地磁测量误差矢量补偿方法研究

精确补偿磁测误差是确保地磁导航精度的一项关键技术。针对磁干扰补偿问题,提出了一种改进的基于模糊自适应卡尔曼滤波的矢量补偿方法。该方法对卡尔曼滤波中的观测矩阵进行修改,有效地解决了某些参数收敛过慢的问题;通过监视实时得到的量测新息的实际方差与理论方差的比值,应用模糊控制理论对卡尔曼滤波的量测噪声协方差进行递推修正,使其逐渐逼近真实噪声水平,进而得到最优估计参数。仿真结果表明,该方法对于时变的量测噪声具有较强的自适应性,总场补偿误差从175.8 nT降低到6.7nT,X、Y、Z方向的补偿误差分别由59.2、110.2、122.2 nT降低到6.0、1.7、1.5 nT,总量和分量补偿精度显著提高。最后通过构建矢量测量系统实验验证了改进方法具有较快的收敛速度且具有更高的补偿精度,为磁场测量误差矢量补偿提供了良好的借鉴。

Component compensation method for distortion magnetic field measurement

Aeromagnetic compensation accuracy is one of the key factors affecting the accuracy of geomagnetic navigation. A component compensation method is proposed based on improved Fuzzy Adaptive Kalman Filtering. The observation matrix in Kalman filter is modified to effectively improve the low speed convergence. By monitoring the variance ratio between the residual output and theoretical residual at each moment, the measurement noise covariance is modified step by step and the optimal parameters are obtained. Simulation results show that this presented method has strong adaptability to time varying measurement noise. The total field compensation error is reduced from 175.8 to 6.7 nT, component error is reduced from 59.2, 110.2, 122.2 nT to 6.0, 1.7, 1.5 nT, respectively. Experiment is carried out by constructing a vector system and its results demonstrate that the proposed method performs better in convergence speed and compensation accuracy. The proposed method can provide a good reference to distortion magnetic field compensation.