shaping Indirect Flight Control System Properties for General Aviation Aircraft

This paper describes calculations and computer simulations concerning handling qualities of general aviation aircraft equipped with an indirect (fly-by-wire) control system. The main idea of this proposal is shaping small aircraft dynamic characteristics in a way that enables all general aviation aircraft to exhibit similar user-friendly properties from the pilot’s point of view. The natural solution of this problem is modifying aircraft dynamic properties to comply with the “ideal model” of a safe and easily controllable airplane. We can improve the handling qualities of an aircraft using the indirect flight control system. In this paper, the model following method was used for controller synthesis, with the purpose of obtaining qualitatively new handling properties and simplifying the control system for pilots with limited professional training. However, a control system designer has to assume responsibility for proper functioning of complex flight control systems. The properties of the optimal controll...

Assessment of aircraft dynamic characteristics in air manoeuvring

Розглянуто аналітичні підходи до оцінки динамічних особливостей маневрених літальних апаратів у широкому діапазоні застосування параметрів їхнього руху

Theory for aircraft handling qualities based upon a structural pilotmodel

A theory for describing the manner in which aircraft dynamic characteristics determine pilot opinion ratings of aircraft handling qualities is discussed. The theory centers upon the role of pilot rate feedback in continuous tracking. A structural model of the human pilot is used to quantify the amount of rate feedback the pilot is required to use in the control of an aircraft in a specific task. Using the model, 35 vehicle configurations that have been evaluated in manned simulation are analyzed. The tasks range from simple single axis, single-loop pitch attitude tracking to precision hover and landing approach, in which control of both vehicle position and attitude are required. The manner in which control system sensitivity affects pilot opinion rating is also investigated. The rate feedback theory is supported by the results of the model-based analyses, where it is shown that the mean square value of the rate feedback signal in the model correlates with the pilot opinion ratings obtained from experiment.

An Analysis of Pilot Adaptation in a Simulated Multiloop VTOL Hovering Task

Human pilot adaptation in a simulated multiloop VTOL hovering task was investigated with a series-loop-closure model. Using the model equations, the pilot-model adaptable parameters were computed from rms hovering performance data measured in flight simulator experiments for a variety of VTOL aircraft configurations. Variations in the aircraft configurations affected both the aircraft's dynamic characteristics and its response to simulated turbulence. The pilot's pitch-loop adaptation generally correlated with the frequency-domain characteristics of the pitch response to turbulence and the pitch response to control inputs. The results of the study show no specific low-frequency attitude gain requirements that must be satisfied by the pilot for the attitude disturbance and dynamic characteristics considered. The influence of the aircraft position-loop characteristics on pilot pitch-loop adaptation was important only for configurations that had small attitude disturbances. For these cases the requirements for position-loop control apparently determined the minimum acceptable pitch-loop crossover frequency. Results also show that the pilot preferred to adjust pitch-loop gain by changing control-stick sensitivity (aircraft gain) rather than by changing his internal gain.