一种基于参数辨识的微小型无人直升机建模方法

A Modeling Method of Miniature Unmanned Helicopter Based on Parameter Identification

针对具有高度非线性、复杂动力学特性的微小型无人直升机,提出了一种基于参数辨识的建模方法。该方法结合了机理建模和系统辨识的优点,通过严格的机理推导建立了微小型无人直升机横纵向通道通用的参数化模型,建模过程着重考虑了主旋翼、平衡杆和机身的耦合对飞行动态特性的影响。利用基于偏相干分析法的频域辨识获得某型无人直升机的关键参数,进而确定模型。模型预测数据和飞行试验数据的比较表明,所建模型很好地反映了该型无人直升机在悬停状态下的动态特性,可以在该状态下以此模型进行自主飞行控制器设计。

The miniature unmanned helicopter exhibits a complex and nonlinear dynamic behavior, open-loop unstable and a high degree of inter-axis coupling. This paper describes a modeling method based on parameter identification for a miniature unmanned helicopter. This method combines the advantages of mechanism modeling and system identification. First, a universal parameter model of roll and pitch channels of a miniature unmanned helicopter is developed by strict mechanism derivation which explicitly accounts for the couplings of rotor. stabilizer bar and fuselage. Second, the key parameters of a certain unmanned helicopter are obtained by frequency identification technique based on partial coherence analysis to have the model built. The model is verified by comparing the model output with the output collected during flight test.