• 제목/요약/키워드: preceding vehicle

검색결과 78건 처리시간 0.02초

단안카메라를 활용한 ACC 시험평가 방법에 관한 연구 (A Study on the Evaluation Method of ACC Test Using Monocular Camera)

  • 김봉주;이선봉
    • 자동차안전학회지
    • /
    • 제12권3호
    • /
    • pp.43-51
    • /
    • 2020
  • Currently, the second level of the six stages of self-driving technology, as defined by SAE, is commercialized, and the third level is preparing for commercialization. The purpose of ACC is to be evaluated as a system useful for preventing and preventing accidents by minimizing driver fatigue through longitudinal speed control and relative distance control of the vehicle. In this regard, for the study of safety assessment methods in the practical environment of ACC. Distance measurement method using monocular camera and data acquisition equipment such as DGPS are utilized. Based on the evaluation scenario considering the domestic road environment proposed by the preceding study, the relative distance obtained from equipment such as DPGS and the relative distance using a monocular camera in the actual test is verified by comparing and analyzing the safety assessment. The comparison by scenario results showed a minimum error rate of 3.83% in Scenario 1 and a maximum of 14.61% in Scenario 6. The cause of the maximum error is that the lane recognition is not accurate in the camera image and irregular operation conditions such as rushing in or exiting the surrounding area from the walkway. It is expected that safety evaluation using a monocular camera will be possible for other ADAS systems in the future.

Semi-Supervised Learning Based Anomaly Detection for License Plate OCR in Real Time Video

  • Kim, Bada;Heo, Junyoung
    • International journal of advanced smart convergence
    • /
    • 제9권1호
    • /
    • pp.113-120
    • /
    • 2020
  • Recently, the license plate OCR system has been commercialized in a variety of fields and preferred utilizing low-cost embedded systems using only cameras. This system has a high recognition rate of about 98% or more for the environments such as parking lots where non-vehicle is restricted; however, the environments where non-vehicle objects are not restricted, the recognition rate is about 50% to 70%. This low performance is due to the changes in the environment by non-vehicle objects in real-time situations that occur anomaly data which is similar to the license plates. In this paper, we implement the appropriate anomaly detection based on semi-supervised learning for the license plate OCR system in the real-time environment where the appearance of non-vehicle objects is not restricted. In the experiment, we compare systems which anomaly detection is not implemented in the preceding research with the proposed system in this paper. As a result, the systems which anomaly detection is not implemented had a recognition rate of 77%; however, the systems with the semi-supervised learning based on anomaly detection had 88% of recognition rate. Using the techniques of anomaly detection based on the semi-supervised learning was effective in detecting anomaly data and it was helpful to improve the recognition rate of real-time situations.

Fuzzy Interacting Multiple Model을 이용한 관측왜곡 시스템의 차량추적 (Vehicle-Tracking with Distorted Measurement via Fuzzy Interacting Multiple Model)

  • 박성근;황재필;류경진;김은태
    • 한국지능시스템학회논문지
    • /
    • 제18권6호
    • /
    • pp.863-870
    • /
    • 2008
  • 본 논문에서는 관측왜곡을 포함하고 있는 적응형 순항제어 시스템개발에 필수적인 필터링 방식에 대한 연구를 진행한다. 앞선 차량의 정확한 추적과 의도파악을 위하여 기본적으로 IMM (Interacting multiple model)을 사용하며 관측의 왜곡을 보상하기 위하여 확률적 퍼지 모델을 세안한다. 확률적 퍼지 모델은 기존의 결정형 퍼지모델과 달리 모델링 오차를 확률로 모델링한다. 끝으로 확률퍼지모델과 IMM을 결합한 FIMM (Fuzzy IMM)을 제안하여 관측왜곡이 발생하는 레이더를 이용한 전방차량의 추적 알고리즘을 제안한다.

안내궤도를 이용한 고무차륜 경량전철 AGT 궤도부설공법 (Method for Constructing a Railway by using a Guide-way for a Rubber-wheeled automated Transit System)

  • 강남훈;이안호;이일화;김창환
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 춘계학술대회 논문집
    • /
    • pp.1793-1798
    • /
    • 2011
  • The railway structure for a rubber-wheeled automated guide-way transit system consists of a driveway and a guide-way. The most important factor of this system is the driveway and the guide-way aligned with each other, especially for curves and inclines section. The conventional construction method caused many problems such as discordancy by constructing the driveway before constructing the guide-way. Therefore, in this paper we introduce a new method of constructing a railway for a rubber-wheeled light rail vehicle; the new method of constructing the guide-way beforehand as a preceding process. The new method for AGT railway system can simplify the construction process and thus the construction costs may be reduced. It should also improve the driving performance and the comfortability in operating of a light rail vehicle.

  • PDF

A New Product Risk Model for the Electric Vehicle Industry in South Korea

  • CHU, Wujin;HONG, Yong-pyo;PARK, Wonkoo;IM, Meeja;SONG, Mee Ryoung
    • 유통과학연구
    • /
    • 제18권9호
    • /
    • pp.31-43
    • /
    • 2020
  • Purpose: This study examined a comprehensive model for assessing the success probability of electric vehicle (EV) commercialization in the Korean market. The study identified three risks associated with successful commercialization which were technology, social, policy, environmental, and consumer risk. Research design, methodology: The assessment of the riskiness was represented by a Bayes belief network, where the probability of success at each stage is conditioned on the outcome of the preceding stage. Probability of success in each stage is either dependent on input (i.e., investment) or external factors (i.e., air quality). Initial input stages were defined as the levels of investment in product R&D, battery technology, production facilities and battery charging facilities. Results: Reasonable levels of investment were obtained by expert opinion from industry experts. Also, a survey was carried out with 78 experts consisting of automaker engineers, managers working at EV parts manufacturers, and automobile industry researchers in government think tanks to obtain the conditional probability distributions. Conclusion: The output of the model was the likelihood of success - expressed as the probability of market acceptance - that depended on the various input values. A model is a useful tool for understanding the EV industry as a whole and explaining the likely ramifications of different investment levels.

영상처리를 이용한 전기자동차 배터리 극판의 검사 시스템 (Inspection System of Electric Vehicle Battery Plate Using Image Processing)

  • 신동원;진병주;윤장규
    • 제어로봇시스템학회논문지
    • /
    • 제20권7호
    • /
    • pp.718-723
    • /
    • 2014
  • In this paper, we developed the inspection system of electric vehicle battery plate using image processing. Four cameras are used for acquiring the principal parts of the plate, and several steps of image processing for extracting significant dimensions of the plate such as widths and lengths. As a preceding step, calibration of four cameras is carried for compensating distorted images using dot-arrayed sheet. Coordinate systems for four cameras are defined where one coordinate system is assigned to the reference coordinate system to which the others are relatively described. Line information of the edge in the windowed image is extracted using elaborate edge-detection algorithm, and finally the intersection points between lines are extracted to calculate widths and lengths of the plate from which the error status of the battery plate is decided.

ELV에서 재제조 부품을 회수하기 위한 해체 우선순위 (Disassembly Priority for Recoverying Remanufacturable Parts(Core) in ELV)

  • 손우현;박상진;목학수
    • 한국산업융합학회 논문집
    • /
    • 제22권6호
    • /
    • pp.591-598
    • /
    • 2019
  • Today, due to the development of the industrial society, the need for sustainable research and development for energy depletion and environmental protection is increasing. Among sustainable research, remanufacturing is an ideal way to meet environmental and economic aspects. In this paper, we investigated the End-of-Life Vehicle(ELV) in order to find the recovery method of the core which is the preceding stage of remanufacturing. The number of End-of-Life Vehicle is increasing year by year, but the core recovery rate from ELV is still low. Therefore, a methodology to determine the disassembly priority of each part is proposed to increase the core recovery rate. Based on the analysis Table through the disassembly process, the decision rule was selected and the weighted score evaluation Table was completed to complete the disassembly priority system. Finally, evaluation was made on gasoline vehicles to determine priorities.

긴급차량 우선신호시스템 운영상의 문제점 도출과 개선방안에 관한 델파이 연구 (Delphi studies on the operational problems of the Emergency Vehicle Priority Signal System and improvement measures)

  • 김진현
    • 한국응급구조학회지
    • /
    • 제26권3호
    • /
    • pp.185-199
    • /
    • 2022
  • Purpose: Prompt arrival of emergency vehicles at the scene is important. Therefore, special cases for emergency vehicles are being applied. However, there remain obstacles that obstruct the prompt arrival during dispatch. Methods: First, a literature review revealed five categories of problems with the emergency vehicle priority signal system. Then, the first Delphi survey was conducted to confirm the validity of the five categories. Further, a second Delphi survey was conducted to identify additional problems, and we used a 5-point Likert scale for a third Delphi survey. Results: A total of 92 items were extracted from preceding studies. The validity of the five categories was confirmed in the first Delphi survey. Then, 123 additional items were derived from the second Delphi survey, and the final 50 items were selected from 93 items obtained from the third Delphi survey. Conclusion: This study revealed problems and improvement measures for improving the operation of the emergency vehicle priority signal system that were not proposed in previous studies.

액체로켓 기반 2단형 소형발사체의 스테이징 및 임무설계 (Staging and Mission Design of a Two-Staged Small Launch Vehicle Based on the Liquid Rocket Engine Technology)

  • 서대반;이준성;이기주;박재성
    • 한국항공우주학회지
    • /
    • 제50권4호
    • /
    • pp.277-285
    • /
    • 2022
  • 뉴스페이스 시대를 대표하는 소형위성 분야에서 발사기회에 대한 수요가 크게 증가하고 있다. 이를 위한 소형위성 전용 발사서비스를 합리적인 가격에 제공하는 것은 많은 스타트업 기업들이 추구하는 새로운 비즈니스 모델이 되고 있으며, 여기에는 저비용 부품과 대량생산, 최적화된 제작 공정이 결합된 비용 절감을 위한 혁신적인 솔루션들이 요구되고 있다. 이러한 흐름 속에서 우리나라에서도 한국항공우연구원에서 제3차 우주개발 진흥 기본계획에 따라 누리호를 통해 개발된 액체로켓엔진 기술을 기반으로 2단형 소형발사체 개발에 대비하여 핵심기술 및 비용절감 기술들을 개발하기 위한 선행기술 연구에 착수하였다. 본 논문에서는 소형위성을 위한 혁신적이며 가격 경쟁력을 가지는 것을 목표로 하는 2단형 소형발사체의 개념을 소개하고, 스테이징 설계 및 2단형 발사체의 전기체 구성안을 포함한 임무설계 결과를 기술하였다.

차량간 상대속도에 따른 차두거리 분포에 관한 연구 -연속류 교통흐름을 중심으로- (A Study on the Spacing Distrubution based on Relative Speeds between Vehicles -Focused on Uninterrupted Traffic Flow-)

  • 마창영;윤태관;김병관
    • 한국도로학회논문집
    • /
    • 제14권2호
    • /
    • pp.93-99
    • /
    • 2012
  • 선행 차량과의 상대속도에 따른 차두거리 분포에 관한 연구를 위해 연속류 도로 중 국도에 설치된 차량검지기(VDS, Vehicle Detection System)의 교통정보 수집자료를 분석하였다. 수집자료를 차선별, 방향별로 정렬하여 선행 차량과 후행 차량 사이의 속도차이인 상대속도와 검지기 통과시간 및 차량의 속도를 이용하여 차두거리를 산출하였다. 모든 시간대를 대상으로 산출된 상대속도와 차두거리의 분석을 통해 두 변수간의 관계를 분석한 결과 고르게 분포하고 있는 것으로 나타났고 동일차량군 주행에서 차두거리의 중간값은 약 40m이며, 이는 자료구축 및 분석부분에서 언급한 A~D영역을 분류함에 있어 기준이 될 수 있었다. 시간대에 따른 차두거리 분포에 대한 분석을 위해 수집된 모든 자료의 교통량을 통해 첨두교통량을 산정하고 이를 기준으로 첨두시간과 비첨두시간을 분류하여 차두거리 분포의 차이를 분석하였다. 첨두시간은 비첨두시간에 비해 상대적으로 앞 차량과의 속도 차이가 적고 차두거리가 좁은 것으로 나타났기 때문에 선행차량과 같은 주행 패턴으로 추종한다고 할 수 있고 비첨두시간는 차두거리가 상대적으로 넓은 것으로 나타났다. 이는 운전자의 행태를 나타낼 수도 있는 것으로 차두거리가 좁을수록 공격적인 운전을 하며 본인의 총 통행시간을 줄이고자 하는 욕구가 크다고 미루어 짐작할 수 있겠다. 하지만 여가통행과 비첨두시간의 경우는 첨두시간에 비해 차두거리가 넓은 것으로 미루어보아 시간적 압박이 적어 상대적으로 여유로운 운전행태를 보인다고 할 수 있겠다.