Prediction of limit cycles in nonlinear system with ideal relay type nonlinearities by using multiple-input describing functions

In this paper we present some results and simulations about the limit cycle prediction in nonlinear systems with relay type nonlinearities using Multiple-input describing functions. The introduction of Describing Functions (DFs) theory is given, together with the derivations of three-sinusoid-input describing functions for the ideal relay nonlinearity. Then the application of this approach for analysis of the limit cycles in second order nonlinear systems with ideal relay type nonlinearity is shown. The applicability of the approach is demonstrated by example.