捷联惯导系统现场标定方法

Field Calibration Method for Strapdown Inertial Navigation System

摘要:

陀螺漂移会对捷联惯性导航系统的导航定位误差产生直接的影响,所以需要用实验的方法标定出陀螺漂移,并进行补偿；陀螺漂移随时间和环境变化,因此采用实验室标定方法会降低系统的精度；文章提出一种基于卡尔曼滤波技术的现场标定方法,给出了现场标定时系统的状态方程,分别推导了采用速度、速度加姿态为观测信息时的量测方程；利用奇异值可观测度分析方法比较机动状态不同,观测信息不同的五种现场标定方案的陀螺漂移的可观测度,从而确定了两种最优现场标定方案,即在以速度为外部观测量的情况下,使载体处于“S”型机动状态和在载体静止的情况下,速度加姿态为观测信息；通过仿真实验验证了这两种标定方案可以有效提高现场标定的精度。

Abstract:

Gyro drift has a direct impact on the navigation and positioning error of strapdown inertial navigation system, so it is necessary to calibrate the gyro drift with the experimental method. The gyro drift changes with time and environment, and the accuracy of the system can be reduced if the laboratory calibration method is used. This paper proposes a field calibration method based on Kalman filtering technique. State equation of calibration system is given directly, two measurement equations using velocity alone and velocity + attitude for the observation information are derived respectively. Singular value method is used to compute observability degree of gyro drift with different mobile states and different observation information of five field calibration schemes. Two optimal field calibration schemes that the carrier is in the “S” maneuver in case of using velocity for the observation information and the carrier is static in case of using velocity and attitude for the observation information are determined. Moreover, simulation experiments are implemented to verify the two schemes based on the field calibration method can effectively improve calibration accuracy.