摘要
A comprehensive method based on system identification theory for helicopter flight dynamics modeling with rotor degrees of freedom is developed. A fully parameterized rotor flapping equation for identification purpose is derived without using any theoretical model, so the confidence of the identified model is increased, and then the 6 degrees of freedom rigid body model is extended to 9 degrees of freedom high-order model. Bode sensitivity function is derived to increase the accuracy of frequency spectra calculation which influences the accuracy of model parameter identification. Then a frequency domain identification algorithm is established. Acceleration technique is developed furthermore to increase calculation efficiency, and the total identification time is reduced by more than 50% using this technique. A comprehensive two-step method is established for helicopter high-order flight dynamics model identification which increases the numerical stability of model identification compared with single step algorithm. Application of the developed method to identify the flight dynamics model of BO 105 helicopter based on flight test data is implemented. A comparative study between the high-order model and rigid body model is performed at last. The results show that the developed method can be used for helicopter high-order flight dynamics model identification with high accuracy as well as efficiency, and the advantage of identified high-order model is very obvious compared with low-order model.
摘要译文
提出了一种基于系统辨识理论的转子自由度直升机飞行动力学建模综合方法。无需使用任何理论模型就可以推导出用于识别目的的完全参数化的转子颤振方程，因此增加了识别模型的置信度，然后将6自由度刚体模型扩展到9自由度高阶模型。导出Bode灵敏度函数，提高频谱计算精度，影响模型参数识别的准确性。然后建立频域识别算法。进一步开发加速技术以提高计算效率，使用这种技术总识别时间减少了50％以上。为直升机高阶飞行动力学模型识别建立了两步法，与单步算法相比，提高了模型识别的数值稳定性。应用所开发的方法，基于飞行试验数据识别BO 105型直升机的飞行动力学模型。最后进行高阶模型与刚体模型的对比研究。结果表明，该方法可用于高精度高效直升机高阶飞行动力学模型识别，与低阶模型相比，识别出的高阶模型的优势非常明显。
WuWei;. Identification method for helicopter flight dynamics modeling with rotor degrees of freedom[J]. Chinese Journal of Aeronautics, 2014,27(6): 1363-1372