Servosila-Device-Reference-0xA020192

• The controller automatically measures the "Moment of Inertia"
during an auto-configuration procedure, and uses the measurement
to compute a correct value for ESC Kp parameter.
Note that measuring the moment of inertia requires that "Viscous Damping
Constant" is measured first.
Since ESC Kp parameter depends on a combined "Moment of Inertia of
Rotor and Payload", it is important that the moment is properly measured,
estimated, or even guessed. Note that direct measurements of the moment
of inertia by the controller can be quite imprecise, especially when a
complex payload is connected to the electrical drive. As errors in the
estimates directly translate into errors in ESC Kp parameter, some manual
adjustments to the ESC Kp parameter might be required.
Tuning intuition:
• The higher a combined "Moment of Inertia of Rotor and Payload"
is, the higher ESC Kp parameter should be.
• INCREASING the parameter too much might causes the motor to
produce an audible "white" noise when running under Electronic
Speed Control (ESC).
• DECREASING the parameter too much causes the drive to arrive to
a commanded speed too slowly, or experience difficulties in
maintaining a constant speed.
If manual adjustments are to be performed, it is recommended to use the
"Spreadsheet" tool for this purpose. Note that when using the tool, it is
better to manually adjust the "Moment of Inertia" and then re-compute the
ESC Kp parameter, rather than adjusting the ESC Kp parameter itself.
Note that the speed here is defined in electrical revolutions per second
(Hz). To convert Hz to motor shaft's revolutions per second, just divide it
by the number of pole pairs. For example, assuming the speed is 20 Hz
(electrical), and Poles Number is 8, then the corresponding speed in motor
shaft's revolutions per second is 20 / (8/2)= 5.0 Hz (revolutions per
second), which is 5 * 60 = 300 RPM.
5
Electronic Speed
Control (ESC): T
sec The "ESC: T" parameter is an integral time constant of a PI controller that
commands torque to maintain a constant speed.
The higher the time constant, the slower the ESC controller reacts to small
perturbations in speed readings.
This parameter should generally be computed using the "Spreadsheet"
software tool. The controller itself can also determine an appropriate value
for this parameter during an auto-configuration procedure.
FLOAT32,
0x2002,
0x23,
rw
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