• 한국군사과학기술학회지
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• 제18권3호
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• pp.226-233
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• 2015

Pose estimation is an important operation for many vision tasks. This paper presents a method of estimating the camera pose, using a known landmark for the purpose of autonomous vertical takeoff and landing(VTOL) unmanned aerial vehicle(UAV) landing. The proposed method uses a distinctive methodology to solve the pose estimation problem. We propose to combine extrinsic parameters from known and unknown 3-D(three-dimensional) feature points, and inertial estimation of camera 6-DOF(Degree Of Freedom) into one linear inhomogeneous equation. This allows us to use singular value decomposition(SVD) to neatly solve the given optimization problem. We present experimental results that demonstrate the ability of the proposed method to estimate camera 6DOF with the ease of implementation.

• 센서학회지
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• 제25권4호
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• pp.285-290
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• 2016

Human sensing is an important but challenging technology. Unlike other methods for sensing humans, a vision sensor has many advantages, and there has been active research in automatic human detection in camera images. The combination of Histogram of Oriented Gradients (HOG) and Support Vector Machine (SVM) is currently one of the most successful methods in vision-based human detection. However, extracting HOG features from an image is computer intensive, and it is thus hard to employ the HOG method in real-time processing applications. This paper describes an efficient solution to this speed problem of the HOG method. Our method obtains edge information of an image and finds candidate regions where humans very likely exist based on the distribution pattern of the detected edge points. The HOG features are then extracted only from the candidate image regions. Since complex HOG processing is adaptively done by the guidance of the simpler edge detection step, human detection can be performed quickly. Experimental results show that the proposed method is effective in various images.

• 반도체디스플레이기술학회지
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• 제20권2호
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• pp.126-130
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• 2021

The ball grid array is one of the packaging methods that used in high density printed circuit board. Solder void defects caused by voids in the solder ball during the BGA process do not directly affect the reliability of the product, but it may accelerate the aging of the device on the PCB layer or interface surface depending on its size or location. Void inspection is important because it is related in yields with products. The most important process in the optical inspection of solder void is the segmentation process of solder and void. However, there are several segmentation algorithms for the vision inspection, it is impossible to inspect all of images ideally. When X-Ray images with poor contrast and high level of noise become difficult to perform image processing for vision inspection in terms of software programming. This paper suggests the solution to deal with the suggested problem by means of using Mask R-CNN instead of digital image processing algorithm. Mask R-CNN model can be trained with images pre-processed to increase contrast or alleviate noises. With this process, it provides more efficient system about complex object segmentation than conventional system.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2012년도 춘계학술발표대회논문집
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• pp.211-214
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• 2012

스트레스는 다양한 질병의 원인이 되며 스트레스의 해소는 질병 예방에 중요한 요인이라 할 수 있을 것이다. 스트레스를 해소시키는 방법 중 한 가지는 청각이나 시각을 이용하는 방법이다. 청각과 시각을 동시에 이용할 수 있다면 그 효과를 극대화 할 수 있을 것이다. 본 논문에서는 음악의 분위기를 자동으로 파악하고, 파악한 음악의 분위기를 표현할 수 있는 음악감성 조명기용 임베디드 리눅스 기반 필드 시스템을 제안하였다. 본 논문에서 제시한 필드서버를 감성조명과 함께 공원이나 가정집 등에 제공할 수 있을 것이고, 음악과 조명을 동시에 제공함으로 현대인 질병의 원인이라 할 수 있는 스트레스 해소가 가능할 것이다. 또한 본 논문의 시스템을 이용하여 임상실험을 실시하여 임상데이터를 확보한다면 심리 치료를 목적으로 하는 의학적 도구로 발전 할 수 있을 것으로 보인다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.289-292
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• 2013

본 논문은 SVM(Support Vector Machine) 학습알고리즘을 이용하여 자동차 썬루프 장치의 볼트 유무를 검사하는 자동차 부품 검사 장비에 관한 것이다. 자동화 시스템은 높은 정밀도와 생산성을 위한 빠른 처리 속도를 요구한다. 이를 위해 본 논문에서는 선형 SVM 학습알고리즘을 활용하여 자동차 썬루프 장치의 볼트 유무를 검사하는 알고리즘을 개발하였다. SVM 알고리즘은 분류를 위한 알고리즘이지만 ROI(Region-Of-Interest) 내의 모든 윈도우에 대한 분류를 수행하여 검출기 역할을 할 수 있도록 한다. 볼트가 있는 경우와 볼트가 없는 경우가 아닌 네거티브 샘플을 확보하기 위해 검출 대상 물체 주변에서 다양한 네거티브 샘플들을 추출한다. 그 결과 물체가 예상 위치에서 다소 빗나가는 경우에도 볼트 유무를 판별할 수 있을 뿐 아니라 볼트의 위치까지 검출할 수 있고, 처리 속도에서 자동화 시스템이 요구하는 수준에 도달함을 실험 결과를 통해 검증한다.

• 한국항행학회논문지
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• 제10권2호
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• pp.113-120
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• 2006

본 논문에서는 로봇 매니퓰레이터가 기준 궤적을 추종할 수 있도록 영상기반 강인제어기를 제안하였다. 카메라로부터 획득된 목표물의 특징점을 원하는 특징점 좌표로 로봇이 이동할 수 있도록 기준 궤적을 생성하고, 제어 입력에 포함되는 로봇 동역학부의 파라미터 불확실성을 보상하기 위한 강인제어기를 설계하였다. 또한 자코비안에 불확실성이 존재하는 경우 이를 보상하기 위한 제어 입력을 갖는 영상기반 강인제어기를 제안하였다. 시스템의 안정도는 Lyapunov 안정도 판별법을 이용하여 검증하였다. 5-링크 2 자유도의 로봇 매니퓰레이터를 대상으로 제안된 제어기를 적용한 모의실험과 실험을 통하여 제어 성능을 입증하였다.

• 제어로봇시스템학회논문지
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• 제21권3호
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• pp.179-186
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• 2015

In this paper, a novel lateral control system is proposed for the purpose of improving lane keeping performance which is independent from GPS signals. Lane keeping is a key function for the realization of unmanned driving systems. In order to obtain this objective, a vision sensor based real-time lane detection scheme is developed. Furthermore, we employ a data fusion along with a real-time steering angle of the test vehicle to improve its lane keeping performance. The fused direction data can be obtained by an IMU sensor and vision sensor. The performance of the proposed system was verified by computer simulations along with field tests using MOHAVE, a commercial vehicle from Kia Motors of Korea.

• 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.

• 센서학회지
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• 제23권3호
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• pp.149-157
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• 2014

This paper considers the ability of counting and positioning multi-targets by using a mobile UWB radar device. After a background subtraction process, distinguishing between clutters and human body signals, the position of targets will be computed using weighted Gaussian mixture methods. While computer vision offers many advantages, it has limited performance in poor visibility conditions (e.g., at night, haze, fog or smoke). UWB radar can provide a complementary technology for detecting and tracking humans, particularly in poor visibility or through-wall conditions. As we know, for 2D measurement, one method is the use of at least two receiver antennas. Another method is the use of one mobile radar receiver. This paper tried to investigate the position detection of the stationary human body using the movement of one UWB radar module.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.269-272
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• 1999

It is still hard to measure the strain distribution over entire surface of a medium or large-size stamped part even by using an automated strain measurement system. Several methods which enable to enlarge the measurement range without losing accuracy and precision are suggested in this study, The superposition of images having different high-lightened or damaged part each other results in an enhanced image. A new method for constructing the element connectivity from a line-thinned image makes it possible to identify up to 1,000 elements. And the geometry assembling algorithm is proved very efficient in which the whole area to be measured is divided into several parts ; the coordinate transformation between every two adjacent parts is obtained from the concept of the least square error ; and the 3-D shape or strain distribution over the whole surface is assembled,