基于PEM的三自由度直升机模型辨识

Model identification of 3-DOF helicopter based on PEM

针对三自由度(3-DOF)直升机平台的特点,提出了一种基于预测误差法(PEM)的模型频域辨识方法,建立了机理模型,运用扫频技术得到巡航飞行状态直升机3个通道的输入—输出数据;分析了偏相干函数和复合窗函数,通过PEM进行了模型的频域辨识,得到了状态空间方程的待辨识参数和直升机的参数化模型。通过时域飞行和模型预测响应的对比,验证了该模型的准确性和该辨识方法的有效性。

Aiming at the characteristics of the three degree of freedom（ 3-DOF） helicopter platform,a frequency domain identification method based on prediction error method（ PEM） is proposed. Mechanism model is constructed,and by using frequency sweep flight technique obtain the input and output data of three channels.Partial coherence function analysis and composite window function analysis are carried out in the system. The identification parameters of state-space equation and the parametric model of helicopter are obtained by prediction error method. It can be verified that the model is accurate and effective through comparison of model prediction response and real flight in time domain.