A Dual-Axis Rotation Scheme for Long-Endurance Inertial Navigation Systems

Rotational modulation is an effective means to reduce the equivalent drifts of rotational inertial navigation system (RINS), so as to enhance the accuracy of RINS in long-endurance navigation. In the single-axis continues rotation scheme, the drift along the rotation axis cannot be modulated. In the dual-axis multiposition transposition scheme, the drifts of three gyroscopes can be modulated to zero, but, when the inertial measurement unit (IMU) is stationary, the inertial sensors errors lead to the rapid divergence of navigation errors. And its modulation effect on slowly varying gyro drifts may be limited. In this article, a modified dual-axis rotation scheme combining the above two modulation schemes is put forward. The theoretical analysis demonstrates that the three axial drifts, the scale factor errors, and the installation errors can be modulated to zero. The simulation results demonstrate that the position accuracy of the proposed scheme is improved compared with the normal schemes. The effectiveness of the proposed scheme in practical application is verified by comparative experiments.