• Title/Summary/Keyword: boundary tracking

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Tracking Algorithm of Vessel's Contour using ML estimation (ML 추정을 이용한 혈관 윤곽 추적 알고리듬)

  • Park, S.I.;Lee, J.S.;Koo, J.Y.;Hong, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.150-153
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    • 1997
  • The proposed tracking algorithm approaches geometrical method or position, direction, width of vessel. This algorithm using continuity of vessel in spatial coordinates used to determine direction of the center point, after estimating boundary point in dynamic region. Therefore the tracking of vessel's contour is tracked contour as direction of entire contour in coronary artery. This algorithm is automatically processed by DIP as a compared with conventional method, because searching area varies adaptively to allocate searching region from extracted information at past. And ML estimation expressed robust method or angiography as evaluating sample values after preprocessing.

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A Robust Controller Design for Robot Manipulators with Hydraulic Actuator Dynamics (유압구동기를 채용한 로봇 매니플레이터에 대한 강인제어기 설계)

  • Park, Gwang-Seok;Hwang, Dong-Hwan
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.598-600
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    • 1998
  • In this paper, a robust controller is proposed to achieve the accurate tracking for uncertain robot manipulators with hydraulic actuator dynamics. The parameter uncertainty can be quantified by the linear parameterization technique. A switching controller is proposed to guarantee the global asymptotic stability of the plant. In order to eliminate the chattering caused by the switching controller, a smoothing controller is proposed using the boundary layer technique around the sliding surface. It is shown that the smoothing controller guarantees the uniform ultimate boundedness of the tracking, error. The proposed controller shows good better tracking performance.

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Adaptive Approaches on the Sliding Mode Control of Robot Manipulators

  • Park, Jae-Sam;Han, Gueon-San;Ahn, Hyun-Sik;Kim, Do-Hyun
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.1
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    • pp.15-20
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    • 2001
  • In this paper, adaptive algorithms on the sliding model control for robust tracking control of robust manipulators are presented. The presented algorithms use adaption laws for tuning both the sliding mode gain and the thickness of the boundary layer to reject a disconitnuous control input, and to improve the tracking performance. It is shown that the robustness of the developed adaptive algorithms are guaranteed by the sliding mode control law and that the algorithms are globally convergent in the presence of disturbances and modeling uncertainties. Computer simulations are performed for a two-link manipulator, and the results show good properties of the proposed adaptive algorithms under large mainpulator parameter uncertainties and disturbances.

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Fast initialization of a F!T tube

  • Willemsen, Oscar H.;Hoppenbrouwers, Jurgen J.L.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.122-125
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    • 2003
  • We describe a new method to initialize the raster and convergence of a flat intelligent tracking (F!T) tube. By splitting up the initialization algorithm into three parts, it can comply with the variety of boundary conditions that are stated for a consumer product. Experiments on raster initialization have shown that the new algorithm speeds up the initialization by one order of magnitude.

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Tracking of Continuously Acting Hearts Using a Geometric Active Contour Model (기하 활성 모델을 이용한 연속적 심장 운동 추적)

  • 김성곤
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.4
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    • pp.17-22
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    • 2002
  • This paper used an active contour model which was based on level set algorithms and bidirectional curve evolution theory in order to track the shape of the heart acting continuously. Most active contour models would be failed in boundary extraction because of their unstable movement in the edge gap locations. In this paper, we suggest a new active contour model using only image intensity value and additional constraint needed for stable extraction. Our model was successfully run on either shape extraction or object tracking without any position constraints of initial curve. Also demonstrated stable movements and showed good results at weak or missing boundary locations.

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Threat Decision Algorithm of Missile Warning Radar Using Azimuth Angular Rate (방위각 변화율을 이용한 방호용레이다 위협 판단 알고리즘)

  • Ha, Jong-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.1
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    • pp.93-101
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    • 2008
  • It is difficult for a MWR(Missile Warning Radar) to perform a threat decision accurately since there is no tracking part which gives more accurate threat information to the MWR. In this paper, the threat decision algorithm is proposed using an azimuth angular rate to improve the accuracy. The azimuth angular rate is dependent upon the direction of an approaching target. The target is classified into a threat or non-threat using a boundary condition of the azimuth angular rate. The boundary condition is determined using the Monte-Carlo simulation. The performance of the proposed algorithm is evaluated using this condition at field tests of MWR. The efficiency of the proposed method for the threat decision is proved by comparing the results of field tests with the simulation results.

Design of Sliding Mode Controller with a SIIM Fuzzy Logic Boundary Layer (간편 간접추론 퍼지논리 경계층을 갖는 슬라이딩 모드 제어기의 설계)

  • 채창현
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.2
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    • pp.45-52
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    • 2004
  • The sliding mode controller with a boundary layer implemented by simplified indirect inference method (SIIM) fuzzy logic was proposed. The components of the sliding line function are used for the inputs of the SIIM fuzzy logic. The proposed control system is simple because there is no need to derive the sigmoid function and there are only four rules. The overall stability of the proposed system and the boundness of the tracking error are proved easily using the Lyapunov theory. We apply the proposed controller to control a nonlinear time-varying system. The computer simulation showed the validity of the proposed control system.

A Study on the Jig - Saw Puzzle Matching (그림조각 맞추기에 관한 연구)

  • Lee, Dong-Joo;Suh, Il-Hong;Oh, Sang-Rok
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.954-958
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    • 1988
  • A jig-saw puzzle matching technique is proposed. Specifically, the geometric patterns of the puzzle pieces are firstly extracted using a boundary tracking algorithm at low resolution. And then, features of the extracted pieces to describe jig-saw puzzle pieces such as angles and distances between corner points, and convexity or concavity of a corner point are obtained from some corner points implying discontinuity of curvature of puzzle pieces' boundary. Finally, a boundary matching algorithm without a priori information of matched puzzle is proposed.

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Adaptive Weight Collaborative Complementary Learning for Robust Visual Tracking

  • Wang, Benxuan;Kong, Jun;Jiang, Min;Shen, Jianyu;Liu, Tianshan;Gu, Xiaofeng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.1
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    • pp.305-326
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    • 2019
  • Discriminative correlation filter (DCF) based tracking algorithms have recently shown impressive performance on benchmark datasets. However, amount of recent researches are vulnerable to heavy occlusions, irregular deformations and so on. In this paper, we intend to solve these problems and handle the contradiction between accuracy and real-time in the framework of tracking-by-detection. Firstly, we propose an innovative strategy to combine the template and color-based models instead of a simple linear superposition and rely on the strengths of both to promote the accuracy. Secondly, to enhance the discriminative power of the learned template model, the spatial regularization is introduced in the learning stage to penalize the objective boundary information corresponding to features in the background. Thirdly, we utilize a discriminative multi-scale estimate method to solve the problem of scale variations. Finally, we research strategies to limit the computational complexity of our tracker. Abundant experiments demonstrate that our tracker performs superiorly against several advanced algorithms on both the OTB2013 and OTB2015 datasets while maintaining the high frame rates.

3D Medical Image Segmentation Using Region-Growing Based Tracking (영역 확장 기반 추적을 이용한 3차원 의료 영상 분할 기법)

  • Ko S.;Yi J.;Lim J.;Ra J. B.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.239-246
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    • 2000
  • In this paper. we propose a semi-automatic segmentation algorithm to extract organ in 3D medical data by using a manually segmentation result in a sing1e slice. Generally region glowing based tracking method consists of 3 steps object projection. seed extraction and boundary decision by region growing. But because the boundary between organs in medical data is vague, improper seeds make the boundary dig into the organ or extend to the false region. In the proposed algorithm seeds are carefully extracted to find suitable boundaries between organs after region growing. And the jagged boundary at low gradient region after region growing is corrected by post-processing using Fourier descriptor. Also two-path tracking make it possible to catch up newly appeared areas. The proposed algorithm provides satisfactory results in segmenting 1 mm distance kidneys from X-rav CT body image set of 82 slices.

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