Relative gain array for MIMO processes containing integrators and/or differentiators

Limitations are revealed for the existing methods to derive relative gain array (RGA) for a MIMO process containing integrators and/or differentiators. This paper proposes a new method to overcome these limitations. The method can handle processes described by either transfer functions or state-space models. The effectiveness and simplicity of the proposed method are illustrated with examples where the existing methods fail to give valid RGAs.