Matlab

Question 1

How do you find the closed loop TF, Gc(s)

Answer 1

Gc=feedback(G*M,1)

This is the TF btw r (target) and y with compensator M

Question 2

How do you find poles of a closed-loop system?

Answer 2

[poles, zeros]=pzmap(Gc)

Question 3

How do you find close-loop s-s gain

Answer 3

Gc0 = bode(Gc,0)

don’t seem to work, ask

Question 4

How to see figure of o/p response to change in r.

Answer 4

step(Gc)

Question 5

How to find poles and residues of a fraction (partial fractions)

Answer 5

Eg:
num=[10]
den=[ 1 5 6]
[r poles k]= residue(num,den)

Question 6

How to convert back from partial fractions to just one merged fraction?

Answer 6

[num den]= residue(r, poles, k)

Question 7

If G=2 /( s +1 )( s + 5 ) how would you compute it on MATLAB w/out expanding the brackets

Answer 7

G= tf ( 2, poly ( [-1 -5] ) )

Question 8

How to find s-s gain

Answer 8

g=bode(G,0)

It basically does G(0) for you - pretty sure

Question 9

How to find coefficients of a high order polynomial if don’t want to expand it all yourself? Eg: ( s+1 )( s+5)(2+3)

Answer 9

poly( [-1 -5 -3] )

ans= 1 9 23 15

Question 10

How to find roots of a polynomial?

Answer 10

roots( [1 5 6] )

Question 11

to extract num and den from tf

Answer 11

[num den]=tfdata(G,’v’)