Servosila-Device-Reference-0xA020192

precise, but at the same time not as energy efficient. Note that more heat is
generated by a motor under Direct Drive Control, than the same motor under
Field Oriented Control (FOC). This is not a problem in many applications
where energy efficiency can be traded for high precision and mechanical
simplicity of Direct Drive Control.
If the feature is enabled, the controller begins to dynamically switch
between Field Oriented Control (FOC) and Direct Drive Control when
executing commands coming from a parent control system. The controller
automatically determines which method of control is the most appropriate
when executing a given command. This switching behavior is influenced by
a "Direct Drive: Speed Limit" parameter, configured in the "Control Laws"
section.
2
Feature: Kickstart 0 or 1 "Kickstart" refers to a method of starting "sensorless" brushless motors, the
ones that do not have Hall sensors or encoders. Since the "Kickstart"
procedure might create ripples of torque at start-up, there is a way to disable
the function altogether by toggling the "Feature: Kickstart" parameter.
If the Kickstart function is disabled, but a "sensorless" motor is used, then
an external application-specific method of starting up the motor needs to be
employed (e.g. pushing an electric scooter to kickstart its motor).
The kickstart function is generally not needed or used for motors with Hall
sensors or encoders, so disabling it does not change anything in that case.
An exception are drives equipped with absolute quadrature encoders. A
challenge with absolute quadrature encoders is that they use an INDEX
signal to identify a zero position each time the drive starts up. The controller
uses the same Kickstart routine to initially rotate such a motor until its
quadrature encoder stumbles upon an INDEX signal. The controller then
switches to Field Oriented Control (FOC) or Direct Drive Control since the
quadrature encoder is then providing an absolute position of the rotor.
BOOL,
0x2004,
0x02,
rw
3 Feature: Field
Weakening
0 or 1 "Field Weakening" is an advanced motor control technique that allows
reaching speeds higher than a rated speed of a brushless motor. It is like
shifting the drive to a higher gear, but electromagnetically. Note that the
higher speeds are reached at the expense of energy efficiency of the
electrical drive.
In normal circumstances, a maximum speed of a permanent magnet
synchronous motor (PMSM) is limited by the voltage of its power supply.
The higher the voltage of power supply is, the higher maximum speed a
brushless motor can reach. The permanent magnets of the rotor produce
Back-Emf voltage in stator coils (just like an electric generator). As the
speed grows, the generated Back-Emf voltage grows too. Whenever the
Back-Emf voltage matches the voltage of power supply, the brushless motor
reaches its maximum speed and cannot accelerate any further. It might be
BOOL,
0x2004,
0x22,
rw
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