Motion Control; Incremental Position Loop - TDE MACNO MINIOPD EXP User Manual

3.3 MOTION CONTROL

3.3.1 INCREMENTAL POSITION LOOP

Name
FLW_ERR_MAX_LSW
POS_REG_KP
FLW_ERR_MAX_MSW
EN_POS_REG
EN_POS_REG_MEM_CLR
Continuous position control during rotation is used to synchronise both speed and space with the
speed reference value used.
To enable this function, set input function I17 "Enable overlapped space loop" to high logic level or
set C239=1. From then on, an internal counter will be save any position errors regarding the space
crossed by the reference value. If the drive RUN command is disabled, the error will be accumulated
until it can be corrected once RUN has been enabled again.
Using parameters P37 (65536=1 mechanical turn) and P39 (number of mechanical turns) it's possible
to set a maximum tracking error threshold, if the absolute error value becomes greater than this
value, the logic output o.9 "Tracking error" goes at high level.
The overlapped space loop reference value is generated by the application and regards the
"theta_rif_pos" value, which is also expressed in electrical pulses for a period of PWM.
Note that once this function has been enabled, the overlapped space loop reference value will
become the real position reference value, while the other speed reference values will represent feed-
forward.
The space loop regulator is a pure proportional gain and its gain can be set on P38: set a value that
ensures a quick response, but one that does not make the motor vibrate at a standstill.
The continuous position control is most commonly applied to the electric axis: by taking the speed
reference value from the MASTER's Simulated Encoder and taking it to the SLAVE's frequency input,
the motion of the two motors can be synchronised. Once the overlapped space loop is enabled, the
two motors will always maintain the same relative position whatever their load. If the SLAVE reaches
its torque limit, the counter will save the position error and then correct it as long as the internal
counter limit has not been reached, in which case the synchronisation will be lost.
3.3.1.1 FREQUENCY SPACE REFERENCE (ELECTRICAL AXES)
Managing a frequency space reference means always guarantee the same phase angle between
master and slave. To do this work is necessary to enable the overlapped position loop with parameter
P239 or bringing at active state input function I17.
It should then provide a speed feed-forward reference, the best solution is to use the frequency
speed reference decoded in time (P224=1 and P219=0), alternatively, wanting to work in pulses,
clear P224=0.
Note: Wanting to manage in space the frequency reference, it's not possible to enable pulses and
decoding in time reference(P224 = 2).
The recommended block diagram is:
User's manual
Description
P37 - Maximum tracking error (less significative
part)
P38 - Kv position loop proportional gain
P39 - Maximum tracking error (less significative
part)
P239 - Enable overlapped space loop
P240 - Enable overlapped space loop memory
clear in stop
Min Max Default
-32767 32767 32767
0.0 100.0 4
0 32767 0
0 1 0
0 1 0
UM Scale
ppr 1
10
rpm 1
1
1
71