AN EVALUATION OF SELECTED DESCRIBING FUNCTIONS OF CONTROL SYSTEM NONLINEARITIES

Abstract

A describing function is an amplitude-dependant generalized transfer function of a nonlinearity which can be used to represent the nonlinearity when its input is approximately sinusoidal. The simpler and more prominent or accurate describing-function generating schemes include (1) the conventional, (2) the minimum average error, (3) the equivalent gain, (4) the new rms, and (5) the corrected-conventional. An evaluation of these various schemes, based on the accuracy with which the describing functions they produce can predict the amplitude and frequency of self-sustained oscillations in a nonlinear system, reveals that the corrected-conventional describing functions are more accurate for single-valued nonlinearities.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1964
Accession Number
AD0603957

Entities

People

  • Robert R. Rankine Jr.

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Air Force
  • Analog Computers
  • Closed Loop Systems
  • Computers
  • Control Systems
  • Control Systems Engineering
  • Differential Equations
  • Digital Computers
  • Engineers
  • Equations
  • Fourier Analysis
  • Fourier Series
  • Linear Systems
  • Nonlinear Systems
  • Plastic Explosives
  • Sine Waves
  • Two Dimensional

Readers

  • Control Systems Engineering.