The describing function method can be considered as an extension to nonlinear systems of the usual Nyquist stability criterion. The origins of the method can be traced back to nonlinear mechanics (Krylov and Bogoliuboff, 1932) but the first workers to apply the approach specifically to control systems were Tustin (1947) and Kochenburger (1950).

Inspec keywords: nonlinear control systems; Nyquist stability

Other keywords: nonlinear mechanics; nonlinear systems; nonlinear control theory; Nyquist stability criterion; describing function method

Subjects: Nonlinear control systems