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CCBU40 COMPACT CONTROLLER BOARD - PRODUCT AND WARRANTY INFORMATION
Version 1.21
X.
CONTROL
The role of the closed-loop control is to make sure that the sensor feedback is equal to the command. This
means that the system gain in closed loop corresponds to the SG sensor gain, provided in the factory verification
sheet.
Warnings:
•
When tuning the control parameters, the user should avoid instability conditions. In case of
instability, there is a risk of damage to the actuators and CCBu40. Please refer to the
application note “Position Control of Piezo Actuators” for hints on how to tune a controller for
piezo actuator. You can download this application note here: http://www.cedrat-
technologies.com/en/products/users-manual.html.
•
The sensor feedback must be in phase with the piezo voltage. This can be checked by
operating the CCBu40 in open loop, the sensor should be in phase with the command. If this is
not the case (in particular with the external sensor option), there is the possibility to adjust
and invert the sensor feedback gain in software if needed.
See digital command ‘G’ in the
Section 0.
The CCBu40 performs a digital control law basically consisting in a PID controller with a selectable and tunable
output filter. Each of the two channels has its own independent controller, which can be tuned independently.
The CCBu40 refresh rate is of 50kSps.
The controller is presented schematically on the Figure 8: Controller structure. The user can modify all control
parameters to optimize the performance. The commands for adjusting the parameters are
identified with ‘’
marks. The details of the commands to adjust the control parameters are given in Section 0.
Figure 8: Controller structure
