双轴旋转惯导载体角运动隔离调制方法研究

Carrier angular motion isolation and modulation method of dual-axis rotation inertial navigation system

传统双轴旋转惯导系统基于载体系对惯性测量单元(IMU)进行有规律的旋转以调制惯性器件误差,然而无规律的载体角运动将影响调制效果。针对这一问题,首先分析了IMU敏感数据、载体姿态以及双轴旋转角度三者之间的数学关系,并提出了基于双轴旋转机构的载体角运动隔离方法。在此基础上,针对载体角运动隔离中角速率控制方法存在的控制难度大、累积控制误差、转轴角速率测量延迟等问题,进一步提出了基于角度控制的双轴隔离旋转调制方法。理论分析和跑车试验数据仿真表明,该方法能有效隔离载体角运动,与传统旋转调制方法相比,其调制效果显著,大部分面运动应用场景下导航位置误差可降低50%以上。

In traditional dual-axis rotation inertial navigation system(DRINS), the inertial measurement unit(IMU) is rotated regularly to modulate the inertial device error based on the carrier coordinate system. However, irregular carrier angular motion of the carrier will affect the modulation effect. Aiming at this problem, the mathematical relationship among IMU sensitive data, carrier attitude and dual-axis rotation angles is analyzed. Then a method of carrier angular motion isolation based on dual-axis rotation mechanism is proposed. On this basis, aiming at the problems of difficulty in control, cumulative control error and measurement delay of angular rate of rotation axis existing in angular rate control method in carrier angular motion isolation, a dual-axis rotation isolation and modulation method based on angle control is proposed. The theoretical analysis and simulation result based on vehicle test data show that the proposed method can isolate the carrier angular motion effectively. Compared with traditional rotation modulation method, the modulation effect of the proposed method is significant, and the navigation position error could be reduced by more than 50% in most surface motion applications.