一种涡轴发动机控制系统自适应扭振抑制方法研究

Study on Adaptive Torsional Vibration Suppression of Turbo-Shaft Engine Control System

关键词:  直升机  发动机  扭振抑制  陷波滤波器  自适应滤波器

Key words:  Helicopter  Engine  Torsional vibration suppression  Notch filter  Adaptive filter

摘要:

为了解决直升机机动飞行时涡轴发动机控制系统扭振不稳定性问题，根据扭矩动力传递链特点，设计了一种基于最小均方差(LMS)的自适应滤波器，以抑制自由涡轮转速中的扭振动态，并与常规的陷波滤波器效果进行了对比。仿真结果表明，在定旋翼转速下，陷波滤波器和基于LMS的自适应滤波器均能抑制1.90Hz对应的固定扭振分量，但后者能使扭振幅值降低至5%以下，滤波效果明显优于前者；同时，变旋翼转速飞行时，发动机端的扭振基频率会随着转速变化在1.30～2.20Hz变动，此时常规陷波滤波器不再适用，而基于LMS的自适应滤波器仍可显著抑制扭振动态。

Abstract:

In order to solve the problem of torsional vibration instability during helicopter maneuvering flight， with analysis of the torque transmission train， the adaptive filter based on least mean square deviation algorithm(LMS) is designed to do torsional vibration dynamic suppression of free turbine and compared with conventional notch filter in the effect of torsional vibration suppression. It is shown that both the notch filter and the adaptive filter based on LMS can eliminate the torsional vibration at the fixed frequency of 1.90Hz in the constant rotor speed， but the latter can reduce the amplitude of torsional vibration to 5% or less， whose filter effect is better than the former. Meanwhile， when the helicopter flies in the variable rotor speed， the low order torsional vibration frequency of the turbo-shaft engine will vary from 1.30Hz to 2.20Hz and the conventional notch filter is no longer applicable， nevertheless， the torsional vibration can still be significantly suppressed by utilizing adaptive filter based on LMS.