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10 Operation
10-10
G5 Series AC Servo Drives With Built-in EtherCAT Communications, Linear Motor Type
Conceptual Diagram of Magnetic Pole Position Estimation
Note
The magnetic pole estimation function estimates the position of each magnetic pole by
judging the movement direction of the motor several times when the force command (electric
current) is applied.
Precautions for Correct Use
Precautions for Correct Use
•
The magnetic pole position estimation function is executed at the first Servo ON after you turn
ON the power supply. Because the Linear Motor operates during magnetic pole position
estimation, take care so that the motor does not hit the mechanical end stop.
•
The magnetic pole position estimation function may not operate successfully if there is a large
unbalanced load or friction.
•
The values in the objects starting from Magnetic Pole Position Estimation Force Command
Time (3922 hex) through to Magnetic Pole Position Estimation Time Limit for Stop (3927 hex)
are the values set when the magnetic pole position estimation function is started. Changes
made during magnetic pole position estimation are not reflected on these values.
Magnetic Pole Position Restoration Method
The magnetic pole position data, once estimated by the magnetic pole position estimation function,
can be stored so that it can be used to control the motor after the power supply is reset.
In the magnetic pole position restoration method, you need to execute magnetic pole position
estimation only once after the power supply is turned ON and, after that, you need not perform
magnetic pole position estimation regardless of whether or not the power supply is reset.
This method is available only when you use an absolute type external encoder.
Index
Name
Unit
Description
Reference
3920 hex Magnetic Pole
Detection Method
Set the magnetic pole detection method.
Select 3 to set the magnetic pole position restoration
method.
(3925 hex, 3926 hex)
(3925 hex, 3926 hex)
3922 hex
3924 hex
(3925 hex, 3926 hex)
3923 hex
3928 hex
Range in which the motor decelerates and
once stops after a force command stops
Movement for Stop Judgment
Movement for Stop Judgment
Movement for Stop Judgment
Range in which the motor
may move in a reverse
direction due to cogging, etc.
Although the time set in 3922 hex
has not expired, the command force
is set to 0 because the amount of
movement exceeded the maximum
movement value set in 3924 hex.
Because the motor is
almost stationary, the
command force is applied
for the time set in 3922 hex.
Force Command
External Encoder Pulses
Time
Single attempt of judging
the motor movement direction