# Mitsubishi Electric FR-A820-00046 Instruction Manual Page 330

Position control under vector control and PM sensorless vector control
Control block diagram
Point table
Position Speed
Pr. 4 to 6, Pr. 24 to Pr. 27,
Pr. 232 to Pr. 239
RH
Pr. 465 to Pr. 494
Pr. 1222 to Pr. 1281
RM
RL
REX
Travel
distance
STF
STR
Command pulse selection
Command pulse
Pr. 428
JOG
Pulse train sign
NP
Fig. 5-57:
Control block diagram
Operation example
● Calculate the speed command so that the difference between the number of pulses of the internal
pulse train (if Pr. 419 = "0", command pulses are used in the inverter from the number of pulses
defined by parameters (Pr. 465 to Pr. 494)) and the number of pulses in the feedback from the
motor terminal encoder (estimated value when PM sensorless vector control is used) is 0, and then
rotate the motor based on the calculation.
– Once a pulse train is input, pulses are accumulated in the deviation counter, and the droop
pulses in this counter become position control pulses and speed command.
– When the motor starts to rotate in response to the speed command from the inverter, feedback
pulses are also generated by the encoder at the same time. Subtract the encoder feedback
pulses or feedback estimate value from the droop pulses in the deviation counter. The
deviation counter keeps rotating the motor while keeping a certain droop amount.
– If the command pulse input stops, the amount of droop pulses in the deviation counter
decreases and thus the speed slows down. When there is no droop pulse, the motor stops.
– If the number of droop pulses becomes smaller than the value set in Pr. 426 "In-position width",
the system determines that positioning is complete and the positioning completion signal
(Y36) is turned ON.
5 - 150
Acceleration/deceleration time
Position command
source selection
Pr. 419
0
Multi-speed,
communication
Electronic
Pr. 424
gear
2
Pr. 420
Pr. 421
Position command
acceleration/deceleration
time constant
Position feed
forward
command filter Position feed
forward gain
Pr. 425
Pr. 423
Model position
control gain
Pr. 446
+
-
integral
Pr. 877
0,1
2
Position
control gain
+
Deviation
counter
-
Pr. 429
Clear signal
selection
(estimated value under PM sensorless vector control)
Parameters
Model speed
control gain
Pr. 828
+
J
Torque coefficient
-
integral
Speed feed
forward gain
0,1
2
1
Pr. 422
+
+
+
+
-
Torque
Speed control
control
Differentiation
Position feedback
0
2
0
M
Encoder
I002535E