유선철 교수

We propose an integral sliding mode controller (ISMC) to stabilse an autonomous underwater vehicle (AUV) which is subject to modelling errors and often suffers from unknown environmental disturbances. The ISMC is effective in compensating for the uncertainties in the hydrodynamic and hydrostatic parameters of the vehicle and rejecting the unpredictable disturbance effects due to ocean waves, tides and currents. The ISMC is comprised of an equivalent controller and a switching controller to suppr

Near underwater structures or the surface of shallow water, acoustic sensing based navigation of autonomous underwater vehicles (AUVs) suffers from inaccurate positioning which is caused by acoustic sensing such as multi-pass and noisy data. In the paper a new underwater navigation method for AUVs is proposed based on artificial underwater landmarks which are recognized by a vision system implemented in the robot. An underwater image processing strategy and an underwater vision environment analy

This paper addresses acoustic camera DIDSON based object recognition method for AUVs (Autonomous Underwater Vehicles). The acoustic camera's characteristics and display method based on various experiments and the acoustic camera model and efficient and reliable image recognition method for AUVs are proposed. As examples, the cubic and cylindrical objects modeled to simulate the image and their recognition test was carried out in experimental tank

We propose a sequential method to extract height information for 3D mapping by using sensor fusion of two sonar devices. The 3D reconstruction using sonar image from forward scanning sonar (FSS) is an ill-posed problem, thus we need additional constraints to extract 3D information from the sonar images. Our approach is to utilize complementary information from an additional sonar which is profiling sonar (PS) and geometric constraints between the installations of two sonars. Two sonars are fixed