Won-Ho Choi

University of Ulsan, Ulsan, Ulsan, South Korea

Are you Won-Ho Choi?

Claim your profile

Publications (5)0.78 Total impact

  • J. UCS. 01/2009; 15:2463-2484.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we propose a new 3-D working point determination method for industrial robot using vision camera system and block interpolation technique with feature points in a vehicle body. To detect the feature points in a vehicle body, we applied the pattern matching method. For determination of working point, we applied block interpolation method. The block consists of 3-D type blocks with detected feature points per section. 3-D position is selected by Euclidean distance between 245 feature values and an acquired feature point. In order to evaluate the proposed algorithm, experiments are performed in glass equipment process in real industrial vehicle assembly line.
    Transactions of the Korean Institute of Electrical Engineers 01/2008; 57(1).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a study on direct torque control method (DTC) using matrix converter fed induction motor. The advantages of matrix converters are combined with the advantages of the DTC technique: under the constraint of unity input power factor, the required voltage vectors are generated to implement the conventional DTC method of induction motor. However, since the first idea about DTC method using MC fed induction motor was suggested by the current researches just focus on some simulation results and a little un-explicit experimental result is carried out. This paper describes the operation of induction motor under the DTC method in steady-state and transient conditions by the experimental results, the discussion about the trend of DTC method using MC is also carried out. Furthermore, the entire system of matrix converter configuration using 7.5 kW IGBT modules (FR35R12KE3V1) is explained in detail.
    Strategic Technology, 2007. IFOST 2007. International Forum on; 11/2007
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a new corner detection method based on the Hessian matrix. The proposed method can detect features of a pattern or input image using eigenvalue and eigenvector of images. The Hessian matrix has information of ellipse with intensity variance, and corner can be detected by using the eigen-value and eigen-vector analysis and decided weight value. In order to evaluate the proposed algorithm, experiments are performed in many type images. As the result of the test image, it shows the better performance than that of conventional Harris, SUSAN, and symmetric corner detectors.
    01/2007;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a self-calibration method of robots those are use in industrial vehicle assembly lines. The proposed method is a position compensation using laser sensor and vision cameras. Because the laser sensor is cross type sensor which can scan a horizontal and vertical line, it is efficient way to detect a feature of vehicle and winding shape of vehicle's body. For position compensation of 3-Dimensional axis, we applied block interpolation method. For selecting feature point, pattern matching method is used and 3-D position is selected by Euclidean distance mapping between 462 feature values and evaluated feature point. In order to evaluate the proposed algorithm, experiments are performed in real industrial vehicle assembly line. As the result of the field test, it shows that robot's working point can be displayed 3-D points. These points are used to diagnosis error of position and reselecting working point.
    Strategic Technology, The 1st International Forum on; 11/2006