AE 305/717: Flight Dynamics and Control

This course mainly concerns the motion of vehicles that tend to fly in the outer atmosphere. The notion of flying here takes into account some sort of lift, or suspension. The vehicle in consideration can itself be thought of as an arbitrary system of deformable bodies joined in harmony. For instance, a bullet can be deemed as single rigid body, whereas a jet transport is a combination of a main elastic body, rotating and articulated subsystems, and fluid subsystems. An astronaut attached to an orbiting spacecraft via a tether, however, is an example of a flexible body system. The motion of the vehicle can incorporate various ideas such as trajectory of the vehicle mass center, attitude of the vehicle, rotation of the vehicle, or in some cases, the relative motion of vehicle subsystems, etc. In this course, we shall restrict ourselves to the flight of aeroplanes in the atmospehere.

We shall revisit the traditional notions of linear systems theory to address the stability and behavior of such systems in response to some input, or some disturbance. In fact, the modern flight dynamics not only considers the study of aerodynamics, stability and control of the airframe, but also the complex interplay between the vehicle and its flight control system.

We shall maily seek answers to the following questions:

  1. How can we determine the stability and the control characteristics of a vehicle, and assure their good behavior?
  2. What qualities can be termed good behavior?
  3. How do we go on ensuring the good behavior in presence of anomalies?

The answer to the first question requires a mathematical formulation of the problem, equations of motion and their soultions, development of dynamical models and investigation of their response to the excitation. The second question merely concerns the motion characteristics, experiences and evaluations of a flight whose behavior can be considered satisfactory. The third one forms a crucial part of the course. We shall need control theoretic tools in order to augment the stability characteristics if the flight behavior is not the one we intended.

Course materials are available at IITB Moodle.