SYSTEM-IDENTIFICATION FROM CLOSED-LOOP DATA WITH KNOWN OUTPUT-FEEDBACK DYNAMICS

This paper formulates a method to identify the open-loop dynamics of a system operating under closed-loop conditions. The closed-loop excita tion data and the feedback dynamics are assumed to be known. Two close d-loop configurations are considered where the system has either a lin ear output feedback controller or a dynamic output feedback controller . First, the closed-loop excitation data are used to compute the close d-loop Markov parameters, from which the open-loop Markov parameters a re recovered from the known feedback dynamics. The Markov parameters a re then used to compute a state space representation of the open-loop system. Examples are provided to illustrate the computational steps in volved in the proposed closed-loop identification method.