• 제목/요약/키워드: Relative Coordinate

검색결과 204건 처리시간 0.033초

비디오 프레임 영상으로부터 제작된 자유 입체 모자이크 영상의 실좌표 등록 (Geocoding of the Free Stereo Mosaic Image Generated from Video Sequences)

  • 노명종;조우석;박준구;김정섭;고진우
    • 한국측량학회지
    • /
    • 제29권3호
    • /
    • pp.249-255
    • /
    • 2011
  • 고중복도 비디오카메라 영상을 이용하여 GPS/INS 및 지상기준점 자료 없이 제작되는 자유 입체 모자이크 영상은 기준 프레임 영상의 3차원 모델좌표계로 표현되는 상호표정요소를 이용하여 제작될 수 있다. 이와같이 제작된 자유 입체 모자이크 영상으로부터 결정되는 3차원 좌표는 3차원 모델좌표계로 나타내게 된다. 따라서 자유 입체 모자이크 영상을 이용하여 절대좌표를 결정하기 위해서는 모델좌표계를 절대좌표계로 변환하기 위한 방법이 필요하다. 일반적으로 서로 다른 두 개의 3차원 직각 좌표계간의 좌표변환은 3차원 상사변환(similarity transformation)이 사용된다. 하지만 자유 입체 모자이크 영상의 3차원 모델좌표는 원점으로부터 떨어질수록 오차가 누적되어 선형변환을 이용한 좌표변환을 수행하기 어렵다. 따라서 이러한 자유 입체 모자이크 영상의 모델좌표를 절대좌표로 변환하기 위한 3차원 비선형 변환 방법이 필요하다. 또한 절대좌표계로 표현된 수치지도와 입체 모자이크 영상을 중첩하여 사용하기 위해서는 자유 입체 모자이크 영상을 실좌표 입체 모자이크 영상으로 변환하기 위한 방법이 필요하다. 따라서 본 연구에서는 자유 입체 모자이크 영상의 3차원 모델좌표를 3차원 절대좌표로 변환하기 위한 3차원 비선형 변환 방법과 이 방법을 기반으로 자유 입체 모자이크 영상을 실좌표 입체 모자이크 영상으로 제작하기 위한 2차원 비선형 변환방법을 제안하였다.

사각형 특징 기반 Visual SLAM을 위한 자세 추정 방법 (A Camera Pose Estimation Method for Rectangle Feature based Visual SLAM)

  • 이재민;김곤우
    • 로봇학회논문지
    • /
    • 제11권1호
    • /
    • pp.33-40
    • /
    • 2016
  • In this paper, we propose a method for estimating the pose of the camera using a rectangle feature utilized for the visual SLAM. A warped rectangle feature as a quadrilateral in the image by the perspective transformation is reconstructed by the Coupled Line Camera algorithm. In order to fully reconstruct a rectangle in the real world coordinate, the distance between the features and the camera is needed. The distance in the real world coordinate can be measured by using a stereo camera. Using properties of the line camera, the physical size of the rectangle feature can be induced from the distance. The correspondence between the quadrilateral in the image and the rectangle in the real world coordinate can restore the relative pose between the camera and the feature through obtaining the homography. In order to evaluate the performance, we analyzed the result of proposed method with its reference pose in Gazebo robot simulator.

절대절점좌표를 이용한 회전체인의 시뮬레이션 (Simulation of a Rotating Chain with an Absolute Nodal Coordinate Formulation)

  • 유완석
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 추계학술대회
    • /
    • pp.649-654
    • /
    • 2004
  • A physically simple but mathematically cumbrous problem of rotating heavy chain with one fixed top point is studied. Nonlinear equation of its two-dimensional shapes of relative equilibrium is obtained and solved numerically. A linear case of small displacements is analyzed in terms of Bessel functions. The qualitative and quantitative behavior of the problem is discussed with the help of bifurcation diagram. Dynamics of the two-dimensional model near the equilibrium positions is studied with the help of simulation using the absolute nodal coordinate formulation (ANCF). The equilibriums are found instable, and the reason of instability is explained using a variational principle.

  • PDF

정면밀링가공에서 인서트의 챔퍼각 변화에 의한 표면거칠기 향상 (Improvement of the Surface Roughness by Changing Chamfered Angle of the Insert in Face Milling)

  • 권원태;이성세
    • 한국정밀공학회지
    • /
    • 제18권7호
    • /
    • pp.155-160
    • /
    • 2001
  • A milling process with 45 degree chamfered inserts produces a perfect flat surface only in theory. It is due to many unwanted factors including thermal effect, dynamic effect, the problem of the controller used and the problem of accuracy of the machine tool. In this study, introduced is a method to improve the surface roughness by redesigning of the chamfer angle of the insert, which traditionally has been 45 degree. First, the relationship between the fixed machine coordinate and the relative coordinate on the insert is derived. This transfer matrix is used to determine the new insert angle to maximize the flatness of the machined surface. A newly designed insert is manufactured, and used to carry out the experiment. It is proved that she insert designed by the proposed method produced a much flatter surface than a traditional one.

  • PDF

비선형 PSE를 이용한 압축성 경계층의 안정성 해석 (STABILITY ANALYSIS OF COMPRESSIBLE BOUNDARY LAYER IN CURVILINEAR COORDINATE SYSTEM USING NONLINEAR PSE)

  • ;박승오
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2007년도 추계 학술대회논문집
    • /
    • pp.134-140
    • /
    • 2007
  • Nonlinear parabolized stability equations for compressible flow in general curvilinear coordinate system are derived to deal with a broad range of transition prediction problems on complex geometry. A highly accurate finite difference PSE code has been developed using an implicit marching procedure. Blasius flow is tested. The results of the present computation show good agreement with DNS data. Nonlinear interaction can make the T-S fundamental wave more unstable and the onset of its amplitude decay is shifted downstream relative to linear case. For nonlinear calculations, rather small difference in initial amplitude can produce large change during nonlinear region. Compressible secondary instability at Mach number 1.6 is also simulated and showed that 1.1% initial amplitude for primary mode is enough to trigger the secondary growth.

  • PDF

영상칩 지상기준점을 이용한 항공사진 번들조정 (Bundle Adjustment of Aerial Photographs using GCP Image Chip)

  • 김기홍;손홍규;김호성;백종하;이재원
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2004년도 추계학술발표회 논문집
    • /
    • pp.239-243
    • /
    • 2004
  • Recently various thematic maps and image maps using aerial photograph and satellite imagery are frequently made. The geo-referencing is essential to make image map and topographic map using aerial photograph and satellite imagery. For this geo-referencing, Ground Control Points (GCPs) are needed. In this paper, we used GPS relative positioning to measure GCP ground coordinate and the accuracy of 8cm level was achieved. We made GCP image chips for the efficiency of geo-referencing and carried out the bundle adjustment of aerial photographs using GCP image chips to acquire the GCP photo coordinate with image matching technique. Finally we analyzed the accuracy of bundle adjustment compared to the accuracy of the case in using digital maps to acquire GCP photo coordinate.

  • PDF

비선형 저차화 관측기의 설계기법 및 구보시스템에의 적용 (A Nonlinear Reduced Order Observer Design and Its Application to Ball and Beam System)

  • 조남훈
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제53권9호
    • /
    • pp.630-637
    • /
    • 2004
  • In this paper, we present a local reduced-order observer for a class of nonlinear systems that have full robust relative degree. The proposed observer utilizes the coordinate change which transforms a nonlinear system into an approximate normal form. The proposed reduce order observer is applied to a ball and beam system, and simulation results show that substantial improvement in the performance was achieved compared with the jacobian linearization observers.

부분 시스템 해석을 위한 상대 직교 좌표를 이용한 다물체 동역학 공식 (Multibody Dynamics Formulation based on Relative Cartesian Coordinates for Subsystem Dynamic Analysis)

  • 김성수;송금정;허재영
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 춘계학술대회
    • /
    • pp.899-904
    • /
    • 2004
  • Multibody dynamics formulation has been developed based on relative cartesian coordinates for subsystem analysis. Relative cartesian coordinates are defined with respect to a reference body of a subsystem. Relative cartesian formulation inherits the same merits of absolute cartesian formulation, such as generality and easy implementation. Two methods have been applied. One is Largrange Multiplier Elimination method and the other is independent coordinate method. A 1/4 car simulation has been carried out to verify the formulations. Since both methods provide identical results, it proves the validity of the formulation.

  • PDF

Motivating Curls

  • Mathewa;Jerold;Kim, Min-Kyeong
    • 한국수학교육학회지시리즈D:수학교육연구
    • /
    • 제4권2호
    • /
    • pp.57-62
    • /
    • 2000
  • we motivate the of the velocity field of a fluid in three ways: from a calculation of the velocity of a rotating fluid relative to a coordinate system rotating with the fluid and from two calculations of a vector form of circulation in small circles or spheres suspended in a moving fluid.

  • PDF