航天器反作用轮扰动建模及参数辨识

为预测反作用轮微振动对航天器产生的影响,提出了一种改进的扰动模型.由于共振造成的扰动放大是反作用轮扰动对卫星姿态精度的最重要影响,改进模型通过引入放大系数体现结构固有频率对扰动的影响.鉴于改进模型的非线性特性,应用模拟退火遗传算法对改进模型进行了参数辨识.设计刚性六分量力测试平台对反作用轮扰动进行测试,并利用实测数据对改进模型及参数辨识结果进行验证.验证结果表明:改进模型准确地反映了反作用轮的扰动特点,模拟退火遗传算法可以提高参数辨识的精度.

Disturbance modeling and parameters identification of reaction wheel assembly on spacecraft

An improved disturbance model was proposed to predict the effects of reaction wheel assembly (RWA) micro-disturbance on the spacecraft. Because the disturbance amplification by excitation of the structure modes was the most dominating effect on spacecraft attitude accuracy by RWA, the improved model expressed the effect of the structure-s nature frequency to disturbance by introducing amplification coefficients. As the nonlinear characteristic of improved model, simulated annealing genetic algorithm was used to identify the parameters of improved model. A rigid six-axis test bed was designed, and the disturbance of RWA was measured. The improved model as well as the results of parameters identification was validated by experimental data. The experimental results show that the improved model captures the disturbance characteristic precisely, and simulated annealing genetic algorithm can improve the identification accuracy.