same transfer function, different step response,Y?
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I recently made a simple cascade speed control system in R2011b,which illustrates briefly as follows:
L=9.02*0.001;
R=0.18;
Bandwidth=1000*2*pi;
Kp=L*Bandwidth;
Ki=R/L;
P=20;
J=297.269/4;
n=191/60*2*pi;
BEMF=159*sqrt(2);
lamda=BEMF/(n*P/2);
K=3*P*lamda/(4*J);
delta=8;
spdKi=Kp/(delta^2* L);
spdKp=Kp/(L*delta*K);
G_speed=tf([K*spdKp K*spdKp*spdKi],[ L/Kp 1 0 0]);
GCloop1=tf([K*spdKp K*spdKp*spdKi],[L/Kp 1 K*spdKp K*spdKp*spdKi]); % close loop transfer function of G_speed (same as next expression)
GCloop = G_speed/(G_speed+1);% close loop transfer function of G_speed (same as previous expression)
figure(1)
step(GCloop1)
figure(2)
step(GCloop)
in R2014b, the step response of GCloop1 and Gcloop are same


But in R2011b, they are different:
.jpeg)
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Can anyone explain why?
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