Delta ASD-A3-0121, User Manual

Page: 159 / 603

Operation Mode ASDA-A3
6-8
Revision December, 2017
6
6.2.5 Electronic gear ratio (E-Gear ratio)
The resolution of ASDA-A3 is 24 bits, which means that it generates16777216 pulses per motor
rotation. Regardless of the encoder resolution (17-bit, 20-bit, or 22-bit), the E-Gear ratio is set
according to 24-bit resolution of ASDA-A3 servo drive.
The Electronic gear ratio changes the resolution. When E-Gear ratio is 1, it generates 16777216
pulses per motor rotation; when you set the ratio to 0.5, then every two pulses from the
command (controller) corresponds to one pulse for the motor. However, larger E-Gear ratio might
create a sharp corner in the profile and lead to a high jerk. To solve this problem, you can apply
an S-curve acceleration / deceleration filter, or a low-pass filter to reduce the jerk. For example, if
you set the E-Gear ratio so that the workpiece is moved at the speed of
1 μm/pulse , then it
means the workpiece moves 1 μm per pulse
.
(1) Motor (2) Ball screw pitch: 3 mm (equals 3000 μm )
WL: Workpiece; WT: platform
Gear Ratio Moving distance per 1 pulse command
Electronic
gear is not
applied
=
1
1
)
Pulse
μm
: (Unit
16777216
3000
1
1
rev
Pulse
16777216
rev
μm
3000
= × =
Electronic
gear is
applied
=
16777216
3000
)
Pulse
μm
: (Unit 1
3000
16777216
rev
Pulse
16777216
rev
μm
3000
= × =
Relevant parameters: please refer to Chapter 8 for detailed descriptions.
Parameters Function
P1.044 E-Gear ratio (Numerator) (N1)
P1.045 E-Gear ratio (Denominator) (M)