降阶扩展卡尔曼滤波在INS/GPS导航系统中的应用

INS/GPS组合可以实现长期稳定、高精度的导航系统，从而替代单一高精度高成本的INS.组合中等精度的INS和MS860系统，应用降阶EKF方法，开发实现“真航向测量系统”( TNDS)的高精度航姿测量。TNDS以PC／104架构的嵌入式计算机采集处理来自INS和MS860的信息；重点推导了TNDS降阶误差模型，并在其中采用降阶的EKF滤波，TNDS系统最后进行了海上试验。试验数据表明：采用降阶EKF滤波后，INS的位置误差σ由100 m减小到40 m;系统航向的误差由原来的0.105°减小到0.034°；纵横摇的误差也相应地减小。整个海上试验验证了TNDS的性能和降阶EKF滤波算法的有效性。

Reduced-order EKF Application in A Marine INS/GPS Navigation System

Integrated navigation for GPS/INS provides alternatives for long-term stability and high accuracy due to their complementary properties. A stand-alone navigation system with high accuracy will be of high cost. Integration of the medium accuracy sensors, with the properly integrated method, can acmeve higher accuracy and long term stability at a lower cost. It is the goal of the present project- TNDS (true north determination system) . The TNDS integrates MS860 and INS with a PC/104 embedded computer system processing the data. The INS error model including the proper error states for the actual physical system TNDS has been developed. Based on the model, a proposed GPS/INS reducedorder J^KF (extended kalman Filter) algorithm design for TNDS and marine tests were achieved. The tests show that the INS position errors are reduced from more than 100 m to 40 m after correction. The heading error a are reduced from 0.105° to 0.034° after correction. The accuracy in roll and pitch is also increased greatly by the integration. Whole set of tests show that the TNDS performance is significantly improved by GPS/INS reduced-order EKF algorithm.