Hiwin D2 Series - Page 46

Operation Principles D2 Series Servo Drive User Manual
3-10 HIWIN MIKROSYSTEM CORP.
MD07UE01-2005
Figure3.6.1.1 Gain margin of Nyquist diagram
 Phase margin
Phase margin is defined as that the angle between the straight line passing through the gain
crossover and the negative real axis of G(jω)-plane, as shown in figure 3.6.1.2.
Phase margin = PM =
G(jω
g
) -180°
Figure3.6.1.2 Phase margin of Nyquist diagram
0
g
ωω =
G
Re
G
j
Im
(
)
Plane
j
G
−
ω
Gain
crossover
ω ←0
1
-1
Phase margin
)
(
p
j
G
ω
0
p
ω
ω =
G
Re
G
j
Im
(
)
Plane
j
G
−
ω
Phase crossover
ω ←0