Precise control and high quality sensing techniques are required for the accurate 3D image mapping of the seafloor by autonomous underwater vehicles (AUVs). Profs. Son-Cheol Yu and Hyunwoo Cho (Dept. of CiTE), with graduate student Mr. Juhyun Pyo, have developed an AUV called Cyclops for high maneuverability. Cyclops has accurate position control and the capability for underwater inspection such as underwater 3D terrain mapping. Their research was published in Ocean Engineering.
The Cyclops AUV has a symmetrical body structure (left-right, and front-rear) and symmetric thruster configurations. The team considered all design steps including hardware implementation and control algorithm development. Thus, Cyclops has similar hydrodynamics with respect to surge, sway, and heave directions. The eight thrusters of the vehicle can generate force vectors in any direction in the 3D space.
Cyclops can achieve accurate positioning performance of the vehicle and it can move in a lawnmower trajectory. This movement is effective at reducing dead reckoning error and obtaining source images with homogeneous optical characteristics for underwater image mosaicing. Alignment and having a high resolution image are the most important factors in 3D mapping. This study focused on the development of a novel hovering type AUV and its performance test with 3D terrain map generation. The source images for the image mosaicing were obtained by the fully autonomous operation of the AUV. In the team’s mosaicing experiment, the hovering performance of the developed AUV critically determined the precision of the 3D map.
This research was supported by the U.S. Office of Naval Research Global and the Gyeongbuk Sea Grant Program funded by the Ministry of Oceans and Fisheries, Korea.