Balanced Model Reduction and Control of Rotor-Bearing Systems

Aneffective technique is applied to the suppression of vibrations inflexible rotor-bearing systems with small gyroscopic effects. A balanced linear-quadratic-Gaussian(LQG) controller design procedure is implemented. The size of thecontroller is reduced in two stages by using (i) abalanced model reduction, and (ii) an LQG balanced reduction. Thecondition for a gyroscopic matrix is developed that allows oneto ignore the rotor gyroscopic effects in the process ofthe controller design, although they are included in the rotordynamics. The approach is illustrated on a typical rotor-bearing system represented by a 48 degree-of-freedom finite element model.