Command
processing
Figure 1 shows the analog torque block mode has the same signal
processing as a velocity loop except that the velocity error signal
(
VelErr
) is set to
VelCmd
not to (
VelCmd - VelFB
) and
that the
VelCmd
clamp is bypassed. Thus, the analog input goes
through a number of signal processing steps before becoming the
motor torque current command
ICmd
.
1. Analog differential amplifier with 1200 Hz low pass filter.
2. High resolution A/D sampled at the velocity loop update rate
and added to the
ADOffset
parameter.
3.
ADF0
adjustable low pass filter to become
AnalogIn
.
4. Bypass the
VelLmtHi
,
VelLmtLo
clamp.
5. Velocity error variable
VelErr
is set equal to
VelCmdA
.
6. The anti-resonance second order velocity loop compensation
block controlled by the
ARF0, ARF1, ARZ0
, and
ARZ1
parameters to become the
FVelErr
variable.
7. The proportional and integral velocity loop compensation
block controlled by the
KVP
and
KVI
parameters
respectively.
8. And finally through the
IlmtPlus
and
IlmtMinus
current command clamp to become the
ICmd
motor torque
current command variable.
Although this looks like a large amount of processing, the options
are only there to allow tailoring the response to fit a particular
application.
A - 2
MA950
