• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.5
• /
• 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.

• Journal of Drive and Control
• /
• v.17 no.3
• /
• 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.

• Journal of Advanced Navigation Technology
• /
• v.15 no.2
• /
• pp.319-325
• /
• 2011

In this paper, we propose the matching model between virtual reality and the real-world for peoples with limited mobility. The proposed matching model is consist of four parts: wearable input device-based PC control, hand-motion pattern recognition, application software, and matching between virtual reality and the real-world. To recognition mouse functions and hand-motion patterns from six-axis coordinate of wearable input device, RF communication is used. In addition, to easily control the real-world, virtual reality has been implemented with realism of the real-world. Some experiments are conducted so as to verify the proposed model, and as a result, hand-motion recognition as well as virtual reality control are well performed.

• Korean Journal of Computational Design and Engineering
• /
• v.7 no.1
• /
• 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.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.12
• /
• pp.585-588
• /
• 2015

The technical challenge of 3D image display using the wireless sensor were applied to variable areas and scopes. This techniques need to very accurate location and speed informations and recognitions to moving objects. The tracking challenges of the moving objects location that combined 3D location and speed sensor were applied to sports and healthcare areas. This areas seek to the accuracy and collections and tightly related to image display and analysis techniques. In this paper, We developed the 3D motion display that can be monitor moving objects on the 3D virtual space. For this works, we constructed the database that collected informations through 9-axis sensor and demonstrated the result of 3D motion display on the Window based environments.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.4
• /
• 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.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.7 s.184
• /
• 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
• /
• v.26 no.6
• /
• 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.

• Journal of the Korea Concrete Institute
• /
• v.11 no.5
• /
• 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.