两种双矢量SINS粗对准方法大俯仰角适应性研究

Research on adaptability of SINS coarse alignment for large pitch angle

摘要:

大俯仰角下捷联惯导粗对准双矢量定姿中，不同矢量组合下，姿态角尤其是方位角对准精确度相差很大，必须慎重选择。对此，给出了2种最常用的粗对准矢量组合模式误差方程，对其主要误差影响因素进行分析。综合传感器误差，利用蒙特卡洛随机打靶方法对全姿态角下粗对准精确度进行仿真，并开展了80°俯仰角转台静态粗对准试验。转台试验中，在惯导陀螺误差约1°/h，加速度计误差约0.1mg情况下，第1种、第2种组合模式方位角粗对准最大误差值分别为20°、7.5°，第2种组合模式约为第1种的1/3；仿真测试中，在惯导陀螺误差约0.1°/h，加速度计误差约1mg，80°俯仰角下，第1种、第2种组合模式下方位角粗对准最大误差值分别为11°与2.2°，前者约为后者的5倍。仿真与试验结果表明，大俯仰角下矢量组合模式是影响惯导姿态角与姿态矩阵粗对准精确度的最主要因素。

Abstract:

Under large pitch angles, in the coarse alignment of the Strapdown Inertial Navigation System(SINS) using dual-vector attitude determination, the accuracy of the attitude angles, especially the azimuth angle, varies greatly under different vector combinations, and must be carefully selected. To address this, two of the most commonly used coarse alignment vector combination error equations are presented, and the main error-affecting factors are analyzed. Considering sensor errors, the accuracy of coarse alignment under full attitude angles is simulated using the Monte Carlo method, and a static coarse alignment experiment was conducted on a turntable at a pitch angle of 80°. In the turntable experiment, with SINS gyro error of about 1°/h and accelerometer error of about 0.1mg, the maximum azimuth angle coarse alignment errors for the first and second combination modes were 20° and 7.5°, respectively, with the second combination mode being about one-third of the first. In the simulation test, with SINS gyro error of about 0.1°/h and accelerometer error of about 1mg, at a pitch angle of 80°, the maximum azimuth angle coarse alignment errors for the first and second combination modes were 11° and 2.2°, respectively, with the former being about five times that of the latter. The results of the simulation and experiment show that the vector combination mode under large pitch angles is the most important factor affecting the accuracy of the coarse alignment of the SINS attitude angles and attitude matrix.