Optimal Design of Moving Short Base-Lines Based on Fisher Information Matrix

Inertial navigation technology is usually selected as the primary navigation method of Autonomous Underwater Vehicles (AUVs). The localization error can gradually increase over time in the absence of other navigation correction information. Moving Short Base-lines (MSBL) mounted in the bottom of mother ship can be fused in the AUVs' integrated navigation system, which can effectively slow down or inhibit the growth of the positioning error. However, different number of baselines and different geometric configuration can cause changes in navigation accuracy. In this paper, the rank and the determinant of the Fisher Information Matrix (FIM) are analysed to obtain the impact of the number of baselines and geometric configuration on the underwater AUVs positioning observability. Then, we get the principles of optimal design of the number of baselines and geometric configuration. Under the conditions meeting the minimum number of baselines, we simulate and compare AUVs' localization errors of two typical geometric configuration. Simulation results show that the design satisfying the principles of optimal design based on FIM can effectively inhibit the growth of the positioning error.