• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.24-29
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• 1999

Proposed in this paper is a modeling and simulation methodology for a virtual manufacturing environment. Based on DEVS formalism[Zeigler 76], the proposed model, so called GKDEVS, is designed to descript the geometrical knematic structure as well as event-driven and continuous state dynamics. In terms of abstract simulation algorithm[Zeigler 84], the simulation method of GKDEVS is proposed for combined discrete-continuous simulation. Using the GKDEVS, and FMS model consisting of a turing machine, a 3-axis machine and a RGV-mounted robot is constructed and simulated.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.88.2-88
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• 2001

In this paper Author introduce a new field named Artificial Life and its main directions of research. That is the research of evolutionary robot and artificial brain. Then author explored the advanced scientific thought hidden in them. Furthermore, the author tries intuitively to show a new type of control that is heuristically raised from artificial life research. It could be named as evolutionary control. This type of control is more like human body´s structure, and it is self-organized.

• Korean Journal of Computational Design and Engineering
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• v.17 no.5
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• pp.312-323
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• 2012

Planetary gearing is a gear system consisting of one or more planet gears, revolving about a sun gear. While the planetary gear system has many advantages- for example, high power density, large reduction in a small volume, multiple kinematic combinations, pure torsional reactions, and coaxial shafting, it has not been widely used because of its high bearing loads, inaccessibility, and design complexity. It is also necessary to shift several pairs of gear profiles at a same time. Therefore, designing profile shifted planetary gear system is a difficult and know-how dependent job. This study provides a practical solution to design a profile shifted gear system by the procedural design scheme, and proposes a bearing integrated structure of the dual stage profile shifted gear system with a robust output end. A dual stage profile shifted gear system with the bearing integrated structure is manufactured by the proposed design scheme in this study. This gear system is verified that it is good enough to commercialize, because it has high performance with high gear ratio and robust output end against axial and radial directional runouts in a small space.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.882-889
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• 2008

A humanoid is a robot with its overall appearance based on that of the human body. When the humanoid moves or walks, dynamic forces act on the body structure. Although the humanoid keeps the balance by using a precise control, the dynamic forces generate unexpected deformation or vibration and cause difficulties on the control. Generally, the structure of the humanoid is designed by the designer's experience and intuition. Then the structure can be excessively heavy or fragile. A humanoid design scenario for a systematic design is proposed to reduce the weight of the structure while sufficient strength is kept. Lower parts of the humanoid are selected to apply the proposed design scenario. Multi-body dynamics is employed to calculate the external dynamic forces on the parts and structural optimization is carried out to design the lower parts. Because structural optimization using dynamic forces directly is fairly difficult, linear dynamic response structural optimization using equivalent static loads is utilized. Topology and shape optimizations are adopted for two steps of initial and detailed designs, respectively. Various commercial software systems are used for analysis and optimization. Improved designs are obtained and the design results are discussed.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.347-352
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• 2012

This paper presents a robotic foot mechanism based on truss structure for walking robots and analyzes its effectiveness for compliant walking. The specified foot mechanism has been modeled by observing the structure and behavior of human foot. The frame of bone used in the human foot is considered as a truss, and the ligaments of the human foot are represented as a simple stiffness element. So such a robotic foot has an advantage to moderate the impact of foot when a walking robot takes a step. As a result, it is practically expected that the proposed robotic foot mechanism can contribute to reduce the physical fatigue of walking robots.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.59-64
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• 2018

In recent years, the solar cell market has steadily grown with the demand for new energies. And wire sawing is one of the most critical processes in manufacturing solar cell wafer which is supposed to affect the breakage of wafers most during the process and afterwards. Generally, the defects of the wafers are generated from the structural vibrations of the machine. In the sawing process, the vibrations cause unnecessary normal stress on the cut surface of wafers, and eventually create the surface damage or leave the residual stress. In this study, the dynamic properties of a wire saw have been analyzed through the frequency response test and the computer simulation. And the effects of the design alterations have been investigated to stabilize the machine structure and further to reduce the vibrations. The result shows that relatively simple design alterations of supporting structure without any change of major parts of the machine can suppress the vibrations of the machine effectively.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.9
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• pp.705-709
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• 2016

Micro-electro-mechanical systems (MEMS) gyroscopes are widely used in various robot applications. However, these conventional gyroscopes need to vibrate the proof mass using a built-in actuator at a fixed resonance frequency to sense the Coriolis force. When a robot is not moving, the meaningless vibration of the gyroscope wastes power. In addition, this continuous vibration makes the sensor vulnerable to external sound waves with a frequency close to the proof-mass resonance frequency. In this paper, a feasibility study of a new type of gyroscope inspired by insect halteres is presented. In dipterous insects, halteres are a biological gyroscope that measures the Coriolis force. Wing muscles and halteres are mechanically linked, and the halteres oscillate simultaneously with wing beats. The vibrating haltere experiences the Coriolis force if the insect is going through a rotational motion. Inspired by this haltere structure, a gyroscope using a thin mast integrated with a robot actuation mechanism is proposed. The mast vibrates only when the robot is moving without requiring a separate actuator. The Coriolis force of the mast can be measured with an accelerometer installed at the tip of the mast. However, the signal from the accelerometer has multiple frequency components and also can be highly corrupted with noise, such that raw data are not meaningful. This paper also presents a suitable signal processing technique using the amplitude modulation method. The feasibility of the proposed haltere-inspired gyroscope is also experimentally evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.481-491
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• 2015

Since the crack in the surface of the concrete acts as the main reason influencing the life span of the structure, regular inspections and maintenance are required. The sealing required for maintenance of the concrete surface is a method of repairing the crack in the surface in the beginning, and is effective in preventing additional cracks and expansion that occurs with time. However, sealing on large sized structures such as tall buildings or bottom parts of bridges are difficult to ensure safety of the workers due to inadequate working environments. Due to this reason, the importance of the need for sealing automation for the maintenance of large sized concrete structures is emerging. This study proposes two control methods to apply robot systems to the sealing of cracks on the bottom parts of concrete bridges. First is the method of automatically tracking the trajectory of cracks. The robot gets the trajectory of the cracks using video information obtained from cameras. Comparing the previous several points and new point, the next point can be estimated. Thus, the trajectory of the crack can be tracked automatically. The other method is sealing by maintaining steady force to the contacting surface. The concrete surface exposed to an external environment for a long time gets an irregular roughness. If robots are able to carry out sealing while maintaining a steady contact force on these rough surfaces, complete equal sealing can be maintained. In order to maintain this equal force, a force control method using impedance is proposed. This paper introduces two developed control methods to apply to sealing robots, and conducts a Lab Test and Field Test after applying to a robot. Based on the test results, opinions on the possibilities of field application of the robot applied with the control methods are presented.

• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.143-154
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• 2020

With the increasing trend of making manufacturing system intelligent and autonomous, the introduction of robot-assist automation, like machine tending system for automated operation of CNC machine tools, is being actively carried out at many industrial sites. Most important part of this intelligent system to install machine tending system, is interface programming between the CNC machine tools and the industrial robot. Despite this importance, however, the machine tending system has many setup problems. it is necessary for difficult re-program of both controllers whenever a new CNC machine tool or robot is introduced. And, the helps of external engineers is required even though trivial changes due to the complex structure of the machine tending system. Authors of this paper introduces the integrated system of the interface between heterogeneous CNC machine tools and industrial robots. In addition, the digital twin implemented inside the machine tool controller enable shop-floor operators to change the interface programming easily. To implement this system, an integrated development environment for 1) an intelligent HMI platform that provide standardized interfaces to heterogeneous CNC machine tools and 2) a robot platform developing application software of various robots, was established. For easy un-tact environment, this paper explain the development of 3) a game-engine based web program of controlling and monitoring machine tending system remotely.

• Composites Research
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• v.35 no.5
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• pp.303-308
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• 2022

PIC (Piecewise Integrated Composite) is a new concept for designing a composite structure with mosaically assigning various types of stacking sequences in order to improve mechanical properties of laminated composites. Also, machine learning is a sub-category of artificial intelligence, that refers to the process by which computers develop the ability to continuously learn from and make predictions based on data, then make adjustments without further programming. In the present study, the tapered box beam type PIC robot arm for carrying and transferring wide and thin LCD display was designed based on the machine learning in order to increase structural stiffness. Essential training data were collected from the reference elements, which were intentionally designated elements among finite element models, during preliminary FE analysis. Additionally, triaxiality values for each finite element were obtained for judging the dominant external loading type, such as tensile, compressive or shear. Training and evaluating machine learning model were conducted using the training data and loading types of elements were predicted in case the level accuracy was fulfilled. Three types of stacking sequences, which were to be known as robust toward specific loading types, were mosaically assigned to the PIC robot arm. Henceforth, the bending type FE analysis was carried out and its result claimed that the PIC robot arm showed increased stiffness compared to conventional uni-stacking sequence type composite robot arm.