Modern Control Engineering

Example Problems and Solutions 523

Frequency (rad/sec)

Phase (deg); Magnitude (dB)

Bode Diagrams

100 101 102100 101 102

From:U 1 From:U 2

− 40

− 20

0

− 100

0

100

− 100

0

100

− 200

0

200

To:

Y^1

To:

Y^2

Figure 7–119
Bode diagrams.

A–7–3. Referring to Problem A–7–2, plot Bode diagrams for the system, using MATLAB.

Solution.MATLAB Program 7–15 produces Bode diagrams for the system. There are four

sets of Bode diagrams: two for input 1 and two for input 2. These Bode diagrams are shown in

Figure 7–119.

MATLAB Program 7–15

A = [0 1;-25 -4];

B = [1 1;0 1];

C = [1 0;0 1];

D = [0 0;0 0];

bode(A,B,C,D)