Bong-Huan Jun

• Korea Institute of Ocean Science and Technology

The Crabster CR200 is an underwater walking robot inspired by crabs and lobsters, designed for precise seabed inspection and manipulation. It maintains stability and position on the seafloor, even in strong currents, by adjusting its posture through six legs, each with four degrees of freedom. The key advantage of the CR200 lies in its ability to r...

This article presents a modeling method for the uncorrelated measurement error of the ultra-short baseline (USBL) acoustic positioning system for aiding navigation of underwater vehicles. The Mahalanobis distance (MD) and principal component analysis are applied to decorrelate the errors of USBL measurements, which are correlated in the x- and y-di...

In this paper, we discuss underwater walking robot technology to improve the quality of raw data in sector-scanning sonar images. We propose a strategy for an efficient and precise sector-scanning sonar image acquisition method for use in shallow, strong tidal water with a curved and sloped seabed environment. We verified the strategy by analyzing...

Various sizes of ROVs are being utilized in offshore industrial, scientific, and military applications all around the world. Because of innovative developments in science and technology, image acquisition devices such as sonar devices and cameras have been reduced in size and their performance has been improved. Thus, we can expect better accuracy...

This paper presents the operations of a multi-beam echo sounder (MBES) installed on the deep-sea remotely operated vehicle (ROV) Hemire. Hemire explored hydrothermal vents in the Forecast volcano located near the Mariana Trench in March of in 2006. During these explorations, we acquired profiling points on the routes of the vehicle using the MBES....

Crabster CR200 is a remotely operated vehicle which has six artificial and articulated legs driven by BLDC motors. It is supposed to walk on the sea floor. As a result, the robot has a very complicated appearance and hydrodynamic forces and moment acting on the robot experience a variety of changes according to configurable legs and body postural p...

In this paper, we describe a design method for the static walking and swimming algorithms of a subsea hexapod robot called Crabster (CR200). CR200 is a 200-m-class seabed walking and flying robot that is specialized in environments with high current and turbid water. To design the algorithms of a hexapod robot, we propose a design method that uses...

This paper presents the development of arm and leg of seabed walking robot named CRABSTER200 (CR200) for precise seabed exploration and underwater works in coastal area with strong tidal current. For seabed walking and precise underwater works, CR200 uses six legs and front two legs can be transformed to manipulators. In order to design robotic arm...

The KRISO (Korea Research Institute of Ships & Ocean engineering) developed the Crabster which is an underwater walking robot with six legs in 2013. This robot is operated on the seabed with high tide and high turbidity environments which is unknown environments. This paper deals with modeling of the Crabster leg with hydrodynamics force for active...

In April 2015, the 4th underwater test of Crabster CR200 was conducted to investigate the mission capability for search and recovery of underwater artefacts. The experiment was conducted from 16th April 2015 to 15th May 2015 off the Mado Island in West Korea. In the experiment, we searched and found artefact specimens successfully in turbid water u...

Generally scanning sonar can be used with ROV or other equipments. When scanning sonar is operated independently of a ROV, it is most often deployed in a stationary tripod, cage or frame, or pole-mounted to survey the seafloor, port wall, and scour at bottom of the bridge. It could offer high accuracy of image position, in comparison with side scan...

In west coast of Korea peninsula, there are some offshore sites where ancient sunken shipwrecks have been discovered. These ships are supposed to carry an amount of artifacts what show lifestyle and culture of the day. In these areas, however, because of fast ocean currents and low visibility, underwater survey and excavation by divers are strictly...

This paper describes the recent preliminary tests of multi-legged seabed walking robot, Crabster(CR200) to prepare sea trials. CR200 will be deployed to west sea of Korea where has strong tidal current and turbid water. The sea trial area has been excavated as marine archaeological site. In order to perform underwater missions in these environmenta...

In this paper, we describe the dynamic tumble-stability analysis of a seabed-walking robot named Crabster (CR200) in forward-incident currents. CR200 is designed to be operated in tidal-current conditions, and its body shape is also designed to minimize hydrodynamic resistances considering hydrodynamics. To analyze its tumble stability, we adopt th...

This paper describes a new approach for a design and finite element analysis (FEA) of a body frame for a multi-legged subsea walking robot, Crabster200, of which the abbreviated name is CR200 and the operating depth is 200 m. Main body of the structural frame of CR200 is designed as a curved-rib-cage structure in order to disperse applied external...

This paper presents a communication protocol among operating programs for the CR200, which is 200m-class subsea walking robot with six legs. The number of operating programs is twelve. We have developed six essential programs, which exchange data using designed message protocol through Ethernet. The inter-program communication protocol includes mes...

This study applied finite element analysis (FEA) to the body frame of the 200-meter class multi-legged subsea walking robot known as Crabster (CR200). The body frame of the CR200 is modeled after the ribcage of a human so that it can disperse applied external loads. It is made of carbon-fiber-reinforced plastic (CFRP). Therefore, the frame is light...

Crabster CR200 is a giant crab robot with six legs and 30 powerful joints developed at the Korea Research Institute of Ships and Ocean Engineering. The robot can help explore ancient shipwrecks in areas of harsh tidal currents and turbid water, where traditional underwater vehicles have trouble operating.

This paper describes the design concept of a bio-inspired legged underwater and estimating its performance by implementing simulations. Especially the leg structure of an underwater organism, diving beetles, is fully adopted to our designing to employ its efficiency for swimming. To make it possible for the robot to both walk and swim, the transfor...

This paper describes the development of a ground test robot platform to study a multi-legged walking robot capable of precise proximity exploration and operations under a shallow sea in the presence of a strong tidal current environment. For both underwater walking and complex operations, a six-legged robot that uses two legs as manipulators during...

This paper describes a finite element analysis (FEA) of the body frame of a subsea robot, Crabster200 (CR200). CR200 has six legs for mobility instead of screw type propellers, which distinguishes it from previous underwater robots such as remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). Another distinguishing characteri...

This paper presents the development of a specialized underwater leg with a manipulator function(convertible-to-arm leg) for the seabed walking robot named CRABSTER200(CR200). The objective functions of the convertible-to-arm leg are to walk on the seabed and to work in underwater for precise seabed exploration and underwater tasks under coastal are...

This paper describes finite element analysis(FEA) for the body frame of 200 meter class multi-legged subsea robot, Crabster200(CR200). The body frame of CR200 is designed as a rib cage in order to disperse applied external loads and is made of carbon fiber reinforced plastic(CFRP) Therefore, the frame is lighter and stronger than a frame of the oth...

This paper describes the development result of an underwater walking robot CR200. The CR200 is 6-legged seabed walking robot designed to work in high current and low visibility environment. The along sectional shape of the body is streamlined to improve the hydrodynamic characteristics. In order to detect the disturbance from the current, we instal...

This paper presents the development of arm and leg of six-legged walking robot for precise seabed exploration and underwater works under coastal area with strong tidal current. For both seabed walking and precise underwater works, the seabed robot named CRABSTER200(CR200) uses six legs during walking and front two legs as manipulators during underw...

This paper introduces operating software for a multi-legged subsea robot, named CR200, which is a 200m-class walking robot. The CR200 can work in shallow and strong tidal current and high turbidity environment by crawling sea floor using six legs to survey shipwreck and scientific research. The CR200 system is similar to traditional remotely operat...

This paper presents a dynamic workspace control method of underwater manipulator mounted on a floating ROV (Remotely Operated vehicle) in undersea. This method is developed for precise linear motion control of a manipulator’s end-effector considering the motion of a floating ROV caused by sea wave. In the proposed method, the motion of ROV is model...

This paper presents a unified mathematical framework for the analysis of mobility and agility of a multi-legged subsea robot. The aim of this research is to analyze a dynamic performance on the multi-legged robot in an underwater environment conditions with hydrodynamic forces, seabed friction, gravity, buoyancy, and so on. The dynamic performance...

In this paper, head alignment of a single-beam scanning sonar installed on a multi-legged underwater robot is described. The multi-legged underwater robot is supposed to survey seafloor, underwater structures, etc. Typical optic cameras, however, are not appropriate to show high quality scenes in a turbid water. Therefore, to collect images in a lo...

This paper presents the development of leg with arm for the CR200 as multi-legged seabed robot as design points, fabrication factors and experiments. The design points of leg with arm were presented and also the manufactured leg with arm was showed. In order to verify the design factors, the experiment of joint driving, pressure-resistant and water...

This paper presents the design and implementation of control architecture for the ISiMI6000 AUV (Autonomous Underwater Vehicle) which is developing by MOERI-KIOST. The ISiMI6000 AUV is a sea-trial AUV up to the 6,000m depth. The control architecture of the ISiMI6000 AUV is a hybrid architecture consisting of the mission layer, the behavior layer, t...

This paper presents the design of an underwater link-joint system for developing of a 200m class six-legged subsea robot. The design includes a process with concept establishment, specific design for joint capability and mechanical drawing. First deals with the definition of degree of freedom which is the link-joint system. Second is the design wit...

This paper presents a real-time process method without real-time operating system (RTOS) for the ISiMI100 Autonomous Underwater Vehicle (AUV). The AUV does not use any RTOS but a user-defined software timer to control the AUV by desired control frequency. The timer supports stable timing occurrence without miss because it was implemented by backgro...

This paper describes the mechanical design of a six-legged walking robot named Little Crabster as a ground test platform of an underwater walking robot. First, the dimensions, joint structure, range of motion, and mass distribution of the robot are determined by considering biological data of the crabs, lobsters, and insects. Second, the joint actu...

In this paper, we present the concept and main mission of the Crabster, an underwater walking robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which comprise the main difference in dynamic characteristics between on-land and underwater robots. Drag and lift forces acting on the underwater link are described...

The MOERI-KORDI has launched a new project to develop multi-legged subsea robot technologies. The objective of 1st stage is to develop a multi-legged robot walking in high tidal current and high turbidity environment while the objective of 2nd stage is to develop a walking and flying robot with 6 legs in deep sea where is calm and clear environment...

In this paper, we present the concept of Crabster (Fig. 1) including the main missions of the robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which makes main difference of dynamic characteristics between the on-land and underwater. Presented model is described as closed-form dynamic equations based on L-E...

Various configurations of underwater docking stations have been developed during the last two decades. In this paper, five parameters are suggested to specify characteristics of the docking stations. And then, we describe docking problem using the five parameters. Unidirectional approach for docking of an under-actuated AUV (Autonomous Underwater V...

This paper presents a unified method for analysis of a mobility and agility of a multi-legged subsea robot in consideration of the tidal current and frictional ground contact. The aim of this research is to analyze an influence of tidal current on the multi-legged robot by utilization of hydrodynamic forces acting on its body and legs. This method...

This paper presents an in-situ correction method to compensate for the position error of an autonomous underwater vehicle (AUV) near the sea floor. AUVs generally have an inertial navigation system assisted with auxiliary navigational sensors. Since the inertial navigation system shows drift in position without the bottom reflection of a Doppler ve...

In this paper, we present a new concept of multi-legged seabed robot for high tidal current environment. The robot moves on seabed by walking with 4 or 6 legs which is different moving mechanism from the existing underwater thrust system such as screw or Caterpillar. The main concept to endure the high current is utilization of hydrodynamic forces...

This paper presents a dynamic workspace control method of underwater manipulator considering a floating ROV(Remotely Operated vehicle) motion caused by sea wave. This method is necessary for the underwater work required linear motioncontrol of a manipulator's end-effector mounted on a floating ROV in undersea. In the proposed method, the motion of...

This paper presents a concise behavior arbitration mechanism for the ISiMI100 Autonomous Underwater Vehicle (AUV) which was developed by MOERI-KORDI. The control architecture of the ISiMI100 AUV is a hybrid architecture consisting of the mission layer, the behavior layer, the logical sensor layer, and the library layer. This paper focuses on the be...

Unidirectional docking of a torpedo-type underactuated AUV (Autonomous Underwater Vehicle) has been developed. In this paper, guidance scheme considering drift caused by ocean currents will be investigated. To compensate drift, we design an ocean current observer. The observer is based on kinematic equations of the AUV. We also suggest a guidance s...

This paper presents an in-situ correction method to compensate the initial position error of an autonomous underwater vehicle (AUV) near sea floor. AUVs generally have an inertial navigation system assisted with auxiliary navigational sensors, such as Doppler velocity log, and/or acoustic positioning systems. Since inertial navigation systems show...

This paper presents a mission language, is called Tiny Mission Language (TML), for the ISiMI100 Autonomous Underwater Vehicle (AUV) which was developed by MOERI-KORDI. The TML can represent any mission easily and freely because it provides most functionality supported by general programming language. The TML provides control statements for manageme...

In this paper, we describe an autonomous design procedure of frequency selective surface(FSS) with genetic algorithm(GA). With a set of characteristics specified by operators in frequency domain, the proposed system searches the best matching pre-manufactured FSS in the pre-constructed data base(DB), sets initial genes of GA with the searched FSS p...

This paper presents a control technique for structured undersea tasks that require a high degree of precision. The overall efficiency of tele-operated underwater manipulation is improved by reducing the burden on the human operator. A new workspace-control system composed of a computer and input devices in workspace was developed to support the ope...

This paper presents a dynamic model estimation using system identification (SI) technique and a multivariable controller design for an unmanned surface vehicle (USV) with two fixed thrusters. The catamaran shaped USV has been developed for marine research and surveying exploration in costal area. To validate the automatic control performance of USV...

This paper presents the design and development of a playback system to replay and analyze the exploration data of an oceanographic survey with a remotely operated vehicle Hemire. Although all the data is logged after exploration, it is complicate and time-consuming for scientists to review and access an entire exploration dataset in an integrated f...

The Korea Ocean Research and Development Institute (KORDI) has developed a small AUV named ISiMI. The mission of ISiMI is to work as a test-bed AUV for the development and validation of various algorithms and instruments required to enhance the AUV's functions. The design concept of ISiMI is that of a vehicle small enough to cruise the Ocean Engine...

This paper introduces an underwater docking procedure for the test-bed autonomous underwater vehicle (AUV) platform called ISiMI using one charge-coupled device (CCD) camera. The AUV is optically guided by lights mounted around the entrance of a docking station and a vision system consisting of a CCD camera and a frame grabber in the AUV. This pape...

In this chpater, the design, implementation and test results of a small AUV named ISiMI are presented. The AUV, ISiMI, developed in KORDI is a test-bed for the validation of the algorithms and instruments of the AUV. For fast experimental feedback on new algorithms, ISiMI was designed to be able to cruise in the Ocean Engineering Basin environment...

Vision guided underwater docking algorithm for an AUV (autonomous underwater vehicle) and a small test-bed AUV named ISiMI have been developed in KORDI (Korea Ocean Research and Development Institute). Underwater experiments were conducted in the previous research. The developed algorithm was based on pure pursuit guidance law. There is an absence...

An AUV (Autonomous Underwater Vehicle) is an unmanned underwater vessel to investigate sea environments and deep sea resource. To be completely autonomous, AUV must have the ability to home and dock to the launcher. In this paper, we consider a class of homing trajectory planning problem for an AUV with kinematic and tactical constraints in horizon...

This paper considers the path tracking problem in a horizontal plane for underactuated (or non-holonomic) autonomous underwater vehicles (AUVs). Underwater mapping has been an important mission for AUVs. Recently, underwater docking has also become a main research field of AUVs. These kinds of missions basically require accurate attitude and trajec...

The increased use of unmanned underwater vehicles (UUV) has led to the development of alternative navigational methods that do not employ acoustic beacons and dead reckoning sensors. This paper describes a simultaneous localization and mapping (SLAM) scheme that uses range sonars mounted on a small UUV. A SLAM scheme is an alternative navigation me...

This paper considers point-to-point navigation of underactuated ships where only surge force and yaw moment are available. In general, a ship's sway motion satisfies a passive-boundedness property which is expressed in terms of a Lyapunov function. Under this kind of consideration, a certain concise nonlinear scheme is proposed to guarantee the clo...

This paper presents an asymptotic formation control scheme for a group of underactuated autonomous underwater vehicles (AUVs) where only three control inputs - surge force, yaw moment and pitch moment are available for each vehicle's six degree of freedom (DOF) underwater motion. Usually, the dynamics agents applied in most of the formation algorit...

This paper presents implementation and test of autonomous underwater vehicles(AUVs) for AUVs fleet. Recently, AUVs have become a main tool to survey underwater in scientific, and commercial applications because of the significant improvement of performance and low working costs. However, it is very time-consuming work to survey a wide area by an AU...

This paper reviews the underwater navigation system based on range measurements from a known reference station and extends it to 3-dimensional coordinate. We formulate the state equation in polar coordinate and derive a condition to keep observability of the navigation system. An autonomous underwater vehicle cruising with constant speed can estima...

This paper describes the task-oriented manipulability of tele-operated robotic arms mounted on a remotely operated vehicle (ROV) and its application to task-oriented joint configurations. The main purpose of the study is to reduce the tele-operator’s burden in performing underwater tasks by enhancing the functionality of the manipulator. Even thoug...

An AUV (Autonomous Underwater Vehicle) being able to dock without surfacing to a launcher or an underwater station can give us long-time duration. It is important for the AUV to be guided to the dock safely. This paper introduces a test bed platform AUV named ISiMI and her optical terminal guidance system. ISiMI uses the optical terminal guidance s...

The ISiMI AUV developed in KORDI (Korea Ocean Research and Development Institute) is a test-bed to develop and validate various algorithms and instruments required to AUV. For the fast experimental feedbacks of the AUV technologies, ISiMI is designed to be a small vehicle enough to cruise in the Ocean Engineering Basin in KORDI and to be handled by...

This paper presents the underwater navigation algorithm based on a multiple sensor fusion for the deep-sea unmanned underwater vehicles (UUVs), composed of two vehicles, a remotely operated vehicle (ROV) 'Hemire' and a depressor 'Henuvy'. The performance of underwater positioning system usually highly depend on that of acoustic sensors such as ultr...

This paper presents a stable formation control scheme for multiple autonomous underwater vehicle (AUV) where the number of independent actuators for each vehicle are less than that of degree of freedom (DOF) of the vehicle's motion. In many of the formation schemes presented so far, the multiple dynamic agents were usually modeled as particles whos...

This paper presents a hybrid underwater navigation and control system for positioning, guidance and control of a deep-sea unmanned underwater vehicle (UUV), HEMIRE. For precise navigation of the UUV, the hybrid navigation system is designed based on strap-down IMU (inertial measurement unit) accompanying with USBL (ultra-short base line), DVL (Dopp...

This paper presents an integrated navigation system for underwater vehicles to improve the performance of a conventional inertial acoustic navigation system by introducing range measurement. The integrated navigation system is based on a strapdown inertial navigation system (SDINS) accompanying range sensor, Doppler velocity log (DVL), magnetic com...

This paper presents an integrated navigational algorithm for unmanned underwater vehicles (UUV) using two acoustic range transducers and strap-down inertial measurement unit (SD-IMU). A range measurement model is derived for a UUV having one acoustic transducer and cruising around two reference transponders at sea floor or surface. The proposed alg...

The more deeply the researches make progress in ocean researches including the seabed resource investigation or the oceanic ecosystem investigation, the more important the role of UUV gets. In case of study on the deep sea, there are difficulties in telecommunications between AUV and ships, and in data communication and recharging. Therefore, docki...

This paper presents a robust NN control scheme for diving behavior of an autonomous underwater vehicle (AUV) whose dynamics can be simplified as a second-order TITO (two-input-two-output) nonlinear function. Because of singularity problem, above dynamics can't be properly solved using general backstepping method although it is in a well known stric...

In order to utilize hydrodynamic drag force on articulated robots moving in an underwater environment, an optimum motion planning procedure is proposed. The drag force acting on cylindrical underwater arms is modeled and a directional drag measure is defined as a quantitative measure of reaction force in a specific direction in a workspace. A repet...

In order to utilize hydrodynamic drag force on articulated robot moving in an underwater environment, a repetitive motion planning method subject to drag optimization is proposed. Repetitive trajectories, a preplanned periodic motion, are obtained from general polynomial trajectory planning method by connecting the end point of trajectory to start...

This paper describes a real-time control architecture for Dual Use Semi-Autonomous Underwater Vehicle (DUSAUV), which has been developed at Korea Research Institute of Ships and Ocean Engineering (KRISO) for being a test-bed of development of underwater navigation and manipulator technologies. DUSAUV has three built-in computers, seven thrusters fo...

This paper presents an integrated underwater navigation system for underwater vehicles using inertial sensors and range sonar. We supposes that two acoustic transponders, called pseudo long baseline (LBL) system, are installed at two reference stations on sea bottom or below surface and/or ice. The navigation system is based on a strap-down inertia...

This paper presents an adaptive nonlinear controller for diving control of an autonomous underwater vehicle (AUV). So far, diving dynamics of an AUV has often been derived under various assumptions on the motion of the vehicle. Typically, the pitch angle of AUV has been assumed to be small in the diving plane. However, these kinds of assumptions ma...

This paper describes a real-time control architecture for DUSAUV (dual use semiautonomous underwater vehicle), which has been developed at Korea Research Institute of Ships & Ocean Engineering (KRISO) for being a test-bed to develop underwater navigation and manipulator technologies. DUSAUV has three built-in computers, seven thrusters for 6 DOF mo...

This paper describes task-oriented manipulability of teleoperated robotic arms mounted on remotely operated vehicle (ROV) and its application to task-oriented joint configurations. Main purpose of the study is to reduce teleoperator's burden in performing underwater tasks by enhancing the functionality of manipulator. Even though a manipulator has...

This paper presents a robust adaptive controller for autonomous diving control of an autonomous underwater vehicle (AUV). It is well known that the dynamics of underwater robotics vehicles (URVs) are highly nonlinear and the hydrodynamic coefficients of vehicles are difficult to be accurately determined a priori. In this paper, the smooth unknown d...