基于格网系的双航海惯导定位信息融合

Positioning information fusion for dual marine INSs based on grid frame

在双轴、单轴旋转调制激光陀螺航海惯导备份配置中,主惯导双轴旋转调制航海惯导故障情况下,针对备份系统单轴旋转调制航海惯导定位精度受方位陀螺常值漂移影响的问题,提出了双航海惯导定位信息融合方法。在格网系下设计了两套系统的联合误差状态Kalman滤波器,以系统间位置参数的差异为观测量,对惯性器件的确定性误差进行估计;建立了定位误差预测模型,对单轴旋转调制航海惯导的确定性定位误差进行预测补偿;通过滤波器、预测模型在地理系与格网系间的相互转换,实现了定位信息融合算法的全球适应性。最后通过仿真、实际系统实验进行了验证,结果表明:对单轴旋转调制航海惯导的定位误差预测补偿后,与补偿前相比其定位误差减小了30%,进而保证了主惯导双轴旋转调制航海惯导发生故障情况下系统的定位精度。

In the case of dual-axis indexing INS and single-axis indexing INS redundant configuration, the positioning accuracy of the single-axis INS（as a backup system） will be affected by the azimuth gyro constant drift upon failure of the dual-axis indexing INS. To solve this problem, a positioning information fusion method for dual marine INSs is proposed. A joint error state Kalman filter of the dual-axis and the single-axis INSs is designed based on the grid frame to estimate the deterministic errors of inertial devices by taking the inter-system position parameter difference as the observation. A position error prediction model for single-axis indexing INS is established to predict and compensate the deterministic errors. The global adaptability of the positioning information fusion algorithm is realized through the transformation between the geographical frame and the grid frame by the Kalman filter and the position error prediction model. Simulation and actual system experiments are conducted to verify the proposed method, and the results show that the position error of the single-axis indexing INS is reduced by 30% after the error compensation, which can ensure the position accuracy in the event of failure of the dual-axis indexing INS.