有关matlab的非线性约束优化求解的问题

这是主程序
clear all
clc
hd=pi/180;
r=0.307;u=0.35;rou=7513;
x0=[261e-3 14.2e-3 50.8e-3 3.2e6 0.062 0.126 0.8727];
x=x0;
Re=2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);
Tf0=0.5*u*pi*x(3)^2*Re*x(4);
md0=0.25*pi*x(1)^2*x(2)*rou;
lb=[245e-3 13.5e-3 48e-3 1.5e6 0.05 0.09 0.82];
ub=[280e-3 15.1e-3 58e-3 7.5e6 0.075 0.16 1.5708];
options=optimset('Algorithm','interior-point','MaxFunEvals',3000);
[x,y]= fmincon('disc_m',x0,[],[],[],[],lb,ub,'disc_y',options);
Re=2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);
Tf=0.5*u*pi*x(3)^2*Re*x(4);
md=0.25*pi*x(1)^2*x(2)*rou;
fprintf('优化前盘式制动器制动力矩Tf0=%3.2f N*m \n',Tf0)
fprintf('优化前制动盘质量md0=%3.2f kg \n',md0)
fprintf('优化后盘式制动器制动力矩Tf=%3.2f N*m \n',Tf)
fprintf('优化后制动盘质量md=%3.2f kg \n',md)
fprintf('优化后的x=%3.3f，%5.4f，%5.4f，%3.0f，%4.3f，%4.3f，%5.4f \n',x)
fprintf('最优解y=%3.2f \n',y)

目标函数
function o=disc_m(x)
%UNTITLED3 Summary of this function goes here
% Detailed explanation goes here
v1=100/3.6;v2=0;u=0.35;rou=7513;A=0.94;
x(3)=50.8e-3;
Re=2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);
Tf=0.5*u*pi*x(3)^2*Re*x(4);
z=0.9;J=4.18;
m=1880;
cd=482;
md=0.25*pi*x(1)^2*x(2)*rou;
E=0.5*m*(v1^2-v2^2);
dt=A*z*E/(J*md*cd);
o=dt/Tf;
end
约束函数
function [c,ceq]=disc_y(x)
%UNTITLED4 Summary of this function goes here
% Detailed explanation goes here
ceq=[];
dh=0.305;dg=0.12;va=8.33;v1=100/3.6;v2=0;P=2.76e6;
lmd=1.1;r=0.307;e=6e6;ul=0.65;u=0.35;cd=482;rou=7513;A=0.94;pm=7.5e6;z=0.9;J=4.18;
j=0.6*9.8;t=(v1-v2)/j;
A1=x(7)/2*(x(6)^2-x(5)^2);
m=1880;
Re=2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);
Tf=0.5*u*pi*x(3)^2*Re*x(4);
beta=0.6;
beta1=4*x(5)*x(6)/((x(5)+x(6))*Re+2*x(5)*x(6));
c(1)=lmd*Tf-ul*m*9.8*r*beta/2;
c(2)=beta1*Re*pi*x(3)^2*x(4)/x(5)/A1/4-P;
c(3)=x(4)-pm;
c(4)=2*A*z*m*va^2/(J*rou*cd*pi*x(1)^2*x(2))-15;
c(5)=x(1)-0.77*dh;
c(6)=x(6)+0.002-x(1)/2;
c(7)=dg/2+0.003-x(5);
c(8)=x(3)/2+0.004+dg/2-(x(6)-x(5))/2;
c(9)=1.27-x(6)/x(5);
c(10)=x(6)/x(5)-1.63;
c(11)=0.25*m*v1^2/t/A1*beta-e;
end

求大神帮忙解答啊 ，毕业设计这个坎过不去了。

c(4)=2*A*z*m*va^2/(J*rou*cd*pi*x(1)^2*x(2))-15;改成
c(4)=2*A*z*m*va^2/(J*rou*cd*pi*x(1)^2*x(2))-20; 试试