• Korean Journal of Computational Design and Engineering
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• v.17 no.5
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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.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.87-96
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• 2013

This paper shows how the performance of an ESC(Electronic Stability Control) system can be affected by the selection of in-vehicle network protocols such as CAN or FlexRay. The vehicle control performance under ESC operation is analyzed by EILS(ECU-In-the-Loop Simulation). The experimental set-up for the EILS of the ESC system consists of two 32-bit microcontroller boards communicated with CAN or FlexRay protocols. A 7-DOF vehicle model and an ESC algorithm with 2-DOF reference vehicle model are implemented on each microcontroller respectively. It is shown by experimental results that the ESC system using the FlexRay protocol can achieve better performance than that using the CAN protocol for a fast and accurate lane changing.

• Computational Structural Engineering
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• v.10 no.4
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• pp.337-347
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• 1997

The dynamic responses of highway bridges are varying depending on the features of either traveling vehicles or bridges. In this study, the probabilistic characteristics of dynamic amplification factors of highway bridges due to traveling heavy vehicles have been examined through analytical simulation processes. The truck with tandem axle and tractor with semitrailer are selected as the representative heavy vehicles, which are modeled with three dimensional 7-DOF and 12-DOF models, respectively. The analytical results have been compared with the experimental results of dynamic loading tests and the validity of the analytical models has been examined. Parametric studies on the means and extreme values of amplification factors have been performed with various traffic conditions such as vehicle types, vehicle weights, surface profiles, number of loading vehicles, loading positions, etc.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3871-3882
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• 1996

In this paper, a closed-form formulation for inverse kinematics of robot manipulators with kinematic redundancy under the constrained environment has been derived using the Kuhn-Tucker condition, the extended Lagrange multiplier method and the working set method. The proposed algorithm satisfies the necessaryand sufficient conditions for optimization subject to equality and inequality constraints. In addition, computationally efficient kinematic control methods have been proposed using differential kinemetics and gradient projection mehtod. The effectiveness of the proposed methods has been demonstrated with a 4-dof planar robot, and then a 7-dof spatial robot as a practical application to the nozzle dam task in the Nuclear Power Plant.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.561-563
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• 1997

In this paper, we identified the Black-box system with serious nonlinerity and fast dynamics using Neural Network. This NN have new structure and learned by RLS. It identify system in real-time without priori data. We use this NN to 7-DOF vehicle identification.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.7 s.112
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• pp.704-711
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1417-1426
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• 2011

Radiofrequency ablation through cardiac catheterization is one of minimally invasive intervention procedures used in drug resistant arrhythmia treatment. To facilitate more accurate and precise catheter navigation, systems for robotic cardiac catheter navigation have been developed and commercialized. The authors have been developing a novel robotic catheter navigation system. The system is a network-based master-slave configuration 3-DOF (Degree-Of-Freedom) robotic manipulator for operation with conventional cardiac ablation catheter. The catheter manipulation motion is composed of the translation (forward/backward) and the roll movements of the catheter and knob rotation for the catheter tip articulation. The master manipulator comprises an operator handle compartment for the knob and the roll movement input, and a base platform for the translation movement input. The slave manipulator implements a robotic catheter platform in which conventional cardiac catheter is mounted and the 3-DOF motions of the catheter are controlled. The system software that runs on a realtime OS based PC, implements the master-slave motion synchronization control in the robot system. The master-slave motion synchronization performance tested with step, sinusoidal and arbitrarily varying motion commands showed satisfactory results with acceptable level of steady state error. The developed system will be further improved through evaluation of safety and performance in in vitro and in vivo tests.

• Journal of Drive and Control
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• v.18 no.4
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• pp.77-83
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• 2021

With the progress in virtual reality technology, various virtual objects can be displayed using head-mounted displays (HMD). However, force feedback sensations such as pushing against a virtual object are not possible with an HMD only. Focusing on force feedback, desktop-type devices are generally used, but the user cannot move in a virtual space because such devices are fixed on a desk. With a wearable force feedback device, users can move around while experiencing force feedback. Therefore, the authors have developed a wearable force feedback device using a magnetorheological fluid clutch and pneumatic rubber artificial muscle, aiming at presenting the elasticity, friction, and viscosity of an object. To date, we have developed a wearable four-degree-of-freedom (4-DOF) force feedback device and have quantitatively evaluated that it can present commanded elastic, frictional, and viscous forces to the end effector. However, sensory evaluation with a human has not been performed. In this paper, therefore, we conduct a sensory evaluation of the proposed method. In the experiment, frictional and viscous forces are rendered in a virtual space using a 4-DOF force feedback device. Subjects are asked to answer questions on a 1- to 7-point scale, from 1 (not at all) to 4 (neither) to 7 (strongly). The Wilcoxon signed rank test was used for all data, and answer 4 (neither) was used as compared standard data. The experimental results confirmed that the user could feel the presence or absence of viscous and frictional forces. However, the magnitude of those forces was not sensed correctly.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.7
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• pp.647-650
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• 2011

This paper presents the development of roll replacement robot system for wire-rod press rolls. The roll replacement robot system consist of a palletized railway truck, a 6-DOF industrial robot manipulator, a roll changing tool and a hydraulic power system. Results of simulation and pilot experiment show the roll changing task can be successfully automated using proposed robot system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.1
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• pp.36-45
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• 1983

In order to characterize the machine tool feed-drive dynamics, thread cutting experiments are performed with cutting conditions and slide-way lubrication varied. During the experiments, the carriage, tool post and tail stock accelerations in the feed direction are measured, and analyzed by employing the spectral analysis method. It is found that the tool post vibration in the feed direction during thread cutting operation is mainly due to those of the carriage and the workpiece. Other structure-related vibrations show little effects on the tool post vibration. The characteristics of the carriage vibration is shown to be fairly consistent, except the vibration amplitude, regardless the variations in cutting condition and lubrication within the experimental range. The experimental results suggest that the feeddrive system can be modelled as a 2 DOF damped oscillatory system.