• Title/Summary/Keyword: yawing

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Comparison of EM 120 Multibeam Echo Sounding Data with SeaBeam 2000 Data Acquired at KODOS(Korea Deep Ocean Study) Area (한국 심해연구지역에서 획득된 EM 120과 SeaBeam 2000의 자료 비교)

  • Lee, Gun-Chang;Kim, Hyun-Sub;Ko, Young-Tak;Jung, Mee-Sook;Ham, Dong-Jin;Kim, Jong-Uk
    • Ocean and Polar Research
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    • v.28 no.4
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    • pp.467-473
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    • 2006
  • The EM 120, a newly installed multibeam echo sounder on RM Onnuri, has several advantages over the previously installed SeaBeam 2000 in performance and thus data quality. The EM 120 system provides a bottom topographic map with high resolution by (1) increasing the number of beams, (2) increasing the across track swath range, (3) measuring the more accurate sound velocity within the water column, and (4) improving stabilization for pitching, rolling, and yawing of the ship. This study compares EM 120 and SeaBeam 2000 echo sounders in terms of the data quality from the same survey area in the Clarion-Clipperton Zone, NE Pacific. Our result shows that the EM 120 provides more precise topographic data than the SeaBeam 2000. Although overall trends of data, such as topographic direction and relief, are similar for both echo sounders, the water depths measured by the EM 120 are shallower than that of SeaBeam 2000 by 80 to 90 meters.

Prediction of Maneuverability of KCS Using Captive Model Test (구속모형시험을 이용한 KCS 선형의 조종성능 추정)

  • Shin, Hyun-Kyoung;Choi, Si-Hoon
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.5
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    • pp.465-472
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    • 2011
  • Recently, ultra large scale of ship is being ordered continuously and because of that, the accurate prediction of ship maneuverability in design stage becomes important matter. The model test like PMM test or CFD analysis are representative methods for predicting the maneuverability of ship. In this study, the captive model tests were carried out for predicting maneuverability of MOERI container ship(KCS) which is opened to the public using X-Y Carriage of Ocean Engineering Wide Tank of University of Ulsan. Considering the dimensions of tank, 2m class model ship was used for captive model test. CMT(Circular Motion Test) was performed for obtaining purer hydrodynamic coefficients related to yawing velocity. For getting hydrodynamic coefficients which cannot be obtained using CMT, PMM test(Planar Motion Mechanism test) were also performed. The maneuverability prediction results by simulation are compared with those of other research institutes.

Dynamic Response Analysis of Bridge-AGT Vehicle Interaction System (교량-AGT 차량 상호작용에 의한 교량의 동적응답)

  • Kim, Hyun-Ho;Rha, Sang-Ju;Song, Jae-Pil
    • Journal of the Korean Society for Railway
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    • v.9 no.5 s.36
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    • pp.561-568
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    • 2006
  • Dynamic equations of motion for the interaction system of bridge and vehicle are derived to investigate the dynamic responses of bridge and vehicles induced by moving automated guide-way transit(AGT) vehicle and surface roughness of bridge. The vehicle model for ACT vehicle is idealized as 11 DOF including yawing, lateral translation and steering of wheels, and the bridges are modeled with finite element method. The AGT vehicle model was verified by experimental study. Parametric studies are carried out to investigate the effect of vehicle speed, surface roughness, stiffness and damping of the suspension system, AGT vehicles and dynamic wheel loads of the AGT vehicles. From the parametric study it can be seen that the dynamic incremental factor of the bridge and dynamic responses of vehicles have a tendency to increase with vehicle speeds, surface roughness and the stiffness of AGT vehicle suspension system. On the other hand those dynamic wheel loads have tendencies to decrease in according to increase of damping of the suspension system.

Design on Yawing And Depth Controller And Analysis of Disturbance Characteristic about the AUV ISiMI (자율무인잠수정 이심이의 선수각 및 심도 제어기 설계와 외란 특성 분석)

  • Ma, Sung-Jin;Jun, Bong-Huan;Lee, Pan-Mook;Kim, Sang-Bong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.351-354
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    • 2006
  • In underwater environment, the control of AUV is difficult, because of the existence of parameter uncertainties and disturbances as well as highly nonlinear and coupled system dynamics. The requirement for the simple and robust controller which works satisfactorily in those dynamical uncertainties, call for a design using the PD or sliding mode controller. The PD controller is very popular controller in the industrial field and the sliding mode controller has been used successfully for the AUV controller design. In this paper, the two controllers arc designed for ISiMI(Integrated Submergible Intelligent Mission Implementation) AUV and the performances are compared by numerical simulation under the modeling uncertainty and disturbances. The design process of PD and sliding mode controller for ISiMI AUV and simulation results are included to compare the performances of the two controllers.

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Clinical Assessment of Temporomandibular Joint Dysfunction (측두하악 관절 장애의 평가)

  • Ryoo, Jae-Kwan;Kim, Jong-Soon
    • Journal of Korean Physical Therapy Science
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    • v.5 no.4
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    • pp.717-728
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    • 1998
  • The Temporomandibural joint(TMJ) is one of the most frequently used joint in the body as $1,500{\sim}2,000$ times per day for the activities of chewing, swallowing, talking, yawing and sneezing. The TMJ are formed by condylar process of mandible and mandible fossa of temporal bone, separated by an articular disc. This articular disc divides into two cavities as upper cavity and lower cavity. The gliding movement occurs in the upper cavity of the joint, whereas hinge movement occurs in the lower cavity. The movements that are allowed at the TMJ are opening, closing, protrusion, retraction and lateral movement. A cause of TMJ dysfunction are capsulitis, internal derangement, osteoarthritis, rheumatoid arthritis, infection and inflammation near the joint, trauma on joint, ankylosis, subluxation or dislocation of joint, injury of articular disc, myositis, muscle contracture or spasm, myofascial pain dysfunction syndrome, dyskinesia of masticatory muscles, developmental abnormality, tumor, connective tissue disease, fibrosis, malocclusion, swallowing abnormality, wrong habits such as bite nail or hair, bruxism, psycological stress and Costen syndrome etc. Assessment of TMJ dysfunction consist of interview, observation, functional examination, palpation, reflex test, joint play test, electromyography and radiologic examination and behavioral and psycological assessment etc.

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A Study on Integrated Control System Design of Active Rear Wheel Steering and Yaw-Moment Control Systems (능동 후륜조타와 요우 모멘트의 협조제어에 관한 연구)

  • Park, J.H.;Pak, J.W.
    • Journal of Power System Engineering
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    • v.8 no.4
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    • pp.57-63
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    • 2004
  • Conventionally, 2WS is used for vehicle steering, which can only steering front wheel. In case of trying to high speed lane change or cornering through this kind of vehicle equipped 2WS, it may occur much of Yaw moment. On the other hand, 4WS makes decreasing of Yawing Moment, outstandingly, so it is possible to support vehicle movement stable. And conventional ABS and TCS can only possible to control the longitudinal movement of braking equipment and drive which can only available to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improved braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

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Flow Characteristics around Archimedes Wind Turbine according to the Change of Angle of Attack (받음각 변화에 따른 아르키메데스 풍력발전 날개 주위의 유동장 변화)

  • Li, Qiang;Kim, Hyun Dong;Ji, Ho Seong;Kim, Kyung Chun
    • Journal of the Korean Society of Visualization
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    • v.11 no.1
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    • pp.28-33
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    • 2013
  • This paper describes aerodynamic characteristics of an Archimedes spiral wind turbine with various angles of attack. The range of angles was controlled from $-30^{\circ}$ (clockwise) to $+30^{\circ}$ (clockwise). The rotating speed of wind turbine at the same angle of attack in both directions was different. The reason why the-maximum rotational speed was observed at $15^{\circ}$ in clockwise direction can be explained based on angular momentum conservation. Quantitative flow visualization around Archimedes wind turbine blade was carried out between $-15^{\circ}$ (clockwise) and $+15^{\circ}$ (counter clockwise) using high resolution PIV method. The relationship between drag force and rotating speeds was discussed. From these results, optimum design on yawing system of Archimedes spiral wind turbine may provide high efficiency on small wind power system.

Durability Evaluation of Gangway Connections for the High Speed Railway Vehicles (고속철도차량 갱웨이 통로연결막의 내구성 평가)

  • Kang, Gil-Hyun;Woo, Chang-Su;Kim, Chul-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4796-4801
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    • 2014
  • To increase the riding comfort and running stability of articulated type high speed railway vehicles(HSRV), it is important that the gangway connections for the passenger car satisfied fire safety, sound proof and durability under triaxial angular displacement (rolling/yawing/pitching) modes. On the other hand, a domestic test standard on the durability of the rubber components has not been determined. In this study, the fatigue life was predicted using the results of the nonlinear finite element analysis and the fatigue properties. Moreover, a fatigue rig test of the component was constructed to examine the durability.

Wind Load and Flow Field Change with Respect to Various Configurations of a Drillship (드릴십 형상에 따른 풍하중 및 유동장 변화)

  • Jung, Youngin;Kwon, Kijung
    • Journal of the Society of Naval Architects of Korea
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    • v.52 no.3
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    • pp.255-264
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    • 2015
  • Wind load and flow field of a drillship with respect to various super structures were experimentally investigated in KARI 1m-wide wind tunnel with an atmospheric boundary layer simulation. Six-component external balance and Particle image velocimetry technique were used to measure wind load and velocity vectors in the flow-field around the model respectively. The experimental model was an imaginary shaped drillship with an approximated model which has 1/640 scale compared with recent typical drillships. The test Reynolds number based on the overall length was about 1.5×106. It was found that dominant factors influencing on ship wind load are cabin shape and cabin height. Round cabin has smaller axial wind load and narrow boundary layer around the ship than rectangular one, but its yawing moment at certain angles becomes higher. Low cabin height also show positive effects on axial wind load too. Hull shape and forecastle shape show relatively small influences on wind loads except for slight changes around ±45° wind directions.

A Measurement Error Correction Algorithm of Road Image for Traveling Vehicle's Fluctuation Using V.F. Modeling (V.F. 모델링을 이용한 주행차량의 진동에 대한 도로영상의 계측오차 보정 알고리듬)

  • Kim Tae-Hyo;Seo Kyung-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.8
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    • pp.824-833
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    • 2006
  • In this paper, the image modelling of road's lane markings is established using view frustum(VF) model. From this model, a measurement system of lane markings and obstacles is proposed. The system also involve the real time processing of the 3D position coordinate and the distance data from the camera to the points on the 3D world coordinate by virtue of the camera calibration. In order to reduce their measurement error, an useful algorithm for which analyze the geometric variations due to traveling vehicle's fluctuation using VF model is proposed. In experiments, without correction, for instance, the $0.4^{\circ}$ of pitching rotation gives the error of $0.4{\sim}0.6m$ at the distance of 10m, but the more far distance cause exponentially the more error. We con finned that this algorithm can be reduced less than 0.1m of error at the same condition.