Tischler Mark B., Remple Robert K. Aircraft and Rotorcraft System Identification. Engineering Methods with Flight-Test Examples

AIAA, 2006. XXXV, 523 p. — ISBN: 978-1563478376.Although many books have been written on the theory of system identification, few are available that provide a complete engineering treatment of system identification and how to successfully apply it to flight vehicles. This book provides the unique perspective of over 20 years of flight-test applications to both aircraft and rotorcraft and is a valuable resource for students, working engineers, and others interested in atmospheric flight mechanics, modeling and simulation, and test and evaluation. It presents proven methods, practical guidelines, and real-world flight-test results for a wide range of state-of-the-art flight vehicles, from small uncrewed aerial vehicles (UAVs) to large manned aircraft/rotorcraft. Beginning with the basic concepts of system identification, each chapter traces a simple simulation example and real flight examples through the step-by-step process from instrumentation and data checking to model extraction and model verification. The frequency-response method, that is unique to this book, is especially well suited for system identification of aircraft and rotorcraft dynamics models from flight-test data. A complete chapter is devoted to higher-order modeling of helicopters. Many applications are included to demonstrate how the products resulting from system identification are used. Specific applications include flight mechanics and handling-qualities analyses, stability margin determination, structural mode determination, and simulation model fidelity assessment. The book assumes knowledge of the basic concepts of aeronautics, Laplace transforms, and flight dynamics and classical control. Emphasis is placed on engineering methods and interpretation of flight-test results and each key method or analysis application is illustrated with graphics obtained from the system identification software (CIFER[registered]) provided with the book. Case studies based on real flight-test projects are included as well as problems for students to solve using the provided CIFER[registered] software. A Solutions Manual, written by Christina M. Ivler and Mark B. Tischler is available from the publisher.Contents.Page
List ofFigures.Page
List ofTables.Page
Nomenclature.Page
Acronyms.Page
Preface.PageIntroduction and Brief History of System Identification in the Frequency DomainBasic Concepts of System ldentification
Relationship Between Simulation
Special Challenges of Rotorcraft System
More About the Role of Nonparametric
Frequency-Response Identification Method
Role and Limitations of Flight-Mechanics
Brief History of the Developmen
Organization of this Book
ProblemsFrequency-Response Method for System IdentificationRoad Map of Frequency-Response
Key Features of the Frequency-Response
Frequency-Response Identification Method
Examples of CIFER Applications
ProblemsDescription of Example CasesPendulum Example Problem
Dynamic Characteristics in Hover
Measurements for Closed-Loop Hover Flight
Test Case Database for Hover
Measurements for Open-Loop Cruise Flight Testing
Test Case Database for Cruise
ProblemsOverview of CIFER softwareBasic Characteristics of the CIFERm Software
Dataflow Through CIFERB
CIFERm User Interface
Examples of CIFERU tilities
Interfaces with Other Tools
ProblemsCollection of Time-History DataOverview of Data Requirements
Optimal Input Design
Recommended Pilot Inputs
nstrumentation Requirements
Overview of Piloted Frequency Sweeps
Detailed Design of Frequency-Sweep Inputs
Flight-Testing Considerations
Open-Loop vs Closed-Loop Testing
Piloted Frequency SweepS
Summary of Key Points in Piloted Frequency-
Computer-Generated Sweeps
Frequency-Response
ProblemsData Consistency and ReconstructionModeling Measurement Errors
Simple Methods for Data Consistency
ProblemsSingle-Input / Single-Output Frequency Response Identification TheoryDefinition of Frequency Response
Relating the Fourier Transform
Simple Example of Frequency-
Calculating the Fourier Transform
nterpreting Spectral Functions
Frequency-Response Calculation
Coherence Function
Random Error in the Frequency-Response Estimate
Window Size Selection and Tradeoffs
Frequency-Response Identification
Pendulum Example
Applications and Examples
ProblemsBare-Airframe Identification from Dat with Feedback Regulation ActiveLimiting Conditions in Closed-Loop
Quantification of Bias Errors
Bias Errors Defined
Numerical Study of Identification
Flight-Test lrnplications
ldentification of Unstable Inverted
ProblemsMulti-Input Identification TechniquesMulti-Input Terminology
Need for Multiple-Input Identification
Simple Two-Input Example
Conditioned Spectral Quantities
Example of aTwo-Input Identification Solution
General MIMO Solution
High Control Correlation
Multiple-Input Identification in CIFER
Example of MIS0 Solution for a Hovering
MIMO Identification Using a Multi-
Determination of Broken-Loop Response
ProblemsComposite WindowingBackground
Composite-Window Approach
Composite-Window Results
COMPOSITE Windowing in Single-
Composite-Windowing Results
Composite-Windowing Results
Composite Results for Structural
Composite Windowing in Spectr
ProblemsTransfer-Function ModelingMotivations for Transfer-Function Modeling
Transfer-Function Modeling
Model Structure Selection
SlSO Transfer-Function Identificatio
Pendulum Example
Handling-Qualities Applications
Flight-Mechanics Characterization Studies
Flight-Dynamics Models for Control
Aeroelastic Model Identification
Subsystem Component Modelin
ProblemsState-Space Model Identification-Basic ConceptsState-Space Model Identification
Background
MIMO State-Space Model Identification
Accuracy Analysis
Key Features of the Frequency-
State-Space Model Structure
State-Space Model Identification in CIFERm Using DERlVlD
Pendulum Example
Identification of a XV-15 Closed-Loop
Structural System Identification
ProblemsState-Space Model Identification: Physical Model StructuresBackground
Equations of Motion for Flight Vehicles
Model Formulation in a State-Space Structure
Frequency-Response Database
Checking the Initial Model Setup
Model Identification and Structure Reduction
dentification of Three-DOF LateraVDirectional
dentification of Three-DOF LateraVDirectional
Accurate Determination of Stability
dentification of a Three-DOF Longitudinal
System Identification of a six-DOF MIMO
ProblemsTime-Domain Verification of Identification ModelsMotivation for Time-Domain Verification
Time-Domain Verification Method
Estimating the Constant Bias and
Correlation Problem
Time-Domain Verification in CIFERB Using VERIFY
Closed-Loop Transfer-Function Model Verification
Bare-Airframe Model Verification
Bare-Airframe Model Verification
ProblemsHigher-Order Modeling of Coupled Rotor/Fuselage DynamicsBackground and Literature on Identification
Hybrid Model Formulation
Hybrid Model Identification
Lead-Lag Dynamics Identificatio
Problems
Appendix A-Summary of Suggested Guidelines