Robustness Analysis and Synthesis for Essentially Nonlinear Systems

Abstract

The research was concentrated on developing an advanced theory of stability and performance analysis of nonlinear dynamical systems. The ultimate goal is to provide algorithms and software for analytical validation of flight control algorithms involving gain scheduling, actuator saturation logical switching, etc., thus reducing the current dependence on extensive simulations in feedback control design. A number of new results were obtained. A study of dynamic behaviour of rate limiters allowed for the first time to develope methods of absolute stability analysis that are capable of discriminating between systems with quasiconcave nonlinearities (such as the saturation) and quasiconvex nonlinearities (such as the deadzone). A software package for rigorous analysis of stability and performance of nonlinear/time-varying/uncertain systems was developed based on the concept of Integral Quadratic Constraints. A new method of gain scheduling for linear feedback design under the condition of control saturation has been developed, with guaranteed stability margins rigorously proven. A unique technique for rigorous analysis of global and semiglobal stability of self-oscillations in higher order relay feedback systems has been developed.

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Document Details

Document Type
Technical Report
Publication Date
Oct 22, 1997
Accession Number
ADA336100

Entities

People

  • Alexandre Megretski

Organizations

  • Iowa State University

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Abstracts
  • Algorithms
  • Classification
  • Closed Loop Systems
  • Complex Systems
  • Computer Science
  • Control Systems
  • Electrical Engineering
  • Engineering
  • Feedback
  • Flight Control Systems
  • Frequency Domain
  • Integrals
  • Integrators
  • Nonlinear Systems
  • Saturation
  • Scheduling (Production)

Fields of Study

  • Engineering

Readers

  • Computational Modeling and Simulation
  • Control Systems Engineering.
  • Operations Research