一种飞轮扰振对成像像移影响的数值分析方法

Numerical Modeling Method for Evaluation of Image Motion Caused by Flywheel Disturbances

为了实现像移大小的可靠预估,建立了一种对从扰振源到成像像移的传递函数进行估算的数值分析方法.首先利用Kistler微扰振测力平台对飞轮扰振进行测量,获得了各向扰振的高精度实测数据.将飞轮安装在高仿真度的整星样机中进行试验,获得了受飞轮微振动影响的图像像移数据.利用飞轮扰振数据和像移数据中的谐波数据建立并求解了一系列以传递函数为待求变量的线性方程组.最后利用所得传递函数对相同批次不同飞轮产品扰振所致像移进行预估.对比预估值和该飞轮实测像移值发现:预估结果和实测结果中谐波特性一致.相对于实测值,预估值在典型响应处误差不高于10%,大部分预估值的绝对误差不超过0.1个像素,所得传递函数可较好的对成像像移进行预估.相较于传统理论建模方法,该方法具有更高的可信度和更快的分析速度.

In order to evaluate the image motion reliably,a numerical analysis method was promoted for calculations of jitter transfer functions between input disturbances and output image motion.Firstly,Kistler table is applied to measure the disturbances of flywheel and precise test data of each disturbances are achieved.Secondly,a flywheel is assembled in a high-fidelity satellite prototype and jitter-affected image motion data are obtained from the prototype.Thirdly,a series of Linear System of Equations(LSE)whose variables are the transfer functions are constructed and solved with the help of harmonic data of flywheel disturbances and image motion.At last,by applying the calculated transfer functions,the evaluation of image motion of another flywheel which comes from the same product series is completed.With the reference to the test data,the evaluated image motion performs the same harmonical characteristics,the relative errors of typical responses in evaluated image motion are less than 10%and most absolute errors of rest parts are no more than 0.1 pixel.Compared with theoretic modeling method,the numerical method is faster and more reliable.