• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1836-1839
• /
• 1997

This paper presents machine vision technique with a camera modeling that accounts for major sources of camera distortion, namely, radial, decentering, and thin prism distortion. Radial distortion causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering, that is, the optical centers of lens elements are not strictly collinear. It is our purpose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.413-416
• /
• 1998

Sensitivity and calibration considerations are most important in the design and implementation of real control systems. Ideally parameter changes due to various causes should not appreciably affect the system's performances. But all the values of physical components of the plants and controllers as well as the relevant environmental conditions change in time, thus the output performance can be deteriorated during the operating span of the system. Naturally the duty of calibration or the prevention of performance deterioration due to excessive component sensitivity should be provided to the control system. In this paper, we propose a digital controller which has the capability of calibration and gain adjustment as well as the execution of control law. Specifically the problems of gain adjustment and offset calibration in the light source and CdS sensor module for position measurement in a flexible link system are considerably resolved. The parameters of measurement module are prone to change due to environmental brightness conditions resulting in poor steady state performance of the overall control system. Thus a proper method is necessary to provide correction to the changed values of gain and offset in the position measurement module. The proposed controller, whenever necessary, measures the open-loop characteristics, andthen calculates the offset and sensor gain correction values based on the prepared standard measurements. It is applied to the control of a flexible link system with the gain and offset calibration porblems in the light sensor module for position to show the applicability.

• 제어로봇시스템학회논문지
• /
• 제17권12호
• /
• pp.1256-1265
• /
• 2011

Automated parking assist systems are being commercialized and rapidly spread in the market. In order to improve odometry accuracy, we proposed a practical odometry calibration scheme of Car-Like Mobile Robot (CLMR). However, there were some open problems in our prior work. For example, it was not clear whether the kinematic parameters always converged or not using the proposed calibration scheme. In addition, test driving had to be carried out "twice" without detailed explanation. This research aims to provide answers for the addressed questions though the convergence property analysis of the calibration scheme. In this paper, we evaluate on the effect of the kinematic parameter error on the odometry error at the final pose by numerical computation. The evaluation will show that the wheel diameter and tread of the CLMR can be calibrated by iterative test drives. In addition, the region of convergence in the parametric space will be discussed. Presented experimental results clearly showed that the proposed calibration scheme would be useful in practical applications.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권1호
• /
• pp.126-142
• /
• 2016

This paper presents a wide-frequency-range, low-power transceiver with an automatic impedance-matching calibration for TV-white-space (TVWS) application. The wide-range automatic impedance matching calibration (AIMC) is proposed for the Drive Amplifier (DA) and LNA. The optimal $S_{22}$ and $S_{11}$ matching capacitances are selected in the DA and LNA, respectively. Also, the Single Pole Double Throw (SPDT) switch is integrated to share the antenna and matching network between the transmitter and receiver, thereby minimizing the systemic cost. An N-path filter is proposed to reject the large interferers in the TVWS frequency band. The current-driven mixer with a 25% duty LO generator is designed to achieve the high-gain and low-noise figures; also, the frequency synthesizer is designed to generate the wide-range LO signals, and it is used to implement the FSK modulation with a programmable loop bandwidth for multi-rate communication. The TVWS transceiver is implemented in $0.13{\mu}m$, 1-poly, 6-metal CMOS technology. The die area of the transceiver is $4mm{\times}3mm$. The power consumption levels of the transmitter and receiver are 64.35 mW and 39.8 mW, respectively, when the output-power level of the transmitter is +10 dBm at a supply voltage of 3.3 V. The phase noise of the PLL output at Band 2 is -128.3 dBc/Hz with a 1 MHz offset.

• 한국측량학회지
• /
• 제32권3호
• /
• pp.205-216
• /
• 2014

Multi-camera systems have been widely used as cost-effective tools for the collection of geospatial data for various applications. In order to fully achieve the potential accuracy of these systems for object space reconstruction, careful system calibration should be carried out prior to data collection. Since the structural integrity of the involved cameras' components and system mounting parameters cannot be guaranteed over time, multi-camera system should be frequently calibrated to confirm the stability of the estimated parameters. Therefore, automated techniques are needed to facilitate and speed up the system calibration procedure. The automation of the multi-camera system calibration approach, which was proposed in the first part of this paper, is contingent on the automated detection, localization, and identification of the object space signalized targets in the images. In this paper, the automation of the proposed camera calibration procedure through automatic target extraction and labelling approaches will be presented. The introduced automated system calibration procedure is then implemented for a newly-developed multi-camera system while considering the optimum configuration for the data collection. Experimental results from the implemented system calibration procedure are finally presented to verify the feasibility the proposed automated procedure. Qualitative and quantitative evaluation of the estimated system calibration parameters from two-calibration sessions is also presented to confirm the stability of the cameras' interior orientation and system mounting parameters.

• 대한토목학회논문집
• /
• 제12권3호
• /
• pp.127-137
• /
• 1992

다목적댐 유역에서의 호우(濠雨)발생지 저수지 실시간(實時間) 운영을 위해서는 Telemeter 설비를 통해 온라인으로 전송된 강우(降雨) 및 유입량(流入量)(수위(水位)) 관측자료를 이용하여 강우(降雨)-유출(流出) 모형(模型)의 매개변수(媒介變數) 신속하게 보정(補正)하고 정확한 유입량을 예측하여야 한다. 지금까지는 유출모형의 매개변수 보정을 모형 운영자의 주관적인 판단 아래 시행착오(試行錯誤)에 의한 수동보정(手動補正) 방법을 사용하여 왔으나 최적화 기법을 이용하여 강우-유출모형의 매개변수를 자동으로 보정할 수 있는 방법을 제시하는 것이 본 연구의 목적이다. 최적화 기법으로는 다양한 조건하에서도 해의 안정성이 우수한 Pattern-Search법을 선정하였으며 목적함수로는 모형에 의해 산정된 유출량과 관측 유출량과의 편차의 제곱에 대한 누계치를 최소화 하는 것으로 하였다. 본 연구를 위하여 개발한 최적화 기법을 현재 한국수자원공사(韓國水資源公社)에서 소양강 다목적댐의 실시간 홍수조절에 사용하고 있는 저유함수(貯留函數) 유출모형의 매개변수를 과거의 홍수사상(洪水事象) 사용하여 자동으로 보정 하는데 적용하였다. 적용결과에 시행착오에 의한 수동보정 방법보다 시간 및 노력면에서 보다 효율적일 뿐아니라 홍수예측 기능도 보다 우수하여 저수지의 실시간 홍수예측 및 홍수조절에 알맞은 것으로 나타났다.

• 한국전자파학회논문지
• /
• 제29권7호
• /
• pp.484-490
• /
• 2018

본 논문은 13.56 MHz 임피던스 자동 정합 시스템 내의 VI 센서를 이용하여 전압 신호와 전류 신호를 측정하고, 부하임피던스를 계산하는 새로운 알고리즘에 대해서 기술하였다. 기존의 $50{\Omega}$ 교정 부하로 하던 방식에서 벗어나 임의의 복소수 교정 부하를 사용하여 에러율이 향상되는 알고리즘을 제안한다. 에러율은 $R_{IN}$ 평균 1 % 이하, $X_{IN}$은 평균 20 %이하 목표로 한다. 일차적으로 믹서를 사용하여 IF 주파수를 계산하여 에러율을 줄였고, 두 번째로 임의의 복소수 부하를 교정 부하로 사용하였을 때 에러율이 $R_{IN}$은 평균 2.7 %에서 평균 0.3 %로 감소하였고, $X_{IN}$은 평균 102 %에서 평균 18.3%까지 감소하였습니다.

• 대한임베디드공학회논문지
• /
• 제15권2호
• /
• pp.79-85
• /
• 2020

IIoT stands for Industrial Internet of Things used in manufacturing, healthcare, and transportation in networked smart factories. Recently, IIoT's environment requires an automated control system through intelligent cognition to improve efficiency. In particular, IIoT can be applied to automatic calibration of production equipment for improved management in industrial environments. Such automation systems require a wireless network for transmitting industrial data. Self-calibration systems in laser transmission paths using wireless networks can save resources and improve production quality by real-time monitoring and remote control of laser transmission path. In this paper, we propose a wireless networked system for self-calibration of laser equipment that requires a laser transmission path, and we show the results of the prototype evaluation. The self-calibration system of laser equipment measures the coordinates of the laser points with sensors and sends them to the host using the proposed application protocol. We propose a wireless network service for the wired motor controller to align the laser coordinates. Using this wireless network, the host controls the motor by sending a control command of the motor controller in an HTTP message based on the received coordinate values. Finally, we build a prototype system of the proposed design to verify the detection performance and analyze the network performance.

• 한국전기전자재료학회논문지
• /
• 제35권2호
• /
• pp.143-148
• /
• 2022

For the purpose of treating health checkups and recovery of patients in a super-aged society, hospitals use devices designed with a reduction circuit of electromagnetic waves associated with the specific absorption rate of electromagnetic waves absorbed by the human body. In this paper, we proposed a filter improvement design method capable of reducing electromagnetic waves. As a result of confirming the validity of the proposed technique through simulation and experimental results, the following result values were obtained. Applying the common-mode (CM) inductor 4 mH to a calibration circuit, noise decreased in a multiband spectrum. Using the differential mode(DM) inductor 40 µH element in the primary calibration circuit, the noise decreased by 15 dB or more in the 3 MHz band spectrum. Also, applying the Admittance Capacitance (Y-Cap) 10 nF element in the secondary calibration circuit resulted in the decrease by more than 30 dB in the band spectrum before 2 MHz. After using a common-mode inductor 4 mH element in the tertiary calibration circuit, it decreased by more than 15 dB in the band spectrum after 2 MHz.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.169-171
• /
• 1995

Automatic control equipment in hydro power plant, such as turbine governor or automatic voltage regulator have to act promptly against for variation of power system, so it is necessary to check and test continuously. During last five years, the performance test of automatic control equipment was performed about 20 units of hydro turbine generator. In this process, because it has complex connection and before calibration, signal conditioner was developed as an auxiliary equipment for performance test. It includes function of signal amplifier, transducer, and meters. As a result of use this equipment for electric governor test at soyang-gang hydro power plant, it was possible to find output data equal to old one.