THORLABS BBD301, Руководство пользователя

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Chapter 6
HA0409T Rev B Aug 2021
Page 52
6.3.3 Advanced - Control Loop SettingsTab
Fig. 6.5 Advanced Control Loop Settings
Position Loop Control Settings
The motion processors within the BBD series controllers use a position control loop
to determine the motor command output. The purpose of the position loop is to match
the actual motor position and the demanded position. This is achieved by comparing
the demanded position with the actual encoder position to create a position error,
which is then passed through a digital PID-type filter. The filtered value is the motor
command output.
Proportional term - - Increasing the proportional (Prop) term will increase the amount
of effective torque used to correct a given position error. Typically this is used to
minimise the amount of position error when an impulse event affects current target
The PID and other closed loop parameters must be set according to the stage
or actuator type associated with the driver, the load being positioned and the
speed/duty cycle of operation. Default values have already been optimized and
stored within the stage, and these are loaded into the controller on power up.
If problems are encountered (e.g. stability of the closed loop position control,
lost motion or incomplete moves) the position PID parameters should be
adjusted to tune the stage for the given application. Normally, only minor
adjustment of the Proportional, Integral and Derivative parameters should be
necessary, and some trial and error will be required before the ideal settings
for a specific application are achieved. In cases where further adjustment of
the control loop parameters is required, the following guidelines are provided
in order to assist in the tuning process.
Caution