Abstract This is a demonstration of the PNLSS Toolbox 1.0. The toolbox designed to identify polynomial nonlinear state-space models from data. Nonlinear can describe wide range systems. An illustration provided on experimental data an electrical system mimicking forced Duffing oscillator, and numerical fluid dynamics problem.

Airway function is usually assessed by tests of forced expiration or, in more specialised laboratories, by measuring airways resistance by whole body plethysmography. Plethysmography depends on the patients' cooperation and requires expensive and bulky apparatus. An alternative non-invasive technique for measuring airflow resistance, using forced oscillation, was introduced by DuBois and collea...

In order to measure the nonlinear features of micromechanical resonators, a free damped oscillation method based on stair-stepped frequency sinusoidal pulse excitation is investigated. In the vicinity of the resonant frequency, a frequency stepping sinusoidal pulse sequence is employed as the excitation signal. A set of free vibration response signals, containing different degrees of nonlinear ...

In this study, a novel analytical solution to the integrable undamping Duffing equation with constant forced term is obtained. Also, new approximate (semianalytical) for nonintegrable linear damping oscillator reported. The given in terms of Weierstrass elliptic function arbitrary initial conditions. With respect it, semianalytical constructed depending on ansatz and exact standard (in absence ...