Integrated Positioning System of Autonomous Underwater Robot and Its Application in High Latitudes of Arctic Zone

摘要

Nowadays various robots are developed and used for deep-water operations and oceanic research including autonomous unmanned underwater vehicles (AUV), which are particularly effective for operations at great depths, under ice, and in other extreme surrounding. A considerable number of such vehicles have been developed in several countries. They are designed for object search, bottom configuration survey, geological survey, scientific research and a wide range of military missions. Modern underwater vehicles generally comprise positioning systems that include onboard autonomous, acoustic and satellite positioning systems (Romero & Lester, 2000; Theseus AUV; Maridan AUV). For example, the autonomous vehicle Hugin by C&C is equipped with an inertial positioning system (IPS) based on fiber-optic gyros, which is integrated with an RD Instruments Doppler log, a depth sensor, a height sensor and an ultra-short base acoustic system (USBL) by Konsberg Simrad. The Maridan company jointly with the Technical University of Denmark and Kearfott Guidance and Navigation Corporation, USA, have developed the Marpos system to be installed onboard an AUV. Marpos is an integrated Doppler inertial positioning system with the high-precision strap-down inertial positioning system KN5053 as its core equipped with laser gyros, which was developed by the Kearfott company. The IPS is adjusted using the data of the RDI Doppler log, which measures the vehicle speed over the bottom or through the water while a DGPS receiver is used for surface positioning. The similar method was applied for development of the Oracle vehicle by Thales-Bluefin. Its positioning is based on the Litton LN-250 MIMU system consisting of three fiber-optic gyros and three accelerometers installed on the inertial unit. In addition the positioning system incorporates the following: a digital quartz pressure (depth) sensor, an ultra-short base acoustic positioning system, and a 600 kHz Doppler log. The positioning system of Boeing/Fugro/ Oceaneering vehicles is based on total integration of all the available sensors including an IPS, a Doppler log, a height sensor, a depth sensor, long-base systems and ultra-short base systems. Russian Institute of Marine Technology Problems (IMTP) FEB RAS has many years of experience of developing and using AUVs for solving practical tasks at depths up to 6,000 m