• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.14-23
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• 2005

In this paper we propose a sensor fusion method for the navigation algorithm which can be used to estimate state vectors such as position and velocity for its motion control using multi-sensor output measurements. The output measurement we will use in estimating the state is a series of known multi-sensor asynchronous outputs with measurement noise. This paper investigates the Extended Kalman Filtering method to merge asynchronous heading, heading rate, velocity of DVL, and SSBL information to produce a single state vector. Different complexity of Kalman Filter, with. biases and measurement noise, are investigated with theoretically data from MOERI's SAUV. All levels of complexity of the Kalman Filters are shown to be much more close and smooth to real trajectories then the basic underwater acoustic navigation system commonly used aboard underwater vehicle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.414-419
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• 2010

This paper describes the design and performance of a hovering AUV 'NOAH' constructed at Jeju National University. We analyse the dynamic performance of NOAH using simulation program and carry out depth control test at small basin. The main purpose of NOAH is to carry out fundamental tests on its attitude control and position control. Its configuration is similar to general ROV appearance for underwater works and dimension is $0.75m{\times}0.5m{\times}0.5m$. It has 4 thrusters of 450watt for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring water depth and a magnetic compass for measuring heading angle. The navigation of the vehicle is controlled by an on-board Pentium III-class computer, which runs with the help of the Windows XP operating system. These give us an ideal environment for developing various algorithm which are needed for developing and advanced hovering AUV.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.387-393
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• 2009

In this paper, a 3-D simulator was developed to estimate visually the performance of propelling and integrated control system of the underwater cleaning robot. Based on the dynamics analysis of the UCR, the 3-D model of the UCR was used in the simulator in which position and velocity are included Also, an input and control system using a joystick was developed, and the simulator was applied to the input and control of the simulator. Moreover, an integrated navigation control system was designed, and its performance was validated by a way-point simulator including a PI-based fuzzy control law.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.177-183
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• 2015

The image information acquired by a model submarine is transmitted through the repeater. The control signal of a position for submarine and its speed is also controlled by the repeater. Shooting images of underwater circumstances are transmitted to the repeater where the received signal controls a position and speed of underwater submarine. This repeater is combined by a buoy that is floating on the surface to relay the signal of image as well as control between a control unit and a submarine whereas the repeater communicates wirelessly with a control unit. Due to wire communication between the repeater and the submarine, the underwater exploration can be smoothly carried out without a risk of loss of a model submarine. Also, connecting to the repeater and control unit wirelessly makes it possible to conduct easily the underwater exploration. The convergence technology that combines a wireless communication and a control as well as a model submarine is designed.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1189-1198
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• 2021

When performing remote tasks using robots in nuclear power plants, a 3D shape measurement system is advantageous in improving the efficiency of remote operations by easily identifying the current state of the target object for example, size, shape, and distance information. Nuclear power plants have high-radiation and underwater environments therefore the electronic parts that comprise 3D shape measurement systems are prone to degradation and thus cannot be used for a long period of time. Also, given the refraction caused by a medium change in the underwater environment, optical design constraints and calibration methods for them are required. The present study proposed a method for developing an underwater 3D shape measurement system with improved radiation tolerance, which is composed of commercial electric parts and a stereo camera while being capable of easily and readily correcting underwater refraction. In an effort to improve its radiation tolerance, the number of parts that are exposed to a radiation environment was minimized to include only necessary components, such as a line beam laser, a motor to rotate the line beam laser, and a stereo camera. Given that a signal processing circuit and control circuit of the camera is susceptible to radiation, an image sensor and lens of the camera were separated from its main body to improve radiation tolerance. The prototype developed in the present study was made of commercial electric parts, and thus it was possible to improve the overall radiation tolerance at a relatively low cost. Also, it was easy to manufacture because there are few constraints for optical design.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.4
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• pp.256-265
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• 2023

This paper describes the results of the development of the submarine Free Running Model (FRM). First, the goal of development was set based on the test conditions and the test environment, and the system was obtained accordingly. The target submarine, Joubert BB2 submarine, was selected with a scale of 18.35 in accordance with the development goal. In order to conduct a submarine FRM test underwater, where communication is impossible, the FRM must operate at least semi-autonomously. For this purpose, an Extended Kalman Filter (EKF) based underwater integrated navigation system and control system using a sailplane and an X-shaped sternplane were designed respectively. In addition, a ballast system was designed to enable the model to float to the water surface in case of an emergency. To verify its propulsion, navigation, and control performance, the FRM tests were conducted in both indoor and outdoor basins. As a result, the relationship between propeller RPM and vehicle speed was derived, and it was confirmed that the navigation and control performance met the target value.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1667-1670
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• 1997

We consider the probelem of identifying and underwater vehicle. It is assumed that a priori information about the parameteric model structure and values of the hydrodynamic coefficients is available from some other schemes. The concept of relative esnsitivity is introduced to plan and efficinet identification procedure. An analysis of the sensitivity of the overall system to a particular hydrodynamic coefficinet provides a tool to evaluate the relative importance of the same coefficient in a particular maneuver. Then it can be made possible to reduce the filter size by selecting some dominatn hydrodynamic coefficients as parameters to be estimated for a given maneuver, and this fact may be used for establishing a gradual identification scheme. The main merit of a gradual identification is substantially reduced computer burden with increased nimerical stability. An illustrative simualtion result is given.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.42-48
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• 2006

This paper proposes the new efficient system design strategies for the acoustic-based underwater multiple modem and media access control protocol. The system aims to establish the acoustic-based communication network of an underwater vehicles for deep sea mining, which ensures a certain level of maximum throughput regardless of the propagation delay of acoustic and allows fast data transmission through the acoustic-based multiple channel.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.3
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• pp.165-171
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• 2014

In this paper, we propose the hardware and software of a test-bed of a hovering AUV (autonomous underwater vehicle). Test-bed to develop as the underwater robot for the hovering -type is planning to apply for marine resource development and exploration for deep sea. The RTU that controls a azimuth thruster and a vertical thruster of test-bed is a intergrated-type thruster. The main control unit that collects sensor's data and performs high-speed processing and controls a movement of test-bed is a underwater hybrid navigation system. Also it transfers position, posture, state information of test-bed to the host PC of user using a wireless communication. The host PC checks a test-bed in real time by using a realtime monitoring system that is implemented by LabVIEW.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.9
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• pp.813-821
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• 2013

In this paper, we present the development of P-SURO II hybrid AUV (Autonomous Underwater Vehicle) which can be operated in both of AUV and ROV (Remotely Operated Vehicle) modes. In its AUV mode, the vehicle is supposed to carry out some of underwater missions which are difficult to be achieved in ROV mode due to the tether cable. To accomplish its missions such as inspection and maintenance of complex underwater structures in AUV mode, the vehicle is required to have high level of autonomy including environmental recognition, obstacle avoidance, autonomous navigation, and so on. In addition to its systematic development issues, some of algorithmic issues are also discussed in this paper. Various experimental studies are also presented to demonstrate these developed autonomy algorithms.