• Title/Summary/Keyword: Position measurement

Search Result 2,294, Processing Time 0.038 seconds

Development of a 3-D Position Measurement Algorithm using 2-D Image Information (2차원 영상 정보를 이용한 3차원 위치 측정 알고리즘 개발)

  • Lee, J.H.;Jung, S.H.;Kim, D.H.
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.12 no.5
    • /
    • pp.141-148
    • /
    • 2013
  • There are several problems in the conventional 2-D image processing and 3-D measurement systems. In the case of the 2-D image processing system, it is not possible to detect elevation data. In a 3-D measurement system, it requires a skillful operator and a lot of time for measuring data. Also, there exist data errors depending on operators. The limitation of detecting elevation data in the 2-D image processing system can be solved by laser diodes. In this study an algorithm that measures the accurate data in a subject face to be detected by combining laser diodes and a commercial CCD camera is developed. In the development process, a planar equation is developed using laser diodes and the equation is used to obtain a normal vector. Based on the results, an algorithm that transforms commercial CCD camera coordinates to 3-D coordinates is proposed. The completed measurement method will be applied to replace a manual measurement system for vehicle bodies and parts by an automated system.

A Study on the Small Disturbance Measurement of Liquid Film Thickness by $Moir\acute{e}$ Fringe ($Moir\acute{e}$ Fringe에 의한 액막 두께 미소 변위 측정 연구)

  • Jeon, H.S.;Kim, K.H.
    • Journal of ILASS-Korea
    • /
    • v.2 no.4
    • /
    • pp.29-35
    • /
    • 1997
  • Liquid film thickness is measured by $moir\acute{e}$ topography which monitored liquid surface. $Moir\acute{e}$ fringe measurement techniques share the inherent simplicity found in optical interferometric techniques have the advantage of use over a greater range of displacement. $Moir\acute{e}$ fringe are the geometric interference patterns observed when two dense line grating are superposed. Light transmitted through a fixed line grating is deviated by the liquid film surface, producing a distored image of the grating. The $moir\acute{e}$ fringe produced by projection of this optically distored grating onto a second stationary grating permit visualization of the liquid surface and measurement of the liquid film thickness. This study measured the small amplitude of liquid film thickness to the $moir\acute{e}$ fringe pattern produced when spherical metal was dropped glycerin put)1 And the measurement of liquid film thickness flowing down an inclined plate are required to calculate the liquid slope in a position.

  • PDF

A numerical method for improving the reliability of knee translation measurement in skin marker-based motion analysis

  • Wang, Hongsheng;Zheng, Nigel
    • Advances in biomechanics and applications
    • /
    • v.1 no.4
    • /
    • pp.269-277
    • /
    • 2014
  • In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center ($11.1{\pm}3.5mm$ vs. $19.9{\pm}5.5mm$). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.

A PHOTOMETRIC STUDY OF THE FACIAL PROFILES OF KOREAN ADULT WOMAN (한국 성인 여성의 안모에 대한 실물 사진 계측학적 연구)

  • Park, Moo-Chull;Kim, Yeo-Gab
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.14 no.1_2
    • /
    • pp.54-64
    • /
    • 1992
  • The balance of facial sop tissue is important factor for the treatment of maxillofacial deformity patients. There are many cephalometric analysis of facial bone but a few soft tissue analysis of face for the orthognathic surgery, especially in the oriental people. This study aimed at examining the mean value of the soft tissue measurement of 120 Korean adult women with the linear and angular measurement and comparing with Caucasian. The results ere as follows. 1. In the frontal linear measurement, Korean women have larger interocular distant and width of nose, but the width of mouth appeared less than Caucasian. 2. In the frontal angular measurement, Korean women have larger inclination of the eye than Caucasian. 3. In the lateral linear measurement, Korean women have more prominent upper and lower lip position than Caucasian and have longer upper facial height comparing with lower facial height than Caucasian. 4. In the lateral angular measurement, Korean women have more convex facial profile and less nasolabial and geniolabial angle. 5. In the lateral facial ratio, Korean women have larger proportion in the lower department below the stomion.

  • PDF

Motion Vector Based Overlay Metrology Algorithm for Wafer Alignment (웨이퍼 정렬을 위한 움직임 벡터 기반의 오버레이 계측 알고리즘 )

  • Lee Hyun Chul;Woo Ho Sung
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.12 no.3
    • /
    • pp.141-148
    • /
    • 2023
  • Accurate overlay metrology is essential to achieve high yields of semiconductor products. Overlay metrology performance is greatly affected by overlay target design and measurement method. Therefore, in order to improve the performance of the overlay target, measurement methods applicable to various targets are required. In this study, we propose a new algorithm that can measure image-based overlay. The proposed measurement algorithm can estimate the sub-pixel position by using a motion vector. The motion vector may estimate the position of the sub-pixel unit by applying a quadratic equation model through polynomial expansion using pixels in the selected region. The measurement method using the motion vector can calculate the stacking error in all directions at once, unlike the existing correlation coefficient-based measurement method that calculates the stacking error on the X-axis and the Y-axis, respectively. Therefore, more accurate overlay measurement is possible by reflecting the relationship between the X-axis and the Y-axis. However, since the amount of computation is increased compared to the existing correlation coefficient-based algorithm, more computation time may be required. The purpose of this study is not to present an algorithm improved over the existing method, but to suggest a direction for a new measurement method. Through the experimental results, it was confirmed that measurement results similar to those of the existing method could be obtained.

Abdominal Wall Motion-Based Respiration Rate Measurement using An Ultrasonic Proximity Sensor (복부 움직임에 따른 초음파 근접센서를 이용한 호흡측정에 관한 연구)

  • Min, Se-Dong;Kim, Jin-Kwon;Shin, Hang-Sik;Yun, Young-Hyun;Lee, Chung-Keun;Lee, Jeong-Whan;Lee, Myoung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.58 no.10
    • /
    • pp.2071-2078
    • /
    • 2009
  • In this paper, we proposed a non-contact respiration measurement system with ultrasonic proximity sensor. Ultrasonic proximity sensor approach of respiration measurement which respiration signatures and rates can be derived in real-time for long-term monitoring is presented. 240 kHz ultrasonic sensor has been applied for the proposed measurement system. The time of flight of sound wave between the transmitted signal and received signal have been used for a respiration measurement from abdominal area. Respiration rates measured with the ultrasonic proximity sensor were compared with those measured with standard techniques on 5 human subjects. Accurate measurement of respiration rate is shown from the 50 cm measurement distance. The data from the method comparison study is used to confirm the performance of the proposed measurement system. The current version of respiratory rate detection system using ultrasonic can successfully measure respiration rate. The proposed measurement method could be used for monitoring unconscious persons from a relatively close range, avoiding the need to apply electrodes or other sensors in the correct position and to wire the subject to the monitor. Monitoring respiration using ultrasonic sensor offers a promising possibility of non-contact measurement of respiration rates. Especially, this technology offers a potentially inexpensive implementation that could extend applications to consumer home-healthcare and mobile-healthcare products. Further advances in the sensor design, system design and signal processing can increase the range of the measurement and quality of the rate-finding for broadening the potential application areas of this technology.

Development of Operational Technology and Integrated Measurement Information Management System for the Radioactivity Measurement Device (방사능 측정장치 운영 기술 및 측정정보 통합관리 시스템 개발)

  • Dong-Sik Jin;Kyeong-Ryeong Kim;Jae-Geun Lee
    • Journal of radiological science and technology
    • /
    • v.47 no.3
    • /
    • pp.183-195
    • /
    • 2024
  • Additional functional upgrades to the large-area compton camera (LACC) measurement device that can provide characteristics evaluation information (nuclear species and radioactivity) and two-dimensional or three-dimensional distribution imaging information of radioactive materials existing in surface or internal of concrete structures are required in terms of work stability and efficiency in order to apply to actual decommissioning sites such as nuclear power plants or medical cyclotron facilities by using this measurement device. To this purpose, the technology that allows radiation workers to intuitively and visually check the distribution of radioactive materials in advance by matching the two-dimensional distribution imaging information of radioactive materials obtained through the LACC measurement device and visual imaging of the measurement zone (10 m × 5 m) was developed. In addition, the separate system that can automatically adjust the position (height) in units of the measurement area size (0.7 m × 0.3 m × 0.8 m) of the LACC measurement device was developed and the integrated management system for characteristics evaluation information and two-dimensional or three-dimensional distribution imaging information obtained per unit of measurement for radioactive materials was developed. These functional upgrades related to LACC measurement device can improve work efficiency and safety when measuring radioactivity of concrete structures and enable the establishment of appropriate decommissioning strategies using radioactivity measurement information for decommissioning nuclear power plants or medical cyclotron facilities.