• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3188-3198
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• 2024

Efficient and secure decommissioning of nuclear facilities demands advanced technologies. In this context, gamma-ray detection and imaging are crucial in identifying radioactive hotspots and monitoring radiation levels. Our study is dedicated to developing a gamma-ray detection system tailored for integration into robotic platforms for nuclear decommissioning, offering a safe and automated solution for this intricate task and ensuring the safety of human operators by mitigating radiation exposure and streamlining hotspot localization. Our approach integrates a Compton camera based 3D reconstruction algorithm with a single Timepix3 detector. This eliminates the need for a second detector and significantly reduces system weight and cost. Additionally, combining a 3D camera with the setup enhances hotspot visualization and interpretation, rendering it an ideal solution for practical nuclear decommissioning applications. In a proof-of-concept measurement utilizing a 137Cs source, our system accurately localized and visualized the source in 3D with an angular error of 1° and estimated the activity with a 3% relative error. This promising result underscores the system's potential for deployment in real-world decommissioning settings. Future endeavors will expand the technology's applications in authentic decommissioning scenarios and optimize its integration with robotic platforms. The outcomes of our study contribute to heightened safety and accuracy for nuclear decommissioning works through the advancement of cost-effective and efficient gamma-ray detection systems.

• 천문학논총
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• 제30권2호
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• pp.683-685
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• 2015

A group of universities have come together with the aim of designing and developing Small Aperture Robotic Telescopes (SmART) for use by students to observe variable stars and transient follow-ups. The group is deliberating on the components of the robotic system; e.g. the telescope, the mount, the back-end camera, control software, and their integration keeping in mind the scientific objectives. The prototype might then be replicated by all the participating universities to provide round the clock observations from sites spread evenly in longitude across the globe. Progress made so far is reported in this paper.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.314-319
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• 2002

The Automation and Control Group at the University of Brasilia is developing an automatic welding station based on an industrial robot and a controllable welding machine. Several techniques were applied in order to improve the quality of the welding joints. This paper deals with the implementation of a laser-based computer vision system to guide the robotic manipulator during the welding process. Currently the robot is taught to follow a prescribed trajectory which is recorded a repeated over and over relying on the repeatability specification from the robot manufacturer. The objective of the computer vision system is monitoring the actual trajectory followed by the welding torch and to evaluate deviations from the desired trajectory. The position errors then being transfer to a control algorithm in order to actuate the robotic manipulator and cancel the trajectory errors. The computer vision systems consists of a CCD camera attached to the welding torch, a laser emitting diode circuit, a PC computer-based frame grabber card, and a computer vision algorithm. The laser circuit establishes a sharp luminous reference line which images are captured through the video camera. The raw image data is then digitized and stored in the frame grabber card for further processing using specifically written algorithms. These image-processing algorithms give the actual welding path, the relative position between the pieces and the required corrections. Two case studies are considered: the first is the joining of two flat metal pieces; and the second is concerned with joining a cylindrical-shape piece to a flat surface. An implementation of this computer vision system using parallel computer processing is being studied.

• 한국광학회지
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• 제26권1호
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• pp.44-53
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• 2015

현재의 이미지 센서기술은 메가픽셀 급에 한정되어 있는데 메가픽셀 급의 이미지 센서로 기가픽셀의 이미지를 생성하기 위해서는 필수적으로 중첩영역의 이미지를 하나로 합성하는 스티칭(stitching) 기법을 쓸 수밖에 없다. 본 논문에서는 로봇파노라마헤드와 스티칭 기법을 사용하여 기가픽셀카메라 기술의 전 과정을 탐구해 보았다. 그리고 이 과정을 통해서 얻어진 경험이나 이해를 바탕으로 듀크대와 BAE의 기가픽셀카메라 기술에 대해서도 설계해석을 시도해 보았다. 또 나아가, 새로운 기가픽셀카메라의 광학구조에 대한 모색도 시도해 보았다. 기가픽셀카메라 기술에서는 스티칭 작업과는 별도로 먼거리의 피사체 혹은 대기오염과 같은 원인으로 발생하는 흐릿한 영상부분을 보정하는 것이 필수적이라는 것도 파악되었다.

• 로봇학회논문지
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• 제6권3호
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• pp.210-219
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• 2011

This paper studies how to combine devices such as monocular/stereo cameras, motors for panning/tilting, fisheye lens and convex mirrors, in order to solve vision-based robotic problems. To overcome the well-known trade-offs between optical properties, we present two mixed versions of the new systems. The first system is the robot photographer with a conventional pan/tilt perspective camera and fisheye lens. The second system is the omnidirectional detector for a complete 360-degree field-of-view surveillance system. We build an original device that combines a stereo-catadioptric camera and a pan/tilt stereo-perspective camera, and also apply it in the real environment. Compared to the previous systems, we show benefits of two proposed systems in aspects of maintaining both high-speed and high resolution with collaborative moving cameras and having enormous search space with hybrid configuration. The experimental results are provided to show the effectiveness of the mixing collaborative and hybrid systems.

• Advances in robotics research
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• 제1권1호
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• pp.81-99
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• 2014

This paper contributes towards the development of a computer vision system for telemonitoring of industrial articulated robotic arms. The system aims to provide precision real time measurements of the joint angles by employing low cost cameras and visual markers on the body of the robot. To achieve this, a mathematical model that connects image features and joint angles was developed covering rotation of a single joint whose axis is parallel to the visual projection plane. The feature that is examined during image processing is the varying area of given circular target placed on the body of the robot, as registered by the camera during rotation of the arm. In order to distinguish between rotation directions four targets were used placed every $90^{\circ}$ and observed by two cameras at suitable angular distances. The results were deemed acceptable considering camera cost and lighting conditions of the workspace. A computational error analysis explored how deviations from the ideal camera positions affect the measurements and led to appropriate correction. The method is deemed to be extensible to multiple joint motion of a known kinematic chain.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.65-68
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• 1999

In this study, an off-line automatic teaching method using vision information for robotic assembly task is proposed. Many of industrial robots are still taught and programmed by a teaching pendant. The robot is guided by a human operator to the desired application locations. These motions are recorded and are later edited, within the robotic language using in the robot controller, and played back repetitively to perform the robot task. This conventional teaching method is time-consuming and somewhat dangerous. In the proposed method, the operator teaches the desired locations on the image acquired through CCD camera mounted on the robot hand. The robotic language program is automatically generated and transferred to the robot controller. This teaching process is implemented through an off-line programming(OLP) software. The OLP is developed for the robotic assembly system used in this study. In order to transform the location on image coordinates into robot coordinates, a calibration process is established. The proposed teaching method is implemented and evaluated on the assembly system for soldering electronic parts on a circuit board. A six-axis articulated robot executes assembly task according to the off-line automatic teaching.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.211-220
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• 2000

Korea Astronomy Observatory(KAO) is working to retrofit its 1m robotic telescope in collaboration with a company (ACE, Astronomical Consultants & Equipment). The telescope system is being totally refurbished to make a fully automatic telescope which can operate in both interactive and fully autonomous robotic modes. Progress has been made in design and manufacturing of the telescope mount, mechanics, and optical performance system tests are being made for re-configured primary and secondary mirrors. The optical system is designed to collect 80% incident light within 0.5 arcsec with f/7.5 Ritchey-Chretien design. The telescope mount is an equatorial fork with a friction drive system. The design allows fully programmable tracking speeds with typical range of 15 arcsec/sec with accuracy of $\pm5$ arcsec/hour. The mount system has integral pointing model software to correct for refraction, and all mechanical errors and misalignments. The pointing model will permit positioning to better than 30 arcsec RMS within $75^{\circ}$ from zenith and 45 arcsec RMS elsewhere on the sky. The software is designed for interactive, remote and robotic modes of operation. In interactive and remote mode the user can manually enter coordinates or retrieve them from a computer file. In robotic mode the telescope controller downloads the coordinates in the order determined by the scheduler. The telescope will be equipped with a CCD camera and will be accessible via the internet.

• International Journal of Control, Automation, and Systems
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• 제6권5호
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• pp.740-745
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• 2008

This paper presents a new non-contact 3D robotic inspection system to measure the precise positions of screw and punch holes on a car body frame. The newly developed sensor consists of a CCD camera, two laser line generators and LED light. This lightweight sensor can be mounted on an industrial robot hand. An inspection algorithm and system that work with this sensor is presented. In performance evaluation tests, the measurement accuracy of this inspection system was about 200 ${\mu}m$, which is a sufficient accuracy in the automotive industry.

• 한국CDE학회논문집
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• 제16권6호
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• pp.437-448
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• 2011

A robotic spatial augmented reality (RSAR) system combines a robotics technology with a spatial augmented reality system (SAR) where cameras are used to recognize real objects and projectors augment information and user interface directly on the surface of the recognized objects, rather than relying on handheld display devices. Moreover, a robotic module is actively used to discover and utilize the context of users and environments. The control of a RSAR system involves several issues from different technical fields such as classical inverse kinematics of motors where projector-camera pairs are mounted, inverse projection problems to find appropriate internal/external parameters of projectors and cameras, and image warping in graphics pipeline to compensate the kinematic constraints. In this paper, we investigate various control issues related to a RSAR system and propose basic approaches to handle them, specially focused on the prototype RSAR system developed in ETRI.