单框架控制力矩陀螺转子动不平衡对遥感卫星成像的影响

Influence of dynamic imbalance of SGCMG rotor on remote sensing satellite imaging

分析了单框架控制力矩陀螺(SGCMG)转子在高速旋转时产生的动不平衡干扰力矩引起的星体颤振角和颤振角速度对TDI CCD相机成像的影响。通过坐标变换将转子坐标系下的干扰力矩转换至星体坐标系下的干扰力矩,将卫星姿态动力学方程计算出干扰力矩引起的星体颤振角位移和颤振角速度代入TDI CCD相机成像像移补偿模型;利用TDICCD相机像点与物点对应模型的仿真系统仿真了陀螺转子在不同转速下引起星体颤振角位移和角速度对相机成像的影响;最后,利用图像对比度和互相关相似性测度分析仿真成像质量。仿真显示:SGCMG转子在转速为3 000 r/min时,横向调制传递函数为0.997,图像互相关相似性测度为0.996 1;转速为6 000 r/min时,横向调制传递函数为0.928 3,图像互相关相似性测度为0.974 8。结果表明:SGCMG转子在高速旋转过程中引起的星体颤振角位移和角速度严重影响了TDI CCD相机的成像质量,应依据颤振的影响对SGCMG实施减震措施。

The influence of vibration angles and vibration angle velocities caused by the dynamic imbalance disturbing torques of a rotor for the Single Gimbal Control Moment Gyro on the TDI CCD camera imaging is analyzed.By coordinate transformation,the disturbance torque is transformed from a rotor coordinate to a satellite coordinate,and then satellite attitude dynamics equations are used to calculate the vibration angular displacements and vibration velocities of stars in an image motion compensation model of the TDI CCD camera.TDI CCD camera simulation system with the material point corresponding to imaging point model is used to analyze the imaging MTF and mutual correlation similarity measure.Experiments show that when SGCMG rotor speed rotates at 3 000 r/min,the MTF horizontal shift is 0.997 and mutual correlation similarity measure is 0.996 1;When SGCMG rotor speed rotates at 6 000 r/min,the MTF horizontal shift is 0.928 3,mutual correlation similarity measure is 0.974 8.The results prove that the quality of TDI CCD scanning images is terribly influenced by vibration angles and angle velocities caused by the dynamic imbalance of the SGCMG rotor.It must carry a damping when the SGCMG is used.