Overview on m Synthesis

qConsider a general feedback system with interconnection *G*. Find a stabilizing controller *K* so that the following m-norm is minimized:

This problem is called m-synthesis.

qThe m-synthesis is not yet fully solved. But a reasonable
approach is to “solve”

by
iteratively solving for* K* and *D*, i.e., first minimizing over *K* with *D* fixed, then minimizing
point-wise over D with *K* fixed, then again over *K*, and again over *D*, etc. This is the
so-called *D-K*** Iteration**.