A unified scheme for rotation modulation and self-calibration of dual-axis rotating SINS

Rotation modulation and self-calibration are the key techniques for error compensation of the strapdown inertial navigation system, which are generally implemented separately. The 16-sequence scheme is widely used for rotation modulation, while the 18-sequence scheme is used for self-calibration. To reduce the complexity of the practical operations, this paper proposes the combination of the rotation modulation scheme and the calibration path and six corresponding design principles of the scheme with both rotation modulation and self-calibration functions. A 48-sequence rotation scheme is designed, which unifies the scheme for self-calibration and rotation modulation. The simulation and experiment results prove that, compared with the 16-sequence rotation modulation scheme, the proposed 48-sequence scheme can reduce the mathematical platform misalignment angle errors and the sawtooth type velocity errors caused by the misalignments of the inertial measurement unit. Besides, its accuracy of self-calibration is better than that of the 18-sequence self-calibration scheme. The velocity errors and position errors can be reduced by about 0.1 m s−1 and 0.2 nm in 3 d.