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.

scholarly journals Output Error Method for Tiltrotor Unstable in Hover

2017 ◽  
Vol 64 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Piotr Lichota ◽  
Joanna Szulczyk
Keyword(s):  
System Identification ◽  
Flight Test ◽  
Model Parameters ◽  
Output Error ◽  
Control Derivatives ◽  
Time Histories ◽  
System Output ◽  
The Time Domain ◽  
And Control ◽  
Error Method

Abstract This article investigates unstable tiltrotor in hover system identification from flight test data. The aircraft dynamics was described by a linear model defined in Body-Fixed-Coordinate System. Output Error Method was selected in order to obtain stability and control derivatives in lateral motion. For estimating model parameters both time and frequency domain formulations were applied. To improve the system identification performed in the time domain, a stabilization matrix was included for evaluating the states. In the end, estimates obtained from various Output Error Method formulations were compared in terms of parameters accuracy and time histories. Evaluations were performed in MATLAB R2009b environment.

scholarly journals ESTIMATION OF THE LATERAL AERODYNAMIC COEFFICIENTS FOR SKYWALKER X8 FLYING WING FROM REAL FLIGHT-TEST DATA

2018 ◽  
Vol 58 (2) ◽  
pp. 77
Author(s):  
Rahman Mohammadi Farhadi ◽  
Vyacheslav Kortunov ◽  
Andrii Molchanov ◽  
Tatiana Solianyk
Keyword(s):  
Test Data ◽  
Flight Test ◽  
Least Square ◽  
Stability And Control ◽  
Information Parameter ◽  
Control Derivatives ◽  
Aerial Vehicle ◽  
Aerodynamic Parameters ◽  
Priori Information ◽  
And Control

Stability and control derivatives of Skywalker X8 flying wing from flight-test data are estimated by using the combination of the output error and least square methods in the presence of the wind. Data is collected from closed loop flight tests with a proportional-integral-derivative (PID) controller that caused data co-linearity problems for the identification of the unmanned aerial vehicle (UAV) dynamic system. The data co-linearity problem is solved with a biased estimation via priori information, parameter fixing and constrained optimization, which uses analytical values of aerodynamic parameters, the level of the identifiability and sensitivity of the measurement vector to the parameters. Estimated aerodynamic parameters are compared with the theoretically calculated coefficients of the UAV, moreover, the dynamic model is validated with additional flight-test data and small covariances of the estimated parameters.

Identification of Aerodynamic Derivatives of a Flexible Aircraft Using Output Error Method

2011 ◽  
Vol 110-116 ◽  
pp. 5328-5335 ◽  
Author(s):  
M. Majeed ◽  
Indra Narayan Kar
Keyword(s):  
Simulated Data ◽  
Flight Test ◽  
Longitudinal Axis ◽  
Model Structure ◽  
Order Model ◽  
Elastic Mode ◽  
Output Error ◽  
Aerodynamic Derivatives ◽  
Derivatives Of ◽  
Error Method

A full order model of an aeroelastic aircraft has too many parameters to yield satisfactory estimates. In this paper, using simulated data, rigid body and aeroelastic derivatives are estimated in longitudinal axis for single elastic mode. The proposed approach uses an integrated model structure. It emphasizes the use of estimation techniques that have the capability to accurately determine modal characteristics in those flight test situations where the measured data is dominated by elastic effects. Output error method in time domain is applied to the simulated flight data to identify the aircraft derivatives.

Rotorcraft Lateral-Directional Oscillations: The Anatomy of a Nuisance Mode

2021 ◽  
Author(s):  
Dheeraj Agarwal ◽  
Linghai Lu ◽  
Gareth D. Padfield ◽  
Mark D. White ◽  
Neil Cameron
Keyword(s):  
Simulation Model ◽  
Simulation Models ◽  
Flight Test ◽  
Flight Simulation ◽  
Stability And Control ◽  
Systems Research ◽  
Control Derivatives ◽  
Research Aircraft ◽  
Level Of Understanding ◽  
And Control

High-fidelity rotorcraft flight simulation relies on the availability of a quality flight model that further demands a good level of understanding of the complexities arising from aerodynamic couplings and interference effects. One such example is the difficulty in the prediction of the characteristics of the rotorcraft lateral-directional oscillation (LDO) mode in simulation. Achieving an acceptable level of the damping of this mode is a design challenge requiring simulation models with sufficient fidelity that reveal sources of destabilizing effects. This paper is focused on using System Identification to highlight such fidelity issues using Liverpool's FLIGHTLAB Bell 412 simulation model and in-flight LDO measurements from the bare airframe National Research Council's (Canada) Advanced Systems Research Aircraft. The simulation model was renovated to improve the fidelity of the model. The results show a close match between the identified models and flight test for the LDO mode frequency and damping. Comparison of identified stability and control derivatives with those predicted by the simulation model highlight areas of good and poor fidelity.

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.

Reduction of Flight Test Data From Linear Accelerometers

1953 ◽  
Vol 57 (510) ◽  
pp. 415-415
Author(s):  
Andrew Mokrzycki
Keyword(s):  
Test Data ◽  
Vertical Plane ◽  
Flight Test ◽  
Flight Path ◽  
The Body ◽  
Body Axis ◽  
List Type ◽  
Type Number ◽  
Arbitrary Body

The problems discussed in this note refer to the simplest case of the use of linear accelerometers, in which the flight path is in the vertical plane of symmetry of the aeroplane, and the acceleration normal to the path is to be determined.Generally two facts are neglected:– (i)That the accelerometer senses along an arbitrary body axis ZB (Fig. 1), instead of along the wind axis Z (normal to the path).(ii)That the accelerometer is not placed exactly at the e.g. of the aeroplane but at some point A, having co-ordinates xA and zA in the body axes.

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