The Identification Methods Of Nolinear Block Oriented Model

Mathematical model is very important for modern idustrial engineering,itis the foundation of a series of control theory and system optimizationcontrol.Then,the precision requirements of mathematical model is more andmore taller in the actual.Relative to the mechanism analysis which can be useto modeling,the identification has its own advantages.Because of the commonexists in nature,how to establish the model of the nonliear system is a vitalrole of engineering practicd. This paper introduces the nonliner block orientedmodel include Hammerstein and Wiener model and their identificationmethods.By simulating some example,getitng identificaiton results.This papermain consist of the following several aspects work.1Introduceing some basic knowledge of system identification andseveral kinds of classic identification methods,described some Hammersteinmodel and its industrial application,in the view of a spsrk ignition enginesHammerstein model of simulation,explain recursive least squares can beapplied in identification problem of Hammerstrin model.Simulating several Hammerstein model and compared identification resules of the auxiliarymodel recursive least suqare algorithm and a first filtering of least squaremehod.2Describing the paricle swarm optimization(PSO) algorithm and itsmodified algorithm.Simluating some examples shows that the PSO andmodified PSO based on global convergence which called SPSO algorithm cansuccessfully in applied to identification problem of the Hammerstein modeland get good parameter estimation.3According to a unified model which can description of variousnonlinear characteristics of the nonlinear model and researching itsidentificaion methods.Successfully estimating parameters of Hammersteinmodel with the unified nonlinear model by PSO algorithm.Through theselection of parameters of the unified model can deal with9differentnonlinear characteristics of Hammerstein model identification problem.4Using SPSO algorithms deal with a Wiener model identificationproblem.The simulation shows that SPSO also can get well parametersestimation under a noise interference.Finally puts forward a identificationmethod of two steps to identify the Wiener model based on SPSOalgorithm.The simulation shows that the algorithm is feasible.