• 제어로봇시스템학회논문지
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• 제9권2호
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• pp.145-151
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• 2003

A global ultrasonic sensor system for self-localization of a mobile robot is proposed in this paper. The global ultrasonic sensor system consists of three or more ultrasonic transmitters fixed at some positions in the world coordinate and receivers in the moving coordinate of a mobile robot. In this global sensor system it is easy to get state vector of the mobile robot in the world coordinate from the distance information between each ultrasonic transmitter and receiver. An extended kalman filter algorithm is used to process the noisy ultrasonic signal and to estimate the state vector. In case of using several independent ultrasonic transmitters, it is necessary to avoid the cross talk among the ultrasonic waves and to synchronize between each ultrasonic transmitter and receiver. The small sized radio frequency modules are adopted to solve the cross talk and the synchronization problem Computer simulation and experiments are carried out to verify the effectiveness of the proposed ultrasonic sensor system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.41.4-41
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• 2002

In this paper we deal with visual servoing that can control a robot arm with a camera using information of images only, without estimating 3D position and rotation of the robot arm. Here it is assumed that the robot arm is calibrated and the camera is uncalibrated. Here we consider two coordinate systems, the world coordinate system and the camera coordinate one and we use a pinhole camera model as the camera one. First of all, the essential notion can be show, that is, epipolar geometry, epipole, epipolar equation, and epipolar constrain. And these plays an important role in designing visual servoing in the later chapters. Statement of the problem is giver. Provided two a priori...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.137-140
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• 1999

A lot of researcher have proposed a method of kernel identifying nonlinear system by use of Wiener kernels[6-7] or Volterra kernel[5] and so on. In this research, the authors proposed a method of identifying Volterra kernels for nonlinear system by use of pseudorandom M-sequence in which a crosscorrelation function between input and output of a nonlinear system is taken[4]. we can be applied to an MISO nonlinear system or a system which depends on its input amplitude[2]. But, there exist many systems in which it is difficult to determine a Volterra kernel having the same time coordinate on the crosscorrelation function. In those cases, we have to estimate Volterra kernel by using its neighboring points[4]. In this paper, we propose a new method for not estimating but obtaining Volterra kernel having the same time coordinate using calculation between the neighboring points. Some numerical simulations show that this method is effective for obtaining higher order Volterra kernel of nonlinear control systems.

• 조명전기설비학회논문지
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• 제26권1호
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• pp.29-37
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• 2012

A simple and effective dead time compensation scheme for a PWM inverter-fed permanent magnet synchronous motor (PMSM) drive using the model reference adaptive control (MRAC) and coordinate transformation is presented. The basic concept is to first transform a time-varying disturbance caused by the dead time and inverter nonlinearity into unknown constant or slowly-varying one by the coordinate transformation, and then use the MRAC design technique to estimate this parameter in the stationary reference frame. Since the MRAC scheme is a suitable way of estimating such a parameter, the control performance can be significantly improved as compared with the conventional observer-based method tracking time-varying parameters. In the proposed scheme, the disturbance voltage caused by the dead time is effectively estimated and compensated by on-line basis without any additional circuits nor existing disadvantages as in the conventional methods. The asymptotic stability is proved and the effectiveness of the proposed scheme is verified.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1233-1240
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• 2004

Recently the need for cooperative control among robots is increasing in a variety of industrial robot applications. Such a control framework enhances the efficiency of the real robotic assembly environment along with extending the robot application. In this paper, an ethernet-based cooperative control framework was proposed. The cooperative control of robots can multiply the handling capacity of robot system, and make it possible to implement jigless cooperation, due to realization of trajectory-synchronized movement between a master robot and slave robots. Coordinate transformation was used to relate among robots in a common coordinate. An optimized ethernet protocol of HiNet was developed to maximize the speed of communication and to minimize the error of synchronous movement. The proposed algorithm and optimization of network protocol was tested in several class of robots.

• 대한치과보철학회지
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• 제29권2호
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• pp.161-175
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• 1991

To understand the biomechanics of the mandibular movement of the patients with T.M.J. disorder, it is necessary to analyze the mandibular movement by the least moving points of instantaneous center of rotation on computer screen. In this study, two subjects without T.M.J. disorder and with normal occlusion and few patients with T.M.J. disorder were selected for obtaining the processing data. The habitual opening and dosing movements were recorded by image recognition system of video and computer and then the mandibular movement and the least moving point were analyzed using computer program for image anaysis of specialized points. The results obtained were as follows: 1. The least moving points of control group during opening and dosing were dose to the mandibular foramen, but in the test group there were differences between two positions of the least moving points during opening and closing. 2. The variations of the least moving point were in the range of $0.02\sim0.05cm$ of X-coordinate and $0.07\sim0.10cm$ of Y-coordinate for control group, whereas in the range of $0.05\sim0.30cm$ of X-coordinate and $0.08\sim1.65cm$ of Y-coordinate for test group. 3. The index of variation during opening and dosing movements was shown in $0.8\sim1.0$ for the control group and in $0.56\sim2.6$ for the test group. 4. After the treatment of the test group No. 4 by occlusal splint the least moving point was dose to the mandibular foramen and the index of variation was changed from 25 to 05. 5. The tracing shape of the least moving point in the test group represented the irregularities compared to the control group. 6. The mandibular opening and dosing movements were simulated on the computer screen following the movement of the least moving point of instantaneous center of rotation.

• 한국측량학회지
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• 제29권3호
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• pp.249-255
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• 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.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.210-213
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• 2000

In the closed range space, the parallel two CCD cameras are used to acquire a pair of stereo image. The acquired stereo image are computed with Wavelet Transform repeatedly and including the low frequency component, the image size of those are reduced. It is the pyramid structure. The optimum matching point is searched to the pixel. Then appling the optimum matching point to DLT, it extract the three - dimensional surface coordinate from a stereo image. The direct linear transformation(DLT) method is used to calibrate the stereo camera compute the coordinate on a three dimensional space. To find the parameters for the DLT method, 30 control points which marked on the cylinder type object are used. To improve the matching algorithm, the paper select the pyramid structure for Wavelet Transform. The acquired disparity information is used to represent the really three-dimensional surface coordinate.

• 한국측량학회지
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• 제14권2호
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• pp.141-150
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• 1996

최근 우리나라에서는 위성측위시스템의 보급에 따라 측지분야에서 뿐만 아니라 지적 및 GIS/LIS 데이터베이스 관리분야에서도 그 활용성이 커지고 있으며, 지구중심좌표계(geocentric coordinate system)에 대한 관심도 높아지고 있다. 이 논문에서는 현행의 측지기준계를 분석하여 지구중심좌표계에 의한 새로운 측지기준좌표계(geodetic reference frame)의 설정방안을 고찰하였고, 이에 따른 국가기준점망의 구축방법과 기존의 좌표체계에서 새로운 좌표체계로 변경하고자할 경우에 고려되어야 할 기준점관리와 성과관리 등에 대하여 고찰하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.424-429
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• 1992

A practical adaptive tracking filter for a maneuvering target is proposed in this paper by combining a modified input estimation technique with pseudo-residuals and a decoupled tracking filter in line-of-sight Cartesian coordinate system. Since the adaptive tracking filter has decoupled structure and computes maneuver input estimates for each axis separately, it requires much less computations compared with the coventional tracking filter with MIE technique without degrading performance. Also, since pseudo-measurement noises in line-of-sight Cartesian coordinate system are much less correlated compared with those of inertial Cartesian coordinate system, the proposed tracking filter produces less false alarms or miss detections to improve the performance.