Improvement of positive position feedback controller for suppressing compressor blade oscillations

Positive position feedback is an important control vibration algorithm as it exhibits very high reduction ratios but at a specific bandwidth. Out of this bandwidth, there exist two peaks with high amplitudes, which is considered the major drawback of this controller. In this paper, we are going to improve its performance by suppressing the two peaks to acceptable levels. That can be done by coupling additional nonlinear saturation controllers (NSC) with the main system to impose a V-curve at each one of the peaks. The V-curves positions are controlled by adjusting the natural frequencies of the NSCs. The overall behaviors of the system with and without control are clarified by the extracted equations via the multiple time scales analysis. Time history and different response curves of the controlled system are included for showing the controller effect. Eventually, validation curves and comparison with previously work are included.