Step Response of a transfer Function with a Multiple Term Numerator.

Obtain the step response of the transfer function given below:

s s + 3 s + 2

T(S) = ------------------------------------

s + 1 s + 11 s + 2 s + 7

num = input('enter the numerator of the transfer function') %% -- Obtain the step response of the transfer function given below: --

den = input('enter the denominator of the transfer function')

step(num,den)

Is there a function that converts the numerator into a single term? The question says to Obtain the step response of the transfer function given.

[Star Strider]

Please supply all the missing multiplication operators, and any necessary parentheses.

[Salik Mallick]

(s) (s + 3) (s + 2)

T(S) = ------------------------------------

(s + 1) (s + 11) (s + 2) (s + 7)

Answer 1

[Mahesh Taparia]

Hi

You can use 'conv' function to find the terms in polynomial form (or in a single term). For your case, you can follow the following line of code

a=[1 0];
b=[1 3];
c=[1 2];
Num1=conv(a,b);
Num=conv(Num1,c)
p=[1 1];
q=[1 11];
r=[1 2];
s=[1 7];
Den1=conv(p,q);
Den2=conv(r,s);
Den=conv(Den1,Den2);
TF=tf(Num,Den);
step(TF) %%%%% It will give step response

Hope it will help.