• 제어로봇시스템학회논문지
• /
• 제17권10호
• /
• pp.983-988
• /
• 2011

This paper presents a robust method for ground plane detection in vision-based applications based on a monocular sequence of images with a non-stationary camera. The proposed method, which is based on the reliable estimation of the homography between two frames taken from the sequence, aims at designing a practical system to detect road surface from traffic scenes. The homography is computed using a feature matching approach, which often gives rise to inaccurate matches or undesirable matches from out of the ground plane. Hence, the proposed homography estimation minimizes the effects from erroneous feature matching by the evaluation of the difference between the predicted and the observed matrices. The method is successfully demonstrated for the detection of road surface performed on experiments to fill an information void area taken place from geometric transformation applied to captured images by an in-vehicle camera system.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 추계학술대회 초록집
• /
• pp.139.1-139.1
• /
• 2011

Electric vehicle use independent electricity of high voltage. if isolation of electricity is destructed, devices and people are considerably damaged. Therefore, detection of ground fault is necessary for electric vehicle. As the existing detection method of ground fault can not detect ground fault when isolation of both positive side and negative side of electricity is destructed, and change of voltage of electricity. This paper proposed detection method for ground fault of both two sides of electricity and change of voltage. The proposed method is verified by analysis of equivalent circuit.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권3호
• /
• pp.161-165
• /
• 2004

In this paper, we have designed the ground faults detection and interrupting controller at normal condition of AC 120v to 240v rating voltage. Ground faults in electrical network have the characteristics of low current, 60㎐ frequency to 2㎑frequency. The load condition are no load and 20A load. The trip level of the controller is 6㎃ with ground faults. The Controller algorithm is implemented using pic16c71 microprocessor.

• 한국건설순환자원학회논문집
• /
• 제5권2호
• /
• pp.177-184
• /
• 2017

최근 한국에서는 많은 지반 침하 사고가 발생하고 있는데, 이는 상하수의 누수 및 손상된 하수관에 기인한 것이다. 본 연구는 지반 침하에 대한 GPR 탐지 데이터의 실증적 자료를 구축하는 것을 목표로 한다. 이러한 목적으로 테스트 베드가 제작되었으며, 제작 변수는 주철관 및 EPS의 매입 깊이 및 수평 거리이다. 탐사결과, 1.5m의 깊이로 매립된 EPS는 검출하기 어려웠으며, 0.5m 거리 내에서 주철관에 밀접하게 매설 된 EPS는 매우 강한 주철관 신호로 탐지가 불가능했다. 또한 본 연구에서는 GPR 탐사 이미지 결과를 처리하기 위해 GPR 이미지 처리 프로그램 (GPRiPP)을 개발했다. 그 주요 기능은 위글파 신호를 증폭시키는 게인 기능이며, 기존 프로그램과 GPRiPP의 이미지 처리 기능은 매우 유사함을 확인하였다.

• 한국도로학회논문집
• /
• 제18권2호
• /
• pp.37-42
• /
• 2016

PURPOSES : The objective of this study is to determine the optimal frequency of ground penetrating radar (GPR) testing for detecting the voids under the pavement. METHODS : In order to determine the optimal frequency of GPR testing for void detection, a full-scale test section was constructed to simulate the actual size of voids under the pavement. Voids of various sizes were created by inserting styrofoam at varying depths under the pavement. Subsequently, 250-, 500-, and 800-MHz ground-coupled GPR testing was conducted in the test section and the resulting GPR signals were recorded. The change in the amplitude of these signals was evaluated by varying the GPR frequency, void size, and void depth. The optimum frequency was determined from the amplitude of the signals. RESULTS: The capacity of GPR to detect voids under the pavement was evaluated by using three different ground-coupled GPR frequencies. In the case of the B-scan GPR data, a parabolic shape occurred in the vicinity of the voids. The maximum GPR amplitude in the A-scan data was used to quantitatively determine the void-detection capacity. CONCLUSIONS: The 250-MHz GPR testing enabled the detection of 10 out of 12 simulated voids, whereas the 500-MHz testing allowed the detection of only five. Furthermore, the amplitude of GPR detection associated with 250-MHz testing is significantly higher than that of 500-MHz testing. This indicates that 250-MHz GPR testing is well-suited for the detection of voids located at depths ranging from 0.5~2.0 m. Testing at frequencies lower than 250 MHz is recommended for void detection at depths greater than 2 m.

• 전기학회논문지
• /
• 제65권2호
• /
• pp.342-348
• /
• 2016

We propose an obstacle detection algorithm for unmanned ground vehicle on uneven terrain. The key ideas of the proposed algorithm are the use of two-layer laser range data to calculate the gradient of a target, which is characterized as either ground or obstacles. The proposed obstacle detection algorithm includes 4-steps: 1) Obtain the distance data for each angle from multiple lidars or a multi-layer scan lidar. 2) Calcualate the gradient for each angle of the uneven terrain. 3) Determine ground or obstacle for each angle on the basis of reference gradient. 4) Generate a new distance data for each angle for a virtual laser scanner. The proposed algorithm is verified by various experiments.

• 한국지능시스템학회논문지
• /
• 제16권5호
• /
• pp.581-586
• /
• 2006

본 논문에서는 무인주행 차량의 자율주행에 사용되는 자계안내시스템에서 지자계를 제거하기 위한 새로운 방법으로 Ground 검출법을 제안한다. 자계안내시스템은 도로에 일정한 간격으로 자계표식을 매설하고 차량이 자계표식으로부터 떨어진 거리를 인식하여 주행하는 방법이다. 차량이 주행 중 측면이탈거리를 알기 위해서는 지자계가 제거된 자계표식의 자계만을 이용해야 한다. 그러나 자계센서는 자계를 검출할 때 자계표식의 자계와 지자계를 함께 계측한다. 지자계는 차량의 주행방향과 경사에 따라 다르게 검출되기 때문에 자계표식의 자계와 더해질 경우 측면이탈거리를 인식하는데 오차를 발생한다. 따라서 본 논문에서는 지자계를 제거하는 새로운 방법을 제안하고, 이를 검증하기 위한 실험 장치를 구성하였다. 그리고 실험을 통하여 제안한 방법의 타당성과 유용성을 입증한다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 추계학술대회 논문집
• /
• pp.174-176
• /
• 2007

Because of accident or leak of electricity, high voltage electricity can be conducted to vehicle chassis and damage human. Therefore the unit for detecting ground fault is necessary to minimize loss of life or equipment damage. Isolation resistance must be monitored for detecting ground fault. GFD(Ground Fault Detection) unit continually generate the pulse voltage between high voltage network and chassis. This will be sensing the returned current, calculate the isolation resistance and make decision the ground fault. This paper describes the method detecting ground fault.

• International Journal of Aeronautical and Space Sciences
• /
• 제6권1호
• /
• pp.8-16
• /
• 2005

This paper describes target detection performance of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR process schemes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR, and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between target detection probability and signal to noise ratio. This paper concludes the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter, When range bins increase.

• 대한전자공학회논문지SD
• /
• 제41권11호
• /
• pp.69-77
• /
• 2004

본 논문에서는 ground bounce 영향과 지연고장 검출을 함께 고려한 효율적인 보드레벨 연결선 테스트 생성 알고리즘을 제안한다. 제안된 알고리즘은 IEEE 1149.1의 연결선 테스트, ground bounce 영향에 의한 바운더리 스캔의 오동작 방지, 그리고 연결선의 지연고장 검출 능력을 포함한다. 본 논문에서 제안하는 기법은 기존의 기법에 비해 연결선의 지연고장 검출능력을 새롭게 추가하였지만, 연결선 테스트에 필요한 총 테스트 패턴 수는 기존의 기법과 비교해서 큰 차이를 보이지 않음을 실험결과에서 확인할 수 있다.