Angular rate matching method for shipboard transfer alignment based on H∞ filter

For a large sized ship moving in the sea, the initial misalignment between two locations is comprised by the static constant misalignment and the dynamic bending misalignment. Angular rate matching transfer alignment has been applied to estimate the misalignment because its rapidity compared with other transfer alignment methods. In fact, the dynamic misalignment is so difficult to be modeled that the estimation based on Kalman filter might not converge. Hence an angular rate matching transfer alignment based on the H^∞ filter is designed in this paper. In the simulation, a trajectory generator generates the dynamic misalignment angle data based on second-order, third-order and fourth-order Markov process. And then the H^∞ filter and Kalman filter are separately applied to estimate the misalignment from the trajectories. The simulation results indicate the H^∞ filter can effectively improve the transfer alignment precision and rapidity when the transfer alignment model is uncertain.