MATLAB Toolbox for Automatic Approximation of Nonlinear Functions

Given a nonlinear dynamical system in analytic form, the paper proposes a novel method for approximating the system by a suitable hybrid model such that the approximation accuracy is maximized. Specifically, the problem of approximating generic nonlinear functions by piecewise affine (PWA) models is considered. We show that under mild assumptions, the task can be transformed into a series of one-dimensional approximations, for which we propose an efficient solution method based on solving simple nonlinear programs. Moreover, the paper discusses a software implementation of the proposed procedure in form of a MATLAB toolbox.