H∞ Control of Transverse-Torsional Coupled Vibrations Using Multiple Active Dynamic Vibration Absorbers

In this paper we discuss the vibration control of a flexible structure which possesses transverse-torsional coupled vibration modes using two active dynamic vibration absorbers. The H∞ control theory is adopted to obtain an output-feedback robust controller by which structural vibrations in two lower vibration modes are reduced without spillover. The statements of the control object are organized into the generalized plant, that is, robust stabilization and sensitivity reduction. A method of synthesis of the controller is presented in which balancing of control inputs is taken into consideration. In numerical analysis and control experiments, it is confirmed that the controller achieves considerably high performance with robust stability.