Assessment of input-output controllability in the presence of control constraints

Two open-loop analysis techniques for assessing input-output controllability in the presence of control constraints are presented. The techniques used are a modified singular value analysis technique and a new optimization-based approach. The case study discussed has, depending on the choice of manipulated variables and measurable outputs, several alternative two-input two-output control schemes. The results are verified by performing closed loop simulations with PI controllers. These show that both methods are able to predict the process' closed loop performance in the presence of control constraints.