Active disk for automatic balancing of rotor-bearing sytems

This paper leads with the active cancellation problem of mechanical vibrations in rotor-bearing systems. The use of an active disk is proposed for actively balancing a rotor by means of locating a balancing mass at a suitable position. Two nonlinear controllers with integral compensation are proposed to put the balancing mass at a specific position. Algebraic identification is used for on-line eccentricity estimation, because of the implementation of this active disk is based on knowledge of the eccentricity. An important property of this algebraic identification is that the eccentricity identification is not asymptotic but algebraic, in contrast to most of the traditional identification methods, which generally suffer of poor speed performance. In addition, a velocity control is designed to take the rotor velocity to a desired operating point over the first critical speed. The controllers are developed in the context of an off-line prespecified reference trajectory tracking problem. Some numerical simulations are included to illustrate the dynamic performance of the closed loop system and the active vibration cancellation.