Research On The Kinematics Model Of AUV And Its Application In The Integrated Navigation

This dissertation researches on a model-aided inertial navigation system (MA-INS) which is applied to AUV. When the additional aiding sources, like the Ultra-short Baseline System (USBL) and the Doppler Velocity Log (DVL), do not work, MA-INS can help the AUV navigate accurately instead.The major work undertaken in this research is summed up as follows:The six degrees of freedom kinetic model is established, and he kinetic models on the horizontal plane and the vertical plane are decoupled and simplified. The calculation method of the hydrodynamic coefficient in the kinematic model is introduced. The uncoupling hydrodynamic coefficients are obtained by simulating the motion of AUV, such as the direct sailing, pitching, heaving, yawing and rolling. And the coupling hydrodynamic coefficients are obtained with the empirical formula. A novel method of modeling the behind-hull propeller force based on software FLUENT is researched. Simulations for declaring the necessity of considering the behind-hull wake were presented to identify the propeller force exactly in respect of the rotational speed of the propeller and the velocity of AUV. In addition, the influence of ocean current was also analyzed. This part analyzes the velocity and the position of AUV respectively, like the direct line movement, the circle line movement, the Z-type horizontal movement, the vertical diving, and other vertical trajectories with SIMULINK. Owing to the lack of the understanding of the characteristics of the external interference signals, the advanced Sage-Husa filtering navigation is analyzed. And simulation indicates that the advanced Sage-Husa filter is able to obtain more accurate velocity and improve the stability of navigation.