Examples and tips
PROGRAMMING MANUAL
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Position mode examples
fig. 12
In this mode the position and speed loop are closed in the Servo Driver. The
TJ1-ML__ sends the position command through the MECHATROLINK-II
network to the Servo Driver, and reads the position feedback.
Note that this system has no sample delay as compared to the position loop
in the Servo Driver, the Demand_Position in cycle "n" with the
Measured_Position in cycle "n".
The Trajexia, for the internal handling, continues to use its own position loop,
so the Following Error that read in the Axis parameter in Trajexia is not the
real one in the Servo-drive. To read the correct Following Error use
DRIVE_MONITOR.
Adjust the rigidity of the servo, the speed loop gain and the position loop
gain at the same time using just proportional position gain. The results are
similar to the MECHATROLINK-II Speed mode with the advantages:
•
The tuning is more simple, only the rigidity (Fn001) and, if necessary, the
feedforward gain (Pn109) needs to be set.
•
The position loop in the servo is faster (250µs) than in Trajexia and it is
turned together with the speed loop.
•
There is no sample time delay between "Target position" and "Measured
position”.
To do a finetune the different gain parameters can be changed individually.
BASE(0)
ATYPE=41 'MECHATROLINK Position mode
SERVO=1
DRIVE_CONTROL=2 'To monitor the Following Error in
'DRIVE_MONITOR
WDOG=1
DEFPOS(0)
loop:
MOVE(81920)
WAIT IDLE
WA(100)
DEFPOS(0)
GOTO loop
Profile generator
M
E
TJ1-MC__
TJ1-ML__
SERVO
+
_
SERVO = OFF
SERVO = OFF
Trajexia
Position Loop is
deactivated
(Gains are not
used!)
ML-II
Position
command
Demanded
position
Measured
position
Position loop
Following
error
Speed
command
Position Loop
Speed Loop
Torque Loop