基于单轴旋转的捷联系统误差特性分析

Error Analysis of SINS Based on Single-axial Rotation

针对旋转捷联惯导系统误差特性,分析转台转轴与当地垂线偏离及尺寸效应对系统导航精度的影响。以单轴旋转为例,论证了旋转调制补偿部分惯性器件偏差的基本原理。推导了惯性测量单元旋转时,转台转轴与当地垂线偏离引起的速度误差表达式;通过引入旋转角速度误差,分析尺寸效应对系统导航精度的影响。在理论分析基础上进行仿真,结果表明转台转轴与当地垂线偏离时系统产生较大定位误差,转速不平稳是导致尺寸效应加剧的主要因素。

The influence of rotation axis offsetting the local vertical and the dimensional effect errors on navigation accuracy in rotary strapdown inertial navigation system was studied.Taking the single-axial rotation as an example,the principle of auto-compensating the inertial elements drift in some inertial sensors was analyzed.The influence of rotation axis offset local vertical on navigation accuracy during the inertial measurement unit（IMU） rotating procedure was analyzed,and the influence of dimensional effect errors on navigation accuracy was also studied on the condition of the IMU rough running.The simulation was presented based on the theoretical analysis,and the results show that the positioning error is caused with the rotation axis offset local vertical,the IMU rough running is the most serious factor leading to the dimensional effect errors.