车辆盘式制动器仿真与优化设计(MATLAB版)

车辆盘式制动器仿真计算与优化设计（上）

运用了fmincon函数来进行求解最优值。

优化主函数：

clear all

clc

hd = pi/180;

r = 0.302; f = 0.35; rou = 7513;

x0 = [ 261e-3 14.2e-3 50.8e-3 3.20e6 0.062 0.126 0.8727 ];

x = x0;

Re = 2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);

Tf0 = 2*f*0.25*pi*x(3)^2*Re*1e6;

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];

[x,y] = fmincon ('disc_m',x0,[ ],[ ],[ ],[ ],lb,ub,'disc_y');

Re = 2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);

Tf = 2*f*0.25*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',Tf) 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)

优化目标函数

function o = disc_m(x)

dh = 0.305; dg = 0.12; va = 8.33; v1 = 100/3.6; v2=0; P = 2.76e6; lmd = 1.15; r=0.307; ul = 0.65; f = 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 = 2*f*0.25*pi*x(3)^2*Re*x(4);

z = 0.9; J = 4.18;

m = 1880;

beta = 0.6;

cd = 482;

md = 0.25*pi*x(1)^2*x(2)*rou;

E = 0.5*m*(v1^2-v2^2)*beta;

a = 0.34;

dt = a*z*E/(J*md*cd);

o = Tf/dt;

优化约束函数

function [c,ceq] = disc_y(x);

ceq = [ ];

dh = 0.315; dg = 0.12; va = 8.33; v1 = 100/3.6; v2=0; P = 2.76e6;

lmd = 1.15; r = 0.307; e = 6e-6; ul = 0.6; f = 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/j;

A1 = 2*0.25*x(7)/2*(x(6)^2-x(5)^2);

m = 1880;

md = 0.25*pi*x(1)^2*x(2)*rou;

Re = 2/3*(x(6)^3-x(5)^3)/(x(6)^2-x(5)^2);

Tf = 2*f*0.25*pi*x(3)^2*Re*x(4);

beta = 0.6; a = 0.34;

c(1) = lmd*Tf-ul*m*9.8*r*beta/2;

c(2) = beta*m*j*r/f/Re/A1/1-2.4e6;

c(3) = x(4)-pm;

c(4) = a*m*va^2*beta/(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(8) = dg/2+0.003-x(5)/2;

c(7) = 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/A1/2*beta-6e6;

代码未完.见下节