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 distance the motor travels for one reference unit to be
set to any value. More specifically, the value is set based on the number of encoder pulses, refer-
ence 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.
Example: Reference Unit = 0.1 µm
If a move reference of 50000 reference units 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 pre-
cision.
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
Example: Load Travel Distance per Load Shaft Revolution= 12 mm (0.47 in), Reference Unit
= 0.01 mm (0.0004 in)
Load travel distance per load shaft
revolution (in distance units)
=
Example of the Load Structure
1 revolution
1 revolution
5 -4
Reference unit
P: Pitch
1 revolution