"step" Function Help

Robert

2013 5 21

0 个回答

9 次查看（30 天）

0 个投票

I am trying to plot a step response with the "step" function. I am getting a plot, but it is not what I expected. My step response jumps up and stays flat, rather than oscillating as expected.

Here is what I am getting: http://imageshack.us/a/img853/2128/68663175.png

Here is what I am supposed to be getting: http://imageshack.us/a/img843/2634/14005675.png

What am I doing wrong, and how can I change my code so it looks like the second picture I posted?? Thanks!

Code:

clear
clc
kp=10;
kd=.3;
j1=1*10^(-3);
j2=2*10^(-4);
b=5.82*10^(-3);
k=5;
num1=[j2 b k];
den1=[j1*j2 (j1+j2)*b (j1+j2)*k 0 0];
g1=tf(num1,den1);
num2=[b k];
den2=[j1*j2 (j1+j2)*b (j1+j2)*k 0 0];
g2=tf(num2,den2);
num3=[kd kp];
den3=1;
c=tf(num3,den3);
t2=g2*c/(1+g1*c);
step(t2)