http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
자율작업용 원격운용잠수정의 추진 특성에 관한 실험 연구
여태경,이윤건,채준보,윤석민,이영준 한국해양공학회 2019 韓國海洋工學會誌 Vol.33 No.5
In autonomous interventions using an underwater vehicle with a manipulator, grasping based on target detection and recognition is one of the core technologies. To complete an autonomous grasping task, the vehicle body approaches the target closely and then holds it through operating the end-effector of the manipulator, while the vehicle maintains its position and attitude without unstable motion. For vehicle motion control, it is very important to identify the hydrodynamic parameters of the underwater vehicle, including the propulsion force. This study examined the propulsion characteristics of the autonomous intervention ROV developed by KRISO, because there is a difference between the real exerted force and the expected force. First, the mapping between the input signal and thrusting force for each underwater thruster was obtained through a water tank experiment. Next, the real propulsion forces and moments of the ROV exerted by thrusting forces were directly measured using an F/T (force/torque) sensor attached to the ROV. Finally, the differences between the measured and expected values were confirmed.
김현희,정기민,박철수,이경창,황용연 한국산업융합학회 2018 한국산업융합학회 논문집 Vol.21 No.6
Remotely operated vehicle(ROV) and autonomous underwater vehicle(AUV) have been used for underwater surveys, underwater exploration, resource harvesting, offshore plant maintenance and repair, and underwater construction. It is hard for people to work in the deep sea. Therefore, we need a vision control system of underwater submersible that can replace human eyes. However, many people have difficulty in developing a deep-sea image control system due to the deep sea special environment such as high pressure, brine, waterproofing and communication. In this paper, we will develop an Ethernet based remote image control system that can control the image mounted on ROV.
UUV Platform Optimal Design for Overcoming Strong Current
Min-Gyu Kim,Hyungjoo Kang,Mun-Jik Lee,Gun Rae Cho,Ji-Hong Li,Cheol Kim 한국해양공학회 2021 韓國海洋工學會誌 Vol.35 No.6
This paper proposes an optimal design method for an unmanned underwater vehicle (UUV) platform to overcome strong current. First, to minimize the hydrodynamic drag components in water, the vehicle is designed to have a streamlined disc shape, which help maintaining horizontal motion (zero roll and pitch angles posture) while overcoming external current. To this end, four vertical thrusters are symmetrically mounted outside of the platform to stabilize the vehicle’s horizontal motion. In the horizontal plane, four horizontal thrusters are symmetrically mounted outside of the disc, and each of them has the same forward and reverse thrust performances. With these four thrusters, a specific thrust vector control (TVC) method is proposed, and for external current in any direction, four horizontal thrusters are controlled to generate a vectored thrust force to encounter the current while minimizing the vehicle’s rotation and maintaining its heading. However, for the numerical simulations, the vehicle’s hydrodynamic coefficients related to the horizontal plane are derived based on both theoretical and empirically derived formulas. In addition to the simulation, experimental studies in both the water tank and circulating water channel are performed to verify the vehicle’s various final performances, including its ability to overcome strong current.
Trajectory Tracking Performance Analysis of Underwater Manipulator for Autonomous Manipulation
Junbo Chae,여태경,이영준,Yoongeon Lee,Suk-Min Yoon 한국해양공학회 2020 韓國海洋工學會誌 Vol.34 No.3
In this study, the end-effector tracking performance of a manipulator installed on a remotely operated vehicle (ROV) for autonomous underwater intervention is verified. The underwater manipulator is an ARM 7E MINI model produced by the ECA group, which consists of six joints and one gripper. Of the six joints of the manipulator, two are revolute joints and the other four are prismatic joints. Velocity control is used to control the manipulator with forward and inverse kinematics. When the manipulator approaches a target object, it is difficult for the ROV to maintain its position and posture, owing to various disturbances, such as the variation in both the center of mass and the reaction force resulting from the manipulator motion. Therefore, it is necessary to compensate for the influences and ensure the relative distance to the object. Simulations and experiments are performed to track the trajectory of a virtual object, and the tracking performance is verified from the results.
비선형 강인 내부루프 보상기를 이용한 6자유도 원격조종 수중로봇의 선형 모델예측 제어
김준식,최유나,이동철,최영진 한국로봇학회 2024 로봇학회 논문지 Vol.19 No.1
This paper proposes a linear model predictive control of 6-DOF remotely operated underwater vehicles using nonlinear robust internal-loop compensator (NRIC). First, we design a integrator embedded linear model prediction controller for a linear nominal model, and then let the real model follow the values calculated through forward dynamics. This work is carried out through an NRIC and in this process, modeling errors and external disturbance are compensated. This concept is similar to disturbance observer-based control, but it has the difference that optimality is guaranteed. Finally, tracking results at trajectory containing the velocity discontinuity point and the position tracking performance in the disturbance environment is confirmed through the comparative study with a traditional inverse dynamics PD controller.
Sangrok Jin,Jihoon Kim,Jongwon Kim,TaeWon Seo IEEE 2015 IEEE/ASME transactions on mechatronics Vol.20 No.5
<P>We introduce a new underwater robotic platform with a tilting thruster mechanism for hovering motion. The tilting thruster mechanism can implement six-degree-of-freedom (DOF) motion with only four thrusters, but tilting motion makes the system nonlinear. We designed a selective switching controller in order to solve the nonlinear problem, and applied it to the robot system. The selective switching controller divides the six-DOF system into two three-DOF subsystems, and switches between subcontrollers according to the error in real time. Dynamic models of a robotic platform and a disturbance model of an attached manipulator are derived for the control design. Using simulation, the stability condition of control is determined, and the validity of the derived dynamic model of the robotic platform and manipulator is verified through comparison between simulation and experiment. A hovering experiment under a disturbance from the manipulator is performed to verify the robustness of the controller. The experimental results validate the successful hovering ability of the proposed robot.</P>