Aerothermodynamic parameter estimation from Space Shuttle thermocouple data during transient flight test maneuvers

1983 ◽  
Author(s):  
J. HODGE ◽  
D. AUDLEY
Keyword(s):  
Parameter Estimation ◽  
Space Shuttle ◽  
Flight Test

Drag Coefficient Identification from Flight Data via Optimal Observer

2014 ◽  
Vol 687-691 ◽  
pp. 787-790
Author(s):  
Rong Jun Yang ◽  
Yao Ye
Keyword(s):  
Parameter Estimation ◽  
Kalman Filter ◽  
Drag Coefficient ◽  
Dynamic Equation ◽  
Unscented Kalman Filter ◽  
Flight Test ◽  
Measurement Noise ◽  
Estimation Technique ◽  
Flight Data ◽  
Coefficient Identification

. For effectively using flight test data to extract drag coefficient, an optimal observer based on parameter estimation technique is proposed. The point mass dynamic equation is used to form the Unscented Kalman Filter (UKF) and the smoother (URTSS) for the estimation of a projectile’s flight states. The projectile flight states are then solved and utilized to extract the drag coefficient information using the observer techniques. The simulation verifies the feasibility of the method: with measurement noise, the accurate drag coefficient is obtained by using the smoother.

Identification of Physical Helicopter Models Using Subspace Identification

2020 ◽  
Vol 65 (2) ◽  
pp. 1-14
Author(s):  
Sevil Avcıoğlu ◽  
Ali Türker Kutay ◽  
Kemal Leblebicioğlu
Keyword(s):  
Parameter Estimation ◽  
State Space ◽  
Nonlinear Optimization ◽  
Physical Parameter ◽  
Test Data ◽  
Flight Test ◽  
The State ◽  
Physical Parameters ◽  
Subspace Identification ◽  
Study Results

Subspace identification is a powerful tool due to its well-understood techniques based on linear algebra (orthogonal projections and intersections of subspaces) and numerical methods like singular value decomposition. However, the state space model matrices, which are obtained from conventional subspace identification algorithms, are not necessarily associated with the physical states. This can be an important deficiency when physical parameter estimation is essential. This holds for the area of helicopter flight dynamics, where physical parameter estimation is mainly conducted for mathematical model improvement, aerodynamic parameter validation, and flight controller tuning. The main objective of this study is to obtain helicopter physical parameters from subspace identification results. To achieve this objective, the subspace identification algorithm is implemented for a multirole combat helicopter using both FLIGHTLAB simulation and real flight-test data. After obtaining state space matrices via subspace identification, constrained nonlinear optimization methodologies are utilized for extracting the physical parameters. The state space matrices are transformed into equivalent physical forms via the "sequential quadratic programming" nonlinear optimization algorithm. The required objective function is generated by summing the square of similarity transformation equations. The constraints are selected with physical insight. Many runs are conducted for randomly selected initial conditions. It can be concluded that all of the significant parameters can be obtained with a high level of accuracy for the data obtained from the linear model. This strongly supports the idea behind this study. Results for the data obtained from the nonlinear model are also evaluated to be satisfactory in the light of statistical error analysis. Results for the real flight-test data are also evaluated to be good for the helicopter modes that are properly excited in the flight tests.

A Flight Test Challenge: Aeroassist for Reuseable, Space-Based Transportation

1986 ◽  
Vol 29 (5) ◽  
pp. 26-31
Author(s):  
Robert Ried
Keyword(s):  
Space Shuttle ◽  
Fluid Dynamic ◽  
Space Station ◽  
Flight Test ◽  
Transportation Systems ◽  
Low Earth Orbit ◽  
Future Challenges ◽  
Ground Test ◽  
Test Flight ◽  
Level Of Understanding

NASA and its predecessor, NACA, have relied on testing to address challenges ranging from early aeronautics to the lunar landing. This is a necessary ingredient to success. Current and future challenges, coupled with technology advances, dictate reliance on productive combinations of testing and analysis. An example of this is provided by the necessary combination of ground test, flight test and computational fluid dynamic analyses required to achieve an efficient, space-based aerobraking orbital transfer vehicle. As the Space Shuttle is key to the Space Station, the Space Station is key to transportation beyond low earth orbit. Now is the time to develop the level of understanding adequate for the next generation of space transportation systems.

Space Shuttle Flight Test Results of the Cosmic Ray Upset Experiment

1984 ◽  
Vol 31 (6) ◽  
pp. 1178-1182 ◽  
Author(s):  
John W. Adolphsen ◽  
John J. Yagelowich ◽  
Kusum Sahu ◽  
W. A. Kolasinski ◽  
R. Koga ◽  
...  
Keyword(s):  
Space Shuttle ◽  
Cosmic Ray ◽  
Flight Test ◽  
Test Results

Uses of parameter estimation in flight test

1983 ◽  
Vol 20 (12) ◽  
pp. 1043-1049 ◽  
Author(s):  
Kenneth W. Iliff ◽  
Richard E. Maine
Keyword(s):  
Parameter Estimation ◽  
Flight Test

Recent Space Shuttle Crew Compartment Design Improvements

1986 ◽  
Vol 30 (14) ◽  
pp. 1376-1380
Author(s):  
Jerry R. Goodman
Keyword(s):  
Waste Management ◽  
Human Factors ◽  
Management System ◽  
Space Shuttle ◽  
Flight Test ◽  
Operational Performance ◽  
Personal Hygiene ◽  
Test Evaluation ◽  
Design Development ◽  
Design Changes

Significant design changes to the Space Shuttle waste management system (WMS) and its related personal hygiene support provisions (PHSP) have been made recently to improve overall operational performance and human factors interfaces. The WMS design improvements involve increased urinal flow, individual urinals, and provisions for manually compacting feces and cleanup materials to ensure adequate mission capacity. The basic arrangement and stowage of the PHSP used during waste management operations were extensively changed to better serve habitability concerns and operations needs, and to improve the hygiene of WMS operations. This paper describes these changes and the design, development, and flight test evaluation. In addition, provisions for an eighth crewmember and a new four-tier sleep station, are described.

Non-linear aerodynamic modelling of unmanned cropped delta configuration from experimental data

2017 ◽  
Vol 121 (1237) ◽  
pp. 320-340 ◽  
Author(s):  
S. Saderla ◽  
R. Dhayalan ◽  
A.K. Ghosh
Keyword(s):  
Parameter Estimation ◽  
Flow Separation ◽  
Linear Models ◽  
Rectangular Cross Section ◽  
Flight Test ◽  
Point Mapping ◽  
Flight Data ◽  
Aerodynamic Model ◽  
Non Linear ◽  
High Angles Of Attack

ABSTRACTThe paper presents the aerodynamic characterization of a low-speed unmanned aerial vehicle, with cropped delta planform and rectangular cross section, at and around high angles-of-attack using flight test methods. Since the linear models used for identification from flight data at low and moderate angles of attack become unsuitable for accurate parameter estimation at high angles of attack, a non-linear aerodynamic model has to be considered. Therefore, the Kirchhoff's flow separation model was used to incorporate the non-linearity in the aerodynamic model in terms of flow separation point and stall characteristic parameters. The Maximum Likelihood (ML) and Neural Gauss-Newton (NGN) methods were used to perform the parameter estimation on one set of low angle-of-attack and one set of near-stall flight data. It is evident from the estimates that the NGN method, which does not involve solving equations of motion, performs on a par with the classical ML method. This may be attributed to the reason that NGN method uses a neural network which has been trained by performing point to point mapping of the measured flight data. This feature of NGN method enhances its application over a wider envelope of high angles of attack flight data.

Longitudinal parameter estimation from real flight data of unmanned cropped delta flat plate configuration

2016 ◽  
Vol 4 (1) ◽  
pp. 2-22 ◽  
Author(s):  
Subrahmanyam Saderla ◽  
Dhayalan R ◽  
Ajoy Kanti Ghosh
Keyword(s):  
Parameter Estimation ◽  
Maximum Likelihood ◽  
Rectangular Cross Section ◽  
Flight Test ◽  
Least Square ◽  
Likelihood Method ◽  
Content Type ◽  
Flight Data ◽  
Aerodynamic Model ◽  
Estimated Parameters

Purpose – The purpose of this paper is to describe the longitudinal aerodynamic characterization of an unmanned cropped delta configuration from real flight data. In order to perform this task an unmanned configuration with cropped delta planform and rectangular cross-section has been designed, fabricated, instrumented and flight tested at flight laboratory in Indian Institute of Technology Kanpur (IITK), India. Design/methodology/approach – As a part of flight test program a real flight database, through various maneuvers, have been generated for the designed unmanned configuration. A dedicated flight data acquisition system, capable of onboard logging and telemetry to ground station, has been used to record the flight data during these flight test experiments. In order to identify the systematic errors in the measurements, the generated flight data has been processed through data compatibility check. Findings – It is observed from the flight path reconstruction that the obtained biases are negligible and the scale factors are almost close to unity. The linear aerodynamic model along with maximum likelihood and least-square methods have been used to perform the parameter estimation from the obtained compatible flight data. The lower values of Cramer-Rao bounds obtained for various parameters has shown significant confidence in the estimated parameters using maximum likelihood method. In order to validate the aerodynamic model used and to increase the confidence in the estimated parameters a proof-of-match exercise has been carried out. Originality/value – The entire work presented is original and all the experiments have been carried out in Flight laboratory of IITK.

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