Yamaha CEmarking RCX221, User Manual

Page: 206 / 468

4-138
Chapter
4
OPERA
TION
11. "MANUAL" mode
11.8.2 Semi-absolute
"Semi-absolute" is the name for a simple absolute scale used in the YAMAHA linear
single-axis robot PHASER series. Robots with this simple absolute scale have a quick
absolute search function that utilizes our unique method to automatically perform an
absolute search on the position detection scale when return-to-origin starts. This function
allows detecting the absolute position with just a minimal movement.
Using this scale drastically reduces the time needed for return-to-origin operation by
PHASER series robots, especially those with long-stroke movements.
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Absolute search
Absolute search (also called "absolute reset") includes the sensor method and stroke end
detection method. Absolute search movement differs depending on the robot position from
which absolute search starts. (In the sensor method, absolute search movement depends
on whether the origin sensor turns on during absolute search. In the stroke end detection
method, absolute search movement depends on whether or not the stroke end is detected
during absolute search.)
After the absolute search is complete, the origin position is set to zero position on the
simple absolute scale.
n
NOTE
Zero position can be shifted by using the "Origin shift" parameter of the axis
parameters.
Refer to "11.8.3 Return-to-origin procedure" for instructions on how to perform return-to-
origin.
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Sensor method: When the origin sensor does not turn on during absolute search
●
Stroke end detection method: When the stroke end is not detected during absolute search
■
Absolute search (1)
Absolute search start position
Return-to-origin direction
:
@
A
Max. 76mm
q
Upon starting return-to-origin, the robot moves in the return-to-origin direction to
start an absolute search.
The robot moves to a maximum position A. The maximum distance that the robot can
move to position A from the absolute search start position is 76mm.
w
The robot moves back from position A, determines the current position, and then
stops. The stop position does not exceed the absolute search start position.