系统识别与飞机颤振

本文在简要综述了系统识别技术在飞机颤振研究中的应用后,介绍了三种系统识别方法。重点讨论了其算法要点及理论基础。对有关数据处理问题也作了适当说明。基于复模态分析和优化技术的传递函数法可以精确识别出全部模态参数,并在带外挂机翼颤振模型试验中获得成功,该法可推广到仅有响应数据的风洞与飞行试验情况。脉冲响应和自回归滑动平均模型法采用了相关和最小二乘技术,可以在较强干扰情况下得到精确结果,后者还可求出估计值与真值的协方差。两种时域方法皆可无需专用信号分析设备而直接利用测量采样数据进行系统识别。

SYSTEM IDENTIFICATION AND AIRCRAFT FLUTTER

After reviewing the application of system identification to aircraft flutter research, three methods of system identification are presented in this paper. Emphases are put on the main points of identification algorithm and its theoretical basis. The problems related to data processing are also discussed. The Transfer Function Method based on complex modal analysis and optimization technique can identify all of the modal parameters accurately. Furthermore, this method has been applied to the flutter model test of a wing with external bodies successfully, The method can be extended to the cases of wind tunnel and flight tests which provide response data only. Adopting the correlation and least square technique, Impulse Function Method and Autoregressive Moving Average Method can gain considerable accuracy in identification of measurement data conteminated with rather strong noise interference. In no need for a special signal analysis instrument, it is possible to make direct use of measurement sampled data from artificial random or transient excitation and response data from natural random excitation with these two time domain methods.