STABILIZATION OF SELF-EXCITED OSCILLATION IN A FLEXIBLE FLUID-CONVEYING-PIPE BY POSITION FEEDBACK CONTROL

Resonances in flexible fluid-conveying-pipes have been theoretically and experimentally analyzed from the practical and physical points of view. The excitation mechanisms for the resonances have been given considerable attention. In contrast with the analysis of the resonance phenomena, there are few studies on the stabilization control method for the self-excited oscillation of a flexible fluid-conveying-pipe. In this paper, we propose a control method for the self-excited oscillation in a fluid-conveying-pipe theoretically and experimentally. The unstable mode of the fluid-conveying-pipe is not any eigenmodes of the flexible pipe without flow because it is non-self adjoint system. In this paper, by not using the eigenmodes of the flexible pipe without flow deriving the unstable mode shape exactly, we propose a stabilization control method which actuates the unstable mode directly. Therefore, under the proposed control method, the spillover is avoidable and only one sensor is required.