scholarly journals Identification of Aeroelastic Models for the X-56A Longitudinal Dynamics Using Multisine Inputs and Output Error in the Frequency Domain

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 24 ◽  
Author(s):  
Jared Grauer ◽  
Matthew Boucher
Keyword(s):  
System Identification ◽  
Test Data ◽  
Flight Control ◽  
Fourier Transforms ◽  
Flight Dynamics ◽  
Flight Test ◽  
Multiple Control ◽  
Output Error ◽  
Short Period ◽  
Flight Dynamics Model

System identification from measured flight test data was conducted using the X-56A aeroelastic demonstrator to identify a longitudinal flight dynamics model that included the short period, first symmetric wing bending, and first symmetric wing torsion modes. Orthogonal phase-optimized multisines were used to simultaneously excite multiple control effectors while a flight control system was active. Non-dimensional stability and control derivatives parameterizing an aeroelastic model were estimated using the output-error approach to match Fourier transforms of measured output response data. The predictive capability of the identified model was demonstrated using other flight test data with different inputs and at a different flight conditions. Modal characteristics of the identified model were explored and compared with other predictions. Practical aspects of the experiment design and system identification analysis, specific to flexible aircraft, are also discussed. Overall, the approach used was successful for identifying aeroelastic flight dynamics models from flight test data.

Case Studies of System Identification Modeling for Flight Control Design

2013 ◽  
Vol 58 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Christina M. Ivler ◽  
Mark B. Tischler
Keyword(s):  
System Identification ◽  
Flight Control ◽  
Control Design ◽  
Flight Test ◽  
Unmanned Aircraft ◽  
Integrated System ◽  
Control Law ◽  
Dynamics Model ◽  
Identification Methods ◽  
Flight Dynamics Model

Flight control design and analysis requires an accurate flight dynamics model of the bare airframe and its associated uncertainties, as well as the integrated system model (block diagrams), across the frequency range of interest. Frequency response system identification methods have proven to efficiently fulfill these modeling requirements in recent rotorcraft flight control applications. This paper presents integrated system identification methods for control law design with flight-test examples of the Fire Scout MQ-8B, S-76, and ARH-70A. The paper also looks toward how system identification could be used in new modeling challenges such as large tilt-rotors and uniquely configured unmanned aircraft.

scholarly journals Results of Short-Period Helicopter System Identification Using Output-Error and Hybrid Search-Gradient Optimization Algorithm

2010 ◽  
Vol 2010 ◽  
pp. 1-17 ◽  
Author(s):  
Ronaldo Vieira Cruz ◽  
Luiz Carlos Sandoval Góes
Keyword(s):  
System Identification ◽  
Flight Test ◽  
Identification Problem ◽  
Hybrid Search ◽  
Output Error ◽  
Aerodynamic Derivatives ◽  
Gradient Optimization ◽  
Short Period ◽  
Test Instrumentation ◽  
The Time Domain

This article focuses on the problem of parameter estimation of the uncoupled, linear, short-period aerodynamic derivatives of a “Twin Squirrel” helicopter in level flight and constant speed. A flight test campaign is described with respect to maneuver specification, flight test instrumentation, and experimental data collection used to estimate the aerodynamic derivatives. The identification problem is solved in the time domain using the output-error approach, with a combination of Genetic Algorithm (GA) and Levenberg-Marquardt optimization algorithms. The advantages of this hybrid GA and gradient-search methodology in helicopter system identification are discussed.

Flight dynamics modeling of elastic aircraft using signal decomposition methods

2019 ◽  
Vol 233 (12) ◽  
pp. 4380-4395 ◽  
Author(s):  
Seyed Amin Bagherzadeh
Keyword(s):  
Empirical Mode Decomposition ◽  
Test Data ◽  
Spectrum Analysis ◽  
Singular Spectrum Analysis ◽  
Flight Dynamics ◽  
Flight Test ◽  
Signal Decomposition ◽  
Identification Process ◽  
Mode Decomposition ◽  
Flight Parameters

To improve the precision and accuracy of the flight dynamic models for elastic aircraft, this paper provides a novel method that extracts observable flight modes from flight test data and uses them in the identification process. For this purpose, a gray-box time-domain method is employed with the nonlinear ARX structure and the Levenberg–Marquardt parameter estimation technique. In the proposed method, the components of the flight parameters are extracted by two signal decomposition techniques, namely the singular spectrum analysis and empirical mode decomposition. These components are inputted into the identification process. Flight test data of the active aeroelastic wing is examined by the proposed method. The results indicate that both the singular spectrum analysis-based and empirical mode decomposition-based identification processes have desired performances in dealing with nontrained flight conditions. Thus, these methods may be utilized as an interpolation method to estimate the aircraft flight dynamics within the flight envelope. However, the empirical mode decomposition outperforms the singular mode decomposition because it is more significant in decomposing flight parameters based on the frequency content. Hence, the empirical mode decomposition may be a better tool to be employed for the aeroelastic aircraft system identification.

Multi sensor data fusion based approach for the calibration of airdata systems

2011 ◽  
Vol 115 (1164) ◽  
pp. 113-122 ◽  
Author(s):  
M. Majeed ◽  
I. N. Kar
Keyword(s):  
Kalman Filter ◽  
Data Fusion ◽  
Test Data ◽  
Flight Control ◽  
Unscented Kalman Filter ◽  
Flight Test ◽  
Sensor Data ◽  
Sensor Data Fusion ◽  
Multi Sensor Data Fusion ◽  
Fusion Methods

AbstractAccurate and reliable airdata systems are critical for aircraft flight control system. In this paper, both extended Kalman filter (EKF) and unscented Kalman filter (UKF) based various multi sensor data fusion methods are applied to dynamic manoeuvres with rapid variations in the aircraft motion to calibrate the angle-of-attack (AOA) and angle-of-sideslip (AOSS) and are compared. The main goal of the investigations reported is to obtain online accurate flow angles from the measured vane deflection and differential pressures from probes sensitive to flow angles even in the adverse effect of wind or turbulence. The proposed algorithms are applied to both simulated as well as flight test data. Investigations are initially made using simulated flight data that include external winds and turbulence effects. When performance of the sensor fusion methods based on both EKF and UKF are compared, UKF is found to be better. The same procedures are then applied to flight test data of a high performance fighter aircraft. The results are verified with results obtained using proven an offline method, namely, output error method (OEM) for flight-path reconstruction (FPR) using ESTIMA software package. The consistently good results obtained using sensor data fusion approaches proposed in this paper establish that these approaches are of great value for online implementations.

Research on the Flight Control for an Asymmetrical X-Quadrotor

2013 ◽  
Vol 313-314 ◽  
pp. 399-402
Author(s):  
Yong Jun Ding ◽  
Xiang Zhou Wang ◽  
Shu Hua Zheng
Keyword(s):  
Test Data ◽  
Dynamic Characteristics ◽  
Flight Control ◽  
Control Method ◽  
Flight Test ◽  
Control Algorithms ◽  
Quick Response ◽  
Asymmetrical Structure ◽  
Control Forces ◽  
Outer Environment

The paper presents an asymmetrical structure of X-quadrotor, which is different from the traditional quadrotor and is more complicated in the analysis of control forces and moments. A novel control method based on backstepping is applied in the attitude loop. And the compensation for perturbations of outer environment and noise of the measurements has been done. Then, various simulations are performed and the results show the system has a quick response with small overshoot and good dynamic characteristics. Finally, the experiments are implemented on the prototype. The flight test data has validated the robustness of the control algorithms.

scholarly journals Flight Path Reconstruction and Parameter Estimation Using Output-Error Method

2006 ◽  
Vol 13 (4-5) ◽  
pp. 379-392 ◽  
Author(s):  
Benedito Carlos de Oliveira Maciel ◽  
Luiz Carlos Sandoval Góes ◽  
Elder Moreira Hemerly ◽  
Nei Salis Brasil Neto
Keyword(s):  
Test Data ◽  
Inertial Sensors ◽  
Flight Test ◽  
Flight Path ◽  
Positioning Systems ◽  
Output Error ◽  
Control Derivatives ◽  
And Control ◽  
Derivatives Of ◽  
Error Method

This work describes the application of the output-error method using the Levenberg-Marquardt optimization algorithm to the Flight Path Reconstruction (FPR) problem, which constitutes an important preliminary step towards the aircraft parameter identification. This method is also applied to obtain the aerodynamic and control derivatives of a regional jet aircraft from flight test data with measurement noise and bias. Experimental results are reported, employing a real jet aircraft, with flight test data acquired by smart probes, inertial sensors (gyrometers and accelerometers) and Global Positioning Systems (GPS) receivers.

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