Abstract
Feedback properties of discrete-time LQG controllers which utilize the optimal statepredictors to compensate L-step computation delays are discussed. First, we derive right and left coprime factorizations of the transfer function matrix of the controller. Using these factorizations, we obtain simple expressions of the sensitivity matrices and the complementary sensitivity matrices at the input and the output of the plant, which clarify effect of the computation delays and the imperfect observation. Furthermore, these expressions are used to show that duality between the feedback properties at the input and those at the output holds for L≥1 and to identify the asymptotic feedback properties obtained by the loop transfer recovery procedures. A simple numerical example is presented to illustrate the feedback properties.
