Position Control; Electronic Gear Function - YASKAWA SGM Series User Manual

Application

5.2.1 Electronic Gear Function

5.2 Position Control

5.2.1 Electronic Gear Function
5
The electronic gear function enables the motor travel distance per input reference unit to be
set to any value. More specifically, the value is set based on the number of encoder pulses, ref-
erence unit (minimum unit of position data for moving the load), and machine gear ratio. When
the electronic gear ratio is 1/1, the motor will move one reference unit per pulse input.
J Setting the Electronic Gear Ratio (B/A)
Determining the Reference Unit
The electronic gear ratio represents the number of encoder pulses per reference unit.
The reference unit is the minimum unit of position data for moving the load, e.g., 0.01 mm,
0.1°, or 0.01 inches.
A 1-pulse input moves the load by 1 reference unit.
Example: Reference Unit = 0.1 µm
If a reference of 50000 pulses is input, the load moves 5 mm
(50000 × 0.1 = 5000 µm = 5 mm).
Determine the reference unit based on factors like equipment specifications and positioning
precision.
Determining the Load Travel Distance per Load Shaft Revolution in
Reference Units
Load travel distance per load
shaft revolution (in reference
units)
Table 5.1 shows an example of the load travel distance per load shaft revolution.
Table 5.1 Example of the Load Travel Distance per Load Shaft Revolution
Load Travel Distance
per Load Shaft
Revolution
P Ball screw
360° Disc table
Belt and pulley
πD
Load travel distance per load shaft
revolution (in distance units)
=
Reference unit
Example of the Load Structure
1 revolution
1 revolution
5 -4
P: Pitch
1 revolution