捷联式重力无源导航系统

Strapdown Gravity Passive Navigation System

为了满足水下运载体长航时、高精度、低成本的导航需要,提出由激光陀螺单轴旋转捷联惯性导航系统、计程仪、深度计、光纤陀螺捷联式重力仪和数字重力异常图组成的捷联式重力无源导航系统。运载体的位置由激光陀螺单轴旋转捷联惯性导航系统给出;光纤陀螺捷联式重力仪、计程仪和深度计组成水下捷联式重力测量系统,以激光陀螺单轴旋转捷联惯性导航系统提供的位置信息、计程仪提供的速度信息和深度计提供的水深信息作为观测量,应用扩展卡尔曼滤波计算出东、北、天坐标系下加速度计比力值,使用低通滤波实时获得重力值和重力异常值。根据存贮在计算机中的数字重力异常图,运用相关极值法,计算得到运载体位置。2019年底,捷联式重力无源导航系统进行了长时间船载试验,对该系统试验数据进行了离线处理。试验结果表明,在匹配海域内,运载体位置误差小于1个重力异常图格网大小。

In order to meet the needs of long-term,high-precision and low-cost navigation of underwater vehicles,a strapdown gravity passive navigation system is composed of a single-axis rotating strapdown inertial navigation system(SINS)based on laser gyro,a log,a depth gauge,a strapdown gravimeter based on fiber optic gyroscope and a digital gravity anomalies.The position of the carrier is given by a single-axis rotating SINS based on laser gyro;An underwater strapdown gravity measurement system is formed of a strapdown gravimeter based on fiber optic gyroscope,log and depth gauge,the position information provided by the axis-rotating strapdown inertial navigation system,the speed information provided by the log and the water depth information provided by the depth gauge are used as observations,the extended Kalman filter is applied to estimate the specific force of accelerometer in the local-level frame,the low-pass filtering is used to obtain the gravity value and the gravity anomaly value in real time;according to the digital gravity anomaly map stored in the computer,the relative extreme value method is used to calculate the position of the carrier.At the end of 2019,the strapdown gravity passive navigation system carried out a long-term shipboard experiment,and the experiment data of the system was processed offline.The experiment results show that:the carrier position error is less than 1 grid size of gravity anomaly map in the matching sea region.