单轴旋转惯导系统载体航向隔离方法研究

Research on yaw angle isolation method of inertial navigation system based on single-axis rotation

有规律地旋转惯性测量单元(inertial measurement unit,IMU)可将惯性器件的慢变误差在导航系中调制成周期性变化的信号,通过积分运算抑制器件该类误差,有效提高惯性导航系统长时间导航精度。基于IMU的测量误差模型,分析了旋转调制技术(rotation modulation technique,RMT)的基本原理和载体航向运动对旋转调制效果的影响。针对载体航向运动降低旋转调制补偿效果这一问题,提出了一种基于载体姿态解算驱动IMU转台的方法,并对该方法进行了理论分析和数学仿真。理论分析和仿真结果表明:该方法可以有效抑制载体航向运动对旋转调制效果的影响。

With the help of periodically rotating inertial measurement unit （ IMU）, the drifts of gyros and the bias of accelerometers are modulated into periodical variable signals, which can be averaged out effectively with integration algorithm. The approach is proved to be an effective and practical way to prevent navigation error buildup and effec- tively improve the long time accuracy of the inertial navigation system （INS）. Based on the measurement error model of IMU, the principle of single-axis rotation modulation technique （RMT） and the effect of vehicle yaw motion on ro- tation modulation are analyzed theoretically. Aiming at the problem that vehicle yaw motion decreases the effeetiveness of rotation modulation technique, a method of driving rotation table is proposed based on yaw attitude algorithm of vehicle. Besides, theoretical analysis and simulation experiment on the method were carried out. Analysis and experiment results indicate that the proposed method can isolate the yaw motion effectively.