Modal-space active damping of a beam-cable structure: theory and experiment

A theory of multiple-actuator modal-space active damping (control) of individual structural vibration modes is first reviewed; then an experiment is described in which the control technique was applied to a laboratory beam-cable structure. Active damping was produced in the three lowest modes (all under 10 Hz) of the structure by a feedback control system consisting of a single velocity sensor, an analog controller, and three force actuators. Both open-loop and closed-loop frequency response functions were measured. A theoretical frequency response analysis is developed, and experimental results are compared with theoretical predictions.