
eps=0.000001;
pi=0;x=0;k=1;
while 1/k>=eps
x=4*(1/k-1/(k+2));
pi=pi+x;
k=k+4;
end
vpa(pi,6)
1-2
syms x y
Y=dsolve('x*D2y-3*Dy=X^2','y(1)=0','y(5)=0');
pretty(simple(Y))
1-3
syms t y
Y=dsolve('D4y+5*t*D3y+6*t*t*D2y+4*Dy=sin(4*t+pi/3)*exp(-5*t)+exp(-3*t)',...
'y(0)=1','Dy(0)=0.5','D2y(0)=0.5','D3y(0)=0.2');
pretty(simple(Y))
1-4
num=[6 4 2 2]; den=[1 10 32 32];
G=tf(num,den)
zpk(G)
2-1
%将m=M=0.5,l=0.3,g=9.81,带入倒立摆模型的状态方程的A,B,C,D
A=[0,1,0,0;65.4,0,0,0;0,0,0,1;-9.81,0,0,0];
B=[0;-6.67;0;2];
C=[1,0,0,0;0,0,1,0];
D=zeros(2,1);
G=ss(A,B,C,D);
Tc=ctrb(A,B)
rank(Tc)
To=obsv(A,C)
rank(To)
step(G)
2-2
function xdot=f(t,x)
xdot=[-5 2 0 0;0 -4 0 0;-3 2 -4 -4;-3 2 0 -4]*x;
xot=[1;2;0;1];
[t,x]=ode45('f',[0 1],xot)
