• 제목/요약/키워드: National control point

검색결과 1,802건 처리시간 0.036초

GPS 상시관측에 연계한 기준점 측량의 오차특성 분석 (Error Feature Analysis of the Control Point Surveying in Connection with GPS Continuous Observation)

  • 윤희천;강기석;조성호
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2003년도 추계학술발표회 논문집
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    • pp.75-80
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    • 2003
  • Most of the control point surveying use a triangulation point and a bench mark with Total Station and Level. nowadays, the research is being accomplished for practical use of GPS. but In this study the optimum time and the optimum occupation time are analyzed, so as to examine possibility of the control point surveying that use GPS continuous station data of National Geography Institute. Also, The efficient surveying methods that compare the result of data that processed using broadcast ephemeris with the result of data that processed using precise ephemeris. As a result of that, Error feature analysis of the control point surveying in connection with GPS continuous observation will provide us estimation of errors and efficient topography information acquisition

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Physical property control for a batch polymerization reactor

  • Kim, In-Sun;Ahn, Sung-Mo;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.263-266
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    • 1996
  • A method to determine an optimal temperature trajectory that guarantees polymer products having controlled molecular weight distribution and desired values of molecular weight is presented. The coordinate transformation method and the optimal control theory are applied to a batch PMMA polymerization system to calculate the optimal temperature trajectory. Coordinate transformation method converts the original fixed-end-point, free-end-time problem to a free-end-point, fixed-end-time problem. The idea is that by making the reactor temperature track the optimal temperature trajectory one may be able to produce polymer products having the prespecified physical property in a minimum time. The on-line control experiments with the PID control algorithm have been conducted to establish the validity of the scheme proposed in this study. The experimental results show that prespecified polymer product could be obtained with tracking the calculated optimal temperature trajectory.

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New MPPT Control Strategy for Two-Stage Grid-Connected Photovoltaic Power Conditioning System

  • Bae, Hyun-Su;Park, Joung-Hu;Cho, Bo-Hyung;Yu, Gwon-Jong
    • Journal of Power Electronics
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    • 제7권2호
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    • pp.174-180
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    • 2007
  • In this paper, a simple control method for two-stage utility grid-connected photovoltaic power conditioning systems (PCS) is proposed. This approach enables maximum power point (MPP) tracking control with post-stage inverter current information instead of calculating solar array power, which significantly simplifies the controller and the sensor. Furthermore, there is no feedback loop in the pre-stage converter to control the solar array voltage or current because the MPP tracker drives the converter switch duty cycle. This simple PCS control strategy can reduce the cost and size, and can be utilized with a low cost digital processor. For verification of the proposed control strategy, a 2.5kW two-stage photovoltaic grid-connected PCS hardware which consists of a boost converter cascaded with a single-phase inverter was built and tested.

Carrier Based Common Mode Voltage Reduction Techniques in Neutral Point Clamped Inverter Based AC-DC-AC Drive System

  • Ojha, Amit;Chaturvedi, Pradyumn;Mittal, Arvind;Jain, Shailendra
    • Journal of Power Electronics
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    • 제16권1호
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    • pp.142-152
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    • 2016
  • Common mode voltage (CMV) generation is a major problem in switching power converter fed induction motor drive systems. CMV is the zero sequence voltage generated due to the switching action of power converters. Even a small magnitude of CMV with a high rate of change may circulate large bearing currents which may damage a machine's bearings and shorten its life. There are several methods of controlling CMV. This paper presents 3-level sinusoidal pulse width modulation based techniques to control the magnitude and rate of change of CMV in multilevel AC-DC-AC drive systems. Simulation and experimental investigations have been presented to validate the performance of proposed technique to control CMV in 3-level neutral point clamped inverter based AC-DC-AC system.

측량기준점 표준화 방안 연구 (Research on Standardization for Survey Control Points)

  • 이현직
    • 대한공간정보학회지
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    • 제23권2호
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    • pp.79-88
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    • 2015
  • 측량기준점은 측량을 포함한 지형공간정보의 생산 및 구축과정에 있어서 기본이 되는 매우 중요한 지형공간정보이다. 현재 우리나라의 측량기준점은 국가기준점, 공공기준점, 지적기준점으로 분류되며 생산, 관리, 운영의 주체가 측량기준점의 종류에 따라 다르다. 또한 측량기준점에 대한 일관된 형식 또는 표준이 정의되지 않아 측량기준점에서 제공되는 기본적인 정보가 상이하고, 측량기준점 간의 연계, 통합 활용 및 관리, 운영이 어려운 실정이었다. 따라서 측량기준점의 효율적인 생산, 관리, 운영, 유통을 위한 표준의 제정이 필요하다. 이에 본 연구에서는 측량기준점의 운영현황을 조사하여 표준의 작성을 위한 측량기준점의 대상을 선정하고, 국내 외의 측량기준점의 성과항목을 조사하여 측량기준점의 표준화 항목과 관리 데이터모델을 결정함으로써 기관표준 및 TTA표준을 제정하고 이를 활성화 할 수 있는 방안을 제시하였다.

용접품질 향상을 위한 저항 스폿 용접용 인버터의 동저항 특성을 이용한 새로운 제어기법 (A Novel Control Method of Resistance Spot Welding Inverter using Dynamic Resistance Characteristics for Weld Quality Improvement)

  • 강성관;정재헌;노의철
    • 전력전자학회논문지
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    • 제20권6호
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    • pp.491-497
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    • 2015
  • This study proposes a new control method for a resistance spot welding inverter to improve weld quality. The proposed method is based on the dynamic resistance characteristics of steel sheets to be welded. A point in the second peak value of the dynamic resistance occurs during one shot of the welding current flow. A constant voltage control is applied from zero to the peak point, and a constant current control is adopted from the peak point to the end of the shot. The mixed mode control of the constant voltage and current guarantees high weld quality. Experiments are conducted with a 5 kA power supply and 0.5 mm steel sheets to compare quality. Experimental results show that weld quality is improved more than 10 times that of the conventional control method.

Z축 운전구조를 갖는 선형 영구자석형 동기 전동기 운전제어에 관한 연구 (A study of control system on Permanent Magnet Linear Synchronous Motor with Z-axis operation structure)

  • 이진하;최철;박한웅;김철우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.654-658
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    • 2003
  • In this study a control system with variable gain schedule using real speed and moving direction is proposed to control a Permanent Magnet Linear Synchronous Motor (PMLSM) with Z-axis operation structure. The implementation of the controller is designed on the DSP TMS320C32 board. PMLSM is operated by using 4-point absolute positions profile with each velocity, acceleration and deceleration. The direction of the initial angle action for starting is set from the lower limit point to the upper limit point on PMLSM operation stroke. The effectiveness of a control system with variable gain schedule is demonstrated by some experimental results.

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SMD Mounter용 선형 영구자석 동기기의 고정밀 위치제어 (High Resolution Position Control of Linear Permanent Magnet Synchronous Motor for SMD Placement System)

  • 김장환;설승기;전정렬;최연규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.314-316
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    • 2001
  • This paper present the position control method for the application of permanent magnet linear synchronous motor. Controller is designed as a conventional P-PI controller, but the extra information is used such as velocity and acceleration from motion profiles. The profiles comes from S-Curve which is an optimized point-to-point motion profiles to achieve fast motions with minimum vibration[2]. In this application, the targets of the position control are maximum 10um position error within 10msec after respective ending point of position profiles. The implementation of the controller has been done in full digital way. All the controller is designed on the DSP TMS320VC33 control board. To prove performance of the controller, the experiment was performed with a servo linear motor.

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Automatic Control Point Measurement and Photo Orientation via Matching with Control Patch

  • Jaw, Jen-Jer;Wu, Yi-Shen
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.375-377
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    • 2003
  • In this study, we employ the control patches, which have been created in previous photogrammetric projects, serving for the candidates of the control points that are likely to be found in the newly taken photos by utilizing image matching technique. Among others, the successful implementation of the above idea lies in the underlying factors: (1). Predicting the control patches and projecting them onto new photos; (2). Alignment of control patches with respect to the new photos; (3). Generating the equivalent ground elements of control patches versus the new photos for the purpose of correlation; (4). Developing effective matching methods and matching strategy; (5). Refining the exterior orientation parameters. What may show significance in this work comparing to traditional aerial-triangulation chain is that whenever at least three matched control patches succeed in a single photo, it follows that single photo orientation is applicable. The experiments suggest the potential efficiency of automatic control point measurement from control patch database and photo orientation by the proposed workflow.

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Modeling of vision based robot formation control using fuzzy logic controller and extended Kalman filter

  • Rusdinar, Angga;Kim, Sung-Shin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제12권3호
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    • pp.238-244
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    • 2012
  • A modeling of vision based robot formation control system using fuzzy logic controller and extended Kalman filter is presented in this paper. The main problems affecting formation controls using fuzzy logic controller and vision based robots are: a robot's position in a formation need to be maintained, how to develop the membership function in order to obtain the optimal fuzzy system control that has the ability to do the formation control and the noise coming from camera process changes the position of references view. In order to handle these problems, we propose a fuzzy logic controller system equipped with a dynamic output membership function that controls the speed of the robot wheels to handle the maintenance position in formation. The output membership function changes over time based on changes in input at time t-1 to t. The noises appearing in image processing change the virtual target point positions are handled by Extended Kalman filter. The virtual target positions are established in order to define the formations. The virtual target point positions can be changed at any time in accordance with the desired formation. These algorithms have been validated through simulation. The simulations confirm that the follower robots reach their target point in a short time and are able to maintain their position in the formation although the noises change the target point positions.