• Title/Summary/Keyword: The technique of localization

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MR spectroscopy using single-shot RF localization technique (단일 RF 펄스를 사용한 3차원 체적 선택 방법을 이용한 MR 스펙트로 스코피)

  • Rim, C.Y.;Chun, K.W.;Ra, J.B.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1989 no.05
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    • pp.51-54
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    • 1989
  • In last several years, a number of volume localization techniques, such as ISIS, VSE, SPARS and STEAM etc., have been developed for the MR spectroscopy. These localizing techniques, however, require application of several RF pulses for the 3-D volume selection and suffer from T1 and T2 decays due to relatively long RF excitation time. In this paper, we propose a single-shot RF pulse localization technique to achieve the localized 3-D volume selection. This technique combines the cylindrical volume selection technique with a radial gradient coil with single-shot RF pulse and the oscillating selection gradient technique, so thai it minimizes the volume selection time. We report some experimental results obtained with the proposed method which appears promising for 3-D volume imaging and localized spectroscopy.

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Artificial Landmark Design and Recognition for Localization (위치추정을 위한 인공표식 설계 및 인식)

  • Kim, Si-Yong;Lee, Soo-Yong;Song, Jae-Bok
    • The Journal of Korea Robotics Society
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    • v.3 no.2
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    • pp.99-105
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    • 2008
  • To achieve autonomous mobile robot navigation, accurate localization technique is the fundamental issue that should be addressed. In augmented reality, the position of a user is required for location-based services. This paper presents indoor localization using infrared reflective artificial landmarks. In order to minimize the disturbance to the user and to provide the ease of installation, the passive landmarks are used. The landmarks are made of coated film which reflects the infrared light efficiently. Infrared light is not visible, but the camera can capture the reflected infrared light. Once the artificial landmark is identified, the camera's relative position/orientation is estimated with respect to the landmark. In order to reduce the number of the required artificial landmarks for a given environment, the pan/tilt mechanism is developed together with the distortion correction algorithm.

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Sonar Grid-map based Localization for Autonomous Mobile Robots (초음파 확률격자지도에 기반을 둔 자율이동로봇의 위치추정)

  • Lee, Yu-Cheol;Lee, Se-Jin;Cho, Dong-Woo;Kang, Chul-Ung;Lim, Jong-Hwan
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.83-85
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    • 2005
  • Exploration involving mapping and localization in an unknown environment is an important task in mobile robots. For this, robot must be able to build a reliable map of surroundings and to estimate the position of it. In this paper, we developed technique for gird-based localization of a mobile robot with ultrasonic sensors using EKF(Extended Kalman Filter). We also describe the information about landmarks detected in the environment. Finally, the robot experiments show the efficiency of our approach in the real environment.

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An Embedded Solution for Fast Navigation and Precise Positioning of Indoor Mobile Robots by Floor Features (바닥 특징점을 사용하는 실내용 정밀 고속 자율 주행 로봇을 위한 싱글보드 컴퓨터 솔루션)

  • Kim, Yong Nyeon;Suh, Il Hong
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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    • pp.293-300
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    • 2019
  • In this paper, an Embedded solution for fast navigation and precise positioning of mobile robots by floor features is introduced. Most of navigation systems tend to require high-performance computing unit and high quality sensor data. They can produce high accuracy navigation systems but have limited application due to their high cost. The introduced navigation system is designed to be a low cost solution for a wide range of applications such as toys, mobile service robots and education. The key design idea of the system is a simple localization approach using line features of the floor and delayed localization strategy using topological map. It differs from typical navigation approaches which usually use Simultaneous Localization and Mapping (SLAM) technique with high latency localization. This navigation system is implemented on single board Raspberry Pi B+ computer which has 1.4 GHz processor and Redone mobile robot which has maximum speed of 1.1 m/s.

Implementation and Empirical Evaluation of Indoor Localization in IEEE 802.15.4 Network (IEEE 802.15.4 네트워크 기반의 실내 위치측정 시스템 구현 및 실험적 분석)

  • Kim, Tae-Woon;Choi, Woo-Yeol;Lim, Hyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1B
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    • pp.162-175
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    • 2010
  • Currently, geographical information is interpreted and adopted in a wide range of context, and used for meeting diverse demands, such as, battlefield, traffic management, or public safety. With such an explosive increase of location-based applications, a considerable amount of research on the localization technique has been carried out. Among them, RSS (Received Signal Strength)-based approach is used especially for the indoor localization due to intrinsic limitations of the indoor environment. In this paper, we perform theoretical and empirical studies on enhancing the accuracy of the RSS-based localization on the IEEE 802.15.4 network. To this end, we set up an indoor testbed and implement a localization system on it. In addition to the theoretical analysis of the localization algorithm that we used, an empirical analysis on the effect of the factors which affect the accuracy of a localization system is carried out. Finally, we suggest some critical guidelines that should be considered for building a highly accurate localization system.

Analysis of Indoor Localization Technology for Exhibition Services and Application Method of VLC/RF Converged Localization (전시 서비스를 위한 실내 측위 기술 분석 및 VLC/RF 결합 측위 적용 방안)

  • Kim, Ki-Yun;Lee, Min-Woo;Cha, Jae-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.1
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    • pp.217-225
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    • 2015
  • Recently, as the supply of smart phone is spreading and the exhibition industries are rapidly growing, future exhibitions are evolving toward active, customized, interactive, tangible services, which can give more satisfaction to visitors. To realize this services, the indoor localization in the exhibition of visitors is very important and according to the accuracy of localization the quality of services for exhibition are also different. In this paper, state-of-the art indoor localization techniques are investigated and new localization method are proposed. To achieve this goal, future exhibition service types are proposed, which are connected with IT technology. And also, BLE(Bluetooth Low Energy) technology including comparison of specifications and representative localization technologies are analysed. Furthermore we performed comparison study and simulation between RF and VLC channels. Finally based on this, we proposed converged VLC and RF(Wi-Fi and BLE) localization technique for exhibition.

Error Minimization of Angular Velocity using Encoders and Gyro (엔코더와 자이로를 이용한 각속도 오차 최소화)

  • Kim, Jung-Min;Do, Joo-Cheol;Kim, Sung-Shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.6
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    • pp.814-819
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    • 2010
  • This paper is presented to study the error minimization of angular velocity for AGV(autonomous ground vehicle). The error minimization of angular velocity is related to localization technique which is the most important technique for autonomous vehicle. Accelerometer, yaw gyro and electronic compass have been used to measure angular velocity. And methods for error minimization of angular velocity have been actively studied through probabilistic methods and sensor fusion for AGVs. However, those sensors still occure accumulated error by mathematical error, system characters of each sensor, and computational cost are increased greatly when several sensor are used to correct accumulated error. Therefore, this paper studies about error minimization of angular velocity that just uses encoder and gyro. To experiment, we use autonomous vehicle which is made by ourselves. In experimental result, we verified that the localization error of proposed method has even less than the localization errors which we just used encoder and gyro respectively.

Fabrication of Anisotropic Hexagram Particles by using the Micromolding Technique and Selective Localization of Patch (미세성형 기술과 패치의 선택적 제거방법을 이용한 이방성의 육각별 입자 제조)

  • Shim, Gyurak;Yeom, Su-Jin;Jeong, Seong-Geun;Kang, Kyoung-Ku;Lee, Chang-Soo
    • Clean Technology
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    • v.24 no.2
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    • pp.105-111
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    • 2018
  • This study presents a novel and eco-friendly process that can precisely control the location of the patches on the patch particles. The method of manufacturing these anisotropic hexagram patch particles consists of sequential combinations of two separate methods such as a sequential micromolding technique for fabricating patch particles and a selective localization method for controlling the location of patches on the patch particles. The micromolding technique was carried out using physicochemically stable material as a micromold. In order to fabricate the highly stable patch anisotropic hexagram particles, the perfluoropolyether (PFPE) micromold was used to the process of the micromolding technique because they could prevent the problem of diffusion of hydrophobic monomers while conventional poly(dimethylsiloxane) (PDMS) micromold is limited to prevent the problem of diffusion of hydrophobic monomers. Based on combination methods of the micromolding technique and the selective localization method, the reproducibility and stability have been improved to fabricate 12 different types of anisotropic hexagram patch particles. This fabrication method shows the unique advantages in eco-friend condition, easy and fast fabrication due to less number of process, the feasibility of a mass production. We believe that these anisotropic hexagram patch particles can be widely utilized to the field of the directional self-assembly.

The High-frequency Induction-heating application for 2700kW power (2700kW급 고주파 유도 가열 장치의 시작)

  • 이영호;김용환;이광수;이현우
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.171-174
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    • 1998
  • The development of the high-frequency induction-heating for 2700kW power range intend to make localization at forging and rolling mill part by technical innovation. And, the development makes to increase our's competitive power at technique, quality and cost. This paper describes the heart of high-frequency induction-heating technique, switching technique, a few problem in common using as an unsatisfied technique, load adjustment technique, system control, diagnostic system, and auto-interface etc.

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Localization of Unmanned Ground Vehicle based on Matching of Ortho-edge Images of 3D Range Data and DSM (3차원 거리정보와 DSM의 정사윤곽선 영상 정합을 이용한 무인이동로봇의 위치인식)

  • Park, Soon-Yong;Choi, Sung-In
    • KIPS Transactions on Software and Data Engineering
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    • v.1 no.1
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    • pp.43-54
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    • 2012
  • This paper presents a new localization technique of an UGV(Unmanned Ground Vehicle) by matching ortho-edge images generated from a DSM (Digital Surface Map) which represents the 3D geometric information of an outdoor navigation environment and 3D range data which is obtained from a LIDAR (Light Detection and Ranging) sensor mounted at the UGV. Recent UGV localization techniques mostly try to combine positioning sensors such as GPS (Global Positioning System), IMU (Inertial Measurement Unit), and LIDAR. Especially, ICP (Iterative Closest Point)-based geometric registration techniques have been developed for UGV localization. However, the ICP-based geometric registration techniques are subject to fail to register 3D range data between LIDAR and DSM because the sensing directions of the two data are too different. In this paper, we introduce and match ortho-edge images between two different sensor data, 3D LIDAR and DSM, for the localization of the UGV. Details of new techniques to generating and matching ortho-edge images between LIDAR and DSM are presented which are followed by experimental results from four different navigation paths. The performance of the proposed technique is compared to a conventional ICP-based technique.