RGA 1977: Dynamic effects of interaction

The interaction measure, or relative gain array, is an analytical tool for approximate, structural examination of multivariable process control designs developed over the last ten years. It is defined in terms of a square process transfer function matrix or gain matrix ??(s) ?? [??ij(s)] and its inverse ??-1(s) ?? [??ij -1(s)] as M = [Mij(s)] where ??ij(s) = ??ij(s)??ji -1 (s). Most of its useful properties can be seen in the steady state case. This paper presents the author´s current teaching practice as well as recent results concerning dynamic effects, relating decoupllng and optimal control.