Scraps of text for incorporation in the VIS Meeting Minutes


Type B (Mark)

Report for week of 1/14

Report for week of 1/21

BS (top priority)

SR2 (priority 2)

SR3 (priority 2)

Talk about problems turning on and off control systems (Terrence and Enzo) From Terrence: Since the PI controller was implemented, the controller keeps accumulator displacements error and converts this error to the output. One problem arose from the mismatch of the control system and the actual hardware. Because the controller output could have a much larger value than the number of counts that can be input to the coil actuators (e.g. the controller says we should input 60000 counts to the actuators but the hardware limits the number of counts), the controller will not function as designed. As a result, the PI would shift to one side (due to insufficient driving force) while the voices coils became saturated at maximum output. Additionally, because the controller is still functioning, the integrator keeps accumulating error and hence the output of the controller keeps increasing but the object is actually stuck. This makes the IP very very unstable when the actuators are saturated.

Give status of oplevs (Terrence and Enzo).

SRM (low priority)