• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.123-131
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• 2014

An INS/vision integrated navigation algorithm is proposed for environments with insufficient number of landmarks. In the proposed algorithm, the raw measurements on the focal plane are directly used in order to cope with the situation where the number of landmarks are not sufficient. In addition to this, the combination of landmarks, which has smallest value of DOP, is used in the update of measurement in order to improve navigation performance. In order to evaluate the performance of the proposed integrated navigation system, Monte-Carlo simulation and van test was performed. The results of the simulation and experiment show that the proposed navigation system gives better navigation performance than an INS/vision integrated navigation system which does not use the raw measurements on the focal plane and the navigation system provides navigation solutions even in environments with insufficient number of landmarks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1813-1819
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• 2011

In this research, the location positioning system supposed is concerned with range recognition technology using phase and magnitude of radio wave and adding technology of image histogram by vision. By the proposed technology, we design the radio transmitter and receiver and realize the measurement system, and save the data in disk that is earned from 900Mhz RF signal, middle frequency 450Khz of analog signal. Range information is earned the data through digital signal processing of IF signal. For the estimation of range measured, we analyze the difference between real range and measurement range, and also suggest the method to improve the measurement error using average processing and amplitude properties.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.4
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• pp.301-308
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• 2016

In this study, a novel method referred as non-marker vision-based displacement measuring system(NVDMS) was introduced in order to measure the displacement of structure. There are two distinct differences between proposed NVDMS and existing vision-based displacement measuring system(VDMS). First, the NVDMS extracts the pixel coordinates of the structure using a feature point not a marker. Second, in the NVDMS, the scaling factor in order to convert the coordinates of a feature points from pixel value to physical value can be calculated by using the external conditions between the camera and the structure, which are distance, angle, and focal length, while the scaling factor for VDMS can be calculated by using the geometry of marker. The free vibration test using the three-stories scale model was conducted in order to analyze the reliability of the displacement data obtained from the NVDMS by comparing the reference data obtained from laser displacement sensor(LDS), and the measurement of dynamic characteristics was proceed using the displacement data. The NVDMS can accurately measure the dynamic displacement of the structure without the marker, and the high reliability of the dynamic characteristics obtained from the NVDMS are secured.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.605-613
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• 2009

In this paper, we studied for the real-time azimuthal measurement of HMD (Head Mounted Display) to control the tele-operated vision system on the mobile robot. In the preexistence tele-operated vision system, a joystick was used to control the pan-tilt unit of the remote camera system. To give the sense of presence to the tele-operator, we used a HMD to display the remote scene, measured the rotation angle of the HMD on a real time basis, and transmitted the measured rotation angles to the mobile robot controller to synchronize the pan-tilt angles of remote camera with the HMD. In this paper, we suggest an algorithm for the real-time estimation of the HMD rotation angles using feature points extraction from pc-camera image. The simple experiment is conducted to demonstrate the feasibility.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.258-266
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• 2014

We present a system for the real-time visual relative navigation of a fixed-wing unmanned aerial vehicle in a GPS-denied environment. An extended Kalman filter is used to construct a vision-aided navigation system by fusing the image processing results with barometer and inertial sensor measurements. Using a mean-shift object tracking algorithm, an onboard vision system provides pixel measurements to the navigation filter. The filter is slightly modified to deal with delayed measurements from the vision system. The image processing algorithm and the navigation filter are verified by flight tests. The results show that the proposed aerial system is able to maintain circling around a target without using GPS data.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.49-65
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• 2004

The purpose of this study is development of posture evaluation and Range of Motion(ROM) system by using digital vision analysis method. The results of this study are as follows. First, Scoliosis evaluation through this research measurement system represent 3mm error in 7 cervical point and deepest lumbar point, 0.7mm error in other point. This mean this research measurement system have a reliability for scoliosis evaluation. Second, for spine line evaluation on high fat subject, we need reconstrection spine line after measurement for fat thickness in 7 cervical point and deepest lumbar point. Third, In pedioscope error test, it present 0.01848cm in X axis and 0.01757cm in Y axis. This results mean pedioscope have a reliability foot evaluation. Forth, Posture evaluation and Range of Motion measurement system by using digital vision analysis method can fast measure in range of motion and foot evaluation and posture. therefore we can expect this system application in young people posture clinic center and hospital and so on.

• 한국가시화정보학회:학술대회논문집
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• 2006.12a
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• pp.1-6
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• 2006

Single-Camera Stereoscopic Vision three-dimensional measurement system has been developed based upon 30-PTV algorithm. The system consists of one camera $(1k\times1k)$ and a host computer. To attain three-dimensional measurements a plate having stereo holes has been installed inside of the lens system. Three-dimensional measurements was successfully attained by adopting the conventional 30-PTV camera calibration methods. As applications of the constructed measurement system, a water droplet mixed with alcohol was constructed on a transparent plastic plate with the contacted fluid diameter 4mm, and the particles motions inside of the droplet have been investigated with the constructed measurement system. The measurement uncertainty of the constructed system was 0.04mm, 0.04mm and 0.09mm for X, Y and Z coordinates.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.409-415
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• 2022

In computer vision, an image of a measurement target is acquired using a camera. And feature values, vectors, and regions are detected by applying algorithms and library functions. The detected data is calculated and analyzed in various forms depending on the purpose of use. Computer vision is being used in various places, especially in the field of automatically recognizing automobile parts or measuring the quality. Computer vision is being used as the term machine vision in the industrial field, and it is connected with artificial intelligence to judge product quality or predict results. In this study, a vision system for judging the quality of automobile parts was built, and the results were compared by applying five machine learning classification models to the produced data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.255-258
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• 1995

Surface profile is an important paramerer to evaluate accuracy of machined worpiece. It is necessary to acquire this data by in-process measurement. Recent researchers have introduced Machine Vision technique to achieve it. But it is difficult to apply it to industry field yet. In this study, in-process measuring system of surface profile is developed using CCD camera. The effect of illuminance according to incident angle is investigated and surface profile from surface tester and illuminance graph are compared experimentally.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.14-21
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• 2006