电传飞机飞行品质低阶等效系统算法研究

Low Order Equivalent System Identification Method to Evaluate Flying Qualities of Fly-by-Wire Aircraft

针对使用飞行试验数据评定电传飞机飞行品质的难题,提出一种电传飞机低阶等效系统频域参数辨识方法;首先,提出了实用的低阶等效系统模型,采用高精度有限傅立叶变换对飞行试验数据进行了精确的频谱分析,使用频域相干性分析法确定了参数辨识的频率范围;然后,采用频域方程误差法、输出误差法和单纯形法相结合的算法,计算得到电传飞机低阶等效系统参数的最优解,获得电传飞机飞行品质指标;最后,使用某型电传飞机的飞行试验数据验证了低阶等效系统算法;结果表明:该算法能够准确地辨识电传飞机的低阶等效系统模型,解决了用飞行试验数据评定电传飞机飞行品质的难题,为电传飞机飞行品质评定提供了技术支持。

Low order equivalent system identification method on frequency domain is proposed to evaluating flying qualities of fly-by-wire aircraft from flight test data.Firstly,practical transfer function models are proposed and spectral analysis is conducted by using high accuracy finite Fourier transform method.Frequency domain coherence analysis technique is used to determine frequency band to be identified.Secondly,frequency domain identification algorithm is developed to compute flying quality indicators by using the output error and equation error parameter identification integrated with Simplex method.Finally,The identification algorithm is validated by certain fly-by-wire aircraft flight test data.The results show that the low order equivalent system identified from flight test data can properly describe the dynamic response characteristics of fly-by-wire aircraft.The method developed can provide technique support for flying quality evaluation of fly-by-wire aircraft.