Specifications

Creating LTI Models
2-15
As an illustration, consider the following simple model of an electric motor.
where istheangulardisplacementoftherotorand thedrivingcurrent.The
relation between the input current and the angular velocity
is described by the state-space equations
where
This model is specified by typing
sys = ss([0 1;–5 –2],[0;3],[0 1],0)
to which MATLAB responds
a =
x1 x2
x1 0 1.00000
x2 –5.00000 –2.00000
b =
u1
x1 0
x2 3.00000
c =
x1 x2
y1 0 1.00000
d =
u1
y1 0
d
2
θ
t
2
d
----------
2
θ
d
td
------
5
θ
++ 3I=
θ
I
uI= yd
θ
dt
⁄
=
xd
td
------
Ax Bu+=
yCx=
x
θ
θ
d
td
------
=
A
01
5– 2–
= B
0
3
= C
01
=