• 한국공작기계학회논문집
• /
• 제16권5호
• /
• pp.211-217
• /
• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.

• 한국기계가공학회지
• /
• 제16권5호
• /
• pp.47-54
• /
• 2017

This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

• 드라이브 ㆍ 컨트롤
• /
• 제17권3호
• /
• pp.33-46
• /
• 2020

We introduce a piece of special-purpose equipment for responding to disasters that has a dual-arm manipulator consisting of six-axis multi joints, and a master-slave operating system controlled by a wearable joystick for intuitive and convenient operation. However, due to the complexity and diversity of a disaster environment, training and suitable training means are needed to improve the interaction between the driver and equipment. Therefore, in this paper, a system that can improve the operator's immersion in the training simulation is proposes, this system is implemented in a virtual environment. The implemented system consists of a cabin installed with the master-slave operation system, a motion platform, visual and sound systems, as well as a real-time simulation device. This whole system was completed by applying various techniques such as a statistical mapping method, inverse kinematics, and a real-time physical model. Then, the implemented system was evaluated from a point of view of the appropriateness of the mapping method, inverse kinematics, the feasibility for real-time simulations of the physical environment through some task mode.

• 한국항행학회논문지
• /
• 제15권2호
• /
• pp.319-325
• /
• 2011

본 논문에서는 거동이 불편한 사람들이 웨어러블 입력장치를 이용하여 정보 접근 향상과 실세계를 효과적으로 제어할 수 있도록 가상현실과 실세계의 정합 모델을 제안한다. 제안하는 정합 모델은 웨어러블 입력장치 기반 PC 제어, 손동작 패턴 인식, 제어를 위한 응용 소프트웨어, 가상현실과 실세계 정합으로 구분된다. 웨어러블 입력장치는 RF 통신 기반 6축 공간좌표를 입력받아 마우스 기능과 손동작 패턴을 판별한다. 또한 실세계에서 이루어질 수 있는 행동들을 가상현실을 통해 사실감을 부여하였고, 거동이 불편한 사람들이 실세계를 쉽게 통제할 수 있는 서비스 모델을 제시하였다. 실험결과, 손동작 패턴을 인식하여 PC와 가상현실 제어를 설계 규격대로 수행됨을 확인할 수 있었고, 거동이 불편한 사람이 웨어러블 입력장치 기반 웹 접근, 멀티미디어 제어와 가상현실을 통해 실세계를 통제할 수 있는 결과를 보였다.

• 한국CDE학회논문집
• /
• 제7권1호
• /
• pp.18-26
• /
• 2002

The suggested modular projection system can have flexible arrangements of screens. Modular and continuous arrangements of the display system enable us to modify the screen configuration easily, so that the system can be used in various applications. The image of each screen is calculated automatically by using window projection and the tracked position of the viewer. This system also uses the off-axis stereoscopic projection for the seamless stereoscopic edge blending of multiple connections of screens. The system has been successfully tested for the general navigation model and the CAU driving simulator with motion platform.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제4권12호
• /
• pp.585-588
• /
• 2015

사물이 실제로 움직이는 속도와 다양한 위치를 정확하게 인식하여 정확하게 3차원 영상정보로 표현하는 기술개발 시도는 무선센서를 활용하여 다양한 분야에서 응용할 수 있다. 3차원 위치 및 속도센서를 조합하여 이동 물체의 위치를 추적하는 시도는 동작의 정확성과 교정을 목적으로 하는 스포츠, 건강관리 분야 등에서 동영상 디스플레이 및 분석 기술과 접목하여 다양한 분석 정보를 제공할 수 있는 특징을 가지고 있다. 본 논문에서는 9축-센서로부터 수집되는 정보를 데이터베이스로 구축하고 이를 웹과 앱의 3차원 공간에서 모니터링할 수 있는 3D 모션 디스플레이를 개발하였다.

• 제어로봇시스템학회논문지
• /
• 제6권4호
• /
• pp.295-304
• /
• 2000

In the teleoperation system, force and velocity signals are communicated between a master and a slave robot. The addition of force feedback to a teleoperation system benefits the operator by providing more information to perform given tasks especially for tasks requiring contact with environment. When the master and slave arms are located in different places, time delay is unavoidable and it is well known that the system can become unstable when even a small time delay exists in the communication channel. The control scheme proposed in this paper is based on the estimator with virtual master model. Delayed signal from the master robot can be replaced by the estimated signal with the virtual master model. This control scheme makes the teleoperation system stable for the given time delay while the conventional scheme is not. This new control scheme is verified through numerical simulations and an experiments using the dual axis testbed of the teleoperation system.

• 한국정밀공학회지
• /
• 제23권7호
• /
• pp.187-193
• /
• 2006

This paper introduces and illustrates the results of a new method for offsetting the triangular mesh generated from multiple surfaces. The meshes generated from each surface are separated each other and normal directions are different. The face normal vectors are flipped to upward and the lower faces covered by upper faces are deleted. The virtual normal vectors are introduced and used to of feet boundary. It was shown that new method is better than previous methods in offsetting the triangular meshes generated from multiple surfaces. The introduced offset method was applied for 3-axis tool path generation system and tested by NC machining.

• ETRI Journal
• /
• 제26권6호
• /
• pp.597-604
• /
• 2004

In stereoscopic television, there is a trade-off between visual comfort and 3-dimensional (3D) impact with respect to the baseline-stretch of a 3DTV camera. It is necessary to adjust the baseline-stretch at an appropriate the distance depending on the contents of a scene if we want to obtain a subjectively optimal quality of an image. However, it is very hard to obtain a small baseline-stretch using commercially available cameras of broadcasting quality where the sizes of the lens and CCD module are large. In order to overcome this limitation, we attempt to freely control the baseline-stretch of a stereoscopic camera by synthesizing the virtual views at the desired location of interval between two cameras. This proposed technique is based on the stereo matching and view synthesis techniques. We first obtain a dense disparity map using a hierarchical stereo matching with the edge-adaptive multiple shifted windows. Then, we synthesize the virtual views using the disparity map. Simulation results with various stereoscopic images demonstrate the effectiveness of the proposed technique.

• 콘크리트학회논문집
• /
• 제11권5호
• /
• pp.79-88
• /
• 1999

The purpose of this paper is to develop a mathematical expression for computing crack angles based on reinforcement volumes in the longitudinal and transverse directions, member end-fixity and length-to-width aspect ratio. For this a reinforced concrete beam-column element is assumed to possess a series of potential crack planes represented by a number of differential truss elements. Depending on the boundary condition, a constant angle truss or a variable angle truss is employed to model the cracked structural concrete member. The truss models are then analyzed using the virtual work method of analysis to relate forces and deformations. Rigorous and simplified solution schemes are presented. An equation to estimate the theoretical crack angle is derived by considering the energy minimization on the virtual work done over both the shear and flexural components the energy minimization on the virtual work done over both the shear and flexural components of truss models. The crack angle in this study is defined as the steepest one among fan-shaped angles measured from the longitudinal axis of the member to the diagonal crack. The theoretical crack angle predictions are validated against experimentally observed crack angle reported by previous researchers in the literature. Good agreement between theory and experiment is obtained.