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Talks and Poster Presentations (with Proceedings-Entry):

M. Hirschmanner, N. Steinschaden, H. Springer:
"Adaptive Control of a Rotor Excited by Destabilizing Cross-Coupling Forces";
Talk: IFToMM Sixth International Conference on Rotor Dynamics, Sydney, Australia; 2002-09-30 - 2002-10-04; in: "Proceedings Sixth International Conference on Rotor Dynamics", (2002), ISBN: 0733419631; 38 - 45.



English abstract:
Active magnetic bearings are important components in modern turbo-machinery in order to improve the vibration performance at high speeds. In this paper two coexisting sources of vibrations are considered. First, mass unbalance excitation as a synchronous periodic disturbance and second, destabilizing cross-coupling forces as generated, for example, by fluid film mechanisms, annular pressure seals or labyrinths of a turbo machine. Active magnetic bearings (AMB) are introduced in this paper to control vibrations of a rigid rotor simultaneously excited by these two types of forces. The basic AMB-control is carried out by a simple PID controller while for the compensation of both excitation mechanisms two independent control algorithms are used. In order to compensate the destabilizing cross-coupling forces a standard least square estimator along with a time varying so-called forgetting factor estimates the unknown parameters of the cross-coupling mechanism. These parameters, for example, depend on the pressure in the machine and other machine operating conditions. The mass unbalance forces are compensated by a recursive gain scheduled algorithm which needs no a priori knowledge either of the amount or the direction of the mass unbalance. By combining these two algorithms a significant reduction of the vibration level is achieved. The behavior of both algorithms and their interaction with each other is studied by numerical simulation.


Created from the Publication Database of the Vienna University of Technology.