An Improved Heave Compensation Algorithm for Strapdown INS in Marine Operations

Heave compensation is crucial for the improvement of marine engineering. However, there remain two main drawbacks in existing methods. One drawback is that the output accuracy of heave information is insufficient. The other drawback is that the consideration of lever arm effect errors is inadequate. To address these challenges, a new heave compensation algorithm is proposed in this paper. Firstly, a vessel’s center of gravity acceleration model incorporating lever arm effect dynamics is established. Secondly, a modified high-pass filter is presented using complementary techniques. A comparative error analysis demonstrates its superiority over traditional digital filters in real-time performance. Thirdly, the algorithm independently updates solutions of the heave of the vessel’s center of gravity and the heave caused by the lever arm vector and the vessel’s attitude to avoid oscillating temporarily. Simulation results verified the better heave measurement accuracy of the proposed algorithm. This algorithm is pivotal to marine engineering.