Study on adaptive torsional vibration suppression methods for helicopter/turboshaft engine system with variable rotor speed

Abstract

AbstractIn order to solve the problem that the low‐order torsional model of the integrated helicopter/turboshaft engine system varies significantly under variable rotor speed, research on adaptive torsional vibration suppression methods is conducted. Meanwhile, two adaptive torsional vibration suppression methods, respectively based on fast Fourier transform (FFT) and the least mean square (LMS), are proposed to suppress the low‐order torsional vibration mixing in power turbine speed. Moreover, these two torsional vibration suppression methods are compared in real‐time performance, suppression effect and robustness of performance. The simulation results show that when and only when the designed frequency of the notch filter is away from the low‐order torsional model, the suppression effect of adaptive torsional vibration filter based on FFT is better than that of constant‐coefficient notch filter, but the real‐time performance is worse. On the contrary, no matter how the low‐order torsional model varies, the adaptive filters based on LMS can suppress the low‐order torsion vibration by more than 82.0% and have more superior real‐time and robustness performance, which can overcome torsional vibration instability of turboshaft engine control system under variable rotor speed effectively with more remarkable adaptive ability.