IMU转动角速度对旋转SINS的精度影响分析

针对惯性测量单元(inertial measurement unit,IMU)旋转角速度变化过程对旋转调制型捷联系统(strapdown inertial nav-igation system,SINS)定位精度的影响进行分析和研究。例举IMU旋转方式并分析旋转自补偿技术调制惯性器件偏差的基本原理;详细推导了IMU运动状态变化过程对调制型捷联系统导航精度的影响并分析了IMU正反转方案的误差特性,最后根据仿真分析确定旋转角速度的选取依据。在理论分析的基础上进行了仿真实验。结果表明,IMU的旋转运动可以有效地调制惯性器件部分偏差,但是旋转角速度的大小及角速度变化过程依然会对调制型捷联系统的定位精度产生影响。

Influence of IMU rotation angular rate on navigation accuracy of rotary SINS

The influence of rotary angular rate variation on navigation accuracy of modulated strapdown inertial navigation system(SINS) was studied.The IMU rotation mode is discussed and the auto-compensation principle of the inertial element bias is analyzed.The influence of the changing process of inertial measurement unit(IMU) kinestate on navigation accuracy of SINS is deduced and the error characteristics of IMU rotation schemes both in backward and forward directions are analyzed.Finally,the selection method of rotation angular rate is determined based onsimulation analysis.Simulation experiment was carried out based on the theoretical analysis.The results show that although partial bias of inertial elements could be modulated by IMU rotation,the positioning accuracy of rotary SINS is still impacted by the rotation angular rate and the change process of the angular rate.