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The linear and nonlinear aerodynamic models are built to investigate the influence of the two models on the parameter identification results. The polynomial modeling method is used to establish the aerodynamic models while the existing dynamic model of aircraft and output error method in time domain are applied to identify aerodynamic parameters at low angles of attack. A comparison is made between...
System identification is an established technique for obtaining a reliable mathematical model of an Unmanned Aerial Vehicle (UAV) using aircraft input output data. In this research, a unique three step procedure is presented for system identification of small scale fixed wing UAV. Flight experiment was conducted with specifically designed maneuvers to identify lateral-directional dynamic model of...
This paper details a method for identifying a set of piece-wise affine linear models that can be used for control design for flapping-winged flight. The paper focuses on diving maneuvers as the application for these models. The flight conditions during the dive are segmented into separate dynamically similar regions, and least-squares is used to estimate affine linear models for each modeling region...
An existing attitude tracking control method developed for a FlyGen airborne wind energy (AWE) system is extended to control a GroundGen AWE system. The GroundGen system produces energy through kite-generated aerodynamic forces that tension a flexible tether attached between the kite center of gravity and a ground generator system. The kite is modelled using a six degree of freedom aircraft dynamics...
Modeling and identification of an aerial vehicle will allow engineers to design and implement guidance and control systems using the mathematical model acquired on flight. Using the mathematical model, several improvements and benefits shall be obtained, such as designing control subsystem using Modern Control Theory; the expected results at the workbench test will correspond more accurately to the...
The angle of attack and the sideslip angle are significant parameters describing the aerodynamics of the aircraft. Specifically, these angles are required for identification of the system parameters such as aerodynamic forces and moment derivatives. For exact measurements, it is necessary to install appropriate air data sensors on board. However, it is sometime difficult to install such apparatus...
Thrust vector can effectively improve the fighter's maneuverability and flight safety, increasing the survival rates in the air combat. As the key component of thrust vectors, the turbojet engine's dynamics and characteristics have a great influence on the performance and control of thrust vectors. This paper would model the dynamics of a small scale turbojet engine through experiment and identification...
A Six DOF nonlinear model of a large unmanned aerial system is developed using two competing approaches in modeling aircraft with V-tail configuration. In one approach the V-tail is projected into horizontal and vertical planes and the aircraft airflow angles, angle of attack and sideslip angle, are used for analysis. This approach has been successfully used to model aircraft with low horizontal tail...
The use of modelling and simulation in any sphere of work must be tempered by an understanding of the extent to which such models are valid. The conditions under which modelling deficiencies and approximations cause accuracy to be lost must be clearly defined so that research or experimental investigations using such models yield meaningful results. This paper considers the validation of a large-scale...
In this paper, application of neural networks combined with partial differentiation of the neural outputs has been discussed to estimate lateral-directional flight stability and control parameter. A neural model capable of predicting generalized force and moment coefficients using measured motion and control variables can be employed to extract aerodynamic parameters from flight data. The Neural Partial...
In this paper, a complete system identification process for identifying flight dynamics model of MAVs (miniature aerial vehicles) is presented. CIFER identification toolkit, which is developed by NASA Ames research center and particularly suitable for identifying rotary-wing aircraft dynamics, is adopted. The modeling procedure is detailed by addressing the following four key steps: 1) data collection...
A mathematical model of an injector powered transonic wind tunnel is developed in this paper. The whole running process is divided into three stages and the model of each child processes is established respectively. The data applied to the parameter identification is obtained from the actual running process. The NARMAX model is adopted as the structure of model and the parameters including the order...
Hardware-in-the-loop simulations are indisputably perceived as an integral part of the avionics design and development process. This paper describes a prototyping framework, which has been employed to develop a digital autopilot for a light sport aircraft. Related simulation processes have been performed on two different ground-testing levels. The first level consisted of a laboratory grade development...
This paper presents a methodology for the system identification of a light weight, small-scale parafoil suspended motorized aircraft, known as a paramotor. The study is concerned with the acquisition of linear models describing both the lateral and longitudinal dynamics of the aircraft, with an emphasis on practical techniques that can be implemented in the real world. The mathematical models developed...
A Multiple Input Multiple Output (MIMO) controller based on the dynamic feedback linearization technique is designed for the robust global stabilization of a new satellite launching strategy called (unmanned) airlaunch. This strategy consists in using a two-stages launching system. The first stage is composed of an airplane (manned or unmanned) that carries a rocket launcher which constitute the subsequent...
This work is based on adapting suitable techniques in real-time aircraft system identification for the use in rigid body dynamic modelling of Unmanned Aerial Vehicles (UAVs). In general due to their reduced size UAVs lend themselves well to the recovery of flight data in full scale atmospheric trials. Timely recovery of the true model parameters is necessary to minimise flight tests for rapid prototype...
Dynamics of flutter is an important consideration in the design of aircraft structures. Flutter is an unstable self-excitation of the structure due to an undesirable coupling of structural elasticity and aerodynamics. Flutter is very difficult to predict and its occurrence can lead to catastrophic structural failure. The dynamics of flutter are affected by several factors including nonlinearities...
A satellite launching procedure known as air-launch is modeled and simulated at the staging phase, where a reusable unmanned aerial vehicle airlaunchs a second (rocket) stage. The airlaunch is modeled as a hybrid system with instantaneous jumps. This paper presents the effects of the variations in mass, inertia and aerodynamic coefficients on the stability of the airlaunch system at the stage separation...
The roll dynamics of a 5kg, 1.3 m high sounding rocket are analyzed in a vertical wind tunnel. Significant turbulence in the tunnel makes the system identification of the effective inertia, damping and asymmetry with respect to roll challenging. A novel method is developed which decouples the disturbance from the rocket frame's intrinsic roll dynamics and allows accurate prediction of roll rate and...
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