• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1994-1998
• /
• 2005

Characteristic analysis of the depth measurement system with a laser, a camera and a rotating mirror has been done and the parameter calibration technique for it has been proposed. In the proposed depth measurement system, the laser beam is reflected to the object by the rotating mirror and again the position of the laser beam is observed through the same mirror by the camera. The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD. There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance. The calibration techniques to minimize the effect of such major parameters are proposed.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.12
• /
• pp.69-76
• /
• 1998

This paper proposes a matrix which represents the confidence in the rotation components of the Iterative Closest Point (ICP) algorithm is image registratiion, The reliability of the ICP algorithm depends on the shape of the object. For example, an object with more complex features shows higher reliablility than the one with rotation symmetry such as a cylinder. We show that the reliablity of the ICP algorithm can be estimated when the input range data has additive noise. Finally, we demonstrate that the proposed reliability formula is in good agreement with the computer simulation.

• International Journal of CAD/CAM
• /
• v.3 no.1_2
• /
• pp.85-95
• /
• 2003

During the design of dies and molds, the cavity of the object is obtained by subtracting it from a surrounding rectangular block. This box is subsequently split into two halves by the parting surface. Similar problems also occur in some RP processes such as LOM, SGC, SLS and 3DP where the machine produces a block inside which the prototype is buried. Determining the orientation of the object inside the box and the corresponding parting surface taking appropriate constraints into account have been addressed by several researchers. However, given the parting surface, the problem of splitting the box development of a software package called OptiLOM (now a module of an RP software Magics 8.0), the authors realized non-triviality of this problem since the loop can spread over as many as 5 faces of the box. In this paper, the authors have tried to bring out the importance of this problem and have presented their algorithm to solve it.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.1
• /
• pp.15-24
• /
• 1996

This paper presents a new method for visual servoing to control the pose(position and orientation) of the robotic manipulators for grasping the 3-D moving object whose initial pose and moving informations are unknown by using the stereo camera. The stereo camera is mounted on the end-effector of robotic manipulator. In order to track the current pose of robotic manipulator to the desired pose, we use the image Jacobian, which is described by the differential transform, relating the change in image feature point to the change in the object's pose with respect to the camera. In this paper the simple PD controller is adopted for the robotic manipulator to track the desired pose. Finally, the effectiveness of the proposed method is confirmed by some computer simulations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.4
• /
• pp.865-870
• /
• 2005

The latest Global Positioning System, wireless communications technology and Location-Based Service bring about the rapid developments of telematics application areas. In the moving object database for telematics, it is very important to deal with database queries related to the real time current positions of a moving objects and the valid tine of the query results as well. In this paper, we propose how to get not only the current result of query but also the valid time and the result after the valid time when a query point and objects are moving simultaneously. We would like to predict the valid time by formula because the current results will be incorrect due to the characteristic of the continuous movements of the moving objects and the future results can not be calculated by iterative computations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.05a
• /
• pp.125-129
• /
• 2006

The analysis of the depth measurement system with multi-sensors (laser, camera, mirror) has been done and the parameter calibration technique has been proposed. In the proposed depth measurement system, the laser beam is reflected to the object by the rotating mirror and again the position of the laser beam is observed through the same mirror by the camera. The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD. There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.9
• /
• pp.539-546
• /
• 2005

This paper describes a method of building the probability grid map for an autonomous mobile robot using the ultrasonic DAF(data association filter). The DAF, which evaluates the association of each data with the rest and removes the data affected by the specular reflection effect, can improve the reliability of the data for the Probability grid map. This method is based on the evaluation of possibility that the acquired data are all from the same object. Namely, the data from specular reflection have very few possibilities of detecting the same object, so that they are excluded from the data cluster during the process of the DAF. Therefore, the uncertain data corrupted by the specular reflection and/or multi-path effect, are not used to update the probability map, and hence building a good quality of a grid map is possible even in a specular environment. In order to verify the effectiveness of the DAF, it was applied to the Bayesian model and the orientation probability model which are the typical ones of a grid map. We demonstrate the experimental results using a real mobile robot in the real world.

• KIPS Transactions on Software and Data Engineering
• /
• v.8 no.2
• /
• pp.61-66
• /
• 2019

Augmented reality is a technology that makes a virtual object appear as if it exists in reality by composing a virtual object in real time with the image captured by the camera. In order to augment the virtual object on the object existing in reality, the homography of images utilized to estimate the position and orientation of the object. The homography can be estimated by applying the RANSAC algorithm to the feature points of the images. But the homography estimation method using the RANSAC algorithm has a problem that accurate homography can not be estimated when there are many feature points in the background. In this paper, we propose a method to filter feature points of a background when the object is near and the background is relatively far away. First, we classified the depth image into relatively near region and a distant region using the Otsu's method and improve homography estimation performance by filtering feature points on the relatively distant area. As a result of experiment, processing time is shortened 71.7% compared to a conventional homography estimation method, and the number of iterations of the RANSAC algorithm was reduced 69.4%, and Inlier rate was increased 16.9%.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.1
• /
• pp.210-216
• /
• 2014

The edge in the image is a part which the brightness changes rapidly between the object and the object or objects and background, and includes information of the features such as size, position, orientation, and texture of the object. The edge detection is the technique that acquires these information of the images, and now the researches to detect edges are making steady progress. Typical conventional edge detection methods are Sobel, Prewitt, Roberts using the first derivative operator and Laplacian method using the second derivative operator and so on. These methods is more or less insufficient that the characteristics of the edge detection in the image added salt and pepper noise. therefore, in this paper, an edge detection algorithm using modified mask that applies different size mask according to noise density of local mask is proposed.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1444-1447
• /
• 2004

The vacuum-cleaner had made the burden of house chore lighten but the operation labour of a vacuum-cleaner had been so severe. Recently, the cleaning robot was producted to perfectly solve the cleaning labour of a house but it also was not successful because it still had a problem of mess-cleaning, which is the clean-up of big trash and the arrangement of newspapers, clothes, etc. The cleaning robot is to just vacuum dust and small trash and has no function to arrange and take away before the automatic vacuum-cleaning. For this reason, the market for the cleaning robot is not yet built up. So, we need a design method and technological algorithm of new automatic machine to solve the problem of mess-cleanup in house. In this paper, a Home Mess-Cleanup Robot(HMR), which has a practical function of the automatic mess-cleanup, is developed. It need functions of agile automatic navigation, novel manipulation system for mess-cleanup. The automatic navigation system has to be controlled for the full scanning of living room, to recognize the absolute position and orientation of the self, the precise tracking of the desired path, and to distinguish the mess object to clean-up from obstacle object to just avoid. The manipulation system, which is not needed in the vacuum-cleaning robot, must have the functions, how to distinguish big trash to clean from mess objects to arrange, how to grasp in according to the form of mess objects, how to move to the destination in according to mess objects and arrange them. Then, it should be an intelligent system so that the mess cleaning task can be autonomously performed in a wide variety of situations and environments. It need to also has the entertainment functions for the good communication between the human and HMR. Therefore, the Home Mess-cleanup Robot with Entertainmental Human Interface is developed in this paper. Finally, the good performance of the designed machine, HMR'4, is confirmed through the results of the mess clean-up and arrangement.