IMU based deformation estimation about the deck of large ship

Accurate attitude information needed by the shipboard equipment is greatly influenced by the deformation of the deck. To solve this problem, some inertial measurement unit (IMU), which is composed by gyros and accelerators, are installed in the key battle points on the deck. The displacement of the key battle point will be measured by the IMU. Inspired by the rapid transfer alignment of inertial navigation system presented by the American scholar Kain, a novel deformation estimation Kalman filter is designed. The measurement model is designed by matching the output of the IMU and the main inertial navigation system of the ship. Then the Kalman filter is applied to estimate the accurate deformation of the key battle point online. The performance of the Kalman filter is influenced by the observability of the system. Observability analysis method named PWCS (piece-wise constant system) is applied for this new presented method. The efficiency of the presented method is proved by theoretical analysis and computer simulation. Simulation results also show that the presented method can estimate the deformation online successfully.