13.7. RGA and Sensitivity
The previous sections have introduced the concept of the RGA, to help determine which input should be paired with which output to form a multivariable control system composed of a number of single input–single output controllers (we refer to this as a MVSISO system). The purpose of this section is to discuss the relationship between relative gain and controller tuning. It should become clear that the RGA gives valuable insight into the failure sensitivity of a control system. We also present numerous examples to illustrate the important concepts.
When tuning a set of SISO controllers to form a MVSISO strategy, it is important to consider the failure sensitivity of the system. For example, consider ...