Nonlinear System Modeling based on System Equilibrium Manifold
Abstract The main objective of the present paper is to provide an approximate method for nonlinear system with a family of equilibrium points (EPs). By investigating the system’s equilibrium manifold (EM) and its expansion form, a class of nonlinear system is modeled analytically. The property of the EM expansion form and the effect of mapping design and parameterizing method to the model have been discussed. Then an approximate nonlinear model for aircraft engine was applied, followed by an identification procedure for aircraft engine. It is shown that the modeling method based on system’s EM can not only comply with the system physical characteristics, but also satisfy the accuracy of modeling requirement. Numerical simulations are given to demonstrate the good precision in capturing the nonlinear behavior of nonlinearities and a simpler structure.
