Research On Intelligent Localization-system For ROV Based On Short Baseline Acoustic Positioning System

In the21st century, underwater robot technology as the most important means ofhuman exploration of the underwater world, underwater exploration robot has beenthe general concern of the people. Super-mini Underwater Vehicles with cable(Remote Operated Vehicle, referred to as the ROV) as one of the underwater robot, ithas a very wide range of uses, often used in rivers, lakes and shallow water, especiallyin the complex environment of the waters.It is easy to carry with a small volume, andit is also very safe and reliable. The Super-mini Underwater Vehicles can use innarrow, contaminated and dangerous water. Mainly used for recurrent detection ofdams, levees, ports, shore, ship. Particularly suitable for the daily sewage waters ofwatercourses, sluice, and waterproof detection work.Accurate determination of the position of ROV when it is operating underwateris very important. Therefore, the establishment of a suitable acoustic positioningsystem is particularly important for ROV. The acoustic positioning system needs witha simple hardware structure, convenient and reliable performance characteristics.In this paper, the acoustic positioning system is established based on a shortbaseline (SBL) system. The ROV’s Operating environment is very complex, so theunderwater acoustic reverberation is very obvious. The acoustic signals which collectby hydrophone is interfered. At the same time, due to the role of currents and waves,ROV underwater location becomes more complex. In order to overcome thehydrophone disruption in the ROV underwater positioning and improve thepositioning accuracy of the positioning system, this acoustic positioning system usethe fuzzy location algorithm based on the equation of motion of ROV underwater andthe Extended Kalman Filtering(EKF) algorithm. These two intelligent algorithms isused to deal with the underwater acoustic signals collected by hydrophone, it canreduce the impact of underwater reverberation and improve the positioning accuracy.Then, the positioning system software is established on the LabView platform, the system combines the intelligent positioning algorithms. At the same time, wemake an underwater experiment in wave tank in order to research the reliability andpositioning accuracy of ROV acoustic positioning system.The experiment results show that a short baseline (SBL) positioning systemwithout intelligent positioning algorithms will be affected of underwater reverberation.Positioning results are not accurate and the trajectory of the ROV cannot meet therequirements. Combines Motion mathematical model of ROV algorithm and extendedKalman Filtering algorithm can effectively exclude the interference of underwaterreverberation and improve the positioning accuracy of the positioning system. WhenROV move with low-speed, the acoustic positioning system can make precisioncontrol in the1m, and ROV movement trajectory is clearer. Acoustic positioningsystem laid a good foundation for ROV applications.