基于双星敏感器的船体姿态测量系统设计

The Design of a Ship Attitude Measurement System Based on Dual Star Sensors

提出了一种基于双星敏感器的船体姿态测量系统。本系统采用两台大视场高精度CCD星敏感器,一台指向船艉,一台指向左舷,组合定姿达到提高横摇角测量精度的目的。选用TH7888A作为CCD传感器,成像后经实时图像处理器提取星点目标位置、灰度信息传给数据处理计算机,通过星图识别、姿态确定获取地心惯性坐标系下视轴指向,经岁差、章动、极移、船位、蒙气差等修正,获得惯导地平系下姿态矩阵。依据标定的星敏感器与甲板坐标系安装矩阵,解算船体姿态角,将两台星敏感器解算的姿态角进行融合,达到获取三个高精度船体姿态角的目的。实验表明,该系统航向、纵摇及横摇测角精度分别达到8.46″、7.16″及5.11″,测量精度高、自主性强且能不随时间漂移。

In order to improve the ship attitude measurement precision of our space TT&C ship,a ship attitude measurement system based on dual star sensors is proposed.The system uses two wild-field-of-view and high-accuracy star sensors are used with one pointing to ship stern and the other pointing to port side,which improves the measurement accuracy of roll angle by hybrid attitude determination.In the system,TH7888Ais used as CCD star sensor,and,after imaging,real-time image processing system extracts star target location and its gray value to data processing computer for obtaining optical axis pointing with respect to inertial space by star recognition and attitude determination.And after the correction of precession,nutation,pole shift,ship position and atmosphere refraction,attitude matrix of star sensor with respect to INS horizontal coordinate system is acquired.According to the calibrated installation matrix of dual star sensors,ship attitude is calculated respectively,and then three high-precision ship attitude angle is obtained by data fusion.It is experimentally found that the accuracy of ship attitude of the system is achieved to 6.9″of course,5.7″of pitch and 4.5″of roll.High accuracy,strong autonomy and non drift with time of the system are obtained.