This module defines the describing function (DF) of a nonlinearity and shows how it may be used to study the behavior of a feedback loop with a single nonlinearity. DFs are derived for single and double valued nonlinearities and examples are given to show how DFs can be used for examining the stability of a nonlinear system. Since the method is approximate comments are made on its accuracy.
Module objectives. When you have completed this module you should be able to:
First year mathematics, Fourier series,transfer functions,frequency response, stability