重力扰动对高精度激光陀螺惯导系统ZUPT的影响分析与补偿

高精度激光陀螺惯导系统广泛应用于车载自主定位定向当中。当不存在外部测速设备的条件下，一般采用零速修正（zero velocity update，ZUPT）对导航误差的发散过程进行约束。常规ZUPT导航算法中重力矢量采用正常重力模型计算获得，忽略了重力扰动对导航精度的影响。考虑到车载自主导航系统对定位精度的要求，本文从重力扰动对惯性导航误差的影响机理分析入手，指出重力扰动是影响高精度ZUPT导航精度的最主要误差源之一。设计提出了两种适用于车载应用的重力扰动实时补偿方案，并在重力扰动变化剧烈的山区地带进行了长距离车载试验。试验结果表明，对于同一组跑车数据，导航时间2 h ZUPT间隔10 min，激光陀螺惯导系统的水平定位精度由补偿前的8.93 m提高到了补偿后的3.75 m，高程定位精度由补偿前的1.63 m提高到了补偿后的0.80 m。重力扰动补偿方法具有重要的工程应用价值。

Effect analysis and compensation of the high precision ring laser gyroscope inertial navigation system ZUPT caused by gravity disturbance

High precision ring laser gyroscope (RLG) inertial navigation system has been widely used in direction and position determination of the land vehicle. On the condition of no external velocity measurement device, zero velocity update (ZUPT) has always been used to restrain the navigation error. In normal way, the ZUPT navigation algorithm calculates the gravity vector by using the standard gravity model, which neglects the effect on navigation precision of the gravity anomaly. Considering the high demand of positioning accuracy of the vehicular autonomous navigation system, the influence mechanism of the inertial navigation error caused by gravity anomaly is analyzed, and it is point out that gravity anomaly is one of the most significant error source of the high precision ZUPT navigation accuracy. Two real-time gravity anomaly compensation methods suitable for vehicular use are proposed here, and a long distance vehicle test is conducted in a mountain region with drastic changing of the gravity anomaly. The test result shows that in one vehicle test data, 2 hours navigation task with 10 min ZUPT interval, the horizontal positioning accuracy is improved from 8.93 m to 3.75 m, the height positioning accuracy is improved from 1.63 m to 0.80 m. The gravity anomaly compensation algorithm shows important engineering application value.