动基座重力梯度仪加速度计标度因数一致性调整方法

Consistency adjusting method for accelerometer scale factor of gravity gradiometer in moving environment

针对基于旋转加速度计原理的高精度重力梯度测量对动态条件下将两组加速度计标度因数不一致性调整到0.1 ppm的需求,提出一种基于Sage-Husa自适应滤波的加速度计标度因数一致性动态调整方法。首先对重力梯度敏感器输出信号进行解调,实现两组加速度计标度因数不一致信号的提取;其次,针对信号易受运动干扰的问题,利用Sage-Husa自适应滤波的方法实时适应不同量级的动态干扰,对标度因数不一致信息进行最优估计;最后,应用PID算法调整加速度计内部电磁线圈电流,实现加速度计标度因数实时调整。航空试验结果表明,在相同的工况下,与常规解调方法对比,所提方法可将航空测量内符合精度由150E@1 km提高至65E@1 km,证明了该方法的有效性。

Aiming at the requirement of high-precision gravity gradient measurement based on the principle of rotating accelerometer to adjust the inconsistency of scale factors of two groups of accelerometers to 0.1 ppm in moving environment,a dynamic adjustment method of accelerometer scale factor consistency based on Sage-Husa adaptive filter is proposed.Firstly,the output signal of gravity gradient sensor is demodulated to extract the inconsistent signal of two groups of accelerometer scale factors;Secondly,aiming at the problem that the signal is vulnerable to motion interference,Sage-Husa adaptive filtering method is used to adapt to different orders of dynamic interference in real time,and the inconsistent information of scale factor is optimally estimated;Finally,PID algorithm is used to adjust the current of the electromagnetic coil in the accelerometer to realize the real-time adjustment of the accelerometer scale factor.The aerial test results show that under the same working conditions,compared with the conventional demodulation method,the proposed method can reduce the internal coincidence accuracy of aerial measurement from 150E@1 km increased to 65E@1 km,which proves the effectiveness of the method.