This paper introduces the Light-weight Work Class ROV URI-L for underwater construction. And the design and implementation of an underwater precision navigation system and dynamic positioning system that is essential for the underwater construction, position maintenance control, path tracking control and precision mapping are described. In this study, to develop an underwater precise navigation system which is the key technology in the operation of underwater robot, USBL, DVL and FOG sensor data are fused to realize a fast and accurate navigation system with high update rate. The developed navigation and DP algorithm was verified by a sea trial test.
KRISO is currently conducting a sixth year research project on ROV development for underwater light work to support underwater construction projects. The production of ROV URI-L for light work was completed as shown in Fig. 1, and an underwater precision navigation algorithm was developed and verified by the November sea trial test in order to develop and verify precision mapping, automatic control technology, and smart ROV operation technology.
In this project, KRISO has been developing underwater robots in the past, and it has been improving the control performance of ROVs with the production company Red One Technology. It is equipped with intelligent algorithms that are easy to operate by main pilots, navigators and supervisors. We are trying to implement a smart ROV system.
It is a high-performance underwater robot that uses multi-beam imaging sonar and forward looking scanning sonar to easily recognize the surrounding environment even in turbid water of the bad sight.
The URI-L weighs about 1.5 tons in air and is ballasted slightly positive buoyancy in water. In order for the ROV to operate freely at a depth of 400m or more, a cage-type TMS (Tether Management System) as shown in Fig.2 is required. The TMS is a home-like type of ROV with a weight of about 1.5 tons. It separates the movement of the ship excited by the wave so as not to affect the ROV.
In addition, the underwater precise and continuous navigation system up to 10Hz that can be considered as the strength of this research is very helpful for the implementation of the precise dynamic positioning control system.
