The emphasis of this paper is on an alternative ap roach to the Loop T
ransfer Recovery (LTR) design problem based on an H(infinity) optimiza
tion of a certain matrix, the Recovery Matrix. The proposed H(infinity
)/LTR method handles both minimum phase systems as well as non-minimum
phase systems in a common framework. In both cases, the H(infinity)/L
TR design problem is transformed into an almost disturbance decoupling
problem. The resulting controllers are all of the same dynamic order
as the plant. As an application, robust control-objectives are studied
, and sufficient conditions for the robust H(infinity) problem are giv
en in a form supported by the design method presented in this paper. F
urthermore, necessary and sufficient conditions for solvability of the
asymptotic recovery problem is given.