6.4.5. Stepper motor closed-loop control. Incremental encoder on motor
The internal jerk units are motor encoder counts / (slow loop sampling period)
correspondence with the load jerk in SI units is:
Load
_
where:
No_encoder_lines – is the motor encoder number of lines per revolution
Tr – transmission ratio between the motor displacement in SI units and load displacement
in SI units
T – is the slow loop sampling period expressed in [s]. You can read this value in the
"Advanced" dialogue, which can be opened from the "Drive Setup".
6.5. Current units
The internal current units refer to the motor phase currents. The correspondence with the motor
currents in [A] is:
where Ipeak – is the drive peak current expressed in [A]. You can read this value in the "Drive
Info" dialogue, which can be opened from the "Drive Setup".
6.6. Voltage command units
The internal voltage command units refer to the voltages applied on the motor. The significance of
the voltage commands as well as the scaling factors, depend on the motor type and control
method used.
In case of brushless motors driven in sinusoidal mode, a field oriented vector control is
performed. The voltage command is the amplitude of the sinusoidal phase voltages. In this case,
the correspondence with the motor phase voltages in SI units i.e. [V] is:
Voltage
where Vdc – is the drive power supply voltage expressed in [V].
In case of brushless motors driven in trapezoidal mode, the voltage command is the voltage to
apply between 2 of the motor phases, according with Hall signals values. In this case, the
correspondence with the voltage applied in SI units i.e. [V] is:
© Technosoft 2011
=
Jerk
[
SI
]
×
No
_
encoder
4
=
Current
[
] A
=
command
[
] V
=
Voltage
command
[
] V
×
π
2
×
3
×
×
_
lines
Tr
T
×
Ipeak
2
×
Current
[
IU
]
65520
×
.
Vdc
1
1
×
Voltage
command
65534
Vdc
×
Voltage
command
32767
86
Motor
_
Jerk
[
IU
]
[
IU
]
[
IU
]
IDMx40 Technical Reference
3
. The