S. Skogestad and I.J. Halvorsen, ``Self-optimizing control: Basic issues and Taylor series analysis'', Paper presented at COSY Workshop, Makedonia, 08-09 Oct. 1998

Abstract.
Which variables should we select to control? It is shown that the idea of selecting the variables that achieve self-optimizing control provides a link between steady-state optimization, feedback control, time scale separation and uncertainty. In summary, we will show that a good candidate variable for a controlled output should have the following properties:

  1. Its optimal value should depend only weakly on disturbances.
  2. On the other hand, it should be sensitive to changes in the independent variables (inputs).
  3. It should be easy to control accurately.