• Journal of information and communication convergence engineering
• /
• 제15권3호
• /
• pp.137-142
• /
• 2017

A general linearly constrained narrowband adaptive array is examined in the eigenvector space. The optimum weight vector in the eigenvector space is shown to have the same performance as in the standard coordinate system, except that the input signal correlation matrix and look direction steering vector are replaced with the eigenvalue matrix and transformed steering vector. It is observed that the variation in gain factor results in the variation in the distance between the constraint plane and the origin in the translated weight vector space such that the increase in gain factor decreased the distance from the constraint plane to the origin, thus affecting the nulling performance. Simulation results showed that the general linearly constrained adaptive array performed better at an optimal gain factor compared with the conventional linearly constrained adaptive array in a coherent signal environment and the former showed similar performance as the latter in a noncoherent signal environment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 F
• /
• pp.2481-2483
• /
• 1999

This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 1991년도 추계종합학술발표회논문집
• /
• pp.215-219
• /
• 1991

This paper is equivalent model transform which reduces the restriction of digitalization in the discrete linear system. This algorithm is the method that weight is given to contribillity and obserbility gramian, the regular matrix T of coordinate transform is obtained and then the state space coefficents of weighted model can be obtained. This study shows the frequency reponse of low quantization error according to the order of weighting function. The result shows that frequency response of the proposed algorithm is better than that of the balanced realization in the system of smaller bit.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
• /
• pp.131-133
• /
• 1998

This paper, proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of the three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
• /
• pp.928-933
• /
• 1998

This paper presents a novel current control system to eliminate the steady state control error and to improve the transient characteristics for PWM AC-DC converter. A general mathematical model of the converter that is represented as a state-space model is first established. The state-space model is used for the simulation of PWM switching converter with the proposed current control system. The proposed sinusoidal tracking control system that does not require coordinate transformations using principle of the integral controller is described. It is proved that the steady state deviation reduces to zero through a transfer function of source current control system. Finally, it is seen that simulations agree with the experimental results in source current and reference of controlled ac current loop.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.188-188
• /
• 2000

The most important problem in target tracking can be said to be modeling the tracking system correctly. Although the simple linear dynamic equation for this model has used until now, the satisfactory performance could not be obtained owing to uncertainties of the real systems in the case of designing the filters baged on the dynamic equations. In this paper, we propose the extended robust Kalman filter (ERKF) which can be applied to the real target tracking system with the parameter uncertainties. A nonlinear dynamic equation with parameter uncertainties is used to express the uncertain system model mathematically, and a measurement equation is represented by a nonlinear equation to show data from the radar in a Cartesian coordinate frame. To solve the robust nonlinear filtering problem, we derive the extended robust Kalman filter equation using the Krein space approach and sum quadratic constraint. We show the proposed filter has better performance than the existing extended Kalman filter (EKF) via 3-dimensional target tracking example.

• 디지털융복합연구
• /
• 제19권8호
• /
• pp.195-203
• /
• 2021

본 연구는 사람의 사용자 전신을 촬영한 이미지를 분석하여, 사용자별 움직임에 대한 정상 가동 범위를 영상으로 디스플레이(display)하는 운동 트레이닝 시스템 구축에 관한 것이다. 본 연구는 입점(立點, standing point)을 기준으로 사용자 전신의 정면과 측면을 촬영하는 카메라부(C), 그리고 카메라부의 촬영 이미지를 분석하여 인체의 관절 위치에 노드(node)를 설정하고, 입점을 원점으로 하는 공간좌표계에 노드를 배치하여 그 사용자의 노드 좌표값을 도출하는 이미지 분석부(I·A)와 이미 설정된 표준 노드 좌표값에 매칭된 운동 동작별 정상 노드 가동범위를 사용자 노드 좌표값에 맞추어 보정하여, 상기에서 언급한 사용자 노드 정상 가동 상태를 정면 영상과 측면 영상으로 생성하여 디스플레이하는 재생부(R·P)를 포함하고 있는 시스템으로 구성된다. 따라서 연구의 방법으로는 주요선행연구와 자료조사를 통해 선행 연구와의 차별성을 기할 수 있는 방법을 제시했으며, 이에 따른 운동 트레이닝 시스템을 구축하고자 하는데 연구의 목적을 둔 것이다.

• Journal of Biosystems Engineering
• /
• 제26권1호
• /
• pp.21-28
• /
• 2001

Major deficiencies of current automation scheme including various robots for bioproduction include the lack of task adaptability and real time processing, low job performance for diverse tasks, and the lack of robustness of take results, high system cost, failure of the credit from the operator, and so on. This paper proposed a scheme that could solve the current limitation of task abilities of conventional computer controlled automatic system. The proposed scheme is the man-machine hybrid automation via tele-operation which can handle various bioproduction processes. And it was classified into two categories. One category was the efficient task sharing between operator and CCM(computer controlled machine). The other was the efficient interface between operator and CCM. To realize the proposed concept, task of the object identification and extraction of 3D coordinate of an object was selected. 3D coordinate information was obtained from camera calibration using camera as a measurement device. Two stereo images were obtained by moving a camera certain distance in horizontal direction normal to focal axis and by acquiring two images at different locations. Transformation matrix for camera calibration was obtained via least square error approach using specified 6 known pairs of data points in 2D image and 3D world space. 3D world coordinate was obtained from two sets of image pixel coordinates of both camera images with calibrated transformation matrix. As an interface system between operator and CCM, a touch pad screen mounted on the monitor and remotely captured imaging system were used. Object indication was done by the operator’s finger touch to the captured image using the touch pad screen. A certain size of local image processing area was specified after the touch was made. And image processing was performed with the specified local area to extract desired features of the object. An MS Windows based interface software was developed using Visual C++6.0. The software was developed with four modules such as remote image acquisiton module, task command module, local image processing module and 3D coordinate extraction module. Proposed scheme shoed the feasibility of real time processing, robust and precise object identification, and adaptability of various job and environments though selected sample tasks.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 추계학술대회
• /
• pp.833-834
• /
• 2016

본 연구는 홀로그램 생성 기술과 증강현실 기술을 융합하여, 공간 상 깊이 값의 변화로 이동하는 타겟을 생성하고, 이를 사격 시스템에 적용함으로써, 현실과 동일한 체감이 가능하면서도 공간적 효율을 극대화한 사격 시스템의 구성 방법에 관한 것이다. 또한 홀로그램으로 생성된 타겟의 특성으로 인해 관측자의 시점에 따라 공간상에서 타겟의 위치가 다르게 확인되는데, 이러한 타겟을 조준하여 격발한 사용자의 타격 지점을 정밀하게 분석하기 위한 목적으로 타격 좌표 추출 및 좌표보정 연산방법 등을 컴퓨터 비전을 활용하여 시스템에 적용하였다.

• Journal of Positioning, Navigation, and Timing
• /
• 제2권2호
• /
• pp.131-137
• /
• 2013

In this study, positioning results that combined the code observation information of GPS and GLONASS navigation satellites were analyzed. Especially, the distribution of GLONASS satellites observed in Korea and the combined GPS/GLONASS positioning results were presented. The GNSS data received at two reference stations (GRAS in Europe and KOHG in Goheung, Korea) during a day were processed, and the mean value and root mean square (RMS) value of the position error were calculated. The analysis results indicated that the combined GPS/GLONASS positioning did not show significantly improved performance compared to the GPS-only positioning. This could be due to the inter-system hardware bias for GPS/GLONASS receivers, the selection of transformation parameters between reference coordinate systems, the selection of a confidence level for error analysis, or the number of visible satellites at a specific time.