LTR techniques for non-minimum phase plants with time-delay

Discusses LTR (loop transfer recovery) design of predictor-based LQG controllers for a plant consisting of a lumped non-minimum phase part and an output time-delay. The authors focus their attention on the feedback property achieved at the plant output side. First, the authors give an explicit representation of the sensitivity matrix obtained by enforcing the conventional LTR procedure. In addition, the authors discuss an application of the partial LTR technique which has been proposed for lumped non-minimum phase plants. The authors show that a feedback property recovered by enforcing the conventional LTR procedure can be recovered by the partial LTR technique. A simple numerical example is presented to illustrate the feedback properties achieved by the LTR techniques.