
1.SYSTEM CONFIGURATION CONFIGURATIONS AND SELECTION B-65222EN/03
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1.3.3 Driving Two Motors
If you want to drive two motors along one axis, select one of the
following control methods according to the connection rigidity
between motors.
NOTE
This subsection gives typical examples when an
incremental linear encoder is used. When an
absolute linear encoder is used, the magnetic pole
sensor and position detection circuit in each figure
are not required. The rules may not always apply to
the actual machine configuration. For details, contact
FANUC.
When the connection rigidity between motors is high
In ordinary cases, torque tandem control is exercised. For linear
motors, velocity tandem control or simple synchronous control can
also be exercised by using common feedback signals in one DSP. In
this case, only one linear encoder is required. The following is a block
diagram for torque tandem control. The same configuration is used for
velocity tandem control and simple synchronous control.
Servo amplifier #2
Servo amplifier #1
Magnetic pole
senso
Linear motor #1
Linear motor #2
Torque
mm
n
Axis #1
Axis #2
Machine
High connection
rigidity between
motors
Linear encoder
Position detection
ir
i
CNC
When the two-output type of position detection circuit is used in an
incremental linear encoder system, control as shown below is also
available:
Servo amplifier #2
Servo amplifier #1
Magnetic pole
sensor
Linear motor #1
Linear motor #2
Position
Axis #1
Axis #2
Machine
High connection
rigidity between
motors
Linear encoder
CNC
Position
detection
circuit
Output #1
Output #2
Position detection
circuit