• Title/Summary/Keyword: Position Measurement

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Realization of High Precision Position Measurement System Using M-sequence Encoded Laser Beam Scanning

  • Takayama, Jun-ya;Shinji Ohyama;Akira Kobayashi
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.107.5-107
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    • 2001
  • In this report, as the active position measurement system, a new method for two-dimensional position measurement system using a concept of semi-open type signal field has proposed. The feature of this system is realizing a position measurement only by scanning the encoded laser beams from scanning points to a measurement field, and observed it. First, both system configuration and encoding method are considered concretely, and M-sequence signal is selected for encoding. Next system design is performed to realize the theoretical measurement accuracy, and applied to a position measurement experiments. Experimental results show that measurement precision is larger than theoretical values. Furthermore, method for improving the measurement ...

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Automatic Guidance System for Tractor based upon Position-measurement Systems (위치(位置) 측정장치(測定裝置)를 이용한 트랙터의 자동(自動) 주행장치(走行裝置))

  • Choi, C.H.
    • Journal of Biosystems Engineering
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    • v.15 no.2
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    • pp.79-87
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    • 1990
  • An automatic guidance system based upon two position-measurement systems was designed to record where the tractor traveled and to guide the tractor along the predetermined path. An algorithm, using the kinematic behavior of tractor movement, was developed to determine the steering angle to reduce lateral position error. The algorithm was based upon constant travel speed, constant steering rate, and zero slip angles of the tractor wheels. The algorithm was evaluated through use of computer simulation and verified in field experiments. Results showed that the distance interval between position measurements was an important factor in guidance system performance. The position-measurement error of the guidance system must be less than 5 cm to be acceptably precise for field operations. An algorithm based upon a variable steering rate might improve the stability of the guidance system. More accurate measurement of tractor position and yaw angle, and faster error processing are required to improve the field performance of the guidance system.

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Measurement of Uncertainty Using Standardized Protocol of Hand Grip Strength Measurement in Patients with Sarcopenia

  • Ha, Yong-Chan;Yoo, Jun-Il;Park, Young-Jin;Lee, Chang Han;Park, Ki-Soo
    • Journal of Bone Metabolism
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    • v.25 no.4
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    • pp.243-249
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    • 2018
  • Background: The aim of this study was to determine the accuracy and error range of hand grip strength measurement using various methods. Methods: Methods used for measurement of hand grip strength in 34 epidemiologic studies on sarcopenia were analyzed. Maximum grip strength was measured in a sitting position with the elbow flexed at 90 degrees, the shoulder in 0 degrees flexion, and the wrist in neutral position (0 degrees). Maximum grip strength in standing position was measured with the shoulder in 180 degrees flexion, the elbow fully extended, and the wrist in neutral position (0 degrees). Three measurements were taken on each side at 30 sec intervals. The uncertainty of measurement was calculated. Results: The combined uncertainty in sitting position on the right and left sides was 1.14% and 0.38%, respectively, and the combined uncertainty in standing position on the right and left sides was 0.35 and 1.20, respectively. The expanded uncertainty in sitting position on the right and left sides was 2.28 and 0.79, respectively, and the expanded uncertainty in standing position on the right and left sides was 0.71 and 2.41, respectively (k=2). Conclusions: Uncertainty of hand grip strength measurement was identified in this study, and a significant difference was observed between measurement. For more precise diagnosis of sarcopenia, dynamometers need to be corrected to overcome uncertainty.

The Comparison Between Blind and Normal Children in Standing Position (시각장애 아동과 정상 아동의 선자세 균형 비교)

  • Kim Chung-sun;Lee Jeong-soon
    • The Journal of Korean Physical Therapy
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    • v.15 no.1
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    • pp.119-154
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    • 2003
  • In this paper, the proprioceptive sensitivity was compared by Foot-Hand task method and the effect of the proprioceptive sensitivity and auditory to the standing position between blind and normal children was measured using BPM for 56 children in 7, 8, 9 and 10 years old. There are three measurement methods are used for BPM : Rest, Forward Looking, 'Sound' position. The following conclusions were obtained from the above measurements. 1. In comparison of proprioceptive sensitivity between blind and normal children, there is no significant difference(p > .05). There is no significant difference in comparison of each age group and also there is no difference in each gender group(p > .05). 2. In comparison of standing position measurement between blind and normal children, there is any difference (p > .05) in three measurement(Rest, Forward Looking, 'Sound' position) but there is no significant difference in each gender difference(p > .05). There is any difference between Rest and 'Sound' position of blind children, also there is any difference between Forward Looking and ' Sound ' position, rest and 'Sound' position of normal children(p > .05). 3. There is no significant difference of correlation between proprioceptive sensitivity test and standing position measurement in Pearson correlation coefficient(p > .05).

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Study on the Compensation of Strain Measurement Error in Sheet Metals (박판 변형률 측정 오차의 보정에 관한 연구)

  • 차지혜;금영탁
    • Transactions of Materials Processing
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    • v.13 no.7
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    • pp.594-599
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    • 2004
  • In the sheet metal forming operations, the strain measurement of sheet panel is an essential work which provides the formability information needed in die design, process design, and product inspection. To measure efficiently complex geometry strains, the 3-dimensional automative strain measurement system, which theoretically has a high accuracy but practically has about 3~5% strain error, is often used. For eliminating the strain error resulted in measuring the strains of formed panels using an automated strain measurement system, the position error calibration method is suggested, which computes accurate strains using the grids with accurate nodal coordinates. The accurate nodal coordinates are calculated by adding the nodal coordinates measured by the measurement system and the position error found using the multiple regression method as a function of the main error parameters obtained from the analysis of strain error in a standard cube. For the verification, the strain distributions of square and dome cups obtained from the position error calibration method are compared with those provided by the finite element analysis and ASAME.

Study on the Error Compensation in Strain Measurement of Sheet Metal Forming (박판성형 변형률 측정 오차보정에 관한 연구)

  • 한병엽;차지혜;금영탁
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.270-273
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    • 2003
  • The strain measurement of the panel in the sheet metal forming is essential work which provides experimental data needed to die design, process design, and product inspection. To measure efficiently the complex geometry strain, the 3-dimensional automative strain measurement system, which has high accuracy in theory, but has some 3∼5% errors in practice, is often used. The object of this study is to develop the error compensation technology to eliminate the strain, errors resulted when formed panels are measured using an automated strain measurement system. To achieve the study object, the position error calibration method correcting coordinates of the grid node recognized by a camera using error functions is suggested. Then the position errors were found by calculating the difference in the position of the cube node between real coordinates and measured coordinates in toms of node coordinates and the error calibration equations were derived by regressing the position errors. In order to show the validation of the suggested position error calibration method, finite element analysis and current calibration method was performed for the initial-blankformed.

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Development of Position Detection System using GPS (GPS를 이용한 위치검지시스템 개발)

  • Han, Young-Jae;Mok, Jin-Yong;Kim, Ki-Hwan;Kim, Seog-Won;Eun, Jong-Phil
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1729-1734
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    • 2007
  • Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. Nowadays, position data inputs to pulse signal from wheel. Perfect position measurement was limited to slip and slide of vehicle. This measurement makes up for the weak points, Position Detection System using GPS develops. By using the system, Korean High Speed Train is capable of accurate fault position detection.

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Reliability of the Joint Neutral Position and Measurement Methods of the Ankle Joint Complex Range of Motion (발목관절 복합체의 가동범위 측정을 위한 중립위치와 측정방법의 신뢰도)

  • Hong, Wan-Sung;Kim, Gi-Won
    • The Journal of Korean Physical Therapy
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    • v.23 no.4
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    • pp.45-51
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    • 2011
  • Purpose: To determine the correct measurement methods of the ankle joint complex range of motion for measuring the neutral position and evaluate the rater reliability. In addition, the impact of training on the rater reliability was also assessed. Methods: The subjects were eleven healthy women, who were evaluated by two physical therapists and one physical therapist recorded the results of the study. Standard goniometer was used as the measurement tool. The ankle and subtalar joint neutral position and the active range of motion of the ankle and subtalar joint were measured. Intra-rater reliability and inter-rater reliability measures were analyzed with intraclass correlation coefficients. Results: Intra-rater reliability and inter-rater reliability ranged from high to medium for the neutral position of the ankle joint complex. Intra-rater reliability for dorsiflexion and plantarflexion measurements was medium, while the inter-rater reliability was high. The range of motion of the subtalar joint was measured, and the intra-rater reliability and inter-rater reliability were low and medium, respectively Also, the intra-rater reliability was increased with formal training of the measurement techniques. Intra-rater reliability was reduced in case the raters had not undertaken the training. Conclusion: In summary, the results obtained with the measurement tools and joint measurement of position, indicate the consistency of repeated measurements made by the same observers. Under the same circumstances along with repetition of the same measurement technique during training caused an increase in the rater reliability of formally trained raters.

Luminance Correction Algorithm Based on Measuring Angle for the Portable Luminance Measurement System (휴대용 휘도측정시스템의 측정각도기반 휘도보정알고리즘)

  • Sun, Eun-Hey;Kim, Dongyeon;Kim, Yong-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.4
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    • pp.321-326
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    • 2016
  • In this paper, we propose a luminance correction algorithm based on measuring position for potable luminance measurement system. Measurement position and angle have an affect on the luminance value. We improve the position-based luminance measurement system using luminance correction algorithm based on the measuring angle. We analyze change of luminance value according to the measurement distance and angle from camera and light source. The certified point-luminance meter is used to evaluate a scene luminance measuring method using the image information of camera. Also, we derive an expression equation for evaluating luminance value from determined position. The performances of the proposed system are verified by using comparative experiments with the point-luminance meter using experimental signboard.

Sensor Nodes Localization for Temperature Distribution Measurement System

  • Ohyama, Shinji;Alasiry, Ali Husein;Takayama, Junya;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1781-1786
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    • 2005
  • In sensor network systems, all the nodes are interconnected and the positional information of each sensor is essential. To measure the temperature, position detection and communication functions are required. Many sensor nodes are distributed to a measurement field, and these sensors have three main functions: they measure the distance to the other nodes, the data of which are used to determine the position of each node; they communicate with other nodes; and they measure the temperature of each node. A novel range measurement method using the difference between light and sound propagation speed is proposed. The experimental results show the temperature distribution as measured with the aid of the determined positions. The positions of every node were calculated with a PC program. Eight nodes were manufactured and their fundamental functions were tested. The results of the range measurement method, which takes relatively accurate measurements, contribute significantly to the accuracy of the position determination. Future studies will focus on 3-D position determination and on the architecture of appropriate sensors and actuators.

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