基于matlab的控制系统与仿真-3

>>sys=tf([5 8],[1 4 6 3 3])

sys =
 
             5 s + 8
  -----------------------------
  s^4 + 4 s^3 + 6 s^2 + 3 s + 3
 
Continuous-time transfer function.

>> step(sys)

G1= tf([1],conv([1 0],conv([1 2 2],[1 6 13])))

G1 =
 
                   1
  ------------------------------------
  s^5 + 8 s^4 + 27 s^3 + 38 s^2 + 26 s
 
Continuous-time transfer function.

>> rlocus(G1)
>> G2= tf([1 12],conv([1 1],conv([1 12 100],[1 10])))

G2 =
 
                  s + 12
  --------------------------------------
  s^4 + 23 s^3 + 242 s^2 + 1220 s + 1000
 
Continuous-time transfer function.

>> rlocus(G2)

>> G3= tf([1 2 4],conv([1 0],conv([1 4],conv([1 6],[1 1.4 1]))))

G3 =
 
                s^2 + 2 s + 4
  -----------------------------------------
  s^5 + 11.4 s^4 + 39 s^3 + 43.6 s^2 + 24 s
 
Continuous-time transfer function.

>> rlocus(G3)
>> sgrid

>> G4= tf([1 2],conv([1 0],conv([1 4],conv([1 8],[1 2 5]))))

G4 =
 
                   s + 2
  ---------------------------------------
  s^5 + 14 s^4 + 61 s^3 + 124 s^2 + 160 s
 
Continuous-time transfer function.

>> rlocus(G4)
>> rlocus(-G4)

G5=zpk([],[0 -1 -2],1.5)

G5 =
 
       1.5
  -------------
  s (s+1) (s+2)
 
Continuous-time zero/pole/gain model.

>> margin(G5)
>> [Gm,Pm,Wcg,Wcp] = margin(G5)

Gm =

    4.0000


Pm =

   41.5340


Wcg =

    1.4142


Wcp =

    0.6118

wn=0.7;
s=tf('s');
n=[0.1,0.4,1.0,1.6,2.0];
for i=n
figure
G=wn^2/(s^2+2*i*wn*s+wn^2);
bode(G);
end

>> G=zpk([-1],[-0.8-1.6*j,-0.8+1.6*j],3)

G =
 
       3 (s+1)
  ------------------
  (s^2 + 1.6s + 3.2)
 
Continuous-time zero/pole/gain model.

>> nyquist(G)

n=[0.4,0.7,1.0,1.3];
for i=n
figure
G=tf([0 1],[1 2*i 1]);
nyquist(G);
end