Hiwin D2 User Manual

D2 Drive User Guide v1.8 3. Operation Principles
HIWIN Mikrosystem Corp. 36
3.9. Velocity ripple
Generally in the motion control, it is always desirable that the motion in the constant-speed
phase is as smooth as possible. The motion stability can be estimated by the index of velocity
ripple. Main factors causing the variation in the constant-speed phase are the motor cogging
force, cable chain, air pipeline, and guideway friction, and so on. This velocity ripple is usually
used for scanning or detecting machines required high stability in the constant-speed phase.
The equation of velocity ripple is:
%,RippleVelocity 100
2
1



V
VV
target
minmax
where V
target
is the target velocity, V
max
is the maximum velocity in the constant-speed phase,
and V
min
is the minimum velocity in the constant-speed phase. As shown in Fig. 3-15, the
velocity ripple of (a) is larger indicated less steadiness; while (b) is smaller indicated better
steadiness.
Fig. 3-15
(a)
(b)
Constant
Velocity
Constant
Velocity
V
max
V
min
V
target
V
min
V
target
V
max

Hiwin D2 Specifications

General

Brand	Hiwin
Model	D2
Category	DC Drives
Language	English