Preprocessing of Prithvi Post Flight data for Parameter Identification

This document presents the methods of preprocessing flight data . The data acquired during flight test contain data spikes and- noise, due to various reasons and requires processing . of data to remove spikes and noise before they are used for any analysis. For this purpose a finite difference method for editing the flight data 'to remove the spikes and Fast Fourier Transfort (FFT) method for filtering the flight data to remove the noise have been used . A software package "PREVRD' incorporating these methods has been developed . The spectral analysis via FFT to select cut-off frequency for filtering has also been incorporated in the PREPRO . The package is validated . using test example and is used successfully for processing PRITHVI post flight data

Flight Data Analysis and Parameter Estimation for LCA - Phase III - Final Report

The Document Briefly Describes The Major Tasks Accomplished In Phase III Of The Project . Flight Test Data Were Generated From Planned Maneuvers At Various Test Points In The Flight Envelope. The Analysis Was No Longer Restricted To Small Amplitude Maneuvers ; Data From Large Amplitude Maneuvers Were Analyzed As Well To Obtain Parameter Estimates Over A Wider Range Of Angle Of Attack . Most Of The Estimates Adhered Closely To The Trends Predicted By Wind Tunnel Database And There Were No Major Surprises Except For The Reduction In Direction Stability And Aileron Control Effectiveness . Results Were Also Obtained For Coefficient Level Matching, Drag-Polar Estimation And Flight Data Analysis With Airbrakes . The Tasks Carried Out Are Discussed In Detail In The Interim Reports/Project Documents (A Complete List Is Provided At The End Of The Report).The Document Also Highlights Certain. Issues That Need To Be Investigated

Aerodynamic Parameter Estimation From Flight Data Of The Unconventional Aircraft

This Document Gives Complete Results Of Parameter Estimation From Flight Data Of The Unconventional Aircraft. It Also Includes The Results Of Handling Quality Evaluation Based On Linear Estimated Models From Flight Data And Simulation Model Validation

Analysis of stabilised output error methods

In the paper, analysis of stabilised output-error methods (SOEMs) for parameter estimation of unstable aircrafts presented. These methods overcome the numerical difficulties encountered in parameter estimation of unstable systems by utilising measured states. The methods, along with the output error method (OEM) and the equation error method (EEM), are briefly described for the sake of comparison. However, the main idea of the paper is to present asymptotic analysis of the SOEM. The results of application of SOEMs to simulated data of an unstable/augmented aircraft are presented

On the orbit determination problem

Various important aspects of the satellite orbit determination problem are critically discussed with a view to emphasizing the importance of a wise choice of suitable system models, coordinates sets, and estimators. We describe several aspects of the orbit determination process and also review much of the available literature on the application of Kalman filter type algorithms to the problem of near-Earth, geosynchronous, and deep-space mission type orbit determination are also addressed. It is believed that this review with a touch of tutorial will enable engineers and scientists to arrive at an orbit determination methodology (ODM) that will have attributes of good numerical stability, efficiency, and precision in orbit estimation

Evaluation of derivative free Kalman filter and fusion in non-linear estimation

In recent literature a derivative free Kalman filter (DFKF) a method that propagates mean and covariance using non-linear transformation is frequently used. In this paper i) factorised version of EKF (UD Extended Kalman Filter or UDEKF) and ii)DFKF are studied and evaluated using various sets of simulated data of the non-linear systems. Sensitivity study of DFKF with respect to tuning parameters used in creation of sigma points and the associated weight is carried out. DFKF is more accurate and easier to implement. A data fusion scheme is involved. It is observed that fusion enhances the estimation accuracy of the state of non-linear plant. Application of DFKF to non linear parameter estimation problem is also demonstrated

Simulation Modeling Of A Transport Aircraft Using Flight Test Data

The Mathematical Models Using Flight Test Data With Respect To A Transport. Aircraft For The Offline Simulation Are Described In This Document. For The Purpose Of Simulation Validation Process, Representative Flight Data Sets Are Selected From A Data Bank Which Was Created Previously Using Data From Actual Flight Maneuvers

From genetics to genetic algorithms: Solution to optimisation problems using natural systems

Genetic algorithms are search procedures inspired by13; natural selection and genetics that can be used to obtain13; global and robust solutions to optimisation problems.13; They find applications i n computer science, engineering,13; economics, linguistics, psychology, biology, etc

Tracking filter and multi-sensor data fusion

In this paper factorization filtering, fusion filtering strategy and related algorithms are presented. Some results of implementation and validation using realistic data are given

Determination of model order for dynamical system

The problem of model order determination, which is an integral part of system identification for dynamical systems of auto-regressive and least square structures is investigated. Twelve model order testing criteria available in the literature are critically evaluated from simulated data and from two different physical processes: (1) human operator responses in compensatory tracking manual control; and (2) wind tunnel mounted model responses to tunnel flow instabilities. The study revealed that of all the criteria tested, only a subset is adequate to establish reliable model order. Based on this observation, a computationally effective working rule is proposed for model order determination for practical dynamical systems