• 센서학회지
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• 제29권6호
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• pp.412-419
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• 2020

In this study, a PID control method for sweeping automatic linearization of a wavelength swept laser is proposed. First, the closedloop transfer function embodying the PID control is derived. Through the simulation of the function, K_p = 0.022, K_i = 0.008, K_d = 0.002 were obtained as the best PID coefficients for fast linear sweeping. The performance test using the PID coefficients showed that linear sweeping was held up well with a 98.7% decrement in nonlinearity after the 10th feedback, and 45 nm sweeping range, 1 kHz sweeping frequency, and 8.8 mW average optical power were obtained. The equipment consists of a fiber Bragg grating array, an optical-electronic conversion circuit, and a LabVIEW FPGA program. Every 5s, automatic feedback and PID control generate a new compensated waveform and produce a better linear sweeping than before. Compared with nonlinear sweeping, linear sweeping can reduce the cumbersome and time-consuming recalibration processes and produce more accurate measurement results.

• 센서학회지
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• 제30권6호
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• pp.420-428
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• 2021

In this study, linearized sweeping of a wavelength sweeping laser was realized. This technique was used to measure the strain on a fiber Bragg grating(FBG) sensor. For linear sweeping, PID control over the wavelength difference between linear and nonlinear sweeping was employed. The performance test showed that linear sweeping with a 46 nm range and a 1 kHz frequency held up well with a 99.5 % decrement in nonlinearity after the 120th feedback. When attached to a strain gage, the FBG sensor registered strain that matched the data sheet within a difference of 4.5[με]. Altogether, linear sweeping can play a leading role in monitoring a safety of large SOC structures as well as in other wavelength sweeping laser related fields.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.293-296
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• 2005

This paper is concerned with the sweeping damping controller for beam. The active damping characteristics can be enhanced by moving the damper along the longitudinal axis. In this paper, the equation of motion for a beam including a sweeping damping controller is derived and its stability is proved by using Lyapunov stability theorem. It is found from the theoretical study that the sweeping damping controller can enhance the active damping characteristics, so that a single damper can suppress all the vibration modes of the beam. To demonstrate the concept of the sweeping damping control, the eddy current damper was applied to a cantilever, where the eddy current damping can move along the axis. The experimental result shows that the sweeping eddy current damper Is an effective device for vibration suppression.

• 전기전자학회논문지
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• 제23권2호
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• pp.606-613
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• 2019

본 논문에서는 파장 스위핑 레이저의 평탄 스위핑을 자동 유지하기 위한 새로운 방식을 제안하였다. 이 방식이 적용된 레이저의 제작 및 실험을 통하여 5시간이 경과하여도 평탄 스위핑 특성이 잘 유지되고 있음을 관찰하였다. 그리고 56nm의 스위핑 범위, 1kHz의 스위핑 주파수, 그리고 8.8mW 의 광 출력 파워도 확인하였다. 제안된 방식은 기존에 스위핑 레이저를 장시간 구동시킬 때 불가피하던 수동 편광 조절의 번거로움을 해소시키고 이 과정에서 요구되던 고가 광 스펙트럼 분석기의 사용을 배제시킨다.

• 제어로봇시스템학회논문지
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• 제7권1호
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• pp.1187-1195
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• 2001

This paper presents a sweeping path planning algorithm for an autonomous smearing robot. An automatic planner generates a sweeping path pattern by proposed five basic procedures. This algorithm rocog-nizes obstacle on the architectural CAD draft and generates subgoals as tracking points which executes the area filling task based on heuristic approach. A sweeping path is planned by sequentially connecting the track-ing points in such a way that(1) the connected line segments should not be crossed, (2) the total tracking points should be as short as possible, and (3) the tracking line should not pass through the obstacle, Feasibility of the developed techniques has been demonstrated on a real architectural CAD draft.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.521-528
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• 2009

본 연구는 일체형 곡물 건조/저장 시스템에 채용되고 있는 Straight Type Sweeping Auger에 대한 성능과 적합성 검사를 실험을 통하여 검증하였다. 일체형 곡물 건조/저장 시스템의 핵심 기술은 선입선출을 가능토록 하는 Sweeping Auger의 설계기술에 있다. 바람직한 Sweeping Auger의 설계방향을 제시하기 위하여 Straight Type Sweeping Auger가 곡물 속에서 회전할 때 원주면에서 유동하는 곡물의 거동을 알아보기 위한 실험을 실시하고 결과 분석을 통하여 원인규명을 하였다.

• 제어로봇시스템학회논문지
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• 제17권12호
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• pp.1210-1218
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• 2011

GA (Genetic Algorithms) are efficient for searching for global optima but may have some problems such as premature convergence, convergence to local extremum and divergence. These phenomena are related to the evolutionary operators. As population diversity converges to low value, the search ability of a GA decreases and premature convergence or converging to local extremum may occur but population diversity converges to high value, then genetic algorithm may diverge. To guarantee that genetic algorithms converge to the global optima, the genetic operators should be chosen properly. In this paper, we analyze the effects of the selection operator, crossover operator, and mutation operator on convergence properties, and propose the sweeping method of mutation probability and elitist propagation rate to maintain the diversity of the GA's population for getting out of the premature convergence. Results of simulation studies verify the feasibility of using these sweeping operators to avoid premature convergence and convergence to local extrema.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.173-176
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• 1996

The transient behavior of the complex-LMS adaptive filter is studied when the adaptive filter is operating on a fixed or sweeping complex frequency sine-wave signal. The first-order difference equation is derived for the mean weights and its closed form solution is obtained. The transient response is represented as a function of the eigenvectors and eigenvalues of input correlation matrix. The mean-square error of the algorithm is evaluated as well. An optimal convergence parameter and filter length can be determined for sweeping frequency sine-wave signals as a function of frequency change rate and signal and noise powers.

• 한국정보통신학회논문지
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• 제18권2호
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• pp.276-281
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• 2014

본 논문은 산업용 로봇을 위한 힘 피드백 제어는 사람의 감각을 기반으로 한 작업을 대체하여 구현하기에 적합한 연마 시스템을 제안하였다. 기존 연마작업의 표면 연마, 비드처리, 기계 가공 디버링 등의 공정은 그 복잡성에서 자동화가 가장 곤란하다고 인식되어 주로 인력에 의존 해왔다. 본 연구에서는 연마 공구를 파지시킨 힘 제어 로봇에 의한 자동 연마 시스템의 구축과 힘 센서로부터 신호 피드백 제어 방식의 특성 파악과 연마 공정에 적응성을 검증했다. 또한 실용화를 목적을 위한 선박의 바닥 및 측면 연마에의 응용을 진행했다. 따라서 자체 제작한 연마로봇을 활용 한 표면 연마작업을 통하여 실험결과를 검증하였다.

• 센서학회지
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• 제26권1호
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• pp.44-49
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• 2017

In this paper, the automatic sweep flattening for wavelength swept laser of SS-OCT has implemented. Through its performance test applied to the laser, 50 nm flat sweeping range, ${\pm}0.5dB$ fluctuation range, 22 sec the time required, and 10 mW average optical power were obtained. This shows that the realized automatic process can replace the inconvenient manual operation used for polarization control of current sweeping laser. Additionally it cuts costs for optical spectrum analyzer necessary to sweep monitoring.