system of nonlinear differential equations

Question

osman 2012-4-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/35765-system-of-nonlinear-differential-equations

I have two systems of nonlinear equation. I need to solve this equation with matlab.I'm searching in the internet but culdn't find the solution could you help me pls? equations are: http://d1204.hizliresim.com/w/k/4kn5l.png

3 个评论
显示 1更早的评论隐藏 1更早的评论

osman 2012-4-17

any suggestion

Walter Roberson 2012-4-17

Do the dots indicate differentiation?

If only theta and x are variable, but you are differentiating theta and x, then what are you differentiating them with respect to? Are you sure they are variables and not functions such as x(t) and theta(t) with differentiation with respect to t ?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

osman 2012-4-29

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/35765-system-of-nonlinear-differential-equations#answer_46170

在 MATLAB Online 中打开

function turev = derivati( t,h )
M_ball=0.0327;
g=9.8;
J_bm=0.0620;
K=4.9100;
Ke=4.77;
R=4.7;
Rb=0.01;
b=1.5279;
a1=0.0050;
V=1;
% h1=theta
% h2=Dtheta
% h3=x
% h4=Dx
% turev1=Dtheta
% turev2=D2theta
% turev3=Dx
% turev4=D2theta
turev=zeros(size(h));
   turev(1) = h(2);
   turev(2) = (K/(R*J_bm)*V)-(K*Ke/R+b)/J_bm*turev(1)-h(3)*M_ball/J_bm*g*cos(h(1));
   turev(3) = h(4);
   turev(4) = g*sin(h(1))/(1+(2/5)*(Rb/a1)^2);
end