• 한국철도학회논문집
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• 제8권1호
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• pp.27-33
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• 2005

This paper presents a development of 6DOF motion platform far a tilting train simulator. The tilting train simulator will be used to verify the tilting electronics and tilting control algorithm which are to be applied the Korean 180km/h tilting train. The tilting train simulator is composed of a 6-axis motion platform, a track generation system, a graphic user interface, and a visualization system with 1600mm-diameter dome screen. In this study, the 6DOF motion platform for a tilting train simulator has been designed and manufactured. The motion platform developed is a motion platform of Stewart type. The inverse kinematic analysis has been performed to determine the length of the links of the platform. Furthermore, the specification of the motors have been evaluated by the equation of motion of the platform.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.235-240
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• 2001

A four degrees of freedom (dof) motion platform for bicycle simulator is developed. The motion platform, capable of the vertical linear and three angular motions, is designed based on analysis of the typical motion characteristics revealed by the existing six dof bicycle simulator. The platform essentially consists of two parts： the three dof parallel manipulator, consisting of a moving platform, a fixed base and three actuators, and the turntable to generate the yaw motion. The nonlinear kinematics and dynamics of the three dof parallel manipulator with multiple closed loop chains are analyzed for tracking control of the motion platform. The tracking performances of the three control schemes are experimentally compared： the computed torque method (CTM), the sliding mode control (SMC) and the PD control. The CTM and SMC, incorporated with the system dynamics model, are found to be equally better in performance than the PD controller, irrespective of the presence of external disturbance.

• 감성과학
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• 제6권1호
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• pp.11-16
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• 2003

본 연구에서는 가상현실사용자들이 모션베이스를 사용함에 따라 가상현실에 대한 평가가 어떻게 달라지는지를 조사하였다. 33명의 피험자를 대상으로 모션베이스 평가설문과 자기보고를 통해 가상현실에서의 현실감, 재미, 멀미감을 조사하고 가상주행 전, 중, 후에 내장근전위, 피부전도도, 말초체온, 말초혈류량, 심박률, 눈 깜박임의 생리신호를 측정, 분석함으로써 모션베이스 유무에 따른 심리ㆍ생리적인 변수들에서의 차이를 알아보았다 모든 피험자는 2주 간격으로 모션베이스 사용조건과 모션베이스를 사용하지 않는 조건에서 두 번 가상현실을 경험하였다. 가상현실에 대한 현실감, 재미항목에서 모두 모션베이스를 사용한 조건이 높은 점수를 나타냈다. 또한 모션베이스를 사용한 조건에서 멀미보고수가 감소하는 경향이 나타났다. Tachyarrythmia의 상대파워 변화량과 PPG 최대진폭의 평균변화량 비교는 모션베이스를 사용한 가상현실 조건이 생리적인 요동을 적게 일으키는 것으로 나타났다 이러한 결과들은 시각제시기와 동기화된 모션베이스를 도입함으로써, 가상현실에 대한 현실감은 높이면서 멀미감은 줄일 수 있다는 가능성을 보여준다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.22-25
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• 2008

Aperture synthesis with platform motion has been presented as a useful tool to achieve the high spatial resolution imaging. Using a motion induced synthetic aperture radiometer (MISAR), a passive microwave image can be achieved with a small number of antennas. Moreover, the MISAR is capable of imaging better than the case without motion, using the same configuration of antenna array. With a platform motion, visibility can be sampled more efficiently, and as a result the imaging performance of the MISAR shows higher quality than the case without platform motion. In this paper, the advantage of MISAR is demonstrated experimentally. Using a laboratory model of inteferometric radiometer, the point source images are obtained under the condition with platform motion and without platform motion. In the experimental results, the point source response of the MISAR shows better quality of sidelobe level and beam efficiency than the case without platform motion.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.736-741
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• 1992

The Stewart platform is one example of a motion simulator which generates 6 DOF motion in space by 6 actuators connected in parallel. The present SISO controllers are designed to track displacement command of each actuator computed from reference 6 DOF motion of platform by Stewart platform inverse kinematics. But this type of control can't cope with external load variation, geometric configuration of motion simulator, and different dynamic behavior of 6 DOF motion. In this paper, a multivariable controller using H- optimal control theory is designed for linerized simulator model with each actuator driving force as control input and platform 6 DOF motion as measured output. Nonlinear simulation result of the H$_{\infty}$ MIMO controller is not satisfied in steady-state characteristics. But the proposed H$_{\infty}$ + PI control scheme shows acceptable performance.e.e.

• 한국해양공학회지
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• 제36권6호
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• pp.390-402
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• 2022

Offshore wind energy has become a major energy source, and various studies are underway to increase the economic feasibility of floating offshore wind turbines (FOWT). In this study, the characteristics of wave-induced motion of a combined wind-wave energy platform were analyzed to reduce the variability of energy extraction. A user subroutine was developed, and numerical analysis was performed in connection with the ANSYS-AQWA hydrodynamic program in the time domain. A platform combining the TLP-type FOWT and the Wavestar-type wave energy converter (WEC) was proposed. Each motion response of the platform on the second-order wave load, the effect of WEC attachment and Power take-off (PTO) force were analyzed. The mooring line tension according to the installation location was also analyzed. The vertical motion of a single FOWT was increased approximately three times due to the second-order sum-frequency wave load. The PTO force of the WEC played as a vertical motion damper for the combined platform. The tension of the mooring lines in front of the incident wave direction was dominantly affected by the pitch of the platform, and the mooring lines located at the side of the platform were mainly affected by the heave of the platform.

• 대한조선학회논문집
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• 제42권2호
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• pp.124-128
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• 2005

This paper describes motion stability of a spar platform with and without a damping plate in regular waves. The heave and pitch motion equation is derived in terms of Mathieu equation and the stability diagram is obtained. It is shown that the spar platform with damping plate has smaller unstable region than that without damping plate in the stability diagram. Model tests are carried out to verify the mathematical analysis. Under the condition that the pitch natural period is approximately double the heave natural period and the heave motion is amplified at heave resonance, unstable pitch motions are evoked. However the unstable motion is stabilized in cases of spar platform with damping plate. Therefore the damping plate is an effective device to stabilize the motion of spar platform.

• 한국정밀공학회지
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• 제12권6호
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• pp.52-63
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• 1995

This paper presents a detailed derivation of the equations of motion for the stable member of a four-axis platform. Gimbal bearing friction is considered for motion analysis. First, dynamic characteristics of platform, gimbal and gyro with Coulomb friction are studied due to vehicle's angular motion. Second, Vehicle's motion is assumed the sinusoidal function and dynamic characteristics of platform, gimbal and gyro are studied. Conclusively, considering effects of Coulomb friction, they could not follow the vehicle's angular motion and have constant errors. In case of sinusoidal motion, relative angles for each gimbal are amplified, but they are sinusoidal function with almost the same phases.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6090-6097
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• 2013

본 연구의 목적은 실감나는 운전 환경을 제공하는 공기압 구동식 드라이빙 시뮬레이터 개발에 있다. 드라이빙 시뮬레이터의 모션 플랫폼은 운전자에게 실제 차량의 사실적인 느낌을 주는 메카트로닉스 장비이다. 모션 플랫폼의 비용은 드라이빙 시뮬레이터를 개발하는데 가장 큰 부분을 차지한다. 저비용으로 모션 플랫폼을 개발하기 위하여 6개의 공압 실린더로 구성된 스튜어트 플랫폼 형태를 기반으로 모션 플랫폼을 자체 제작하였다. 스튜어트 플랫폼은 조이스틱의 작동신호에 대한 응답으로 만족할 만한 추종성능을 보여주었다. 상용의 레이싱 게임 소프트웨어 중의 하나인 rFactor를 이용하여 드라이빙 시뮬레이터의 가능성을 확인하였다.

• 한국CDE학회논문집
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• 제17권5호
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• pp.333-341
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• 2012

Modeling and simulation is important for military training. People can feel perspective when stereoscope images are created using multi-channel visualizations. A submarine oscillates when the submarine is just below the surface of the sea, so that the reconnaissance becomes difficult. Also, the operator should read the information of the target within 6 seconds using the periscope. The operator must have experience. To solve these problems, stereoscopic multi-channel visualization has been tested. The iCAVE system of KAIST provides a large-scale screen, 7 PCs, and 14 projectors to create the stereoscope images. To simulate the motion of a submarine just below the ocean surface, a 4-DOF motion platform is used. The motion data is transmitted to the visual system and the motion platform through the UDP protocol. Variety of weather conditions are created using the Vega Prime software. The stereoscopic multi-channel visualization and the motion platform system created a realistic simulation system.