• Title/Summary/Keyword: laser distance sensor

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Implementation of the SLAM System Using a Single Vision and Distance Sensors (단일 영상과 거리센서를 이용한 SLAM시스템 구현)

  • Yoo, Sung-Goo;Chong, Kil-To
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.6
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    • pp.149-156
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    • 2008
  • SLAM(Simultaneous Localization and Mapping) system is to find a global position and build a map with sensing data when an unmanned-robot navigates an unknown environment. Two kinds of system were developed. One is used distance measurement sensors such as an ultra sonic and a laser sensor. The other is used stereo vision system. The distance measurement SLAM with sensors has low computing time and low cost, but precision of system can be somewhat worse by measurement error or non-linearity of the sensor In contrast, stereo vision system can accurately measure the 3D space area, but it needs high-end system for complex calculation and it is an expensive tool. In this paper, we implement the SLAM system using a single camera image and a PSD sensors. It detects obstacles from the front PSD sensor and then perceive size and feature of the obstacles by image processing. The probability SLAM was implemented using the data of sensor and image and we verify the performance of the system by real experiment.

Navigation Using Fuzzy Control in Mobile Robot (이동로봇에서 퍼지제어를 이용한 방법)

  • 권대갑;이봉구
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.784-789
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    • 1994
  • In the mobile robot research, monitoring the present status and self-navigating the robot in various environment are signifiant. This paper treates a navigation algorithm using a fuzzy logic and a sensor system - laser range finder. The navigation algorithm using a fuzzy logic is achieved by organizing the knoweledge base for self-navigation of mobile robot. In order that mobile robot is economically arrived the goal, the knowledge base is applied to acquire the informations of moving distance, direction, and velocity in every cycle time.

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A Study on the Comparison between an Optical Fiber and a Thermal Sensor Cable for Temperature Monitoring (온도 모니터링을 위한 광섬유 센서와 온도센서 배열 케이블의 비교 연구)

  • Kim, Jung-Yul;Song, Yoon-Ho;Kim, Yoo-Sung
    • Journal of the Korean Geotechnical Society
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    • v.23 no.4
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    • pp.15-24
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    • 2007
  • Two kinds of temperature monitoring technology have been introduced in this study, which can measure coincidently temperatures at many points along a single length of cable. One is to use a thermal sensor cable comprizing of addressable thermal sensors. The other is to use an optic fiber sensor with Distributed Temperature Sensing (DTS) system. The differences between two technologies can be summarized as follows: A thermal sensor cable has a concept of "point sensing" that can measure temperature only at a predefined position. The accuracy and resolution of temperature measurement are up to the capability of the individual thermal sensor. On the other hand, an optic fiber sensor has a concept of "distributed sensing" because temperature is measured practically at all points along the fiber optic cable by analysing the intensity of Raman back-scattering when a laser pulse travels along the fiber. Thus, the temperature resolution depends on the measuring distance, measuring time and spatial resolution. The purpose of this study is to investigate the applicability of two different temperature monitoring techniques in technical and economical sense. To this end, diverse experiments with two techniques were performed and two techniques are applied under the same condition. Considering the results, the thermal sensor cable will be well applicable to the assessment of groundwater flow, geothermal distribution and grouting efficiency within about loom distance, and the optic fiber sensor will be suitable for long distance such as pipe line inspection, tunnel fire detection and power line monitoring etc.

Hierarchical Object Recognition Algorithm Based on Kalman Filter for Adaptive Cruise Control System Using Scanning Laser

  • Eom, Tae-Dok;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.496-500
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    • 1998
  • Not merely running at the designated constant speed as the classical cruise control, the adaptive cruise control (ACC) maintains safe headway distance when the front is blocked by other vehicles. One of the most essential part of ACC System is the range sensor which can measure the position and speed of all objects in front continuously, ignore all irrelevant objects, distinguish vehicles in different lanes and lock on to the closest vehicle in the same lane. In this paper, the hierarchical object recognition algorithm (HORA) is proposed to process raw scanning laser data and acquire valid distance to target vehicle. HORA contains two principal concepts. First, the concept of life quantifies the reliability of range data to filter off the spurious detection and preserve the missing target position. Second, the concept of conformation checks the mobility of each obstacle and tracks the position shift. To estimate and predict the vehicle position Kalman filter is used. Repeatedly updated covariance matrix determines the bound of valid data. The algorithm is emulated on computer and tested on-line with our ACC vehicle.

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A Study on High-precision Autofocus Matching Device for Smoke Detector Based on IR Laser (IR 레이저 기반 연기감지기를 위한 고정밀 자동초점 정합장치에 관한 연구)

  • Kim, Gwan-Hyung;Shin, Dong-Suk;Oh, Am-Suk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2759-2764
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    • 2014
  • Smoke detector is commonly used to reduce fire detection time. However, technical problems regarding its inaccuracy of laser beam-receiving point on the surface of the sensor associated with incoming interference are identified when the laser transmitter and receiver are installed at a distance of about 100m. In this paper, we propose the auto focus alignment algorithm with high precision to adjust tilting angle of lasers caused by environmental interference so that solve existing issues using multi-level worm gear set.

Lightweight Algorithm for Digital Twin based on Diameter Measurement using Singular-Value-Decomposition (특이값 분해를 이용한 치수측정 기반 디지털 트윈 알고리즘 경량화)

  • Seungmin Lee;Daejin Park
    • IEMEK Journal of Embedded Systems and Applications
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    • v.18 no.3
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    • pp.117-124
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    • 2023
  • In the machine vision inspection equipment, diameter measurement is important process in inspection of cylindrical object. However, machine vision inspection equipment requires complex algorithm processing such as camera distortion correction and perspective distortion correction, and the increase in processing time and cost required for precise diameter measurement. In this paper, we proposed the algorithm for diameter measurement of cylindrical object using the laser displacement sensor. In order to fit circle for given four input outer points, grid search algorithms using root-mean-square error and mean-absolute error are applied and compared. To solve the limitations of the grid search algorithm, we finally apply the singular-value-decomposition based circle fitting algorithm. In order to compare the performance of the algorithms, we generated the pseudo data of the outer points of the cylindrical object and applied each algorithm. As a result of the experiment, the grid search using root-mean-square error confirmed stable measurement results, but it was confirmed that real-time processing was difficult as the execution time was 10.8059 second. The execution time of mean-absolute error algorithm was greatly improved as 0.3639 second, but there was no weight according to the distance, so the result of algorithm is abnormal. On the other hand, the singular-value-decomposition method was not affected by the grid and could not only obtain precise detection results, but also confirmed a very good execution time of 0.6 millisecond.

An Autonomous Mobile System based on Detection of the Road Surface Condition (노면 상태 검출에 기반한 자율 주행 시스템)

  • Jeong, Hye-C.;Seo, Suk-T.;Lee, Sang-H.;Lee, In-K.;Kwon, Soon-H.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.5
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    • pp.599-604
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    • 2008
  • Recently, many researches for autonomous mobile system have been proposed, which can recognize surrounded environment and navigate to destination without outside intervention. The basic sufficient condition for the autonomous mobile system is to navigate to destination safely without accident. In this paper, we propose a path planning method in local region for safe navigation of autonomous system through evaluation of the road surface distortion(damaged/deformed road, unpaved road, obstacle and etc.). We use laser distance sensor to get the information on the road surface distortion and apply image binalization method to evaluate safe region in the detected local region. We show the validity of the proposed method through the computer simulation based on the artificial local road map.

Detection Method Analysis for Train Correct Position Stop in Manual Operation for PSD System (수동운전 방식에서의 PSD시스템을 위한 정위치정차 판독방법 분석)

  • Lee, Moo-Ho;Yang, Gi-Hee;Park, Jung-Soun
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1678-1684
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    • 2007
  • Platform Screen Door(PSD) has been installed in train manual operation section(ATS/ATC) by SeoulMetro since 2005. PSDs are now operating at 17 stations in SeoulMetro lines. As a result, it increases the safety of passenger, makes a comfortable platform and saves the energy of air conditioning. For PSD operation, train shall stop within 600mm of the train stop reference point. In train manual operation section, the detection system of train position is required to notify the train driver of train position and to ensure the condition that train stops the correct position for PSD operation. To detect the train stop position, the optical sensor shall be installed at platform. However, in case of SeoulMetro lines, the detection criterions of the train correct position stop are different because of using various types of trains which have different size and shape of front cars. In this paper, to solve this problem, the precise detection algorithm of the train stop at the correct position is used, and Laser distance measure sensor is introduced to notify the distance form the reference point of the train correct stop to train driver. This system has been applying to Seoul Metro line total.

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Illumination Invariant Ranging Sensor Based on Structured Light Image (조명잡음에 강인한 구조광 영상기반 거리측정 센서)

  • Shin, Jin;Yi, Soo-Yeong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.12
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    • pp.122-130
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    • 2010
  • This paper presents an active ranging system based on laser structured-light image. The structured-light image processing is computationally efficient in comparison with the conventional stereo image processing, since the burdensome correspondence problem is avoidable. In order to achieve robustness against environmental illumination noise, an efficient image processing algorithm, i.e., integration of difference images with structured-light modulation is proposed. Distance equation from the measured structured light pixel distance and system parameter calibration are addressed in this paper. Experiments and analysis are carried out to verify performance of the proposed ranging system.

A Fast Ground Segmentation Method for 3D Point Cloud

  • Chu, Phuong;Cho, Seoungjae;Sim, Sungdae;Kwak, Kiho;Cho, Kyungeun
    • Journal of Information Processing Systems
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    • v.13 no.3
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    • pp.491-499
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    • 2017
  • In this study, we proposed a new approach to segment ground and nonground points gained from a 3D laser range sensor. The primary aim of this research was to provide a fast and effective method for ground segmentation. In each frame, we divide the point cloud into small groups. All threshold points and start-ground points in each group are then analyzed. To determine threshold points we depend on three features: gradient, lost threshold points, and abnormalities in the distance between the sensor and a particular threshold point. After a threshold point is determined, a start-ground point is then identified by considering the height difference between two consecutive points. All points from a start-ground point to the next threshold point are ground points. Other points are nonground. This process is then repeated until all points are labelled.