基于切换模型的无人直升机偏航通道系统辨识方法∗

摘要

针对直升机偏航通道中舵机控制量的饱和非线性问题，提出基于切换模型的无人直升机偏航通道系统辨识方法。首先分析无人机偏航通道的特征，建立包含饱和单元的切换模型。其次通过扫频实验采集辨识所需的数据，并在频域下采用遗传算法辨识得到切换模型的所有参数。再根据实验数据分析辨识模型的残差序列，得到系统的残差模型，并利用该残差模型修正辨识得到的无人机偏航通道模型，进一步提高模型的准确度。最后通过实验数据分析文中模型的准确性，并利用该模型设计无人机飞行控制器。实验结果也证明模型的有效性。%Aiming at the saturation nonlinearity in the yaw channel of a small-scale unmanned helicopter, a switch model based identification method for the unmanned helicopter yaw channel is proposed. Firstly, the characteristics of the yaw channel are analyzed and a switch model including a saturation unit for the controller is established. Experimental data for the model identification are collected by utilizing some sweep frequency control signals. Based on the data, the parameters of the switch model are identified through the genetic algorithm method. The residual error signal is calculated, analyzed and utilized to modify the model obtained, and thus the accuracy of the model is further increased. The effectiveness of the proposed method is validated by some flight data. By utilizing the obtained model, a flight controller is designed and then employed to control the helicopter. The experimental result further demonstrates the validity of the indentified yaw model.