改善航天器反作用轮扰动实验模型参数的辨识方法

Identification Method to Improve Disturbance Model Parameters of Reaction Wheel

反作用轮系统是影响航天器姿控系统精度的主要扰动源之一．建立反作用轮扰动模型的目的是预测扰动对航天器产生的影响,并采取相应的控制方法和隔离系统．基于反作用轮的扰动实验模型,通过对反作用轮扰动实验数据的分析,确定出反作用轮扰动实验模型中的参数:谐波数和幅值系数,并在此基础上提出了能量补偿法,最后进行了数值仿真．结果表明,谐波数的辨识精度不超过0．04％,当采用振幅谱法计算幅值系数时,误差高达15．5％;而用能量补偿法,其幅值系数的精度不超过1．1％．可见能量补偿法提高了幅值系数的辨识精度．本文研究为改善航天器姿态控制精度和稳定度奠定了一定的基础．

Reaction wheel is one of the main disturbance sources that affect the precision of attitude control system of spacecraft. The purpose of setting up a disturbance model of reaction wheel is to predict the effects of the disturbance on the spacecraft, and then adopt corresponding control methods and isolation systems to restrain them. This paper presents the experimental disturbance model of reaction wheel. By analyzing the experimental data of reaction wheel, the parameters of the disturbance model, harmonic numbers and amplitude coefficients are determined. The energy compensation method is then given. The simulation results show that the identification accuracy of harmonic numbers does not exceed 0.04%. When adopting the amplitude spectrum method to compute the amplitude coefficients, the error is high up to 15.5%, however the error not over 1.1% when adopting energy compensation method. It indicates that the energy compensation method improves the identification accuracy of amplitude coefficients. This paper aims at providing a certain basis for improving the attitude control precision and stabilization of the spacecraft.