R&D (FilterCavity)
YuhangZhao - 01:23, Saturday 19 September 2020 (2216)
Sensing and driving matrix for AA

According to the actuation calibration in elog1877, the driving of 5urad can be represented in the unit of counts.

The excitation is therefore decided to be the following table (at 2Hz).

Input Yaw excitation Input Pitch excitation End Yaw excitation End Pitch Excitation
227 793 186 961

According to this excitation, the response (sensing matrix) is as the following table

  WFS1_p WFS1_y WFS2_p WFS2_y
Input_y_exc 48 470 36 248
Input_p_exc 275 70 180 33
End _y_exc 66 180 73 161
End_p_exc 269 143 292 74

The offset of these signals is listed as the following table

  WFS1_p WFS1_y WFS2_p WFS2_y
offset 31 20 29 13

Then subtracting the offset from the sensing matrix. The sensing matrix (after substracting) is used to decide the driving matrix index magnitude. The principle is that if the response is larger, the driving needs to be also larger. Without considering the coupling between pitch and yaw, the driving matrix is decided to be

  WFS1 WFS2
input_p 1.6 -1
end_p 0.9 1
input_y -1.9 1
end_y -1.1 1

The sign of the above driving matrix is decided by the time-series measurement yesterday.