基于水平罗经的捷联惯导系统自动零速修正

Strap-down INS automatic zero velocity update base on level gyrocompass

为提高车载捷联惯性导航系统(SINS)的定位和姿态精度,分析了SINS静态罗经对准原理,并推广至行进过程中,借助里程仪测速辅助实现姿态动态、持续对准。同时,通过此动态罗经回路控制律对里程仪测速噪声进行平滑,并对平滑后速度加以检测,实现了零速修正(ZVU)的停车自动识别;停车瞬间利用动态罗经对准回路对系统姿态进行修正,速度误差归零,并依据相邻停车时刻记录的速度误差拟合曲线积分值修正系统位置误差。最后,采用此方案进行了长达4h(约160km)的三组跑车实验,每10min停车ZVU(1s),达到的定位精度为44.2m(CEP),姿态精度优于0.5′。

For improving the positioning and attitude precision of vehicle Strapdown Inertial Navigation System（SINS）, the paper analyzes the static gyrocompass alignment principles（SINS）, and then, with the assistance of odometer velocity output, applies it to dynamic conditions as vehicle is moving. Meanwhile, through the velocity smoothing by dynamic gyrocompass alignment control algorithms, the vehicle＇s parking automatic identification with zero-velocity updating is realized. As soon as vehicle stops, the system corrects the attitude information with the dynamic alignment result, sets velocity zero, and corrects position error by the velocity error curve fitting between two latest stop time. At last, three vehicle experiments about 4 h （160 km） are implemented according to this method. The result shows that the positioning precision is 44.2 m （CEP） with ZVU （1 s） every 10 min, and the attitude precision is better than 0.5 ＇.