• 한국안전학회지
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• 제30권6호
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• pp.110-116
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• 2015

A 3D camera-based on-site work-related musculoskeletal disorder risk assessment(WMDs) tool has been developed. The device consists of Kinect a 3D camera manufactured by Microsoft, a servo-motor, and a mobile robot. To complement inherent narrow field of view(FOV) of Kinect, Kinect is rotated according to PID servo-control algorithm by a servo-motor attached underneath, to track movement of a subject, producing skeleton-based motion data. With servo-control, full 360 degrees tracking of a test subject is possible by single Kinect. It was found from experimental tests that the proposed device can be successfully employed for on-site WMDs risk assessing tool.

• 한국정밀공학회지
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• 제27권9호
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• pp.43-51
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• 2010

Speed, accuracy and smoothness are the important properties of pan-tilt camera. In the case of a high ratio zoom lens system, low vibration characteristic is a crucial point in driving pan-tilt mechanism. In this paper, a novel micro-stepping controller with a function of reducing vibration was designed using field programmable gate arrays (FPGA) technology for high zoom ratio pan-tilt camera. The proposed variable reference current (VRC) control scheme reduces vibration decently and optimizing coil current in order to prevent the step motor from occurring missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378kpps micro-step driving, and increase maximum acceleration in motion profiles.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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• pp.55-62
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• 1998

This paper presents a method of controlling camera to present virtual space to participating users meaningfully. The users interact with each other by means of dialogue and behavior. Users behave through their avatars. So our problem comes down to controlling the camera to capture the avatars effectively depending on how they interact with each other. The problem is solved by specifying camera control rules based on cinematography developed by film producers. A formal language is designed to encode cinematography rules for virtual environments where people can participate in the story and can influence its flow. The rule has been used in a 3D chatting system we have developed.

• 제어로봇시스템학회논문지
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• 제12권9호
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• pp.856-860
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• 2006

A CCD camera is used to determine the position of the point sources that influence the measurement accuracy in the absolute interferometer. The principle of determination method is based on the GPS in which the position is determined by more than 3 distance information from the known positions. Two-dimensional array of photo-detectors in the CCD camera is used as known positions. Performing optimization of the cost function constructed with phase values measured at each pixel on the CCD camera, the position coordinates of each source is precisely determined.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.1001-1008
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• 2001

This paper presents a new camera calibration algorithm for ill-conditioned cases in which the camera plane is nearly parallel to a set of non-coplanar calibration boards. for the ill-conditioned case, most of existing calibration approaches such as Tsais radial-alignment-constraint method cannot be applied. Recently, for the ill-conditioned coplanar calibration Lee&Lee[16] proposed an iterative algorithm based on the least square method. The non-coplanar calibration algorithm presented in this paper is an iterative two-stage procedure with extends the previous coplanar calibration algorithm. Through the first stage, camera, position and orientation parameters as well as one radial distortion factor are determined optimally for a given data of the scale factor and the focal length. In the second stage, the scale factor and the focal length are locally optimized. This process is repeated until any improvement cannot be expected any more Computational results are provided to show the performance of the algorithm developed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1617-1620
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• 1997

This paper describes the camera caliberation based-neural network with a camera modeling that accounts for major sources of camera distortion, namely, radial, decentering, and thin prism distortion. Radial distoriton causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering, that is the optical centers of lens elements are not strictly collinear. Thin prism distortion arises from imperfection in lens design and manufacturing as well as camera assembly. It is our purpose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing. The performance of proposed camera aclibration is illustrated by simulation and experiment.

• 로봇학회논문지
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• 제11권1호
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• pp.33-40
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• 2016

In this paper, we propose a method for estimating the pose of the camera using a rectangle feature utilized for the visual SLAM. A warped rectangle feature as a quadrilateral in the image by the perspective transformation is reconstructed by the Coupled Line Camera algorithm. In order to fully reconstruct a rectangle in the real world coordinate, the distance between the features and the camera is needed. The distance in the real world coordinate can be measured by using a stereo camera. Using properties of the line camera, the physical size of the rectangle feature can be induced from the distance. The correspondence between the quadrilateral in the image and the rectangle in the real world coordinate can restore the relative pose between the camera and the feature through obtaining the homography. In order to evaluate the performance, we analyzed the result of proposed method with its reference pose in Gazebo robot simulator.

• 대한치과마취과학회지
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• 제12권1호
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• pp.33-37
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• 2012

Dental treatment under general anesthesia is considered a good way for behavioral control in disabled patients. General anesthesia for disabled patients sometimes requires difficult airway management. In this case, intra-oral camera is great helpful to intubation. Originally, the intra-oral camera is designed to facilitate diagnosis dental disease. The intra-oral camera is very efficient on intubation. Laryngeal photo taken by Intra-oral camera can be good guide for difficult intubation. In this report, an 11-year-old boy with chromosomal anomaly received dental care under general anesthesia. And he had a potentially difficult airway. We achieved nasotracheal intubation successfully with intra-oral camera.

• 센서학회지
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• 제23권1호
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• pp.66-71
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• 2014

Vision is the most important sensing capability for both men and sensory smart machines, such as intelligent robots. Sensed real 3D world and its 2D camera image can be related mathematically by a process called camera calibration. In this paper, we present a novel linear solution of camera calibration. Unlike most existing linear calibration methods, the proposed technique of this paper can identify camera parameters explicitly. Through the step-by-step procedure of the proposed method, the real physical elements of the perspective projection transformation matrix between 3D points and the corresponding 2D image points can be identified. This explicit solution will be useful for many practical 3D sensing applications including robotics. We verified the proposed method by using various cameras of different conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.440-440
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• 2000

In general, camera calibration is consisted of Indoor and Outdoor system. In case of Indoor system, it was optimized experimental condition. However, Outdoor system is different camera parameters for each image that is compared to equaled position. That is, it imply that camera parameters are varied by an environment with light or impulse noise, etc. So we make use of Image sequence because that they provide the more information for each image. In addition to, we use Corresponding line because it has less error than Corresponding point. Corresponding line has also the more information. In this paper, we suggest on-line camera calibration method using the time-varying Image sequence and Corresponding line. So we calculate camera parameters with intrinsic and extrinsic parameters in On-line system.