• Title/Summary/Keyword: distance measurement error

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A Study on Scale-Invariant Features Extraction and Distance Measurement for Localization of Mobile Robot (이동로봇의 위치 추정을 위한 스케일 불변 특징점 추출 및 거리 측정에 관한 연구)

  • Jung, Dae-Seop;Jang, Mun-Suk;Ryu, Je-Goon;Lee, Eung-Hyuk;Shim, Jae-Hong
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.625-627
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    • 2005
  • Existent distance measurement that use camera is method that use both Stereo Camera and Monocular Camera, There is shortcoming that method that use Stereo Camera is sensitive in effect of a lot of expenses and environment variables, and method that use Monocular Camera are big computational complexity and error. In this study, reduce expense and error using Monocular Camera and I suggest algorithm that measure distance, Extract features using scale Invariant features Transform(SIFT) for distance measurement, and this measures distance through features matching and geometrical analysis, Proposed method proves measuring distance with wall by geometrical analysis free wall through feature point abstraction and matching.

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Analysis of Distance Measurement Accuracy in Aerial and Satellite Image Photogrammetry (항공사진측량과 위성영상측량에서 거리측정 정확도 연구)

  • Kim, Hyung-Moo;Tcha, Dek-Kie;Nam, Guon-Mo;Yang, Chul-Soo
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.253-255
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    • 2010
  • Needs to study on distance measurement accuracy in aerial and satellite photogrammetry are rapidly increased. However, conventional studies show some confused definitions between measurement accuracy and measurement precision as well as standard deviation(STDEV) and root mean square error(RMSE or RMSD). So, Finite definitions of measurement accuracy and measurement precision as well as STDEV and RMSD are addressed in this paper. Experiment result show using correct definitions improve the distance measurement accuracy in aerial and satellite photogrammetry rapidly, but not the distance measurement accuracy in aerial and satellite photogrammetry.

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Phoneme Similarity Error Correction System using Bhattacharyya Distance Measurement Method (바타챠랴 거리 측정법을 이용한 음소 유사율 오류 보정 개선 시스템)

  • Ahn, Chan-Shik;Oh, Sang-Yeob
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.6
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    • pp.73-80
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    • 2010
  • Vocabulary recognition system is providing inaccurate vocabulary and similar phoneme recognition due to reduce recognition rate. It's require method of similar phoneme recognition unrecognized and efficient feature extraction process. Therefore in this paper propose phoneme likelihood error correction improvement system using based on phoneme feature Bhattacharyya distance measurement. Phoneme likelihood is monophone training data phoneme using HMM feature extraction method, similar phoneme is induced recognition able to accurate phoneme using Bhattacharyya distance measurement. They are effective recognition rate improvement. System performance comparison as a result of recognition improve represent 1.2%, 97.91% by Euclidean distance measurement and dynamic time warping(DTW) system.

Distance Measurement System using A Stereo Camera and Radial Pattern Target for Automatic Berthing Control

  • Mizuchi, Yoshiaki;Ogura, Tadashi;Hagiwara, Yoshinobu;Suzuki, Akimasa;Kim, Youngbok;Choi, Yongwoon
    • Journal of Power System Engineering
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    • v.17 no.5
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    • pp.121-127
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    • 2013
  • In this paper, we propose a distance measurement system for automatic berthing control using a stereo camera mounted on a rotation control device, and a radial pattern target. Automatically controlling the position and attitude of a ship aims to prevent maritime accidents due to human error. Our goal is to measure the relative distance between a ship and an onshore or offshore target for berthing. Therefore, the distance should be continuously measured while tracking a fixed point on a target. To this end, we developed a stereo camerabased distance measurement system that satisfied these requirements. This paper describes the structure and principle of the measurement system. We validate the distance error for target incline due to the relative position and attitude between a camera and a target in miniature scale. In addition, the findings of an experiment in an outdoor environment demonstrate that the proposed measurement system has accuracy within 1 m at a range of 20-100 m which is the acceptable accuracy for automatic berthing.

A Measurement Error Correction Algorithm of Road Image for Traveling Vehicle's Fluctuation Using V.F. Modeling (V.F. 모델링을 이용한 주행차량의 진동에 대한 도로영상의 계측오차 보정 알고리듬)

  • Kim Tae-Hyo;Seo Kyung-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.8
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    • pp.824-833
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    • 2006
  • In this paper, the image modelling of road's lane markings is established using view frustum(VF) model. From this model, a measurement system of lane markings and obstacles is proposed. The system also involve the real time processing of the 3D position coordinate and the distance data from the camera to the points on the 3D world coordinate by virtue of the camera calibration. In order to reduce their measurement error, an useful algorithm for which analyze the geometric variations due to traveling vehicle's fluctuation using VF model is proposed. In experiments, without correction, for instance, the $0.4^{\circ}$ of pitching rotation gives the error of $0.4{\sim}0.6m$ at the distance of 10m, but the more far distance cause exponentially the more error. We con finned that this algorithm can be reduced less than 0.1m of error at the same condition.

Development of Measurement System of Moving Distance Using a Low-Cost Accelerometer

  • Cho, Seong-Yun;Kim, Jin-Ho;Park, Chan-Gook
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.130.4-130
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    • 2001
  • In this paper, a measurement system of moving distance is developed. The error compensation method is also proposed using the characteristics of walking motion. As personal navigation systems and multimedia systems are emerging into the commericial market, men´s moving distance is considered as one of the important information. GPS offers the information easily but GPS can be used only when the satellites are visible. INS can calculate the moving distance anywhere but error is increased with time due to the sensor bias. In this paper, to detect the human walking distance a measurement system of moving distance only using low-cost accelerometer is developed. The sensor bias is estimated and compensated using the walking motion characteristics. The performanced of the proposed system is verified by experiment.

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Design and Implementation of Magnetic Induction based Wireless Underground Communication System Supporting Distance Measurement

  • Kim, Min-Joon;Chae, Sung-Hun;Shim, Young-Bo;Lee, Dong-Hyun;Kim, Myung-Jin;Moon, Yeon-Kug;Kwon, Kon-Woo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.8
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    • pp.4227-4240
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    • 2019
  • In this paper, we present our proposed magnetic induction based wireless communication system. The proposed system is designed to perform communication as well as distance measurement in underground environments. In order to improve the communication quality, we propose and implement the adaptive channel compensation technique. Based on the fact that the channel may be fast time-varying, we keep track of the channel status each time the data is received and accordingly compensate the channel coefficient for any change in the channel status. By using the proposed compensation technique, the developed platform can reliably communicate over distances of 10m while the packet error rate is being maintained under 5%. We also implement the distance measurement block that is useful for various applications that should promptly estimate the location of nearby nodes in communication. The distance between two nodes in communication is estimated by generating a table describing pairs of the magnetic signal strength and the corresponding distance. The experiment result shows that the platform can estimate the distance of a node located within 10m range with the measurement error less than 50cm.

Creepage Distance Measurement Using Binocular Stereo Vision on Hot-line for High Voltage Insulator

  • He, Wenjun;Wang, Jiake;Fu, Yuegang
    • Current Optics and Photonics
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    • v.2 no.4
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    • pp.348-355
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    • 2018
  • How to measure the creepage distance of an insulator quickly and accurately is a problem for the power industry at present, and the noticeable concern is that the high voltage insulation equipment cannot be measured online in the charged state. In view of this situation, we develop an on-line measurement system of creepage distance for high voltage insulators based on binocular stereo vision. We have proposed a method of generating linear structured light using a conical off-axis mirror. The feasibility and effect of two ways to solve the interference problem of strong sunlight have been discussed, one way is to use bandpass filters to enhance the contrast ratio of linear structured light in the images, and the other way is to process the images with adaptive threshold segmentation and feature point extraction. After the system is calibrated, we tested the measurement error of the on-line measurement system with a composite insulator sample. Experimental results show that the maximum relative error is 1.45% and the average relative error is 0.69%, which satisfies the task requirement of not more than 5% of the maximum relative error.

Implementation and Performance Analysis of DGPS & RTK Error Correction Data Real-Time Transmission System for Long-Distance in Mobile Environments

  • Cho, Ik-Sung;Ha, Chang-Seung;Yim, Jae-Hong
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.291-291
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    • 2002
  • DGPS(Differential Global Positioning System) and RTK(RealTime Kinematic) is in one of today's most widely used surveying techniques. But It's use is restricted by the distance between reference station and rover station and it is difficult to process data in realtime by it's own orgnizational limitation in precise measurement of positioning. To meet these new demands, In This paper, new DGPS and RTK correction data services through Internet and PSTN(Public Switched Telephony Network) have been proposed. For this purpose, we implemented performance a DGPS and RTK error correction data transmission system for long-distance using the internet and PSTN network which allows a mobile user to increase the distance at which the rover receiver is located from the reference in realtime. and we analyzed and compared DGPS and RTK performance by experiments through the Internet and PSTN network with the distance and the time.

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Study on Development of Embedded Source Depth Assessment Method Using Gamma Spectrum Ratio (감마선 스펙트럼 비율을 이용한 매립 선원의 깊이 평가 방법론 개발 연구)

  • Kim, Jun-Ha;Cheong, Jea-Hak;Hong, Sang-Bum;Seo, Bum-Kyung;Lee, Byung Chae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.1
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    • pp.51-62
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    • 2020
  • This study was conducted to develop a method for depth assessment of embedded sources using gamma-spectrum ratio and for the evaluation of field applicability. To this end, Peak to Compton and Peak to valley ratio changes were evaluated according to 137Cs, 60Co, 152Eu point source depth using HPGe detector and MCNP simulation. The effects of measurement distance of PTV and PTC methods were evaluated. Using the results, the source depth assessment equation using the PTC and PTV methods was derived based on the detection distance of 50 cm. In addition, the sensitivity of detection distance changes was assessed when using PTV and PTC methods, and error increased by 3 to 4 cm when detection distance decreased by 20 cm based on 50 cm. However, it was confirmed that if the detection distance was increased to 100 cm, the effects of detection distance were small. And PTV and PTC methods were compared with the two distance measurement method which evaluates the depth of source by the change of net peak counting rate according to the detection distance. As a result of source depth assessment, the PTV and PTC showed a maximum error of 1.87 cm and the two distance measurement method showed maximum error of 2.69 cm. The results of the experiment confirmed that the accuracy of the PTV and PTC methods was higher than two distance measurement. In addition, Sensitivity evaluation by horizontal position error of source has maximum error of less than 25.59 cm for the two distance measurement method. On the other hand, PTV and PTC method showed high accuracy with maximum error of less than 8.04 cm. In addition, the PTC method has lowest standard deviation for the same time measurement, which is expected to enable rapid measurement.