The attached plot shows the control filter, the existing boost filter, and a proposed filter addition to the HEPI controls.

As we had at LLO, I think we should have a true integrator on the HEPI loops to compensate for long term drifts introduced by hydraulic pressure, thermal expansion, etc. so that the HEPI platforms  can be considered to be stable alignment-wise.

Also, why is there so much high frequency gain? It seems like the actuator watchdogs will trip due to acoustic noise or EMI with this kind of design. Perhaps a little low passing can be done without too much harm to the 10 Hz phase margin.