Structurally stable PWL approximation of a simple dynamical system

Biophysical and Electronic Engineering Department, University of GenoaVia Opera Pia 11a, I-16145 Genova, ItalyEmail: Marco.Storace@unige.itAbstract—This paper concerns the piecewise-linear (PWL) approximation of the cusp normal form,which is a well-known nonlinear dynamical system.Evenifappliedtoasimpleexample,themethodcanbeeasily generalized and allows one to define a strategyto calculate the optimal coefficients for the PWL ap-proximation. It is possible to choose either an approx-imation accuracy almost uniform all over the approx-imation domain, or an approximation particularly ac-curateintheneighborhoodsofsignificantsetsofpoints(bifurcation curves or invariant sets), or a compromisebetween these two situations. The numerical results inthe considered example confirm the reliability of theproposed approach.1. IntroductionThis paper deals with the piecewise-linear (PWL)approximation (in view of structurally stable circuitimplementations) [1] of known nonlinear dynamicalsystems with bounded dynamics governed by the fol-lowing set of ordinary differential equations: