A Practical Approach to Robustness Analysis with Aeronautical Applications

1. Front Matter

   Pages i-xxv

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2. Preliminaries

   1. Introduction to μ and LFTs

      Pages 3-28

   2. Applicative Examples

      Pages 29-40

3. Computation of a Standard LFT Structure

   1. Realization of Uncertain Systems Under an LFT Form

      Pages 43-52

   2. Applications

      Pages 53-59

4. μ Applications

   1. Computation of μ Bounds

      Pages 63-79

   2. Applications of the μ Tools

      Pages 81-92

5. Skewed μ Applications

   1. Skewed μ Problems in Robustness Analysis

      Pages 95-102

   2. Computation of Skewed Bounds

      Pages 103-113

   3. Application of the Skewed μ Tools

      Pages 115-120

6. Nonstandard Applications

   1. Robustness Analysis of Flexible Structures

      Pages 123-141

   2. Robustness Analysis in the Presence of Time Delays

      Pages 143-162

   3. Nonlinear Analysis in the Presence of Parametric Uncertainties

      Pages 163-181

7. Back Matter

   Pages 183-205

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1. MOTIVATION In many physical situations, a plant model is often provided with a qualitative or quantitative measure of associated model uncertainties. On the one hand, the validity of the model is guaranteed only inside a frequency band, so that nearly nothing can be said about the behavior of the real plant at high frequencies. On the other hand, if the model is derived on the basis of physical equations, it can be parameterized as a function of a few physical parameters, which are usually not perfectly known in practice. This is e.g. the case in aeronautical systems: as an example, the ae- dynamic model of an airplane is derived from the flight mechanics eq- tions. When synthesizing the aircraft control law, it is then necessary to take into account uncertainties in the values of the stability derivatives, which correspond to the physical coefficients of the aerodynamic model. Moreover, this airplane model does not perfectly represent the be- vior of the real aircraft. As a simple example, the flight control system or the autopilot are usually synthesized just using the aerodynamic model, thus without accounting for the flexible mechanicalstructure: the c- responding dynamics are indeed considered as high frequency neglected 1 dynamics, with respect to the dynamics of the rigid model .

• Scope
• Standard
• calculus
• computation
• form
• framework
• missile
• online
• proof
• time
• tool

• ONERA-CERT, Toulouse, France

  Gilles Ferreres

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