Atmospheric Flight Dynamics and Control

In This Section

Atmospheric Flight Dynamics and Control

Synopsis:

The course covers all five aspects of flight dynamics and control in an integrated format – the equations of motion; aerodynamic modeling; steady-state analysis and control power; dynamic and modal analyses including modal approximations; and synthesis of stability-augmentation and autopilot control laws. The course contains a clear, rigorous, yet practical treatment of conventional topics dealing with rigid vehicles, while also extensively addressing the flight dynamics and control of elastic vehicles. Key topics include: the rigorous derivation of the equations of motion for rigid and flexible aircraft via Newton and Lagrange; a review/tutorial on lumped-mass vibrations including rigid-body degrees of freedom; modeling the effects of static and dynamic elastic deformation on the forces and moments; modal analysis of rigid and flexible vehicles; elastic effects on vehicle control (e.g., filtering, sensor and actuator placement); a case study on active structural mode control; plus other examples involving a flexible hypersonic vehicle and large flexible aircraft. The material on flexible vehicles is presented from a “flight-dynamics” rather than a “structural-dynamics” perspective.

The dynamics-based synthesis of stability-augmentation control laws is strongly connected to the natural modes, and specifically addresses the multi-input/multi-output character of the dynamic system. An integrated treatment of linear dynamic models is used throughout, including transfer functions, state-variable models, and polynomial-matrix representations. Typical autopilot control laws are synthesized using loop-shaping techniques, including discussions of typical sensors and gain scheduling. Finally, the student is briefly introduced to the classical “crossover” pilot model and its implications regarding flight control. MATLAB® and Simulink are used extensively in the many examples involving real aircraft.

Key Topics:

  • A clear, rigorous, yet practical treatment of conventional topics in flight dynamics – extensive aerodynamic modeling, static trim and stability, dynamic analysis; modal approximations and modal analysis using eigenvalues and eigenvectors.
  • Extensive coverage of more-advanced topics - development of the non-linear equations of motion in several important coordinate frames, plus the equations of motion for elastic vehicles; effects of variable mass or a rotating, spherical earth on the equations of motion.
  • Logical integration of all the facets of the subject using the overarching framework of non-linear systems analysis, including perturbation theory.
  • Dynamics-based synthesis of stability-augmentation control laws directly tied to the vehicle’s natural modes; consideration of the multi-input/multi-output effects present; sensor/actuator selection and gain scheduling; loop-shaping synthesis of typical autopilot modes; gain and phase stabilization and active control of elastic modes; an introduction to the “crossover” pilot model.
  • Extensive usage of MATLAB® and Simulink in the many examples involving real aircraft.

Who Should Attend:

The course is invaluable to anyone involved with the development of flight-dynamic models, or with their use, such as in control-law development or flight simulation. It is appropriate for the young engineer that wants a solid foundation in flight dynamics, aerodynamic modeling, and conventional, practical, flight-control-law synthesis, as well as the more established professional that wants both a review of the basic topics plus exposure to more advanced topics such as the flight dynamics of elastic vehicles. The rigorous yet practical treatment of the material will also be of interest to educators in aerospace or mechanical engineering.

Course Information:

Type of Course: Instructor-Led Short Course
Course Level: Intermediate


Course scheduling available in the following format:


  • Course at Conference
  • On-site Course
  • Standalone/Public Course

Course Length: 2 days
AIAA CEU's available: yes

Outline

Course Outline:


I. Introduction and Review
A. Small Perturbation Theory for Non-Linear Systems
B. Vectors Differentiation, Coordinate Transformations, Direction-Cosine Matrices
C. Basic Aerodynamics of Lifting Surfaces
II. The Non-Linear and Perturbation Equations of Motion
A. Rigid-Body Equations of Motion – Flat Earth
B. Effects of Rotating Masses, Variable Mass, Spherical, Rotating Earth
C. Point-Mass Performance Equations
D. Equations of Motion for Elastic Vehicles
E. Tutorial on lumped-mass vibrations with rigid-body degrees of freedom
III. Modeling the Forces and Moments on the Vehicle
A. Description of the Modeling Framework
B. Aerodynamic and Propulsive Forces and Moments
C. Forces and Moments Due to Perturbations and Gusts
D. Effects of Elastic Deformation on the Forces and Moments – Generalized Forces
IV. Analysis of Steady and Quasi-Steady Flight
A. Equilibrium Reference Conditions
B. The Concept of Aerodynamic Static Stability-And Criteria
C. Analysis of Steady Rectilinear Flight, Turning Flight, and Quasi-Steady Pull-Up Maneuvers
1. Linear Flight-Dynamic Analysis
D. Eigenanalysis of linear systems
E. Aircraft Transfer Functions, Modal Analysis, and Modal Approximates
F. Cross-Axis Coupling
G. Vehicle Design to Achieve Desirable Dynamic Characteristics
V. Feedback Stability Augmentation
A. Dynamics-Based Augmentation, Multi-Input/Multi-Output Effects, Coupling Numerators
B. Pitch, Roll, Yaw Dampers; ARI’s, Short-Period and Phugoid Stabilization.
VI. Automatic Guidance and Control – Autopilots
A. Loop Shaping, Inner and Outer Loops, and Frequency Separation
B. Attitude Control, Response Holds, Path Guidance, Structural-Mode Control
VII. Control Characteristics of the Human Pilot

Course Outline

• Introduction and Review
    o Small Perturbation Theory for Non-Linear Systems
    o Vectors Differentiation, Coordinate Transformations, Direction-Cosine Matrices 
    o Basic Aerodynamics of Lifting Surfaces
• The Non-Linear and Perturbation Equations of Motion
    o Rigid-Body Equations of Motion – Flat Earth
    o Effects of Rotating Masses, Variable Mass, Spherical, Rotating Earth
    o Point-Mass Performance Equations
    o Equations of Motion for Elastic Vehicles
    o Tutorial on lumped-mass vibrations with rigid-body degrees of freedom
• Modeling the Forces and Moments on the Vehicle 
    o Description of the Modeling Framework
    o Aerodynamic and Propulsive Forces and Moments
    o Forces and Moments Due to Perturbations and Gusts
    o Effects of Elastic Deformation on the Forces and Moments – Generalized Forces
• Analysis of Steady and Quasi-Steady Flight
    o Equilibrium Reference Conditions
    o The Concept of Aerodynamic Static Stability-And Criteria
    o Analysis of Steady Rectilinear Flight, Turning Flight, and Quasi-Steady Pull-Up Maneuvers
• Linear Flight-Dynamic Analysis
    o Eigenanalysis of linear systems
    o Aircraft Transfer Functions, Modal Analysis, and Modal Approximates
    o Cross-Axis Coupling
    o Vehicle Design to Achieve Desirable Dynamic Characteristics
• Feedback Stability Augmentation 
    o Dynamics-Based Augmentation, Multi-Input/Multi-Output Effects, Coupling Numerators
    o Pitch, Roll, Yaw Dampers; ARI’s, Short-Period and Phugoid Stabilization.
• Automatic Guidance and Control – Autopilots 
    o Loop Shaping, Inner and Outer Loops, and Frequency Separation
    o Attitude Control, Response Holds, Path Guidance, Structural-Mode Control
• Control Characteristics of the Human Pilot

Instructors

Course Instructor:


Dr. David K. Schmidt is an internationally recognized expert in atmospheric flight dynamics and control. Early in his career he served on the technical staffs of the McDonnell Douglas Missiles and Space Corp. and the Stanford Research Institute. While later he served as a summer faculty fellow at the USAF Flight Dynamics Laboratory and as a visiting sabbatical professor at NASA’s Langley Research Center. Over his 30-year academic career, he has been a member of the engineering faculties of, in order, Purdue University, Arizona State University, and the University of Maryland at College Park. He is currently Professor Emeritus at the University of Colorado.

He has been an invited member of several national review panels on aerospace research, including several organized by the National Academy of Engineering and the USAF Scientific Advisory Board. In service to AIAA, he has served as the General Conference Chair for the Guidance, Navigation and Control Conference and has chaired the GN&C Technical Committee, he is a past member of AIAA’s Education Editorial Board, and he was an associate editor of the Journal of Dynamics, Guidance, and Control. Dr. Schmidt is the author of "Modern Flight Dynamics," published by McGraw-Hill (2011), plus over 200 research articles on flight dynamics and man-machine control systems. And in 1997, Dr. Schmidt received AIAA’s highest honor in his field when he was awarded the Mechanics and Control of Flight Award. He is a fellow of AIAA.