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新虫 (初入文坛)

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虫号: 3846962
注册: 2015-05-03
专业: 工程热力学

[求助] Matlab拟合反应动力学参数结果偏差很大啊，求大神指点程序当如何修改已有1人参与

最近一直在拟合反应动力学参数，花了很大功夫试着编好了代码，却始终不能得出文献中的参数结果，求大神帮忙指点一下程序。在此拜谢了。
code:
function KineticsEst5
clear all
clc
k0 = [0.5 0.5 0.5 0.5 0.5 0.5];       % 参数初值
lb = [0  0  0  0  0  0];                % 参数下限
ub = [+inf  +inf  +inf  +inf  +inf  +inf]; % 参数上限
x0 = [4.96 24.43 26.32 17 38.72];
ExpData = ...
[
0 4.96          24.43 26.32
5 5.635 28.29 30.715
10 6.31    32.15 35.11
15 6.77          34.225 34.98
20 7.23          36.3 34.85
25 7.065 39.285 33.525
30 6.9          42.27 32.2
35 7.08          45.46 29.7
40 7.26          48.65 27.2
50 8       51.215 24.495
60 8.74          53.78 21.79
75 8.605 58.01 19.12
90 8.47          62.24 16.45
]
yexp = ExpData(:,2:4);
% 使用函数fmincon()进行参数估计
[k,fval,flag] = fmincon(@ObjFunc4Fmincon,k0,[],[],[],[],lb,ub,[],[],x0,yexp);
fprintf(\\\'\\\\n使用函数fmincon()估计得到的参数值为:\\\\n\\\')
fprintf(\\\'\\\\tk1 = %.4f\\\\n\\\',k(1))
fprintf(\\\'\\\\tk2 = %.4f\\\\n\\\',k(2))
fprintf(\\\'\\\\tk3 = %.4f\\\\n\\\',k(3))
fprintf(\\\'\\\\tk4 = %.4f\\\\n\\\',k(4))
fprintf(\\\'\\\\tk5 = %.4f\\\\n\\\',k(5))
fprintf(\\\'\\\\tk6 = %.4f\\\\n\\\',k(6))
fprintf(\\\'  The sum of the squares is: %.1e\\\\n\\\\n\\\',fval)
k_fmincon = k;
% 以函数fmincon()估计得到的结果为初值，使用函数lsqnonlin()进行参数估计
k0 = k_fmincon;
[k,resnorm,residual,exitflag,output,lambda,jacobian] = ...
lsqnonlin(@ObjFunc4LNL,k0,lb,ub,[],x0,yexp);
ci = nlparci(k,residual,jacobian);
fprintf(\\\'\\\\n\\\\n以fmincon()的结果为初值，使用函数lsqnonlin()估计得到的参数值为:\\\\n\\\')
fprintf(\\\'\\\\tk1 = %.4f ± %.4f\\\\n\\\',k(1),ci(1,2)-k(1))
fprintf(\\\'\\\\tk2 = %.4f ± %.4f\\\\n\\\',k(2),ci(2,2)-k(2))
fprintf(\\\'\\\\tk3 = %.4f ± %.4f\\\\n\\\',k(3),ci(3,2)-k(3))
fprintf(\\\'\\\\tk4 = %.4f ± %.4f\\\\n\\\',k(4),ci(4,2)-k(4))
fprintf(\\\'\\\\tk5 = %.4f ± %.4f\\\\n\\\',k(5),ci(5,2)-k(5))
fprintf(\\\'\\\\tk6 = %.4f ± %.4f\\\\n\\\',k(6),ci(6,2)-k(6))
fprintf(\\\'  The sum of the squares is: %.1e\\\\n\\\\n\\\',resnorm)
% ------------------------------------------------------------------
function f = ObjFunc4Fmincon(k,x0,yexp)
tspan = [0,5,10,15,20,25,30,35,40,50,60,75,90];
[t x] = ode45(@KineticEqs,tspan,x0,[],k);
y(:,1:3) = x(:,1:3);
f = sum((y(:,1)-yexp(:,1)).^2) + sum((y(:,2)-yexp(:,2)).^2) + sum((y(:,3)-yexp(:,3)).^2);
% ------------------------------------------------------------------
function f = ObjFunc4LNL(k,x0,yexp)
tspan = [0,5,10,15,20,25,30,35,40,50,60,75,90];
[t x] = ode45(@KineticEqs,tspan,x0,[],k);
y(:,1:3) = x(:,1:3);
f1 = y(:,1) - yexp(:,1);
f2 = y(:,2) - yexp(:,2);
f3 = y(:,3) - yexp(:,3);
f = [f1; f2; f3];
% ------------------------------------------------------------------
function dxdt = KineticEqs(t,x,k)
dxdt =  ...
[ (k(1)*x(1)+k(6)*x(3))
(k(2)*x(1)+k(5)*x(3))
(k(3)*x(1)+k(4)*x(2)-(k(5)+k(6))*x(3))
(-(k(1)+k(2)+k(3))*x(1))
(-k(4)*x(2))
];

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