User`s guide

tf
11-228
with common denominator and sample time of 0.2 seconds.
nums = {1 [1 0];[–1 2] 3}
Ts = 0.2
H = tf(nums,[1 0.3],Ts) % Note: row vector for common den. d(z)
Example 4
Compute thetransfer functionof the state-spacemodelwit h the followingdat a.
To do this, type
sys = ss([–2 –1;1 –2],[1 1;2 –1],[1 0],[0 1])
tf(sys)
Transfer function from input 1 to output:
s
-------------
s^2 + 4 s + 5
Transfer function from input 2 to output:
s^2 + 5 s + 8
-------------
s^2 + 4 s + 5
Example 5
You can use a
for loop to specify a 10-by-1 array of SISO TF models.
s = tf('s')
H = tf(zeros(1,1,10));
for k=1:10,
H(:,:,k) = k/(s^2+s+k);
end
The first statement pre-allocates the TF array and fills it with zero transfer
functions.
Discrete-Time
Conventions
The control and digital signal processing (DSP) communities tend to use
different conventions to specify discrete transfer functions. Most control
dz
()
z 0.3
+=
A
2– 1–
12–
,= B
11
21–
,= C
10
,= D
01
=