针对重力卫星质心在轨标定问题,提出了一种将预测滤波与卡尔曼滤波相结合的标定算法。该算法首先利用磁力矩器产生一个明显大于干扰力矩的周期性力矩作用于卫星上,然后利用陀螺数据实现了卫星角加速度的预测滤波估计,并通过静电加速度计信息设计卡尔曼滤波器,实现卫星质心的标定;最后进行了数学仿真,仿真结果表明该算法针对卫星的角加速度及质心位置能够实时估计,三轴最佳标定精度分别为[0.062 8 0.032 4 0.041 4]mm,实现了卫星质心较为精确的标定。
A method for on-orbit calibration of center of mass for gravity satellite was proposed,based on a predictive filter fusing extended Kalman filter estimation algorithm.Firstly,a periodic magnetic torque which was more larger than other external torques was applied to the satellite.Secondly,the observation of gyro was used to estimate angular acceleration based on the predictive filter.Finally,an extended Kalman filter was used to estimate the satellite′s center of mass.The numerical results indicate that the angular acceleration and center of mass can be real-time estimated.The calibration accuracy of three axes is [0.0628 0.0324 0.0414]mm,which demonstrates the effectiveness of the proposed method.