arxoutline.m

基于MATLAB系统辨识工具箱的离线辨识程序

function [m,fit]=ARXoutline(u,z,ts,N,nns,nnt)
%获取模型结构参数范围
nas=nns(1);nat=nnt(1);
nbs=nns(2);nbt=nnt(2);
nk=nns(3);
if (nat-nas+1)*(nbt-nbs+1)>150
    return 
end
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%获取实验数据，及数据预处理
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servo=iddata(z,u,ts);
servo.InputName='position';
servo.OutputName='distance';
ze=servo(1:N);
%figure, plot(ze(1:1000))
%ze=dtrend(ze);
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%模型检验及最优模型选择
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temp=0;
for k1=nas:nat
    for k2=nbs:nbt
            m11=arx(ze,[k1 k2 nk]);         %采用基于最小二乘法估计的ARX模型辨识
            [yh,fit]=compare(ze,m11);       %计算不同结构模型的的适应度
            if fit>temp
               temp=fit;m=m11;              %选择适应度最高的模型
               nn=[k1 k2 nk];
            end
            clc;
    end
end
%figure, compare(ze,m);                      %模型检验
[yh,fit]=compare(ze,m);