Syllabus:
Monitors particular servo channels for onset of instabilities
Summary:
Servomon looks for sudden increases in user-specified frequency bands of servo channels that could signal the onset of instability. Tunable parameters allow specifying a trigger based on absolute increase in band-limited power, on fractional increase w.r.t. the remaining spectrum, or on simple magnification. The specified bands may be wide, e.g., the region just below unity gain frequency which is subject to gain peaking when gains are adjusted too high. Or the bands may be narrow, corresponding to narrow, excitable resonances above the servo's bandwidth, e.g., butterfly" test mass vibration modes.
E2 plans:
We will be playing around with the servomon parameters during the E2 run, deciding which servos to monitor with it and which frequency bands to look at. We will certainly tune to the known butterfly modes, but I need to understand better the various servo loop gain curves before trying to detect gain peaking. We may also tune to vertical bounce modes.
Contact:
Keith Riles and Dave Chin
Department of Physics
University of Michigan
500 E. University Ave.
Ann Arbor, MI 48109-1120
Office: (734) 764-4652
Lab: 936-1034
Fax: 936-6529
kriles@umich.edu