Land-based replication technology for shipborne trials of strapdown inertial navigation system

Current testing methods for marine Strapdown Inertial Navigation Systems primarily rely on computer simulation and shipborne trials. The computer simulation is difficult to replicate actual device error characteristics accurately, while the shipborne trial is costly and lacks repeatable testing scenarios. To overcome these limitations, this paper proposes a Hardware-in-the-Loop simulation scheme based on a high-precision three-axis turntable. The proposed method first generates ideal ship-motion and IMU data, then establishes an environmental-equivalence compensation model to account for differences in the Earth’s rotational angular velocity, gravity, and vehicle motion between the target marine environment and the laboratory. Furthermore, it establishes the correspondence between the angular velocity compensation and the three-axis rotation rates of the turntable, analyzes the impact of turntable indexing errors and rotation rate errors on the land-based replication, and achieves the replication of the at-sea inertial navigation test environment within the laboratory. Finally, the scheme’s effectiveness and reliability were validated through comparison with actual sea trial data. The results demonstrate that this scheme provides an efficient and cost-effective laboratory testing methodology for marine INS, particularly for navigation equipment designed for specialized environments such as polar regions.