Position Based In-Motion Alignment Method for an AUV

This paper describes a position based in-motion alignment method for underwater navigation of an AUV(Autonomous Underwater Vehicle). For proper estimation of the position and orientation of the AUV the navigation algorithm requires accurate initial values of its position and attitude. However, it is difficult to obtain exact attitude of the AUV in the marine environment, because of the AUV’s body drift caused by flow of the water. To avoid this, in general, the initial alignment is performed on shore using gravitational acceleration, with further launching of AUV into the water. In this paper, we propose the in-motion alignment algorithm that is able to accurately estimate azimuth in the marine environment. Additionally, the proposed method allows to correct velocity of the AUV.