IDENTIFICATION OF SYSTEM, OBSERVER, AND CONTROLLER FROM CLOSED-LOOP EXPERIMENTAL-DATA

This paper considers the identification problem of a system operating in a closed loop with an existing feedback controller. The closed-loop system is excited by a known excitation signal, and the resulting tim e histories of the closed-loop system response and the feedback signal are measured. From the time history data, the algorithm computes the Markov parameters of a closed loop observer, from which the Markov par ameters of the individual open-loop plant, observer, and controller ar e recovered. A state-space model of the open-loop plant and the gain m atrices for the controller and the observer are then realized. The res ults of the paper are demonstrated by an example using wind tunnel air craft flutter test data.