Arnaud, Sheila

Today we worked on the OpLev damping more, including making the modification to the etmx and Itmx models needed to route the damping through the drivealign matrix for both PUM and UIM.  These models (h1susetmx and h1susitmx) committed to svn.

The problem with the pitch loop saturating the DAC was the high frequency noise, as Keita suggested.  I added a low pass at 10 Hz, and now the loop runs with the intended gain without saturating the DAC.  The first screen shot attached shows the coil driver outputs with the loop in last night's configuration (dashed lines), and with both PIT and YAW damping loops engaged (solid lines).  (The max is 130000 counts). 

The next plot shows the performance of these loops (blue is both loops on, red is neither on).  We get a factor of 5 improvement at 0.45 Hz in Pitch, and a factor of 10 at 0.13 Hz in Yaw.  The Pitch RMS is reduced by 60%, while Yaw rms is reduced by 50%.  

The Pitch loop gain is half of what I had originally indented, the current set up is shown in the attached screen shot.