旋转惯导系统中转轴方向对系统调制精度的影响

不同轴向的惯性器件误差在惯导系统中的误差传播特性不同,因此在旋转惯导系统中转动机构选择不同转轴方向对系统精度的调制效果不同。分析了在选择不同轴向作为旋转轴时对导航系统精度的影响,并根据转台转轴与机体系、惯性器件(IMU)系之间存在的夹角关系,将其分为两种方案进行讨论,转轴与IMU系存在夹角以及转轴与机体系存在夹角。通过分析,前者在调制效果上与传统的单轴旋转惯导系统相同,而后者会改变调制效果。在此基础上,进一步推导分析了第二种方案下不同转轴方向与系统定位精度之间的内在关系,提出了一种在长时间导航情况下的转轴方向选择方案,并进行了仿真验证。仿真结果表明,与传统单轴旋转惯导系统相比,该方案显著提高了系统的导航定位精度,对在不同情况下转台转轴方向的选择具有一定的工程应用参考价值。

Analysis on rotation SINS precision modulated in different directions

Since the errors of inertial components along different axes have different propagation characteristics,and different turntable axis directions could produce different modulation effects on single-axis rotation inertial navigation system.In this paper,the effects of different turntable axis directions on system precision are analyzed.According to the relation of turntable axis to body coordinate and Inertial Measurement Units(IMU) coordinate,two schemes are discussed: one is inclined angle exists between turntable axis and IMU coordinate,the other is inclined angle exists between turntable axis and body coordinate.The Analysis shows that the modulate effect of the first scheme is the same as that of the traditional single-axis rotation inertial navigation system;and the second scheme changes the modulation effect.On the basis of the second scheme,the relation between turntable axis direction and system precision is deduced,and a new scheme of shaft direction selection for long time navigation is proposed,which significantly improves location accuracy compared with traditional single-axis rotation inertial navigation system.Results in different shaft direction choices could provide references for engineering application.