ode 45 , odeset, nonnegative

2 次查看（过去 30 天）
jorge reula
jorge reula 2019-5-17
编辑： jorge reula 2019-5-18
I am working with ODE 45, in the simulation of a vehicle's damping system. I want to limit the displacement of the wheels, since they would sink in the earth, however the program eliminates many positive peaks for no reason. How could I avoid this error?
  2 个评论
Jan
Jan 2019-5-17
"the program eliminates many positive peaks for no reason" - this is not clear enough yet. Please post the code and explain, what "positive peaks" are. Of course the code does not do anything "for no reason". But why it is doing what can be explained only, if you share the code.
jorge reula
jorge reula 2019-5-18
编辑：jorge reula 2019-5-18
if true
% code
endwhen the nonnegative command is entered, in equations 1 and 5, center of mass and pitch respectively,
% cut the curve appropriately, but when I cut the answer of equations 3 and 7 cut positive parts
% that should not.
%%%%SCRIPT
% %ARGO 1.3
clc
clear all
%Vehicle information
mb=1114/2; %MASA MEDIO VC
I=97.89; %MOM IN [kg/m^2]
kb=16000; %COEF EL AMORT
b=1500; %COEF AMORT
mwi=75; %MASA RUEDA
kwi=160000; %COEF EL RDA
kbt=kb;
bt=b;
Lt=2.521; %LONG TOT
ld=0.7;
lt=-(Lt-ld);
h=0.1;
e=0.5; %ANCHO LOMO [m]
v=100/36; %VEL VC [m/s]
t=[0 4];
CI=[0 0 0 0 0 0 0 0]; %COND INICIAL Zb(1) Zbp(2) Zw1(3) Zwp1(4) tita(5) titap(6) Zw2(7) Zwp2(8)
opts = odeset('AbsTol',1e-6,'Reltol',1e-4,'nonNegative',[3 7],'MaxStep',0.1,'refine',4);
[T,y]=ode45(@solu,t,CI,opts,mwi,mb,b,kb,kwi,I,v,e,Lt,lt,ld,bt,kbt,h); % %CENTRO DE MASA % figure (1) subplot(2,1,1) plot(T,y(:,1)) title('CM') grid legend('P') % % %PITCH subplot(2,1,2) plot(T,y(:,5)) title('PITCH') grid legend('P') %wheel figure (2) plot(T,y(:,3),T,y(:,7)) title('RUEDA del') grid legend('PR1')%,'PR2') %%%% ODE45Ffunction function[y]=solu(t,CI,mwi,mb,b,kb,kwi,I,v,e,Lt,lt,ld,bt,kbt,h) ue=h*cos((2*pi*v/e)*(t-0.5)); %wave if (0.5<=t && t<0.5+(e/v)) u=ue; u1=0; elseif 0.5+(e/v)+(ld-lt)/(v)<=t && t<0.5+(e/v)+(ld-lt)/(v)+(e/v) u=0; u1=ue; else u=0; u1=0; end % CENTRO DE MASA y(1,1)=CI(2); y(2,1)=(-b*(CI(2)+ld*CI(6)-CI(4))-bt*(CI(2)+lt*CI(6)-CI(8)))/(mb) + (-kb*(CI(1)+ld*CI(5)-CI(3))-kbt*(CI(1)+lt*CI(5)-CI(7)))/(mb); % RUEDA 1 y(3,1)=CI(4); y(4,1)=(b*(CI(2)+ld*CI(6)-CI(4))+kb*(CI(1)+ld*CI(5)-CI(3))-kwi*(CI(3)-u))/(mwi); % RUEDA 2 y(7,1)=CI(8); y(8,1)=(bt*(CI(2)+lt*CI(6)-CI(8))+kbt*(CI(1)+lt*CI(5)-CI(7))-kwi*(CI(7)-u1))/(mwi); % PITCH y(5,1)=CI(6); y(6,1)=((-b*(CI(2)+ld*CI(6)-CI(4))*ld-kb*(CI(1)+ld*CI(5)-CI(3))*ld)/I + (-bt*(CI(2)+lt*CI(6)-CI(8))*lt-kbt*(CI(1)+lt*CI(5)-CI(7))*lt)/I);

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

jorge reula
jorge reula 2019-5-17
%when the nonnegative command is entered, in equations 1 and 5, center of mass and pitch respectively,
% cut the curve appropriately, but when I cut the answer of equations 3 and 7 cut positive parts
% that should not.
%%%% SCRIPT
% %ARGO 1.3
clc
clear all
%Vehicle information
mb=1114/2; %MASA MEDIO VC
I=97.89; %MOM IN [kg/m^2]
kb=16000; %COEF EL AMORT
b=1500; %COEF AMORT
mwi=75; %MASA RUEDA
kwi=160000; %COEF EL RDA
kbt=kb;
bt=b;
Lt=2.521; %LONG TOT
ld=0.7;
lt=-(Lt-ld);
h=0.1;
e=0.5; %ANCHO LOMO [m]
v=100/36; %VEL VC [m/s]
t=[0 4];
CI=[0 0 0 0 0 0 0 0]; %COND INICIAL Zb(1) Zbp(2) Zw1(3) Zwp1(4) tita(5) titap(6) Zw2(7) Zwp2(8)
opts = odeset('AbsTol',1e-6,'Reltol',1e-4,'nonNegative',[3 7],'MaxStep',0.1,'refine',4);
[T,y]=ode45(@solu,t,CI,opts,mwi,mb,b,kb,kwi,I,v,e,Lt,lt,ld,bt,kbt,h);
% %CENTRO DE MASA
%
figure (1)
subplot(2,1,1)
plot(T,y(:,1))
title('CM')
grid
legend('P')
%
% %PITCH
subplot(2,1,2)
plot(T,y(:,5))
title('PITCH')
grid
legend('P')
%wheel
figure (2)
plot(T,y(:,3),T,y(:,7))
title('RUEDA del')
grid
legend('PR1')%,'PR2')
%%%% ODE45Ffunction
function[y]=solu(t,CI,mwi,mb,b,kb,kwi,I,v,e,Lt,lt,ld,bt,kbt,h)
ue=h*cos((2*pi*v/e)*(t-0.5)); %wave
if (0.5<=t && t<0.5+(e/v))
u=ue;
u1=0;
elseif 0.5+(e/v)+(ld-lt)/(v)<=t && t<0.5+(e/v)+(ld-lt)/(v)+(e/v)
u=0;
u1=ue;
else
u=0;
u1=0;
end
% CENTRO DE MASA
y(1,1)=CI(2);
y(2,1)=(-b*(CI(2)+ld*CI(6)-CI(4))-bt*(CI(2)+lt*CI(6)-CI(8)))/(mb) + (-kb*(CI(1)+ld*CI(5)-CI(3))-kbt*(CI(1)+lt*CI(5)-CI(7)))/(mb);
% RUEDA 1
y(3,1)=CI(4);
y(4,1)=(b*(CI(2)+ld*CI(6)-CI(4))+kb*(CI(1)+ld*CI(5)-CI(3))-kwi*(CI(3)-u))/(mwi);
% RUEDA 2
y(7,1)=CI(8);
y(8,1)=(bt*(CI(2)+lt*CI(6)-CI(8))+kbt*(CI(1)+lt*CI(5)-CI(7))-kwi*(CI(7)-u1))/(mwi);
% PITCH
y(5,1)=CI(6);
y(6,1)=((-b*(CI(2)+ld*CI(6)-CI(4))*ld-kb*(CI(1)+ld*CI(5)-CI(3))*ld)/I + (-bt*(CI(2)+lt*CI(6)-CI(8))*lt-kbt*(CI(1)+lt*CI(5)-CI(7))*lt)/I);

类别

在 Help Center 和 File Exchange 中查找有关 Applications 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by