[From Bill Powers (2012.12.07.0520 MST)]
Martin Taylor 2012.12.06.23.52
Note that the Touchette & Lloyd paper you posted assumes that the
disturbance is observable by the controller. Can we take that as prima
facie evidence that this kind of control will not be possible in any
case where the disturbance can’t be observed? Closed-loop control does
not, of course, require observing the disturbing variable.