• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.51-58
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• 2008

In this paper, we propose a place modeling based on the distribution of scale-invariant features, and a place recognition method that recognizes places by comparing the place model in a database with the extracted features from input data. The proposed method is based on the assumption that every place can be represented by unique feature distributions that are distinguishable from others. The proposed method uses global information of each place where one place is represented by one distribution model. Therefore, the main contribution of the proposed method is that the time cost corresponding to the increase of the number of places grows linearly without increasing exponentially. For the performance evaluation of the proposed method, the different number of frames and the different number of features are used, respectively. Empirical results illustrate that our approach achieves better performance in space and time cost comparing to other approaches. We expect that the Proposed method is applicable to many ubiquitous systems such as robot navigation, vision system for blind people, wearable computing, and so on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1675-1683
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• 2018

This paper is a study on modeling of an NFC antenna to be inserted into a steel pallet for conveying selected good products through a vision system to a threaded screw from CNC equipment. The CNC equipment used here incorporates the information communication technology (ICT) corresponding to the Internet of Things (IoT), and the smart factory system technology that produces information by exchanging information freely in two directions by connecting the POP corresponding to the service Internet is evolved Equipment. Therefore, it is possible to collect position information on the threaded workpiece by applying NFC antenna designed considering iron pallet used for material management so as to grasp estimated completion time and actual production amount according to production instruction from existing analog type equipment to POP monitoring system And investigated its characteristics.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.415-418
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• 2007

가까운 미래에 인간생활에 활용될 지능형 로봇은 인간과 공존하면서도 효과적으로 인간을 도와줄 수 있는 인간친화형 로봇이라 할 수 있다. 이러한 것을 실현하기 위해서 로봇은 미지의 환경 내에서 자신의 위치 및 방향을 인식해야 할 필요가 있다. 더욱이, 이것은 일상생활에서 자연스럽게 이뤄지는 것이 당연하다. 로봇을 제어하는 가장 중요한 문제중의 하나로서 이동로봇의 주행에서의 위치불확실성을 해결함으로서 로봇의 위치를 추정하는 것이 바람직하다 할 수 있다. 본 논문에서는 실내외 공간에서 인간을 포한함 이동물체의 영상정보를 이용하여 이동로봇의 자기위치를 인식하기 위한 방법을 제시하고 있다. 제시한 방법은 로봇자체의 DR센서 정보와 카메라에서 얻은 영상정보로부터 로봇의 위치추정방법을 결합 한 것이다. 그리고 이동물체의 이전 위치정보와 관측 카메라의 모델을 사용하여 이동물체에 대한 영상프레임 좌표와 추정된 로봇위치 간의 관계를 표현할 수 있는 식을 제시하고 있다. 또한 이동하는 인간과 로봇의 위치와 방향을 추정하기 위한 제어방법을 제시하고 이동로봇의 위치를 추정하기위해서 칼만필터 방법을 적용하였다. 그리고 시뮬레이션 및 실험을 통하여 제시한 방법을 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.529-532
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• 2012

This paper presents the system modeling, analysis, and controller design and implementation with a inverted pendulum system in order to test robust algorithm for sweeping machine. The balancing of an inverted pendulum by moving pendulum robot like as 'segway' along a horizontal track is a classic problem in the area of control. This paper will describe two methods to swing a pendulum attached to a cart from an initial downwards position to an upright position and maintain that state. The results of real experiment show that the proposed control system has superior performance for following a reference command at certain initial conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.4937-4943
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• 2012

Butterfly valves have been used to control the flow rate of various fluids in many industries because it have unique manageability compare to other valves. The flow rate passing through the butterfly valves can be controlled according to the coefficient of capacity calculated by disk angle change. In this study, flow analysis by 3D modeling was performed to derive the coefficient of capacity to evaluate and improve newly developed butterfly valves. Also, required measurement system was established to verify the performance of the valves, and to compare with the calculated results.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1005-1013
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• 2008

This paper describes a new sensor system for 3D range measurement using the structured infrared light. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and the projected infrared light are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Identification of the cells from the pattern is the key issue in the proposed method. Several methods of correctly identifying the cells are discussed and verified with experiments.

• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.298-311
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• 2015

Nowadays, automatic digging operation of an excavator is a big challenge due to the complexity of digging environment, the hardness of soil and buried obstacles into the ground. In order to achieve the maximum soil bucket volume, this paper introduces a novel engineering model that was developed as a virtual excavator in the design phase. Through this model, the designs of mechanical and control systems for autonomous excavator are executed and modified easily before developing in real testbed. Based on a concept of an autonomous excavation, a mechanical system of excavator was first designed in SOLIDWORKS, and a soil model also was modeled by finite-element analysis in ANSYS, both modeled models were then exported to ADAMS environment to investigate the digging behavior through virtual simulation. An intelligent control strategy was generated in MATLAB/Simulink to control the excavator operation. The simulation results were demonstrated by effectiveness of the proposed excavator robot in testing scenarios with many soil types and obstacles.

• The Research Journal of the Costume Culture
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• v.28 no.4
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• pp.409-419
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• 2020

Building on Technology Readiness and Acceptance Model(TRAM), the study aimed to examine how technology readiness affects consumers' perceptions of ease of use, usefulness, and risk, which in turn predict their intention to use retail service robots. Specifically, the study proposed that technology readiness motivators (optimism and innovativeness) would influence perceived ease of use and usefulness, while technology readiness inhibitors (discomfort and insecurity) would affect perceived risk. The study further examined if the perception factors (ease of use, usefulness, and risk) contribute to intention to use retail service robots. A survey method was used with data collected from Korean consumers. The final sample size was 418. The data was analyzed using structural equation modeling. Findings of the study revealed that technology readiness motivators positively affected perceived ease of use and usefulness while innovativeness had no impact on usefulness. All the inhibitors increased perceived risk. Lastly, as hypothesized, perceptions of ease of use, usefulness, and risk predicted intention to use retail service robots. This study extended the retail technology literature by applying and validating TRAM to the context of consumer acceptance of retail service robots. The study further helped marketers and retailers by highlighting the importance of technology readiness in improving consumer perceptions and responses towards retail service robots.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.314-321
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• 2002

An endoscope is usually inserted into the human body for the inspection of the gullet, stomach, and large intestine (colon) and this may cause discomfort to patients and damage to tissues during diagnostic or therapeutic procedures. This situation necessitates a self-propelling endoscope. There are many kinds of mechanism to move in a rigid pipe. However, these methods are difficult to apply directly to the endoscope. The main reason is that human intestine cannot be considered as a uniform, straight, and rigid pipe. This paper proposes a flexible loop wheel mechanism, which is adaptable to the human intestine. This mechanism is designed and fabricated by a simple modeling, and tested by an experiment. Finally, the actuator is inserted into the pig colon.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.630-639
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• 2004

The Stewart platform manipulator is a closed-kinematics chain robot manipulator that is capable of providing high structural rigidity and positional accuracy. However, this is a complex and nonlinear system, so the control performance of the system is not so good. In this paper, a new robust motion control algorithm is proposed. The algorithm uses partial state feedback for a class of nonlinear systems with modeling uncertainties and external disturbances. The major contribution is the design of a robust observer for the state and the perturbation of the Stewart platform, which is combined with a variable structure controller (VSC). The combination of controller and observer provides the robust routine called sliding mode control with sliding perturbation observe. (SMCSPO). The optimal gains of SMCSPO, which is determined by nominal eigenvalues, are easily obtained by genetic algorithm. The proposed fitness function that evaluates the gain optimization is to put sliding function. The control performance of the proposed algorithm is evaluated by the simulation and experiment to apply to the Stewart platform. The results showed high accuracy and good performance.