• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.276-276
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• 2000

This paper presents the efficient algorithms for the pose determination of a circular object with and without a priori knowledge of the object radius. The developed algorithms valid for a circular object are the result of the elaboration of Ma's work [2], which determines the pose of a conic object from two perspective views. First, the geometric constraint of a circular object and its projection on the image plane of a camera is described. The number of perspective views required for the object pose determination with and without a priori knowledge of the object radius is also discussed. Second, with a priori knowledge of the object radius, the pose of a circular object is determined from a single perspective view. The object pose information, expressed by two surface normal vectors and one position vector, is given in a closed form and with no ambiguity. Third, without a priori knowledge of the object radius, the pose of a circular object is determined from two perspective views. While the surface normal vectors are obtained from the first view, the position vector is obtained from the two views.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.125-131
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• 1999

In this paper, the algorithms which can track the two dimensional moving circular object using simple vision system are described. In order to track the moving object, the process of finding the object feature points - such as centroid of the object, corner points, area - is indispensable. With the assumption of two-dimensional circular moving object, the centroid of the circular object is computed from three points on the object circumference. Different kinds of algorithms for computing three edge points - simple x directional detection method, stick method. T-shape method are suggested. Through the computer simulation and experiments, three algorithms are compared from the viewpoint of detection accuracy and computational time efficiency.

• Spatial Information Research
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• v.20 no.2
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• pp.165-172
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• 2012

The query of the K closest object pairs between two object sets frequently occurs at recently retrieval systems. The circular location property of objects should be considered for efficiently process queries finding such a K nearest object pair. In this paper, we propose the optimal algorithm finding the K object pairs which are closest to each other in a search space with a circular domain and show its performance by experiments. The proposed algorithm optimizes the cost of finding the K nearest object pairs by using the circular search distances which is much applied the circular location property.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.5-8
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• 2000

In this paper, a technique to estimate the circular object's center and radius under noisy condition is described. The technique is based on Davies'Hough transform approach to circular object location but more robust to noise and faster to estimate the circle by using an area of cumulated points.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.905-910
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• 2008

In this paper, a circular motion table which is able to simulate movement of object is designed and the experiment of control system using circular motion table is presented. Circular motion table is consisted of three axes changed on length and of ball splines which keep vertical centre axis of circular plate. Variable length of three axes make circular plate incline as vertical centre axis is kept on vertical center axis of circular motion table. It is designed that control system drives three servo motor, that is, make change length of axis simultaneously or independently. And this paper presents example of flight simulation using circular motion table. it will contribute toward nurture expert manpower of aerospace/robotics to popularize circular motion table and make an experiment using it.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.819-822
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• 2007

In this paper, we propose an object-tracking of mobile robots using CHT(Circular Hough transform) algorithm. The proposed method extracts the region of moving objects using 1-D projection algorithm, and detects circular objects using CHT. In order to verify the effectiveness of the proposed tracking method, we perform experiments of ball shape object-tracking using mobile robot based on ARM processor with CMOS camera.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.85-88
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• 2009

In multimedia database systems, the nearest neighbor Query occurs frequently and requires the processing cost higher than other spatial Queries do. It needs the measurement of search distance that the number of searched nodes and the computation time in an index can be minimized for optimizing the cost of processing the nearest neighbor query. The circular location property of objects is considered to accurately select the nodes which will be searched in the nearest neighbor query. In this paper, we propose the processing method of nearest neighbor queries be considered a circular location property of object where the search space consists of a circular domain and show its characteristics. The proposed method uses the circular minimum distance and the circular optimal distance, the search measurement for optimizing the processing cost of nearest neighbor queries.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.933-938
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• 1990

A method of recognizing 2-dimensional polygonal object is proposed by using a concept of generalized incremental circle transform. The generalized incremental circle transform, which maps boundaries of an object into a circular disc, represents efficiently the shape of the boundaries that are obtained from digirized binary images of the objects. It is proved that the generalized incremental circle transform of an object is invariant to object translation, rotation, and size, and can be used as feature information for recognizing two dimensional polygonal object efficiently.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.78-84
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• 2008

This paper presents a fast modeling technique of virtual pottery using force feedback based on a circular sector element method. Previous techniques for simulating deformable objects such as finite element method (FEM) are limited in real-time haptic rendering due to their complexity and expensive computational cost. In our model, circular sector elements which fully represent features of pottery's shape are closely gathered and piled together. This allows efficient deformable object modeling through a decrease in the number of elements and reducing computational cost.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.13-24
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• 2011

This paper deals with a 3D-pose (orientation and position) estimation problem of a circular object in 3D-space. Circular features can be found with many objects in real world, and provide crucial cues in vision-based object recognition and location. In general, as a circular feature in 3D space is perspectively projected when imaged by a camera, it is difficult to recover fully three-dimensional orientation and position parameters from the projected curve information. This paper therefore proposes a 3D pose estimation method of a circular feature using a coplanar point. We first interpret a circular feature with a coplanar point in both the projective space and 3D space. A procedure for estimating 3D orientation/position parameters is then described. The proposed method is verified by a numerical example, and evaluated by a series of experiments for analyzing accuracy and sensitivity.